Page Number - Indian Institute of Technology Kanpur · 4:30 pm Prateek Khare Development of polymer based nanocomposite in situ functionalized with nanoparticles and carbon-nanofibers

Page Number

About Chemference ……………………………………………….. 1

Message from Head………………………………………………… 2

About Chemical Engineering Department……………….. 3

Program at a Glance……………………………………………….. 4-5

About the Plenary Speaker……………………………………. 6-7

Abstracts : Talks……………………………………………………. 8-19

Abstracts: Posters………………………………………………… 20-41

Organising Committee …………………………………………. 42

Research Scholar Day 2016 Page 1

RESEARCH SCHOLAR DAY

Department of Chemical Engineering

Indian Institute of Technology Kanpur

5th November 2016

Inspired by the adage, “The important thing in science is not so much to

obtain new facts as to discover new ways of thinking about them”, the

Department of Chemical Engineering, IIT Kanpur organizes the one-day annual

symposium simply entitled “Research Scholar Day” to celebrate and show-case

the frontier chemical engineering research by its post-graduate students. Senior

PhD students share their on-going research in the form of oral talks and poster

presentations to fellow students, faculty, invited academicians and other

attendees. In addition to valuable feedback and critique of their work, the

occasion helps promote meaningful collaboration through increased awareness

on the various on-going research activities in the department and also promotes

strong student-faculty bonding. An eminent scientist from outside IITK is also

invited to deliver a plenary talk as a highlight of the symposium. The occasion

provides a unique platform for intellectual growth of the students through

exchange of ideas, thoughts, vibes and inspirations in the stimulating and vibrant

ambiance.

Page 2 Department of Chemical Engineering, IITK

The Department of Chemical Engineering at IIT Kanpur has

established itself as one of the best destinations in the country for

chemical engineering research and education. The “Research Scholar

Day" of the department provides a perfect opportunity to showcase the

research work carried out by our post-graduate students, and also

provides a platform for deliberations and discussions, both within the

department as well as with the larger Institute community. The

department is indeed very proud of the achievements and contributions

made by our post-graduate students, and we are sure that the seminars

will be exciting and thought-provoking. We welcome all of you to

attend the symposium.

Prof. V. Shankar


The Department of Chemical Engineering at IIT Kanpur is among the nation's top ChE

schools. We are endowed with highly distinguished and committed faculty, a vibrant

graduate program attracting the nation’s best young researchers and a highly competitive

undergraduate program. Our research portfolio encompasses fundamental and applied

research in emerging and core areas of chemical engineering. It spans the frontier areas of

sustainable process engineering, complex fluids and flows, energy and environment,

nanoengineering and science and multi-scale molecular simulations. We also have strong

research collaborations with the industry for solving design, control and optimization

problems as well as involved problems related to interfacial phenomena, macromolecules

and complex fluids. Many of our in-house technologies have been patented and sold to

venture capitalists and are at an advanced stage of commercialization. Our research is

published in top-notch international journals and the training of our post-graduates is very

rigorous, both in terms of breadth of courses studied as well as depth in the chosen area of

research. Over the years, our faculty has published over 30 textbooks and research

monographs and our students have gone on to become leaders in industry and academia.

Currently, we are eighteen faculty members, who excel in diverse facets of cutting-edge

chemical engineering research, ~150 highly sought after PhD research scholars, ~60 M. Tech

scholars and ~300 undergraduates students, and. The multifarious activities of the

department are ably supported by eighteen technical/administrative support-staff members.

We conduct cutting-edge experimental research in state-of-the art infrastructure, which

includes the DST sponsored nano-technology center, one among the only five such facilities

across the nation. We also participate extensively in R&D and consulting for a host of

chemical and processing industries in India and abroad with several ongoing projects

spanning a wide industry spectrum.

The department has been continually adapting and responding to the rapidly changing

economic, social and technological scenario at the national and international levels. From

modest beginnings as a fledgling undergraduate program in the early 1960s, ChE@IITK has

grown into a unique blend of passionate research and pedagogical pursuits. If you share such

a passion, do seriously consider joining us as a faculty or a student.

www.iitk.ac.in/che/

Time Speaker Title

9:15 am Gurmeet Singh Corporate Research :A Beverages Perspective

9:00 am Program Inauguration

Plenary Talk

Session Chair: Mayank Agarwal

Time Speaker Title

10:30 am Shweta Jatav Revisiting Phase Behavior of Aqueous Suspension of

Laponite: A Rheological Perspective and Microscopic

Evidence

11:00 am Asheesh

Shukla

Rheology of aging soft glassy materials

11:30 am Anoop Kumar

Gupta

Spheroids in Non-Newtonian Fluids: Momentum & Heat

Transfer Characteristics

12:00 pm Ashok Kumar Effect of confinement on free convection from heated

cylinders in non-Newtonian fluids

12:30 pm D. Giribabu Role of solid and fluid constitutive behavior on the stability

of flow past deformable solid surfaces

1:00 pm Anitha

Kommu

Adsorption, structural and dynamic properties of Ethanol-

waterin Graphene and Hexagonal Boron Nitride Slit Pores

Complex Fluid Flow, Rheology and Molecular Simulations

Session Chair: Amrita Goswami


Time Speaker Title

2:30 pm Sadanandam

Namsani

Tuning the gold-graphene interface thermal conductance by

vacancy defects

3:00 pm Pranava

chaudhari

A Two Objective Formulation for the Data Fitting Exercise

of a Multi-Component Reactor System

3:30 am Mosumi Sinha Sensing mechanisms of doped thin film and self-assembled

polyaniline based flexible gas sensors

4:00 pm Gargi Mishra PEGylated Carbon Nanocapsule: A Universal Reactor and

Carrier for In Vivo Delivery of Hydrophobic and

Hydrophilic NP’s

4:30 pm Prateek Khare Development of polymer based nanocomposite in situ

functionalized with nanoparticles and carbon-nanofibers for

environmental and energy applications

5:00 pm Koshal

Kishore

Design of electro catalysts and support for oxygen and

chlorine evolution reactions

Nanoscience and Nanotechnology

Session Chair: Gaurav Rawal

Poster Presentation

5:30 pm onwards L 16 Foyer


Director, Global R & D , Unilever

Food & Beverages, Bengaluru

Karnataka, India.

Dr. Gurmeet Singh


Dr. Gurmeet Singh is currently Director, Global R&D (Beverages),

Unilever, Bengluru. He has a 18+ years experience FMCG R&D and

innovations. After graduating with a B Tech in Chemical

Engineering IIT Delhi (1989), Dr Gurmeet obtained PhD in

Chemical Engineering from Pennsylvania State University. Later, he

joined Pennsylvania State University as an Assistant Professor and

worked on designing bioreactors for plant tissue and cell cultures for

more than 3 years before joining Unilever R&D in 1998. He has

worked there in various roles developing new technologies for tea

and tea based beverages and scaling these technologies up to semi-

commercial scale. He has diverse experience spanning three

continents including North America, Asia and Europe, across both

industry and academia. Currently he is leading a global research

program for disruptive innovation and new product development in

tea based beverages.


Corporate R&D: A Beverages Perspective

This talk will ponder over the diverse challenges that chemical

engineers working in a corporate R&D environment face and the

skill set encompassing both technical competence, managerial

qualities, interpersonal skills and team-work, necessary for

surmounting these challenges. The talk will draw liberally from the

speaker’s personal experiences in beverages R&D to bring out the

key role of chemical engineers in conceptualizing, formulating and

implementing the R&D vision of an FMCG corporate giant.

9:15 am

Revisiting Phase Behavior of Aqueous Suspension of Laponite:

A Rheological Perspective and Microscopic Evidence

Shweta Jatav and Yogesh M Joshi

Investigating microstructure of suspensions with particles having anisotropic

shape that share complex interactions is a challenging task leading to competing

claims. This work investigates phase behavior of one such system: aqueous

Laponite suspension, which is highly contested in the literature, using

rheological and microscopic tools. Remarkably, we observe that over a broad

range of Laponite and salt concentrations, the system overwhelmingly

demonstrates all the rheological characteristics of the sol-gel transition leading

to percolated network. Analysis of the rheological response leads to fractal

dimension that primarily depends on the Laponite concentration. We also obtain

the activation energy for gelation, which is observed to decrease with increase in

Laponite as well as salt concentration. Significantly, the cryo-TEM images of

the post-gel state clearly show presence of a percolated network formed by inter-

particle bonds. The present work therefore conclusively establishes the system to

be in an attractive gel state resolving a long standing debate in the literature.


10:30 am

Rheology of Aging Soft Glassy Materials

Soft glassy materials such as concentrated suspensions and emulsions, colloidal

gels, foams, pharmaceutical and cosmetic creams, hair gel, etc., are out of

thermodynamic equilibrium soft materials that are kinetically constrained from

attaining the equilibrium state. The components of the same undergo small

adjustments in search of the progressively low free energy state. This process is

termed as aging. On the other hand, when such systems are subjected to a

deformation field, the process of aging gets reversed, and is termed as shear

melting or rejuvenation. The rheological behavior of soft glassy materials under

given deformation field is usually a result of competition between aging and

rejuvenation. Soft glassy materials are time dependent on one hand and

demonstrate yield stress on the other. In this thesis we study aging as well as

yielding characteristics of different kinds of commercial and model soft glassy

materials.

We first investigate commercial hand dishwasher pastes, which consist of

surfactants, clay, water and abrasive calcite particles, and have soft solid like

consistency with elastic modulus higher than loss modulus. These suspensions

have solid volume fraction of about 36 %, which we have attributed to bonding

between abrasive particles leading to formation of space spanning attractive gel

phase. In dynamic strain sweep experiments, these systems show two step

yielding behavior, where first yield strain is largely independent of frequency.

While second yielding event depends of frequency of oscillation. The yielding

behavior is also dependent on type of surfactant used in the paste. We have

studied the effect of using three different surfactants (LAS, AOS, and SLES) in

the pastes. Pastes show different modulus, and different yielding behavior..

Asheesh Shukla and Y.M. Joshi


11:00 am

Anoop Kumar Gupta and R.P. Chhabra

Most of the structured fluids like high molecular weight polymers, suspensions,

emulsions and foams, worm-like micellar solutions, fibre-reinforced composites,

etc., encountered in many industrial settings display viscoplastic behaviour with a

range of threshold stress levels (fluid yield-stress). Depending upon the

magnitude of the local stress, the material can behave like an elastic solid

(unyielded) or like a fluid (yielded). In other words, if the prevailing stress level

at a point is below the fluid yield stress, the material will not shear (deform).

Hence, the mixing, heating/cooling of such fluids is for more difficult than their

Newtonian counterparts. Owing to the fundamental significance and pragmatic

considerations, significant research efforts have been expended to elucidate the

influence of fluid yield stress on the convective momentum and heat transport in

external boundary layer flows. While voluminous results on the forced-, free- and

mixed-convection heat transfer from bluff bodies like spheres and 2-D cylinders

is now available, very little is known about the effect of particle shape of body of

revolution on the drag and heat transfer in viscoplastic fluids. One convenient

prototype to explore this aspect is to use objects of spheroidal shapes which are

free from geometrical singularities. By simply varying the aspect ratio and/or the

axis of rotation, it is possible to span wide ranges of particle shapes such as

spheres, prolates and oblates. In this study, the governing equations for the

forced-, free-, and buoyancy-assisted mixed-convection from an isothermal

spheroidal particle immersed in Bingham plastic fluids have been solved using

the finite element based solver COMSOL Multiphysics® under the laminar,

steady, axisymmetric flow conditions over the wide ranges of the pertinent

dimensionless parameters as: Reynolds number, (in forced- and mixed-

convection); Bingham number, ; Richardson number, (in mixed-convection);

Prandtl number, Rayleigh number, (in free-convection), Prandtl number, and

aspect ratio of the spheroid,

Spheroids in Non-Newtonian Fluids: Momentum &

Heat Transfer Characteristics


11:30 am

Non-Newtonian fluids such as foams, emulsions, slurries, gels, toothpaste, butter,

jam, etc. are encountered in a wide range of applications. In many instances,

these fluids are required to be heated or cooled during the course of their

manufacture or disposal or to achieve the desired product specifications. Hence,

the free convection from a circular cylinder denotes an idealization of several

industrial applications such as pipes carrying steam and other fluid

streamsexposed to atmosphere, heating and air conditioning ducts installed inside

buildings and enclosuresin close proximity of the walls etc. In free convection,

the fluid motion is solely induced by the density stratification due to the

prevailing temperature gradients. The extent and type of confinement therefore

exerts a strong influence on the resulting velocity and temperature fields in the

proximity of a heated cylinder thereby influencing the overall rate of heat

transfer. In this work, the steady two – dimensional laminar natural convection

heat transfer has been modeled in power – law and Bingham plastic models

(regularized using the Papanastasiou model) to capture two distinct non-

Newtonian features, namely, shear-dependent viscosity and yield stress. The

resulting nonlinear equations have been solved numerically using the finite

element method based solver, COMSOL Multiphysics. A detailed discussion of

the momentum and heat transfer phenomena is presented and analyzed in terms

of streamlines, size and shape of yielded/unyielded zones, temperature contours,

iso-shear rate contours, velocity fields and Nusselt number as functions of the

pertinent parameters as introduced below. In particular, the coupled governing

momentum and energy equations have been solved over the following ranges of

kinematic (Grashof number, Gr; Prandtl number, Pr; power-law index, n and

Bingham number, Bn) and geometric (δ, R/L and H/D) parameters: 10 ≤ Gr ≤

105, 0.7 ≤ Pr ≤ 100, 0.3 ≤ n ≤ 1.8, δ = 0.25, 0.2, 0.1, 0 ) – in power-law fluids; 10

≤ Gr ≤ 105, 10 ≤ Pr ≤ 100, 0.01 ≤ Bn ≤ 100, δ = 0.25, 0.2, 0.1, 0 –in Bingham

plastic fluids for two side – by – side cylinders enclosed in a square enclosure.

Effect of Confinement on Free Convection in Non-

Newtonian Fluids from Heated Cylinder

Ashok Kumar and R.P. Chhabra


12:00 pm

D Giribabu and V. Shankar

The present work focuses on the effect fluid constitutive behavior in fluid flow

past deformable solid surfaces using theoretical and computational approaches.

Earlier studies in this area have mostly focused on Newtonian fluid flow past a

single layer of deformable solid which is modeled using either a linear elastic or

non-linear, neo-Hookean model. In this work, we are considering plane Couette

flow of non-Newtonian fluid especially power-law model past a deformable solid

and this has relevance in understanding biological flows where biological vessels

such as arteries carrying blood which is a non-Newtonian fluid. We specifically

consider the power-law model for the fluid and demonstrate the role of shear

thickening and shear thinning on the stability of “wall modes” and “inviscid

modes” present in the Newtonian flow. Our results show a significant effect of

the shear thinning/thickening nature of the fluid on the wall mode scaling, and

also shows that inviscid mode is the most unstable mode for shear thinning fluids

having power law index less than 0.3.

Role of Solid and Fluid Constitutive Behavior on The

Stability of Flow Past Deformable Solid Surfaces


12:30 pm

Anitha Kommu and Jayant K Singh

The industries discharge a variety of pollutants, such as heavy metals, organic

toxins, and oils, in water resources. Exposure of these contaminants in water

causes adverse health effects on various forms of life. Effective removal of

pollutants from industrial wastewater can be separated by adsorption techniques.

Graphene and hexagonal boron nitride (hBN) sheets are promising materials for

removal of organic pollutants. In this work, the suitability of the sheets for the

separation of ethanol-water mixture is investigated by studying the adsorption

and structural behavior of ethanol-water mixtures within different sizes of slit-

width (7 to 13 Å) using molecular dynamics. The simulation results indicate that

the selectivity of ethanol varies with the pore width and also for different

surfaces (graphene and hBN). The 9 Å pore shows more efficiency in the

separation of ethanol-water system. The selectivity of ethanol is higher at 9 Å

and lower for 7 Å pore size in the hBN and graphene slit pores. For all slit width

(7 to 13 Å) selectivity of ethanol is higher for hBN compared to the graphene

surface. At lower pore width, molecular sieving plays an important role for

separation of ethanol whereas at higher pore width separated by adsorption. The

diffusion coefficients of water and ethanol molecules substantially decrease with

decrease in pore width for both graphene and hBN surfaces. The residence

autocorrelation function of water and ethanol molecules decreases with increase

in the slit-width. Water and ethanol molecules confined between the graphene

and hBN sheets with slit-width of 7 Å resides for longer time as compared to

water and ethanol molecules confined between 9 Å and 13 Å. The water and

ethanol molecules shows higher residence time and lower diffusion coefficient

values on hBN as compared to the graphene slit pore.

Adsorption, Structural and Dynamic Properties of Ethanol-

Water Mixtures in Graphene and Hexagonal Boron

Nitride Slit Pores


1:00 pm

Sadanandam Namsani and Jayant K Singh

Graphene-metal nanocomposites are promising materials to address the heat

dissipation problems in nanoscale electronic devices. The high power densities in

the current generation electronic devices require increased thermal conductance

(TC) across the interface to avoid the formation of hot spots and eventual failure

of the device. To this end, we have investigated the TC across the gold-graphene

interface for various thicknesses of the graphene layer and different temperatures

using ab-initio derived force-field based molecular dynamics (MD) simulations.

The TC is found to increase with the temperature in the range of 50 K-300 K and

after 300 K there is no effect of temperature. The TC also decreases with

increasing number of graphene layer from one to three. However, further increase

in the number of graphene layer has no effect on the value of TC. It is well

known that defects affect the thermal conductance of a material. In this work, we

continued our investigation of the TC of the graphene-gold composite, and

studied the effect of defect vacancies on TC for the temperature range of 50 K -

300K. We found increase in thermal conductance with increasing vacancy size

and density of defects in the graphene sheet. The change in the mechanism of

interfacial thermal transport is explained using vibrational density of states

(VDOS) of graphene and defect rich graphene. VDOS shows the defects in

graphene sheet enhance the out-of plane low frequency vibrational modes within

graphene, and thus facilitates high heat transfer across the interface with the low

frequency out-of plane vibrational modes of gold. This demonstrates that the TC

across the gold-graphene interface can be tuned by adjusting the defect vacancy

size and density of the defects.

Tuning the Gold-Graphene Interface Thermal

Conductance by Vacancy Defects


2:30 pm

A reactor model of multi-component reactor system (MCRS) with a complex

reaction mechanism involves both kinetic and hydrodynamic parameters. These

parameters are tuned by fitting the experimental data on the reactor model in the

data fitting exercise. The experimental data of a MCRS are usually in the form of

multiple responses corresponding to its different components and for the

different experimental cases . The data fitting exercise involves an error

formulation between experimental and model data. The prediction capability of

the tuned reactor model obtained from the data fitting exercise depends on this

error formulation. The error formulation for the single response data is generally

used in form of single objective optimization as the sum of square of the error

values between experimental and model data for different experimental cases .

The minimization of this objective ensures that the converged error values are

well distributed with both positive and negative values for the single response

data. The error formulation for the multi response data using the same approach

is formed by summing all the squared error values in a single objective for

different experimental cases of each of the responses . This single objective only

ensures that converged error values are well distributed with both positive and

negative values but if any error values of a given response (component) are

analyzed, they might be predominantly positive or negative. This is because this

single objective formulation for multi response data by summing all the squared

error values is not able to classify error values corresponding to its different

responses. The data fitting exercise with this error formulation leads to a tuned

reactor model with inherent positive or negative biases for its different

components. The proposed method is compared with the reported Box and

Draper method using a maleic anhydride circulating fluidized bed reactor model,

which is a MCRS. Three different forms of responses (mole percentage,

conversion-selectivity and molar conversions) are used in both the reported and

the proposed methods to make six different cases.

Pranava Chaudhari and Sanjeev Garg

A Two Objective Formulation for the Data Fitting

Exercise of A Multi-Component Reactor System


3:00 pm

Flexible gas sensors, with possible benefits in low manufacturing costs and form

factors, are an emerging field in the area of flexible electronics. The use of

conducting polymer based sensing elements on flexible substrates are

investigated due to several advantages over conventional metal oxide based

sensors because of its tunable electronic properties, sensing at room temperature

and amenable processing. The sensitivity and selectivity of such sensors are

important performance parameters and their low values limit their utilization in a

wide range of applications. Therefore, it is necessary to investigate the

mechanisms affecting sensitivity and selectivity of such sensors along with the

optimization of different materials, geometries, and processes to make them

versatile.

In this work, first doped nanoscale polyaniline thin films were used for sensing

different pollutant gases like NH3, NOx etc. and their detailed sensing

mechanisms were studied through energy consideration to explain the sensing

behaviour. Then, different doped polyaniline structures (fibers and clusters) were

synthesized and also tested for gas sensing of the analytes followed by the

understanding of transport, reaction and transduction mechanism involved.

Detailed response correlations were developed utilizing the parameters extracted

from transport (diffusivity), reaction (time constant of adsorption and

desorption), transduction (temperature and concentration dependent transduction)

mechanism along with physicochemical characteristics (specific surface area) of

the sensing material. Correlations were well-fitted for a range of analytes with

different structures of doped polyaniline. In the follow-up work, kinetic evolution

of the doped polyaniline structures was studied to enhance their gas sensing

performance. In subsequent work, surface functionalized substrates were used to

fabricate self-assembled doped polyaniline based flexible gas sensors.

Mousumi Sinha and Sidharth Panda

Sensing Mechanisms of Doped Thin Film and Self-

Assembled Polyaniline Based Flexible Gas Sensors


3:30 pm

Gargi Mishra, Sri Sivakumar &. Ashutosh Sharma

We have developed PEGylated mesoporous carbon nanocapsule as a universal

nanoreactor and carrier for the delivery of highly crystalline

hydrophobic/hydrophilic nanoparticles (NPs) which shows superior

biocompatibility, dispersion in body fluids, good biodistribution and NPs

independent cellular uptake mechanism. The hydrophobic/hydrophilic NPs

without surface modification were synthesized in-situ inside the cavities of

mesoporous carbon capsules (200-850 nm). Stable and inert nature of carbon

capsules in a wide range of reaction conditions like high temperature and harsh

solvents, make it suitable for being used as nano/micro-reactors for the syntheses

of a variety of NPs for bio-imaging applications, such as: NaYF4:Eu3+(5%),

LaVO4:Eu3+(10%), GdVO4:Eu3+(10%), Y2O3:Eu3+(5%), GdF3:Tb3+(10%), Mo,

Pt, Pd, Au and Ag. Multiple types of NPs (Y2O3:Eu3+(5%) (hydrophobic) and

GdF3:Tb3+(10%) (hydrophilic)) were co-loaded inside the carbon capsules to

create a potential multimodal agent for magneto-fluorescence imaging. Our in

vivo study clearly suggests that carbon capsules have bio distribution in many

organs including liver, heart, spleen, lungs, blood pool and muscles.

PEGylated Carbon Nanocapsule: A Universal Reactor &

Carrier for In Vivo Delivery of Hydrophobic and

Hydrophilic Nanoparticles


4:00 pm

Metal nanoparticles (NPs) functionalized nanocomposite with polymer matrix

have attracted tremendous research interest due to their unique characteristics

such as high surface area, good electrical, mechanical, and thermal stability. The

materials including porous carbon-beads and film are frequently derived from

such hybrid nanocomposites (metal-carbon-polymer). Such nanocomposite

materials are successfully employed in variety of applications as adsorbents,

catalysts, micofluidic devices, drug delivery, and electrodes for biosensor and

fuel cell. Transition metals are relatively less expensive than precious noble

metals and have good chelating, electrical and catalytic properties. Therefore, the

incorporation of such metals for the fabrication of nanocomposite is frequent.

However, stability and effective contact of such metal NPs are still a big

challenge in the different existing nanocomposite materials which are eluted in

the environment when used as former forms in the flow conditions. To address

this issue, a new methodology is being used for the fabrication of new class of

hybrid nanostructure (nanocomposite) materials and polymerization is used as

important tool to tune the various prerequisite properties for different end

applications. Transition metal NPs are incorporated during polymerization step,

just before curing. The physicochemical properties for example, porosity, thermal

and mechanical stability are tuned by either introducing NPs- supported carbon

nanofibers (CNFs) as fillers or by adding different polymers having unique

functionalities for e.g., chitosan polymer and Ag-NPs for adsorptive capabilities

and antibacterial properties, respectively. Later such in situ doped metal NPs are

either exposed by thermal treatment (carbonization/activation) to produce porous

carbon matrix or without degrading their mechanical stability of the polymer

matrix using laser-ablation technique. The micro-texture generated such as

microchannels or micro pillars enhance the surface to volume ratio for efficient

contact of NPs with target materials albeit in flow condition

Prateek Khare and Nishith Verma

Development of Polymer Based Nanocomposite In Situ

Functionalized with NP’sand CNF for Environmental &

Energy Applications


4:30 pm

Koshal Kishore and Raj G. Pala

An approach to decreasing the overpotential, increasing the stability, and

optimizing the noble-metal composition of electrocatalysts for the oxygen

evolution reaction (OER) in the acidic media is demonstrated. The composition

of the electrode with the maximal activity is Ru0.258Ti0.736Zn0.006Ox, and its

activity is four times higher than that of RuO2. The electro-chemical stability

towards the OER follows the order RuTiZn > RuTi > RuZn > Ru. The trends in

activity and stability are rationalized via changes in electronic structure and

molecular roughness of the electrodes.

Supports in which the electrocatalysts are deposited play a crucial role in OER

activity as they influence surface roughness, morphology and conductivity of

electrodes. In this regard, we have designed and demonstrated a hybrid support,

with earth abundant metals as interlayer between Co3O4 electrocatalyst and

carbon paper. Both electronegativity and conductivity of metal influence the

OER activity. The OER activity of electrodeposited Co3O4 is found to have a

linear relationship with electrical conductivity with electron donor metals (e.g.

Ti, Al) and electron acceptor metals (e.g. Cu, Mo, W) individually.

The seawater electrolysis offers opportunity for energy storage in form of

hydrogen and generation of important industrial chemicals like chlorine. During

seawater electrolysis, both oxygen and chlorine gas evolve at anode and their

selectivity can be controlled upto a certain degree through modulation of surface

and electronic structure of the electrocatalyst. In this context, the selectivity

towards chlorine evolution during seawater electrolysis using electrodeposited

Cu-doped RuO2 has been investigated. At lower doping concentration (2%), Cu-

doped RuO2 has been found to promote chlorine selectivity than RuO2. The

present work offers important insight on catalyst design taking account of

selectivity of chlorine and oxygen evolution during seawater electrolysis.

Design of Electrocatalysts and Support for Oxygen

and Chlorine Evolution Reactions


5:00 pm

Natural Convection in Bingham Plastic Fluids in a Square Enclosure From Two

Differentially Heated Cylinders

Lubhani Mishra, R.P.Chhabra,

Laminar natural convection has been numerically investigated for a confined geometry of

two differentially heated horizontal cylinders in a square enclosure filled with Bingham

plastic fluid. The coupled governing differential equations, namely, continuity, momentum

and energy have been solved using the finite element method to elucidate the effect of the

relevant dimensionless parameters, i.e., Grashof number (Gr), Prandtl number (Pr) and

Bingham number (Bn) over the ranges of conditions: 102 ≤ Gr ≤ 104; 0.7 ≤ Pr ≤ 100 and

0.01 ≤ Bn ≤ Bnmax. Extensive results have been obtained for the velocity and temperature

fields which are visualised in terms of streamlines, isotherms, yield surfaces and iso-shear

rate contours delineating the solid-like and fluid-like behaviour and plots of the local and

average Nusselt number for the aforementioned ranges of parameters.

Forced Convection in Bingham Plastic Fluids from a Confined Heated Square

Cylinder

Pragya Mishra, and R.P.Chhabra

The aim of the present study is to elucidate the effect of confinement on the momentum

and heat transfer characteristics for a confined heated square cylinder submerged in

Bingham plastic fluids for the following range of conditions: Bingham number, 0.01 ≤ Bn

≤ 100, Reynolds number, 0.1 ≤ Re ≤ 40, Prandtl number, 10 ≤ Pr ≤ 100 and blockage

ratio, = 0.2, 0.3, 0.4. The governing equations (continuity, momentum and energy) and

boundary conditions coupled with the Papanastasiou regularization for the discontinuous-

viscosity behavior of Bingham plastic fluids have been solved numerically using

COMSOL Multiphysics (Version 4.3a). Extensive numerical results are presented over the

wide range of pertinent parameters namely, Bingham number, Reynolds number and

blockage ratio spanned herein in terms of streamlines, morphology of yielded/unyielded

regions and drag coefficient. Furthermore, heat transfer characteristics have been

examined in terms of isotherm contours, local Nusselt number and average Nusselt

number.


Effect of the laminar Pulsatile Flow on Momentum & Heat Transfer in Power-law

Fluids from a Heated Cylinder

Sanjay Gupta and Raj P. Chhabra

This study examines the changes to the flow and heat transfer induced by a non-zero mean

sinusoidally varying flow past a cylinder. The momentum and energy equations have been

solved using the finite element scheme over wide ranges of dimensionless parameters as

follows: Reynolds number (0.1-40), Prandtl number (0.7-100), power-law index (0.3-1.4),

Strouhal number ( /4- ) and amplitude (0.2-0.8). The detailed kinematics of the flow and

temperature fields are visualized in terms of the streamlines, isotherm contours, the average

and time average drag coefficient and Nusselt number in the close proximity of the cylinder.

The amplitude of the pulsations leads to enhancement in the overall mixing of fluids and the

heat transfer rate. The fluid shear-thinning behavior promotes heat transfer in line with that

seen in non-pulsating flows and simple predictive correlation is developed for Nusselt

number.

Importance of Boat and Chair Rings in Liquid-Amorphous Transition of Super cooled

Tetrahedral Liquids

Nandlal Pingua and Pankaj A.Apte

The amorphous phases of tetrahedral materials are often useful in technological applications

(e.g. amorphous silicon used in solar cell and thin-film transistor LCD displays) as well as to

understand the fundamental aspects of the transition involving such phases. When a

tetrahedral liquid is supercooled (i.e., cooled below the melting temperature at a sufficiently

fast rate so as to avoid crystallization), it leads to the formation of amorphous states

consisting of atoms with local tetrahedral environment. In this work, we study the

mechanism of transition of deeply supercooled tetrahedral liquid into amorphous states. We

perform molecular dynamics (MD) simulations of supercooled silicon (SW silicon) and water

(mW water) modeled by Stilinger-Weber potentials. We study liquid-amorphous transition at

the stability limits of these liquids (1060 K for SW silicon and 205 K for mW water) with a

focus on thermodynamic and structural characterization of the transition. We find that the

transition state is marked by increase in the ratio of chair rings to boat rings, as compared to

those in the liquid region of the trajectory



Numerical modeling of two-dimensional laminar flow of Bingham plastic across a

rotating cylinder

Pooja Thakur, N. Tiwari and R. P Chhabra

The present study numerically investigates two-dimensional laminar flow past a circular

cylinder rotating with a constant angular velocity in an incompressible Bingham plastic

fluid. One of the distinct features of this class of fluids is their dual nature, which leads to

the formation of yielded (fluid-like) and unyielded (solid-like) sub-domains in a given flow

configuration. It thus stands to reason that mixing of such fluids tends to be intrinsically

slow and difficult. Preliminary results of the flow in pipes and ducts seem to indicate that

imposing rotation, pulsation, vibrations, etc. tend to augment the yielded regions.The

numerical simulations have been performed for the following range of other parameters:

Reynolds number 0.1-40, Bingham number 0-102 and non-dimensional rotational velocity

0-5 in the steady flow regime. The purpose of this study is to elucidate the effects of

Reynolds number, Bingham number and rotational velocity on the yield surfaces, the drag

and lift coefficients, torque acting on the rotating cylinder, control the vortex shedding and

understand the underlying flow mechanism.

Influence of surfactant monolayer on the stability of a liquid film flowing over a

heated substrate

Ashna Srivastava, Naveen Tewari

The influence of surfactant monolayer on the stability of a liquid film flowing due to

gravity over a heated substrate is examined. The governing equations are simplified to a

yield tractable model for the film-thickness evolution using lubrication approximation. At

the leading edge of the heater, the temperature gradient creates a Marangoni stress that

leads to a pronounced capillary ridge. Insoluble surfactant is also introduced from the

upstream direction. In the presence of an insoluble surfactant, significant surfactant

accumulates at the stagnant point located inside the capillary ridge that immobilizes the

interface, eliminating the stagnant point and thus reducing the amplitude of the capillary

ridge. A linear stability analysis reveals that even at a small surfactant concentration is

sufficient to suppress the rivulet instability


Stability analysis of thin liquid film flowing over heterogeneously heated porous

substrate

Tara Chand Kumawat and Naveen Tiwari

A linear stability analysis of a thin liquid film flowing over a locally heated porous substrate

is carried out. Navier-Stokes and Darcy-Brinkman equations are used to govern fluid flow

within the thin liquid film and porous medium, respectively. The governing equations are

simplified assuming lubrication approximation to obtain film thickness evolution equation.

The normal component of velocity is assumed continuous whereas a tangential stress-jump

condition is imposed at the liquid-porous substrate interface. The liquid film is getting

heated with a locally embedded heater beneath the porous substrate. A thermocapillary ridge

appears at the upstream edge of the heater due to surface tension gradient that generates

Marangoni stresses, acting in the opposite direction of the constant rate liquid flow. It is

observed that the ridge becomes unstable beyond a critical Marangoni number leading to the

formation of rivulets that are periodic in spanwise direction. The characteristic

dimensionless parameters to isotropic and homogenous porous medium such as Darcy

number, porosity and stress-jump coefficient are found to have stabilizing effect on the thin

film

Tracking instability of polymeric fluid flow through micro-tubes

Bidhan. and V.Shankar

Flow of polymer solution through tubes has gained recent importance due to its immense

practical importance. Turbulent drag reduction is one such application. It was observed that

adding small amounts of polymer to the solvent has a suppressing effect on transition.

However recent work reveals that when the concentration is increased beyond a certain

critical value, the transition occurs at a lower Reynolds number. In our work we investigate

the flow patterns for such polymeric flows wherein the polymer initiates transition at a lower

Reynolds number. Micro tubes with a diameter of the order of 200 microns is fabricated in

PDMS. Pressure driven flows are carried out through such micro-tubes and the flow pattern

is analysed using micro-particle image velocimetry. Velocity profiles obtained through such

a technique is verified by obtaining velocity profiles for Newtonian fluid and matching it

with the theoretical velocity profiles. By obtaining velocity for such flows we characterize

transition for such flows.


Spatio-temporal stability analysis of flows past a neo-Hookean solid

Ramkarn Patne and V. Shankar

Disturbances given to a fluid flow past a rigid surface show wide range of behavior as space

and time progresses. Here we study flow past soft surfaces where surface waves in solid and

Tollmein-Schilliting (TS) waves in fluid interact to make given fluid flow unstable. We use

Kupfer-Bers and Briggs-Bers method to investigate the spatio-temporal evolution of

infinitesimal disturbances to classify the system as absolutely and convectively unstable,

which then helps out in understanding phenomena like drops formation in capillary jet and

transition of flows to turbulence. Particularly we study Couette flow and it is observed that

for certain thickness ratio of soft solid to fluid, spatio-temporal analysis shows absolute

instability as the only way for transition to turbulence.

Ice nucleation on nanotextured surfaces

Atanu K Metya and Jayant K Singh

The formation of ice affects many industrial processes such as transportation, power and

agriculture Thus, in order to minimize or control the ice formation on the various surfaces,

scientists and engineers have put their efforts into designing ice–repellent materials for

various practical applications. Recently, there has been significant interest in developing such

material based on super–hydrophobic surfaces with a subsequent improvement in

performance and stability However, the same super-hydrophobic surface need not be an anti-

icing surface Thus, to design a suitable material for improving anti-icing efficiency in

various industrial processes and applications, efforts are required to understand the principle

underlying mechanism of ice nucleation.

In this work, we address the nucleation behavior of a supercooled cylindrical water

droplet on nanoscale-textured surfaces using molecular dynamics simulations. Ice nucleation

rate at 203 K on graphite based textured surfaces is evaluated using the mean fast-passage

time method. We further investigate the role of nanopillar height on ice nucleation. The

nucleation rate is found to enhance with increasing nanopillar height.


Capture of SO2 Using Functionalized Bilayer Graphene Nanoribbons

Manish Maurya and Jayant K. Singh

Grand canonical Monte Carlo simulation (GCMC) is used to study the adsorption of pure

SO2 using functionalized bilayer graphene nanoribbon at 303 K. The mole percent of

functionalization considered in this work are in the range of 3.125 % to 6.25 %. The

functional groups considered in this work are OH, COOH, NH2, NO2 and CH3. GCMC is

further used to study the selective adsorption of SO2 from binary mixtures of SO2/N2, of

variable composition using functionalized bilayer graphene nanoribbon at 303 K. This study

shows that adsorption and selectivity of SO2 increase after functionalization of nanoribbon

compared to hydrogen terminated nanoribbon. The order of adsorption capacity and

selectivity of functionalized nanoribbon is found to follow the order COOH > NO2 > NH2 >

CH3 > OH > H. Selectivity of SO2 is found to be maximum at a pressure less than 0.2 bar.

Furthermore, SO2 selectivity and adsorption capacity decreases with increase in the molar

ratio of SO2/N2 mixture from 1:1 to 1:9.

Understanding Adsorption Behavior of Silica Nanoparticles over a Cellulose Surface in

in Aqueous Medium

Parul Katiyar, Tarak K Patra, Jayant K Singh, Deboleena Sarkar and Amitava Pramanik

The suspension and adsorption of silica nanoparticles (NPs) on a cellulose surface, in an

aqueous medium is investigated using Brownian dynamic simulations. Interactions are

modelled within the framework of the DLVO theory. Our analysis predicts the accumulation

of negatively charged NPs near a negatively charged surface depending on the Debye

screening length of medium. A crossover from suspension to adsorption of negatively

charged silica NPs onto a negatively charged cellulose surface has been reported as the

screening length ( ) of the medium increases. The behavior of NPs is explained using the

potential of mean force analysis. The amount of NPs adsorbed depends on their bulk volume

fraction and . Further, the effects of electrical potentials of NP and surface on the adsorption

are reported. The adsorbed particles form a disordered monolayer, and undergo sub diffusive

motion.

Influence of Salts on Gelation of Aqueous Laponite Dispersion

Khushboo Suman and Y. M. Joshi

Physical aging in aqueous dispersion of smectite clay Laponite XLG leads to the formation

of gel like structure in the substance. This aggregation process is initiated due to the presence

of dissimilar charges on the face and edge of the colloidal layered silicate. In this work, we

study the impact of various ionic salts on the gelation process of aqueous Laponite

dispersions. Addition of certain salts such as sodium chloride promote the gelation process,

while there also exists a group of salts like tetrasodium pyrophosphate which delay this

process. The escalation in gelation process in case of certain salts can be attributed to the

decrease in repulsive forces and vice versa. Also, to investigate the effect of these forces on

gelation time, we study the electrostatic interactions for mixed electrolyte system

The Cystal-Melt Interfacial Free Energy Computation Using Thermodynamic

Integration (TI) Method

Anil Mangla and Pankaj A.Apte

Information regarding crystal melt interface is essential in understanding solidification and

nucleation in super cooled liquids. Crystal-melt interfacial free energy and its anisotropy are

the key factors that control the morphology and kinetics of the crystal growth from the melt.

Currently, experimental techniques to measure the anisotropy of crystal-melt inter-facial

energy are not available, and hence many computational methods have been developed.

Thermodynamic Integration (TI) method developed by Davidchack and Laird [J. Chem.

Phys. (2003)] constitute an important class of such methods. But it involves (1) lengthy

calculations and (ii) hysteresis in various steps that affects the precision of the free energy

computation. An improved method by Benjamin and Horbach [J.Chem.Phys.(2014)]

addresses the problem of hysteresis substantially but it is lengthier than earlier method given

by Davidchack and Laird [J.Chem. Phys.(2003)]. In this work we are trying to come up with

a new TI method that retains the basic elements of the TI approach by Benjamin and

Horbach, but which at the same time is less computationally demanding. We also plan to

apply this technique for computation of crystal-melt inter-facial energy of silicon.


Bio-Inspired Nano-Patterned Material for Reversible Adhesion

Nitish Singh and Animangsu Ghatak

Adhesive pads at the feet of several creatures like beetles, flies and geckoes are capable of

attaching to variety of surfaces and generating adhesion strength several times their own

body weight. In contrast to most man-made visco-elastic glues, these adhesives do not get

contaminated by particulate matters and are therefore used several times over the lifetime of

these animals. There have been several attempts to mimic these structures with some success,

although, scaling up over a large area in an economically viable process remains a challenge.

Self-assembled patterning is a promising method for generation of hierarchical structures

which can resolve scale-up problems like expensive lithographic technique. Here we describe

such a process in which a crosslinkable material, such as silicone oligomers is moulded

against a rough gel. We show that this process results in surface patterns of length-scales

varying from few microns to tens of nano-meters. Furthermore, these surfaces adhere

strongly but reversibly to smooth and rough substrates alike and can be washed to remove the

contaminants.

Bio-Inspired Optical Lens

Abhijit Chandra Roy and Animangsu Ghatak

Taking inspiration from nature and solving some of the existing problems of our daily life is

an interesting piece of work. The visual systems of Trilobite, an extinct sea creature, are

known to consist of one of the most advanced optical lens systems in the natural world:

calcite made bi-convex aspheric lenses. Their large depth of field, minimal spherical

aberration, and superior light gathering ability have drawn the attention of physicists,

material scientists and evolutionary biologists alike, but their complex geometry has made

replication of such lenses difficult by conventional fabrication methods. In this context, we

have presented here a one-step process for generating such complex shapes. Our process

involves crosslinking of a polymeric liquid dispensed as a droplet on a substrate with

particular geometric and chemical features. We have shown that the fabricated lens structure

can drastically reduce the optical aberration of this lens (~ 5 times compare to the

conventional spherical lens).



Ultrasensitive Flexible Capacitive Pressure Sensor with Structured Elastomeric

Dielectric Layers

Gaurav Rawal and Animangsu Ghatak

Highly flexible pressure sensors are crucial for development of e-skin which is of critical

importance for artificial intelligence. Recently different types of flexible pressure sensors

(using Silver Nanowires, Gold nanowires, organic field transistors and techniques like

lithography etc.) have been developed and explored, but the use of such techniques limit the

fabrication of these sensors at large scale and increase the cost. Here, we have attempted to

address this problem by designing a flexible capacitive pressure sensor with a cheap paper

electrode (with high conductivity 10S/cm ) made by depositing copper on a trace paper and

silicone based elastomer as dielectric, with cylindrical pillar structure inexpensively

adapted on it. The flexible cylindrical structures on ecoflex in between highly conductive

trace paper based electrodes provide a high sensitivity. The sensor gives high sensitivity in

low pressure regime and the sensitivity decreases at high pressures. The dependence of

sensitivity of the device is studied with changing geometric factors like diameter, height

and pitch of the cylindrical pillars.

Flow Through Multihelical Microchannel

Pravat Rajbanshi and Animangsu Ghatak

Three dimensionally (3D) oriented micro fluidic channels are important for host of

scientific and engineering applications. Examples of such fluidic devices are multi-helical

micro-channels which consist of multiple helical flow paths joined together along their

contour length. These channels have recently been explored to accomplish rapid mixing of

liquids at low Reynolds number flow and also for the generation of micro-droplets of one

fluid into another. In conventional micro mixer, mixing is slow, because in absence of

turbulence, mixing occurs by molecular diffusion. However, 3-D flow profiles inside such

channels are yet to be explored and understood. Here, we have presented simulation of 3-

dimensionally oriented multihelical micro fluidic vessels to investigate the 3-D flow

patterns and mixing phenomena. Axial length, helix angle, helix radius and asymmetry of

the channel cross-section are varied easily to achieve desired mixing. From simulations, it

is found that the mixing efficiency gradually increases with increase in axial length of the

channel, helix angle and asymmetry of the channel cross-section.


Shear Fracture Resistance of Soft Brittle Gel Depends upon Shape of Contact Area

Krishan Kant Kundan and Animangsu Ghatak

Shear mode fracture of material occurs in joints of large engineering structures such as in

bridge, petroleum exploration, rock sedimentation, etc. To examine the shape effect in the

shear fracture, we have conducted the displacement-controlled experiment on brittle

hydrogel of varying modulus, in which blocks are connected through a joint of different

geometric shape. For the same contact area between the two blocks, the various geometric

shapes showed different fracture energy. In some cases, the fracture occurs catastrophically

after attaining Fmax , in another instance. The initiation of cracks and its propagation

depends on the geometric shape along with the modulus of the material. To investigate the

effect of aspect ratio of circular joint on fracture energy, we have conducted experiments

with the elliptical opening of different aspect ratios varying from 0.32 to 3.125. The

fingering phenomena in shear fracture starts near the periphery of the opening, spreads

radially inward, and merges at the end of fracture.

Catalytic Wet Air Oxidation of Wastewater Using Novel Carbon-Based Materials

In-Situ Dispersed with Transition Metal Nanoparticles

A. Teja , A. Yadav, N. Verma

Wet air oxidation (WAO) technique is extensively applied to treat industrial wastewater

effluents. However, the operating conditions are severe, requiring relatively larger

pressures (5-30 atm) and temperatures (150-400oC). In the present study, the carbon-based

materials in-situ dispersed with transition metal (Fe) nanoparticles were prepared for the

effective removal of organic model pollutant such as phenol in wastewater, using catalytic

WAO. The metal-carbon composite was prepared by the carbonization and activation of

the phenolic precursor-based spherical beads (~ 0.5 mm) in which the metal nanoparticles

were in-situ added during a polymerization stage and was further decorated with carbon

nanofibers using chemical vapour deposition. The catalytic WAO efficiency of the material

was investigated using a pressure batch reactor and an overall removal efficiency of > 95%

was achieved under the optimized operating conditions, indicating the potential scale-up of

the prepared material for the treatment of industrial wastewater effluents containing

organic pollutants.


Adsorptive Desulfurization of Diesel Oil Using Activated Carbon Fibers (Acfs)-

Supported Copper and Nickel Metal Nanoparticles

Yogendra Nath Prajapati and Nishith Verma

Present study describes the preparation of copper and nickel metal/metal oxide-dispersed

activated of carbon fibers (ACFs) for the adsorptive desulfurization of dibenzothiophene

(DBT). The adsorbents were prepared using pore filling method and subsequent heat

treatment. The prepared adsorbents were characterized using SEM, XRD, BET, and TPR.

The optimum adsorbent dose was found 8 g/L. The quasi-equilibrium condition for the

desulfurization process was reached in 4 hr. Approximately 85-92 % of the maximum

adsorption capacity (55-60 mg/g) was achieved within 10 min of adsorption. CuO/ACFs

showed better adsorption performance than NiO/ACFs and Ni/ACFs despite having less

BET surface area and mesopore volume for a DBT concentration of 500 mg/L. The initial

rate of adsorption for Ni/ACFs was found the highest owing to relatively high mesopore

content. The thermodynamic study showed that the adsorption was endothermic in nature.

The enthalpy and entropy were found to be depended on the adsorption temperature.

Economic Optimum Plantwide Control

Vivek Kumar. and Nitin Kaistha

Optimal steady operation of chemical plants requires “seeking” optimal values for any

economically dominant unconstrained setpoints as their optimal value changes with

disturbances and changes in operating conditions. This poster will present two techniques

for updating such unconstrained setpoints, namely, hill-climbing and real time optimization

(RTO). The application and quantitative economic benefit of these techniques is

demonstrated on a reactor-separator-recycle process and an ester purification process. Both

energy minimization for a given throughput (Mode I) and throughput maximization (Mode

II) are evaluated. For the disturbance scenarios studied, quantitative results show an

economic benefit of up to 5% compared to constant setpoint operation.


Synchronization of Charge Carrier Separation by Tailoring the Interface of Si–Au–

Tio2 Heterostructures via Click Chemistry for PEC Water Splitting

Gyan Prakash Sharma and Raj G. Pala

Electrochemical potential gradients that are established due to appropriate band edge

alignment in heterostructures can synchronize the movement of electron and hole in opposite

direction. Such synchronization is critical for efficient photoelectrochemical devices and can

be achieved by tailoring the interface of heterostructures. To this end, we fabricate a tailored

interface of Si–Au–TiO2 heterostructure over stainless steel ((Si–Au–TiO2)/SS) for effective

charge carrier separation. The fabricated electrode possesses the following tailored interfaces

to enhance the charge-carrier separation: 1) Si, Au, and TiO2 form the interface with SS, 2)

Si–TiO2, and Si–Au interface facilitates the quenching of H+ generated in Si and 3) TiO2

forms the interface with the electrolyte solution to facilitate hole transport. We observed

ABPE of ~0.4%@~0.9 V applied bias, ISTC of ~0.085 (or 8.5%) @1.66 V vs. RHE and

ESPH conversion efficiency of ~3.3%@~1.0 V applied bias.

Electrocatalytic Behaviour of Pd25zr75 Metallic Glass for Hydrogen Evolution

Reaction

A.Sahu and R.G.S. Pala

Metallic glasses are amorphous metallic alloys having disordered atomic-scale structure,

synthesized by melt and quench process. Due to its unique property of high density of low

coordination sites it behaves as a preferable material for catalysis. Because of its conducting

nature it is also appreciated as good electrocatalyst.We have used Pd25Zr75 metallic glass as

electro catalyst for Hydrogen evolution reaction. In 1 M NaOH solution it showed very less

activity because of presence of inactive Zr oxide layer on the surface but after the treatment

it showed better activity. In 1 M H2SO4 solution, first its activity increases because of

increase in active surface area due to dissolution of inactive Zr from the surface. It finally

turns to porous Pd rich surface showing constant activity. Its Structure and morphology is

characterized by (Scanning Electron Microscopy) SEM and 3-D profiler analysis. For

compositional analysis (X-Ray Photoelectron Spectroscopy) XPS,(X-Ray Diffraction) XRD

has been performed.


Catalyzing the Cubic-to-Hexagonal Phase Transition Activation Barrier in Nayf4 via

Enhanced Surface Adsorption

Sulay Saha and Raj G.Pala

Synthesis of high purity hexagonal NaYF4 is critical for many optoelectronic applications.

Lower reaction temperature favors cubic NaYF4 and phase transformation to hexagonal

phase is possible at higher temperature (≥180̊ C) when synthesized in presence of oleic

acid. The oxidation of oleic acid (C-18) to azelaic acid ligands (C-9) enables cubic

hexagonal phase transformation at a temperature of 48̊ C. The phase transformation from

cubic hexagonal phase involves a disorder order phase transition as all the cationic sites

can be occupied by either Na or Y in cubic phase while hexagonal phase is more ordered

structure. As both carboxyl and hydroxyl groups of adsorbents strongly adsorps on Y-

terminated surfaces while having no interaction with Na-terminated surfaces of the cubic

phase and hence, their adsorption promotes near-surface segregation of Y. This biasing of

occupancy towards more ordered arrangement promotes the formation of more ordered

phase and correspondingly reduces the activation barrier for transformation to the more

ordered hexagonal phase..

EIS Investigation of Tailored Gold/Rutile-Tio2/Anatese-Tio2 Interface via Click

Chemistry for Photo electrochemical Water Splitting

Gyan Prakash Mourya and Raj G. Pala

Photo electrochemical (PEC) water splitting is the method of splitting the water molecules

on surface of semiconductor catalyst into hydrogen and oxygen gases by application of

electrical energy and solar energy. At semiconductor electrolyte interface the processes

occurring plays the important role for determining the efficiency of the PEC.

Electrochemical Impedance Spectroscopy (EIS) is the powerful technique for determination

of incidences occurring at the interface. In this work four different types of hetero structure

i.e. Au@R-TiO2@A-TiO2@SS, R-TiO2@A-TiO2@SS, R-TiO2@SS, A-TiO2@SS is

compared and shown that addition of the gold increases the efficiency of the PEC. At the

same instance the charge transport and charge separation phenomenon is explained through

the EIS. Chemical capacitance is used to explain the charge storage at the interface. Charge

transport occurs through the trap states are explained through the EIS circuit.


Transition of ionic liquid-ethanolamine mixture from Newtonian to non-Newtonian

shear thinning fluid after CO2 absorption

Ashok Ummirereddi. Raj G. Pala

We have studied the rheological properties of monoethanolamine (MEA), task specific

ionic liquid (TSIL), mixtures of different compositions of MEA and TSIL pre and post

CO2 capture. We have used 1-butyl-3-(2-(diethylamino)ethyl) imidazolium bis

(trifluoromethyl sulfonyl) imide (DEAEBIM TF2N) TSIL in this study. Before CO2

capture, both MEA, and DEAEBIM TF2N show Newtonian behavior and MEA shows

lesser viscosity than ionic liquid. Mixture of MEA and DEAEBIM TF2N of different

compositions form a homogeneous mixture and shows the Newtonian behavior before

CO2 absorption and viscosity varies linearly with the composition. Upon CO2 absorption,

MEA, and DEAEBIM TF2N showed the Newtonian behavior and ethanolamine shows

20-fold higher viscosity than ionic liquid. FTIR study suggests that CO2 physisorbs in

DEAEBIM TF2N and chemisorbs in MEA. Further, the mixture of ethanolamine and ionic

liquid showed the non-Newtonian shear thinning behavior and this shear thinning behavior

is due to drops of ionic liquid-CO2 encapsulated in the MEA-CO2 are broken down

during the application of shear rate and offers less resistance to flow.

Lithium Ion Intercalation Mechanism into Ramsdellite and Γ-Mno2

Prashant Kumar Gupta. Raj .G.Pala

Lithium ion batteries have revolutionized the portable electronics market. Polymorphs of

MnO2 have been widely favored in battery industries due to its low cost, less toxicity and

superior safety. Among different polymorphs of MnO2, it has been seen that γ-MnO2

(generally regarded as the intergrowth of ramsdellite (2×1 channel) and pyrolusite (1×1

channel)) is most electrochemically active form.

In the present work, we study the intercalation of Li in γ-MnO2 and proposing lithium

intercalation mechanism in ramsdellite and the γ-MnO2 using DFT computation. We

propose that Li ion intercalate in ramsdellite phase at tetrahedral sites close to the edge

sharing oxygen till Li concentration is 0.5 followed by Li insertion at the octahedral site

near the corner sharing oxygen.


Effect of Adding Noble and Non-Noble Metals to Ni/Mgal2o4 Catalyst on the High

Pressure Activity of Steam Reforming of Methane

Sanjay Katheria. Gautam Deo

Nickel based catalysts have been often used for steam reforming of methane (SRM). The

two important parameters for these catalysts are activity and stability. Also important is

the evaluation of these parameters at high reactor pressures. Previous studies reveal that

Ni-based bimetallic catalysts show superior activity and in some cases higher stability.

The second component of the bimetal may be a noble or non-noble metal. This study

demonstrates the effect of doping a previously prepared 15%Ni/MgAl2O4 with 5%Co,

0.5%Rh and 1%Pt and using them for SRM at ambient (1 bar) and high (10 bar) reactor

pressures. Doping the previously prepared catalyst showed an increase in activity relative

to the supported Ni catalyst at both pressures. However, the effect of adding Rh or Pt

showed a higher activity and better stability compared to Co. To further improve the

catalytic performance of using non-noble metals as dopants requires additional studies.

Computational Approach to Understand Ni-Based Alloy Catalysts for CO2

Hydrogenation to CH4

Koustuv Ray and Goutam Deo

Ni based bimetallic catalysts containing metals Fe, Co and Cu are gaining prominence for

reforming and hydrogenation reactions involving CO2. Specifically, we have reported

improved catalytic activity for the CO2 hydrogenation to CH4 using Ni-Fe bimetallic

catalysts in comparison to Ni, Ni-Co and Ni-Cu catalysts. It is even more surprising that a

particular Ni:Fe ratio is crucial for the higher activity. The improved catalytic activity

appeared to stem from Ni3Fe alloy formed in the particular Ni-Fe catalyst. Other alloy

catalysts for the similar ratio are less active. It is revealed that incorporation of Fe/Co/Cu

in Ni system for the similar Ni:M (M = Fe/Co/Cu) ratio changes the structural, surface

and electronic properties of the alloy catalysts in a non-monotonic fashion. Finally, the

catalytic activity and the key electronic properties were correlated.


Carbon Dots Decorated Tio2 Nanofibers for Effective Usage as a Photo Catalyst

Narendra Singh, Ankit Tyagi, and Raju Kumar Gupta

Environmental degradation issue is a serious global concern because its direct impact

over human and animal health, so issue needs to be addressed. TiO2 nanofibers are

attractive over last decades due to their low cost, simple preparation method and wide

area of use such as photo catalysts, solar cells, supercacitors, etc. In this work, electro

spinning method was utilised to prepare one dimensional TiO2 nanostructure. In next

step, lemon peel derived carbon dots (CDs) were deposited over TiO2 nanofibers using a

linker molecule (6-aminohexanoic acid). TiO2 and carbon dots interfaces cause effective

excitons separation and enhance the photo catalytic activity of the material. TiO2-CDs

heterostructure showed ~2.5 times higher photo catalytic activity than TiO2 alone for the

methylene blue degradation.

Effect of Doping in Improvement of Supercapacitive Charge Storage for

Electrospun Tio2 Nanofibers

Ankit Tyagi, Narendra Singh and Raju Kumar Gupta

Electrochemical capacitors are the devices, which can give high power density upto 105

kW kg-1 but suffers from low energy density. TiO2 is the material which abundant on

earth and environmental friendly it also gives the good cycling property during charging

and discharging of electrochemical capacitors. We have used simple electrospinning

technique to prepare TiO2 and doped TiO2 nanofibers for the electrochemical capacitor

applications. The electrochemical characterization techniques such as cyclic

voltammetry, galvanostatic charge-discharge and electrochemical impedance

spectroscopy have been used to characterize the material for its electrochemical

properties, while SEM, TEM, XRD etc. techniques have been used for their

morphological, structural and physical characterization.

Improved Energy Density of Batio3-PVDF Polymer Nanocomposites

Prateek and Raju Kumar Gupta

Nowadays, increasing energy requirements demand to develop new, low-cost, and

environmentally friendly energy conversion and storage systems such as batteries, fuel cells,

electrochemical capacitors, and dielectric-based capacitors. Among these energy-storage

technologies, dielectric or electrostatic capacitors possess an intrinsic high power density

that is associated with very fast energy uptake and delivery, and thus hold great promise for

the development of high performance power electronics used in hybrid electric vehicles,

medical devices, and electrical weapon systems. The polymer nanocomposites are most

commonly used as dielectric because of high breakdown strength of polymers and high

dielectric constant of ceramic nanomaterials. In the present work, polyvinyledene fluoride

(PVDF) is used as polymer, while barium titanate (BaTiO3) nanomaterials are used as

fillers. The experimental results show that addition of BaTiO3 nanomaterials increases the

dielectric properties, namely dielectric constant, electric polarization, breakdown strength,

etc.

Fabrication and Characterization of Organic-Inorganic Hybrid Perovskite Solar Cell

Rahul Ranjan and Raju Kumar Gupta

Energy is one of the major concerns in growing world. Solar cells based on Perovskite

absorbers promise to break the prevailing paradigm by combining both ultimately low cost

and high efficiency. They have become an attractive light-absorber system with a rapid

improvement of cell efficiencies from less than 4% in 2009 to a certified 20.1% in 2014 thus

giving serious competition to Si solar cell. Such a high photovoltaic performance is

attributed to optically high absorption characteristics and balanced charge transport

properties with long diffusion lengths. This work is related to study the formation of

Perovskite film using different characterisation techniques such as X-ray diffraction (XRD),

UV-vis spectroscopy. Film morphology has been studied using scanning electron

microscopy (SEM). Further devices were made using these films via spin coating method in

nitrogen filled Glove Box. The inverted structure of ITO/PEDOT:PSS/ Perovskite /PCBM

/Al was used. The optimization of PEDOT:PSS was done which includes thickness

variation, composition variation. With optimized device efficiency of ~6% was achieved.


Genetic Studies of Azoreductase Gene from Klebsiella Pneumoniae

Shweta Dixit and Sanjeev Garg

The biological treatment of toxic azo dyes, is a relatively inexpensive and ecofriendly way to

remove the dyes from wastewater. A bacterial strain was isolated and identified as Klebsiella

pneumoniae by 16S rDNA gene sequence analysis. Methyl orange (100 mg l-1, model azo

dye) was decolorized more than 95% in less than 24 h using the isolated strain. The AzoK

gene in Klebsiella pneumoniae coding for the enzyme azoreductase, was cloned in pGEM-T

vector and sequenced to check the integrity of the gene. The cloned gene was then expressed

in E. coli and its azoreductase activity was characterized. The recombinant E. coli is

envisaged to be used at source points to decolorize the wastewater.

Reverse Engineering the Controlled Drug Delivery Devices

Anurag Pramanik and Sanjeev Garg

The conventional drug dosage forms have drawbacks which can be addressed using the

controlled drug release. The control release devices generally involve a drug encapsulated

within a bio-degradable polymer and the release is controlled by diffusion. Despite many

advances in the polymeric controlled release devices, there is still a need for efficient

methods to design devices with desired release profiles. This study proposes to use in silico

models to simulate the drug release from a controlled drug delivery device in a fluid flow

model. The effects of several parameters including, mutual diffusion and partition coefficient,

shape/size and type of the delivery device on the release profile were studied. The controlled

delivery of Paclitaxel for a sustained period in the pharmaceutical window using different

biodegradable and biocompatible polymers in a reverse engineering framework was studied.

The practical benefit of the proposed approach is to predict design without actually

synthesizing the device



Enhanced Electrochemical Performance of Ag Encapsulated Coaxial Carbon

Nanofibers as Free-standing Anodes in Li-ion Batteries

Shilpa and Ashutosh Sharma

Silver with a high theoretical capacity for lithium storage is an attractive alloy based anode

for Li-ion batteries. However, high cost of silver and large volume changes associated with

AgLix alloy formation during charge/discharge cycles lead to electrode pulverization and

rapid capacity fading, restricting its practical application. Designing nano-dimensioned core-

shell architectures with active metal encapsulated within a core is a novel and effective

approach to mitigate the mechanical cracking process in electrodes. In this work, we

demonstrate a simple and inexpensive one-step method for fabricating a core-shell structured

Ag-C hybrid electrode for a high energy/power density and long cycle-life lithium ion

battery. A thin mat (~ 60 μm) composed of hollow one-dimensional carbon nanofibers

(diameter~ 300 nm and shell thickness ~20nm) encapsulating Ag nanoparticles has been

obtained through coaxial electrospinning followed by calcination and carbonization. The

nanofiber mat being mechanically stable and electrically conducting is used as a free-

standing electrode dispensing off all the inactive components, ie, the binder, conductive

additive and the copper current collector which only add to the battery weight and volume.

The electrode delivers a reversible capacity of 740 mAh/g (more than twice that of

conventional carbon anodes) at a current density of 50 mA/g, showing ~ 85% capacity

retention after 100 cycles.

PDMS Nanostructures for Drug Delivery Applications

Auhin Kumar Maparu, Beena Rai, Ashutosh Sharma and Sri Sivakumar

Polydimethylsiloxane (PDMS) is the most popular member in the class of polysiloxanes. It is

widely used in medical applications like catheters, insulation for pacemakers and ear & nose

implants. It is also used in membrane based separation and purification, sensors, microfluidic

devices, energy generation and storage devices. In most of these applications, it is utilized as

a dense film, composite coating or as microfluidic channel. In this study, we report for the

first time, a room temperature synthesis of PDMS nanoparticles and nanofibers via

nanoemulsion route. Due to their soft nature, optical transparency, chemical inertness,

solvent-specific swelling, excellent biocompatibility and gas-permeability, these PDMS

nanostructures are expected to evolve as a promising material for controlled delivery of

therapeutic agents.


Paper Based Biosensors for Early Detection of Oral Cancer from Salivary

Biomarkers.

Subhadeep Mitra and Ashutosh Sharma

Cancers of the oral cavity account for 40% of head and neck cancers and include

squamous cell carcinomas of the tongue, floor of the mouth, buccal mucosa, lips, hard and

soft palate, and gums. In spite of therapeutic and diagnostic advances, the 5-year survival

rate for oral squamous cell carcinoma (OSCC) remains at about 50%. One of the major

factors accounting for the poor outcome of patients with OSCC is that a great proportion of

oral cancers are diagnosed at advanced stages and, therefore, treated late. Given the fact

that current diagnostic method is falling short to detect the disease early enough we propose

a paper based biosensor to detect oral cancer biomarkers from saliva by using impedance

spectroscopy technique. We feel devices such as the one proposed here can be extremely

helpful as a point of care device (POC). It can be used by not so skilled persons especially

in rural settings of India where tobacco consumption rate is high and so are the cases of oral

cancers. By measuring the levels of potentially dangerous biomarkers people who are at

high risk can be screened and advised for further treatment well before it is too late.

Study of surface nanomechanical properties of electrospun polyacrylonitrile (PAN)

nanofibers/ poly(dimethyl siloxane) composites

Tushar Deshpande, Yogesh Singh, Sandip Patil, Y. M. Joshi and Ashutosh Sharma

We studied surface nanomechanical properties of electrospun polyacrylonitrile (PAN)

nanofibers/poly(dimethyl siloxane) composites using force spectroscopy and force mapping

modes of atomic force microscopy. PAN nanofibers with amount 0.1, 0.3, 0.5, 0.7, 1.0

(%wt) were dispersed in the elastic PDMS (10:1) by solution mixing to fabricate PDMS

films having elasticity gradients. As the sample surface is elastically non homogeneous, our

studies were focused on measurement of hysteresis (plasticity index) between loading and

unloading curves in AFM indentation experiments. The comparisons of composite

substrates with control 10% crosslinked PDMS were performed. The results show

heterogeneity of viscoelastic-plastic properties of PAN nanofiber/PDMS composites.

Plasticity index variation can be attributed to the distinct organization of electrospun PAN

fibers in the PDMS matrix and thereby it can describe the mechanical state of the PAN

nanofiber/PDMS composites.

Surface Debonding of Polystyrene Films under Solvent- Non-Solvent Mixture

Aqeel Malani and Ashutosh Sharma

Surface debonding (wrinkling) of polystyrene (PS) (MW=280,000 g/mol) films with

thickness ranging from 20nm to 200nm is observed by placing a drop of N,N-dimethyl

formamide (DMF)-water mixture. Wrinkles on the films are observed under drop and at drop

edges as well as upon immersion under the solvent- non-solvent mixture between 80 to 96%

(v/v) DMF in water. Addition of further DMF in water leads to spontaneous dewetting of PS

film; whereas no wrinkling is observed when less than 80% DMF is added to water. Efforts

to attain orderly wrinkles were done using pre-patterned PS films. PS fims were patterned by

nanoimprint lithography. Another approach undertaken to get well-ordered wrinkling is by

varying substrate surface energy.

Change in Spectral Property of Carboxylate Dyes: Role of Surface Reactivity

Abhi Mukherjee and Siddhartha Panda

Organic dye molecules are useful components of instruments for optical detection. Dyes,

both in solution phase and in immobilized condition, are used for this purpose. Studies have

shown that spectral property of dyes are different in solution and in immobilized state. In

this work we have studied the optical properties of dyes in solution as well as in

immobilized condition. Three platforms were used to immobilize the dyes, they were

silicon, PET and PDMS. Time dependant density functional theory (TDDFT) was used to

calculate the absorption spectra of free and attached dyes.B3LYP and CAM-B3LYP hybrid

functional along with 6-31G (d) and 6-31G (d,p) basis sets were used for theoretical

calculations. The theoretical an experimental absorption spectra were then compared to

understand how the nature of the surface affects the spectra of the immobilized dye

molecules.



Effect of Microfluidic Channel Geometries on Capture Efficiency

Shipra Verma and Siddhartha Panda

Heterogeneous immunosensors are utilized for detection of disease biomarkers in body

fluids. Flow based immunosensors, using micro fluidic channels, have several advantages

like faster mixing, lesser response time, multiple detection etc. Enhanced capture efficiencies

of the antigens (Ag) in the carrier fluids by the surface immobilized antibodies (Ab)

facilitates lower detection limits and thus early detection of disease. The capture process

involves transport of Ag from the bulk solution to the surface immobilized Ab and then the

Ag-Ab reaction, which are transport limited. There is a need to enhance transport so the

driving forces and mixing strategies have been used to enhance the capture efficiency. In

microfluidic channels, the smallest dimension plays critical role in Ag transport to the

immobilized Ab. Also it is affected by modulation of the flow pattern. In this work we focus

on the effect of secondary flow which leads to higher mixing and thus could help obtaining

the geometries for the optimum performance.

A Conducting Polymer Based Sensor for Detection of Heavy Metal from Water

Kusumita Dutta and Siddhartha Panda

A copolymer based sensor surface is developed from aniline and N-phenylglycine by

different electrochemical techniques- chronoamperometry, chronopotentiometry and cyclic

voltammetry on stainless steel electrode for detection of cadmium. These materials were

characterised using Fourier transform infrared microscopy, field emission scanning electron

microscopy. The copolymer surfaces were modified with iminodiacetate for capturing heavy

metals. Square wave voltammetry was performed to detect cadmium. The limit of detection

was found 100 ppb for the films produced by chronoamperometry and cyclic voltammetry

while 90 ppb for the film synthesized by chronopotentiometry. In order to study the

interference, several ions had been used with varying concentration in presence of 100 ppb

conc. of cadmium. It has been observed that the interfering ions are not getting detected by

SWV except Zn at concentration of 10 ppm or more. The interfering ions have been divided

into four categories- no interfering, less interfering, moderately interfering and heavily

interfering. We have established the detection limit of cadmium in presence of these ions. In

order to study mechanism, an attempt was made to establish the reason for the interference

using barrier width as the parameter.

Kuldeep Singh [email protected]

Sanjay [email protected]

Gaurav [email protected]


Vidisha Singh Rathaur

Shalini Arora

Shradha mandloi

Vikash Kumar

S.V. Siva Krishna

Shankar Kumar Sain

Amrita Goswami

Aqeel Malani

Lakshmi Ramrao Kushwaha

Lubhani Mishra

Mayank agarwal

Pawan Kumar Tiwary

Puneet Kumar Chaudhary

Documents

Page Number - Indian Institute of Technology Kanpur · 4:30 pm Prateek Khare Development of polymer based nanocomposite in situ functionalized with nanoparticles and carbon-nanofibers