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NANOFINISHES FOR UV PROTECTION IN
TEXTILESMYTHILI TUMMALAPALLI
2010TTZ8217
SUBMITTED TODR. BHUVANESH GUPTA
INTRODUCTION
UVA (320 to 400 nm)
UVB (290 to 320 nm)
UVC (200 to 290 nm)
UV-B irradiance at the surface based on the abundance of ozone, as measured by NASA’s Total Ozone Mapping
Spectrometer (TOMS) instrument during the month of November, 2000.
Courtesy: http://www.cushnshade.com
INDUSTRIAL SCENARIO
Aerospace
Aviation
Petrochemical
Electronics
Machinery
Environment
Protection..
Ultraviolet Protection Factor (UPF)
EVALUATION OF UV PROTECTION
Eλ = erythemal spectral effectivenessSλ = solar spectral irradiance in W/m2/nmTλ = spectral transmittance of fabricΔ λ = the bandwidth in nmλ = the wavelength in nm
Solar Protection Factor (SPF)
MED = Minimum Erythrymal Dose
Higher the UPF and SPF values, better the UV protection by the fabric
Courtesy: http://www.cushnshade.com
UV PROTECTIVE TEXTILES
Fiber chemistry
Fabric construction, porosity, thickness and weight;
Moisture content
Dye concentration, whitening agents, UV absorbers
Finishing chemicals
FACTORS – UV PROTECTION
METHODS OF UV PROTECTION IN TEXTILES
UV absorbers Colors
Finishes - - NANO
Nanotechnology - structures sized between 1 to 100 nm in at least one dimension
ZnO, TiO2 , ZrO - absorb the UV radiation
ZnO, TiO2 - non-toxic, compatible with human skin, chemically stable under both high temp. and UVR, easily available
NANOFINISHES
High surface-to-volume ratio - adhere well to the fabric
Transparent appearance
High surface area and high surface energy - bound to the surface of the fibres by van der Waals forces - wash fastness
Continued…
Cotton/polyester
Higher UPF
Woven better UPF than knitted
Polyester/cotton blend - better UPF than pure cotton - UV absorption of polyester
APPLICATION OF NANO ZnO BY PADDING MANGLE
Karthivelu et al., Indian Journal of Fibre & Textile Research, Vol. 34, September 2009, pg. 267-273
Hexamethyelenetetramine and zincnitrate
Cotton fabric - treated in hot water to obtain 1D needle-shaped nano ZnO crystallites
ZnO ON SiO2 SOL COATED COTTON - HYDROTHERMAL METHOD
DEVELOPMENT OF NANO ZnO PARTICLES – SEM IMAGES
(a) before treatment, (b) after soaking in the SiO2 solution, (c) after chemical deposition of ZnO, and (d) after hot water treatment at 100 °C for 2.5 h
(a) before treatment, (b) after soaking in the SiO2 solution, (c) after chemical deposition of ZnO, and (d) after hotwater treatment at 100 °C for 2.5 h.
(a) before treatment, (b) after soaking in the SiO2 solution, chemical deposition of ZnO, and boiling water treatment for 3 h, and (c) after 20 washes
Mao et al., Thin Solid Films, Vol. 517, 2009, pg. 2681–2686
CeO2 -excellent UV absorption - low photocatalytic activity
CeO2 + ZnO - reduce the catalytic and photocatalytic activities
Fine ZnO:CeO2 particles with very small size - unique UV absorbing ability, high stability at high temp., high hardness, and low activity as catalyst
ZnO:CeO2 NANOPOWDERS AS UV ABSORBERS
J. F. Lima et al., Applied Surface Science, Vol. 255, 2009, pg. 9006–9009
Layered fabric systems with electrospun ZnO nanocomposite fiber webs - various conc of ZnO in a range of web area densities
Extremely thin, Light-weight, Mechanically flexible
Desired functionalities imparted without significant increases in weight or thickness
ELECTROSPUN ZnONANOCOMPOSITE FIBERS
SEM micrographs of (a) electrospun polyurethane nanofiber web, (b) electrospun polyurethane/ZnO nanocomposite fiber web and the cross-sectional view of a nanocomposite fiber (inset), and (c) cross-sectional view of a layered fabric system
S. Lee, Fibers and Polymers, Vol.10, No.3, 2009, pg. 295-301
Anti microbial + UV protective
POLYESTER WITH ALGINATES & TiO2 NANOPARTICLES
Transmission spectra of PES fabrics loaded of with TiO2 nanoparticles
D. Mihailovic et al., Carbohydrate Polymers, Vol. 79, 2010, pg. 526–532
Particle-embedded acrylic coatings transparent to visible light but absorb UVR
UV absorption behavior of nano- and micron size particles
Thick coatings of 10 μm and 20 μm applied to Kevlar fabrics
TiO2 EMBEDDED ACRYLIC COATINGS ON KEVLAR
Absorption spectra from various size TiO2 particles
P. Katangur et al., Polymer Degradation and Stability, Vol. 91, 2006, pg. 2437 – 2442
Cotton, Polyester, Cotton/Polyester Blend – Coated with ZnO – Gamma Irradiation for curing
UPF increased with an increase in the concentration of the UV absorber
USE OF GAMMA RADIATION
M. H. Zohdy et al., European Polymer Journal, Vol. 45, 2009, pg. 2926–2934
SEM micrographs of (a) uncoated polyester fabrics (b) ZnO coated polyester
SEM micrographs of (a) untreated Cotton fabrics (b) Alum/ZnO coated fabric
UPF &UV transmittance of coated PET fabrics
UPF & UV transmittanceof coated cotton fabrics
Large surface area – better UV absorption
Transparent appearance on coatings
Applied using different techniques
Reasonable wash fastness
Can be used to produce multifunctional components
CONCLUSION
Richard A. Scott, “Textiles for Protection,” Woodhead Publishing Limited, 2005.
D. Saravanan, AUTEX Research Journal, Vol. 7, No 1, March 2007.
Hoffmann et al., Arch Dermatol, Vol. 137, August 2001.
Karthivelu et al., Indian Journal of Fibre & Textile Research, Vol. 34, September 2009, pg. 267-273.
Mao et al., Thin Solid Films, Vol. 517, 2009, pg. 2681–2686.
J. F. Lima et al., Applied Surface Science, Vol. 255, 2009, pg. 9006–9009.
S. Lee, Fibers and Polymers, Vol.10, No.3, 2009, pg. 295-301.
D. Mihailovic et al., Carbohydrate Polymers, Vol. 79, 2010, pg. 526–532.
P. Katangur et al., Polymer Degradation and Stability, Vol. 91, 2006, pg. 2437 - 2442.
H. Zhang et al., Polymer Degradation and Stability, Vol. 94, 2009, pg. 278–283.
M. H. Zohdy et al., European Polymer Journal, Vol. 45, 2009, pg. 2926–2934.
www.wikipedia.org
Fernando et al., Nanotechnology Applications in Coatings, ACS Symposium Series, American Chemical Society, Washington D.C., 2009.
M. D. Newman et al., Journal of American Academy of Dermatology, October 2009.
REFERENCES
THANK YOU