Electrostatic

Forcesby, FaNtasi’athe forces between particles that are caused

by their electric charges.

• Van der Waals attractive force• Electrostatic repulsive force

• Electrical double layer

COLLOID

• Colloidal particles often carry an electrical charge and therefore attract or repel each other.

• The charge of both the continuous and the dispersed phase, as well as the mobility of the phases are factors affecting this interaction.

Why Lemon Makes Milk Curdle??

influence on stability of emulsions• When milk becomes too acidic, like when we add

lemon juice or when it goes sour, the negative charge on the casein groupings becomes neutralized.

• Now instead of pushing each other apart, the casein starts to clump together. Eventually large enough clumps are formed that we can actually see the separation, and then we have curdled milk.

• the lemon juice decreases the pH of the emulsion toward the isoelectric point of the proteins, thereby reducing the electrostatic repulsion between the droplets and causing droplet aggregation.

Electrostatic coating

• Painting industry• principle :charge powder particles to similar

polarity, charged particles repel each other, forming a cloud across the coating area.

Electrostatic coating• The coating is typically applied

electrostatically and is then cured under heat to allow it to flow and form a "skin".

• not having the need to clean the equipment so much, cleaner environment for

• does not require a solvent to keep the binder and filler parts in a liquid suspension form

reference

• http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V02-4P00K0M-1&_user=4187955&_coverDate=10/31/2007&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000012438&_version=1&_urlVersion=0&_userid=4187955&md5=45fa35b6bdc2550cc0f4ac755ca2da1f&searchtype=a

• http://www.thekitchn.com/thekitchn/food-science/food-science-why-lemon-makes-milk-curdle-088057

• http://www.answers.com/topic/powder-coating