G silicic acid commonly known as silica gel partial

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: gel a) Elastic gels (e.g. jellies, jams, and corn starch puddings) b) Nonelastic gels (e.g. silicic acid, commonly known as silica gel) • Partial dehydration of an elastic gel leads to the formation of an elastic solid from which the original sol can be regenerated by the addition of water. Dehydration of a nonelastic gel, on the other hand, leads to a glass or powder, which has little elasticity. • If an elastic gel such as gelatin is placed in water, it swells, water having been imbibed b y the gel; the proc ess is know n as imbibition. • Nonelastic gels, may take up solvent but they do not swell-the liquid enters t he pores of the gel but, si nce the walls a re rigi d, the volume of the gel does not change. • Gel formation occurs in particular with molecules that can exist as extended chains. As the sol turns into a gel, the chains become interlocked so that the viscosity i ncrea ses and e ventually a se mi -solid ma terial is produced. E MULSIONS An e mulsion consists of droplets of one liquid dispersed in another liquid. Silicone oil in water em...
View Full Document

This note was uploaded on 10/25/2012 for the course CHEMISTRY 570.448 taught by Professor Billball during the Fall '10 term at Johns Hopkins.

Ask a homework question - tutors are online