Hair gel
Encyclopedia : H : HA : HAI : Hair gel
Hair gel is a kind of gel that is put in hair to stiffen it into a particular hairstyle. The results it produces are usually similar to but stronger than those of hair spray and weaker than those of hair glue.
Many brands of hair gel in North America and the UK come in numbered variants. Higher numbered gels maintain a greater "hold" on hair, while lower numbers do not make the hair as stiff and in some products give the hair a wet look. Some forms of hair gel include temporary coloring for the hair, usually in unnatural colors associated with various subcultures.
Hair gels often contain cationic polyelectrolyte polymers, i.e. polymers with lots of positively charged groups, often polyvinylpyrrolidone. The charges causes the polymer to stretch out and making the gel more viscous since the stretched out polymer takes up more space than a coiled polymer and thus resists the flow of solvent molecules around it. The positive charges are also binding the gel to the negatively charged amino acids abundant on the surface of keratin molecules hair is made of. More complicated polymer formulas exist, eg. a copolymer of vinylpyrrolidone, methacrylamide, and N-vinylimidazole. [link]
Hair gel usually consists of:
- water, providing most of its mass
- water-soluble polymer, usually a cationic polyelectrolyte like polyvinylpyrrolidone that binds to the hair, polyvinyl alcohol, hydroxypropyl cellulose
- a humectant and plasticizer, usually a sugar alcohol, eg. sorbitol
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.