Carbomer is a type of molecule which is usually obtained by the insertion of Carbon units in a certain molecule. It is a polymer of acrylic acid crosslinked with a polyfunctional molecule or compound such alkyl ethers of sucrose and/or pentaerythritol. 
It is also referred to as polyacrylic or polyacrylate.
Types of Carbomers:
In the National Formulary, there are six types of carbomers' monographs:
1. Carbomers 910
2. Carbomers 934
3. Carbomers 934P (The suffix "P" shows that this is a highly purified product and can be used orally). 
4. Carbomers 940
5. Carbomers 941
6. Carbomers 1342 
Properties of Carbomers:
1. White powder (Fluffy)
3. Soluble in water
4. pH of 1% aquous dispersion is 2.5 to 3.0
5. Incompatible with phenol and resorcinol
6. Products of Carbomers are sensitive to light
It is mostly used as a suspending agent in Pharmaceutical industry. They are also used as gelling agents at the concentration of 0.5 to 2.0 % in water. 
Page # 2444, Encyclopedia of Pharmaceutical Technology by James Swarbrick.
 18.18, Part 4 Pharmaceutical necessities, A Practical Guide to Contemporary Pharmacy Practice by Judith E. Thompson and Lawrence Davidow.
A Practical Guide to Contemporary Pharmacy Practice by Judith E. Thompson and Lawrence Davidow
The National Formulary X : Tenth Edition
Martindale: The Complete Drug Reference, 35th Edition: Book and CD-ROM Package
Remington: The Science and Practice of Pharmacy
Copyright (c),2008, jeepakistan.blogspot.com