Search results
Results from the WOW.Com Content Network
This structural formula uses embedded text for its chemistry symbols. Licensing. ... structure of subunit of a silicone hydrogel as found in soft contact lenses.
Silicone caulk can be used as a basic sealant against water and air penetration. In organosilicon and polymer chemistry, a silicone or polysiloxane is a polymer composed of repeating units of siloxane (−O−R 2 Si−O−SiR 2 −, where R = organic group). They are typically colorless oils or rubber-like substances. Silicones are used in ...
The crosslinks which bond the polymers of a hydrogel fall under two general categories: physical hydrogels and chemical hydrogels. Chemical hydrogels have covalent cross-linking bonds, whereas physical hydrogels have non-covalent bonds. [citation needed] Chemical hydrogels can result in strong reversible or irreversible gels due to the covalent ...
This page was last edited on 8 September 2019, at 23:48 (UTC).; Text is available under the Creative Commons Attribution-ShareAlike 4.0 License; additional terms may apply.
The word "silicone" was first used by Frederic Kipping in 1901. He invented the word to illustrate the similarity of chemical formulae between Ph 2 SiO and benzophenone, Ph 2 CO, although he also stressed the lack of chemical resemblance due to the polymeric structure of Ph 2 SiO, which is not shared by Ph 2 CO. [25]
The chemical formula of PDMS is CH 3 [Si(CH 3) 2 O] n Si(CH 3) 3, where n is the number of repeating monomer [Si(CH 3) 2 O] units. [4] Industrial synthesis can begin from dimethyldichlorosilane and water by the following net reaction: n Si(CH 3) 2 Cl 2 + (n+1) H 2 O → HO[Si(CH 3) 2 O] n H + 2n HCl. The polymerization reaction evolves ...
An upturned vial of hair gel Silica gel. A gel is a semi-solid that can have properties ranging from soft and weak to hard and tough. [1] [2] Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady state, although the liquid phase may still diffuse through this system.
Chemical symbols are the abbreviations used in chemistry, mainly for chemical elements; but also for functional groups, chemical compounds, and other entities. Element symbols for chemical elements, also known as atomic symbols , normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised.