Narrow Results

Self-assembled-monolayer (SAM) has a special characteristic that it can template the growth of inorganic crystals under the ordinary conditions, which is similar to the action in the living bodies. In the present study, the precipitation of apatite on "OH" terminated SAM surface(silicon) was observed after soaked in SBF (Simulated Body Fluid). On the contrary, little apatite was formed on the SAM surface with "Phenyl" headgroups. PTCS (Phenyltrichlorosilane) was employed to make "Phenyl" terminated hydrophobic SAM . After UV irradiation for 2 hours, "-OH" terminated hydrophilic SAM was obtained. The effects of such factors as pH and Ca/P molar ratio in SBF solution, soaking temperature and time .etc, on the crystallization of apatite were investigated. XRD results revealed the preferentially oriented crystallization of apatite on "OH" terminated SAM.

A simple nonaqueous reaction scheme for transforming the surface of plastics from hydrophobic to hydrophilic is presented. The chemical modification is achieved by the base-catalyzed trans-esterification of polyethylene terephthalate (PET), which is a commonly used plastic. Its use in blood collection tubes is discussed. The surface modification is permanent, inexpensive, rapid, and does not release contaminants. It also causes no optical or mechanical distortion of the plastic. This work demonstrates the power of chemistry to transform common materials.