Biomimetic apatite formation on polyethylene photografted with vinyltrimethoxysilane and hydrolyzed

A photografting technique to produce functional groups of silanol able to induce apatite nucleation was attempted on polyethylene substrate for biomimetic formation of bone-mineral-like apatite layer on its surface. The polyethylene surface was subjected to vapor-phase photografting of vinyltrimethoxysilane and subsequently to hydrolysis. The photografting formed methoxysilyl groups on the polyethylene substrate, which was changed into silanol groups successively by the hydrolysis in a hydrochloric solution. The polyethylene modified in this way formed a dense and homogeneous bone-mineral-like apatite layer in a solution with ion concentrations 1.5 times that of human blood plasma. This result indicates that the biomimetic process in combination with a polymeric grafting technique might provide a homogeneous bone-mineral-like apatite coating even on polymer fibers to be woven into an apatite–polymer composite with three-dimensional structure analogous to that of natural bone.