Sol-Gel Synthesis of S-containing Porous Gel Monolith

Abstract

Porous gel monolith was synthesized from (3-mercaptopropyl)trimethoxysilane (MPTMS) by a sol-gel method assisted by cross linkage of mercapto groups. We formed thioacetal or disulfide bonds for the cross linkage. It is known that MPTMS itself is difficult to turn into gel on acidic conditions and instead oligomers are obtained owing to the large mercaptopropyl group. Additionally, Au ions were selectively reacted with the obtained gels. When an obtained colorless gel was soaked in a chloroauric acid solution, the gel turned brown and was getting dark depending on the soaked time; on the other hand, the color of the solution turned from yellow to colorless.