Low-index mesoporous silica films modified with trimethylethoxysilane

Spin-on mesostructured films were prepared from tetraethoxysilane (TEOS) as a silica source and nonionic triblock copolymer Pluronic F127 as a templating agent. The films were treated with trimethylethoxysilane (TMES) vapor before and/or after calcination. The porosity of the calcined films was increased with a rise of the molar ratio of F127/TEOS in the precursor solutions. The TMES vapor treatments reduced refractive index of the mesoporous silica films to 1.23 and effectively improved their mechanical strength.