Abstract
Ethyl-modified polysilsesquioxane (PSQ) liquid has been synthesized by a cosolvent-free liquid-phase hydrolysis and polycondensation of ethyltrimethoxysilane-water binary system. Thermal curing of the PSQ liquid yields a monolithic ultraviolet (UV)-transparent PSQ glass. This organic-inorganic hybrid glass would be a new silica-based UV transparent material derived at relatively low temperature.