Octa(dimethylsiloxy)silica cages (Q8M8H) undergo rapid self-polymerization in the presence of a fluoride catalyst to form complex 3D porous structural network materials with specific surface areas up to 650 m2 g-1. This establishes a new method to form bio-derived high inorganic content soft silicas with potential applications in filtration, carbon capture, catalysis, or hydrogen source.