Effects of Functionalization on Photo-Actuatable Octa(dimethylsiloxy)silsesquioxane-Azobenzene Network Gels and their Substance Loading and Unloading Efficiencies

The synthesis, analysis, and effect on solvent uptake of styrene, alcohol, amino, and perfluoro functionalized silsesquioxane-azobenzene hybrid gels are discussed. 4,4’-diallyloxyazobenzene and octa(dimethylsiloxy)silsesquioxane (Q8M8H) gels are generated using hydrosilylation chemistry. These gels were modified through two routes: in-situ and post-synthesis modification, depending on the compatibility of the modifiers. The dynamic gel systems react to visible and UV light to expand and contract, giving them sponge-like properties. The effects on their solvent uptake load and preference for various solvents/pollutants are detailed below, and general characteristics are illustrated through FTIR, TGA, and SEM imaging. We find that selectivity for certain substances can be obtained but at the cost of total absorptivity of the gel systems.