Design and characterization of silicone micromaterials: A systematic study

Abstract Silicone micromaterials were synthesized using two surfactant-free methods: the Stober synthesis or solidification in spontaneously formed emulsions (the Ouzo effect) and their physicochemical properties were evaluated. The effect of the chemical structure of a silicone precursor on the morphology of formed microstructures was considered. For that purpose, various organosilicon compounds containing in their structure T-units and D-units, methyl groups, ethylene linkages, and cyclotetrasiloxane rings were used as silicone precursors. All materials existed as sub-micron sized particles, although they differed considerably in morphology and dispersity (spherical particles with a diameter of about 490 and 740 nm, cauliflower-like structures, large rough-surfaced aggregates). The chemical composition of the microstructure surface was examined using XPS. The porosity of silicone materials was assessed on the basis of nitrogen adsorption isotherms. The specific surface area (SBET) varied substantially and ranged from 5 to 379 m2/g. For the first time the microelastic modulus of the silicone materials was determined using AFM measurements. We found that the structure of the organic part had a large impact on the microelasticity of the material. The microelastic modulus of the silicone materials (11–33 GPa) was significantly lower compared to silica (59 GPa).