Anisotropic and Reversible Deformation of Mesopores and Mesostructures in Silica-Based Films under Mechanical Stimuli toward Adaptive Optical Components

Abstract

Deformation of the mesostructures in surfactant/silica hybrid films and mesoporous silica films prepared on bulky elastomeric substrates is investigated by compressing the substrates along an in-plane direction of the films. The mesostructure in the surfactant/silica hybrid film consists of organized micelles and a silica matrix. The micelles are removed in the mesoporous silica films to leave mesopores. A grazing-incidence small-angle X-ray scattering investigation reveals that the mesostructures with C2mm symmetry anisotropically change under a compressive strain of 6% in both films; shrinkage of the lattice parameters is along the direction of compression and extension in the normal direction. Deformation is reversible below a strain as high as 6%. Anisotropic deformation of the mesostructures results in an anisotropic change of the refractive indices normal and parallel to the direction of the compression. Compression of the surfactant/silica hybrid film induces a decrease of the refractive index para...