Abstract
Polysilsesquioxanes can be regarded as organic－inorganic hybrid materials in a molecular level. We can readily tune the properties of the materials for realizing the desired ones by changing the contents or types of organic components. In advance, the hierarchical structures have potentials for generating further characteristics distinctly different from those of the constituents. From this viewpoint, polyhedral oligomeric silsesquioxanes (POSS) are attractive as a cornerstone in highordered materials. Herein, we review recent studies about octa-substituted POSS-based functional materials and specifi cally explain the design concepts for applying the signifi cant characteristics of POSS for the material properties. In the former parts, we introduce the examples concerning the POSS fi llers for improving thermal stability and modulating the refractive indices of the matrices. We will also mention about the recent study on the POSS-based ionic liquid. In the latter parts, we describe the application of POSS-based materials in aqueous media. Particularly, we explain the upconversion system of the light energy in water and the advanced MRI contrast agents based on the water-soluble POSS materials.
