Hybrid nanostructure formation on hollow glass microparticles as thermally insulating composite elements

In this study, we attempt formation of hybrid nanostructure on hollow glass microparticles (HGMPs) as promising unit elements towards building insulating composite materials at low material cost with scalability. As first approach, pre-synthesized hollow silica nanospheres (HSNS) are attached on HGMPs, mediated through diluted binder components. In resulting composite structures, HSNS were preferentially located in junctions between HGMPs assisted by capillary effect, serving as phonon scattering centers at bottleneck locations in terms of thermal transport, while minimizing use of costly hollow nanomaterials. On the other hand, direct synthesis of ZnO nanowires on HGMPs enabled excellent control of nanowire orientation, facilitating mechanical coupling among neighboring HGMPs yet maintaining favorable thermal aspect to induce phonon scattering effect. Currently, composite level materials of practical dimension are under fabrication in conjunction with thermal and mechanical characterizations, and investigation on fundamental mechanisms relevant.