Shell-thickness control of hollow SiO2 nanoparticles through post-treatment using sol-gel technique toward efficient water confinement

Hollow structures possess a confinement function, which enables the handling and use of functional liquids. In this study, we focus on the confinement of water in the inner spaces of hollow SiO2 nanoparticles (HSNPs). Water is introduced into the hollow spaces passing through the mesopores of the shells. The introduced water is then confined by thickening the shell through a post-treatment using silicon alkoxides. HSNPs with a variety of shell thicknesses are prepared by tuning the synthetic conditions of the reaction media and the alkoxides. It is found that the amount of water retained in a hollow space is increased with shell thickness. The resultant water-HSNP nanocomposites exhibit effective far-infrared absorption. The facile confinement approach reported in this study will lead to highly functional complex nanocomposites, such as isolated metal nanoparticles-water-silica.

Automated summary

The study focused on the confinement of water in hollow SiO2 nanoparticles, with water introduced into the hollow spaces passing through the mesopores of the shells and then confined by thickening the shell. It was found that the amount of water retained increased with shell thickness, and the resulting water-HSNP nanocomposites exhibited effective far-infrared absorption capabilities. The easy confinement approach reported in this study may lead to highly functional complex nanocomposites.