The super-hydrophobic IR-reflectivity TiO₂ coated hollow glass microspheres synthesized by soft-chemistry method

Abstract

The super-hydrophobic and IR-reflectivity hollow glass microspheres (HGM) was synthesized by being coated with anatase TiO₂ and a super-hydrophobic material. The super-hydrophobic self-cleaning property prolong the life time of the IR reflectivity. TBT and PFOTES were firstly applied and hydrolyzed on HGM and then underwent hydrothermal reaction to synthesis anatase TiO₂ film. For comparison, the PFOTES/TiO₂ mutual-coated HGM (MCHGM), PFOTES single-coated HGM (F-SCHGM) and TiO₂ single-coated HGM (Ti-SCHGM) were synthesized as well. The MCHGM had bigger contact angle (153°), but smaller sliding angle (16°) than F-SCHGM (contact angle: 141.2°; sliding angle: 67°). Ti-SCHGM and MCHGM both showed similar IR reflectivity with ca. 5.8% increase compared with original HGM and F-SCHGM. For the thermal conductivity, coefficients of F-SCHGM (0.0479 W/(m K)) was basically equal to that of the original HGM (0.0475 W/(m K)). Negligible difference was found between the thermal conductivity coefficients of MCHGM-coated HGM (0.0543 W/(m K)) and Ti-SCHGM (0.0546 W/(m K)).