Preparation of Near IR Reflective Materials via Hollow Ballotini Enwrapped by TiO_2

摘要

Near IR reflective functional material was made via hollow ballotini enwrapped by TiO2 according to IR reflective principles. Metatitanic acid covers on the surface of hollow ballotini through electrostatic attraction as pH is less than 2.5. The results of SEM and XRD spectrum show that TiO2 enwraps hollow ballotini well and the crystal form is anatase. When TiO2 covering thickness is below 0.5 μm, reflectance swells along with the increase of thickness, whereas above 0.5 μm it keeps stable. Coatings made from mixing enwrapped HB with styrene-acrylic latex were coated on aluminum foil, and reflectances were mensurated. It is found that reflectance keeps stable when the coating can wrap the base and reflectances of the coating in visible range and in near IR range are 86% and 81%, respectively.