Ultrafine nano-TiO2 loaded on dendritic porous silica nanoparticles for robust transparent antifogging self-cleaning nanocoatings

Abstract

Multifunctional nanocoatings with mechanical robustness, high transparence, antifogging and self-cleaning have attracted significant attention because of their wide applications in glass-related fields. However, it is still very difficult to construct this kind of multifunctional nanocoatings due to the requirement of their comprehensive structure parameters. In this work, we successfully fabricated robust transparent antifogging self-cleaning nanocoatings by employing dendritic porous silica nanoparticles (DPSNs) evenly loaded with 2–3 nm of small TiO2 nanoparticles (NPs) as a building block. A series of DPSNs@X% TiO2 nanocomposites with tunable weight ratios (X%) of TiO2/DPSNs from 10% to 60% were firstly prepared by controlling the growth of TiO2 on the heterogeneous interface of center-radial large pores of DPSNs, followed by calcination. Noteworthily, DPSNs@10% TiO2 exhibited highest photocatalytic and antibacterial performance mainly due to uniform distribution of TiO2 NPs, their small sizes of 2–3 nm and center-radial pore. Therefore, DPSNs@10% TiO2 was chosen as an optimized building block and combined with acid-catalyzed silica sol (ACSS) to develop an excellent suspension for multifunctional nanocoatings. The obtained glass slide with the optimal nanocoating showed photocatalytic self-cleaning behavior, high transparence, hydrophilic (WCA = 6.2°) antifogging, and high mechanical robustness, which can withstand 4B tape adhesion test and 3H pencil scratching test. This work provides an important exploration for developing multifunctional nanocoatings.