Flexible core-shell Cs x WO3-based films with high UV/NIR filtration efficiency and stability

Photothermal-Driven Polymer for a Smart Window with Adaptive Solar Modulation

Although the thermochromic smart windows with adjustable sunlight transmittance to achieve energy savings are gradually improving, they are still difficult to use, limited by their unreasonable thermal response temperature, slow switching time, and poor durability. Here, we demonstrate a dual-function hybrid thermoresponsive smart window device (CPH) by trapping the phase-change polyHEA-HDA polymer (HEA = hydroxyethyl acrylate, HDA = hexadecyl acrylate) and polydopamine@CsxWO3 (PDA@CWO) core-shell nanoparticles within glasses. The introduced PDA@CWO nanoparticles substantially increase the energy transformation efficiency of solar energy to heat due to their outstanding photothermal conversion. When the temperature increases above the phase-transition temperature of polyHEA-HDA polymer, the copolymer components in the composite material undergo a reversible crystalline-amorphous transition, which enables the transformation of the whole smart window from transparency to opaque in a low ambient temperature. The light transmittance in the solar range can be dynamically modulated between 54.8 and 22.9% with a low ambient temperature while maintaining acceptable visible light transparency and effective UV shielding. A model house testing proves an indoor temperature cooling of 7.1 °C. This study offers a new approach to designing an energy-saving smart window system with multifunctionality.

Solid SiO2-Sealed Mesoporous Silica for Synergistically Combined Use of Inorganic and Organic Filters to Achieve Safe and Effective Skin Protection from All-Band UV Radiation

To effectively shield the full band of ultraviolet (UV) radiation and provide desirable protection, the combination of inorganic and organic filters was often used to protect human skin from the serious harm of UV exposure. However, the incompatibility of different filters and their mutual negative effect limit the production of multifilter sunscreen. In addition, the hazard of reactive oxygen species (ROS) produced by inorganic filters after UV exposure and the skin permeability of organic filters remain unresolved problems. In this study, titanium dioxide (TiO₂) and diethylamino hydroxybenzoyl hexyl benzoate (DHHB), two kinds of common filters with complementary UV shielding range, were first encapsulated into large mesoporous silica nanoparticles (MSN, ∼300 nm) to obtain MSN-TiO₂ and MSN-DHHB. Also, a SiO₂ coating was then made to seal and stabilize the MSN-TiO₂ and MSN-DHHB. The structure, UV screen function, and safety of the SiO₂-coated filters, MSN-TiO₂@SiO₂ and MSN-DHHB@SiO₂, were evaluated. The good mechanical stability exhibited by the solid SiO₂ layer prevented the release and skin penetration of the sealed DHHB and the photocatalysis of TiO₂. Furthermore, the combination of MSN-TiO₂@SiO₂ and MSN-DHHB@SiO₂ in sunscreen cream showed excellent UV shielding performance on covering the whole UV radiation range without mutual interference. Therefore, coating SiO₂ over MSN is a feasible strategy for entrapping various filters to improve their photostability, preventing skin penetration and ROS generation, and enhancing their compatibility with different sunscreen formulations.

Dual-functional NIR/UV-shielding poly(lactic acid) nanocomposite films through CWO@PDA core–shell nanoparticles

Fabrication of dual-functional NIR/UV-shielding PLA nanocomposite films by constructing interfacial stereocomplex crystallites.