Zhexu Song,Yingjie Shi,Tianfu Zhou,Meiqi Yang,Meina Yu,Yanzi Gao,Cheng Zou,Huai Yang
The polymer-stabilized liquid crystal (PSLC) dimming film has garnered widespread attention due to its energy-saving features and good electro-optical performance, making it highly suitable for smart windows in automotive and architectural applications. However, its poor mechanical properties severely limit its large-scale flexible film production and wide application due to its internal fine and fragile polymer network. Enhancing the processability and peel strength of PSLC films remains particularly challenging because electro-optical performance degrades rapidly with increasing polymer content. Herein, a PSLC film with ultrahigh peel strength and good electro-optical performance is attained through well-controlled rapid photopolymerization of epoxy monomers using photoinitiators 1173 and 1176. The polymerization time is greatly shortened from hours to a few minutes, and the polymer content of this composite film is increased to over 20 wt % by carefully controlling light intensity, photoinitiator, and monomer composition, while retaining good electro-optical performance. The peel strength and contrast ratio are improved by over 40 times and 3 times, respectively, compared to epoxy PSLCs prepared by normal cationic polymerization. The peel strength of this film is incredibly high, about 500 times that of a traditional PSLC device, and is even higher than those of some polymer-dispersed liquid crystal films. The cycle stability and thermal stability of PSLC films have also been significantly improved a lot. The dependence of monomer composition on the microstructures, electro-optical, and mechanical properties of the PSLC film has been systematically studied. This research provides a novel strategy for the fabrication of high-performance PSLC films toward next-generation energy-efficient smart windows.
In recent years, smart windows have been gradually applied and developed in the fields of environmental protection, energy management, smart camouflage and display. With the continuous upgrading of market demand, smart windows with both visible and infrared band modulation functions are the future development trends. However, the optical modulation of smart windows is usually limited in the visible light band (380–780 nm). In this paper, we report a novel smart window by doping antimony doped tin oxide (ATO) nanoparticles (NPs) into polymer stabilized liquid crystal (PSLC) films. These films have the widest waveband modulation function among those reported so far, covering the visible and infrared regions (380–5500 nm). The transmittance of the as-prepared smart films can be changed reversibly from highly transparent (78.5%) state to a strong light scattering (10%) state in the visible region. In addition, due to the localized surface plasmon resonance of ATO NPs, up to 80.7% of the infrared invisible light can be effectively shielded. The significance of this research is to provide theoretical and technical support for the broadband optical modulation of novel smart windows.