Engineered Ionene/PNIPAM Hybrid Dual-Response Material Generating Tunable and Unique Optical Modes for Adaptive Solar Transmittance Modulation

Self-Adaptive Reflectance Film for Passive Temperature Regulation in Diverse Environments

Passive thermal-regulation strategies have become increasingly important due to the strain alleviated on power grids for temperature management. Designing a system capable of automatically switching between cooling and heating modes in response to changing ambient conditions presents several specific challenges that engineers and researchers are actively addressing. In this research, a CaCl2 incorporated PNIPAM coated fluorinated poly(aryl ether) (FPAE) porous film with tunable reflectance is developed. The aim is to mitigate the reliance on active cooling systems, which consume significant amounts of energy. The moisture-temperature dual sensitive film exhibits a tunable reflectance range between 91.1% and 39.1% via phase change of the PNIPAM layer. Coupled with an infrared emissivity of 96.0%, a daytime cooling of 10 °C compared to the control experiment is achieved. Coating the film with a photothermal layer results in an adaptive Janus film that is capable of autonomous switching between heating and cooling, and demonstrates a heating of 22.5 °C in a cold environment. The facile preparation method, excellent cyclic stability, mechanical properties, and UL-94 V-0 rating enable promising applications of the smart film under diverse living environments.

An Ultrafast, Energy-Efficient Electrochromic and Thermochromic Device for Smart Windows

Smart windows nowadays undertake the esteemed obligation of reducing energy consumption as well as upgrading living experience. This project aims to devise a smart window that responds to both electricity and heat, with the intention of achieving energy efficiency, privacy preservation, and enhanced decorative attributes. Through the implementation of a novel electrochromic material design, coupled with the optimization of electrochromic devices (ECDs), a high-performance ECD is obtained, demonstrating coloring/bleaching time of 0.53/0.16 s, a transmittance modulation of 78% (from 99% to 21%), and superior performance in six dimensions. Furthermore, temperature-responsive units and an ionic liquid are incorporated into the electrolyte system to create a novel thermochromic gel electrolyte with transmittance modulation from 80% to 0%, and excellent thermal insulation (6.4 °C reduction). Ultimately, an electro- and thermochromic device is developed, featuring an ultrafast color-switching speed of 0.82/0.60 s and multiple working modes. Overall, this work showcases a prospective design pathway for the development of next-generation ultrafast-switching, and energy-efficient intelligent windows.

The Evaluation of Visual Clarity and Comfort of Light Environment in Multimedia Classroom

In order to clarify the quantitative relationship between students’ visual clarity, comfort, and environmental brightness in the light environment of multimedia classrooms in colleges and universities and obtain the threshold and influence trends of brightness, visual clarity, and visual comfort in the light environment of the multimedia classroom, this paper proposes the research on the relevant influence parameters of the light environment of the multimedia classroom. Based on the analysis of the current situation of multimedia use in China, this paper proposes taking brightness as the main parameter of indoor light environment evaluation to carry out students’ subjective evaluation experiments. The brightness range that can reflect the visual clarity and visual comfort of the experimenter is extracted by using multimedia combined with screen projection and HDRI technology. Finally, by analyzing the experimental data, combined with the operational definition of the psychophysical threshold, the functional relationship between visual clarity, comfort, and brightness in the light environment of a multimedia classroom is obtained through regression analysis and the threshold and extreme point data are calculated. The experimental results show that when the brightness range is 370.83 cd/m2 ≤ X ≤ 558.47 cd/m2, it has better visual clarity and visual comfort. When the brightness contrast is close to 10 : 1, the visual clarity is the highest; when the brightness contrast is close to 5 : 1, the visual comfort is the highest and decreases on both sides with the change in its value. Conclusion. The results of this experimental study can provide a basis for formulating and revising relevant laws and regulations in the future and provide a reference for the light environment design of multimedia classrooms in China.