A Novel Kind of Smart Thermotropic Material and Its Optical and Thermal Properties

摘要

Thermally induced switching temperature,spectral transmittance of a novel kind of smart thermotropic material developed by a different mixing proportion of hydroxypropyl methyl cellulose (HPMC),Sodium Chloride (NaCl) and pure water was measured. Switching speed from transparent state to light scattering state of thermotropic layer in double glazing window was analyzed with numerical simulation and the results show that thermotropic layer has the most significant changes in the heating rate in the first hour,especially in the first half hour. Its temperature reached 36.8 and can cause a reduction in light transmittance to below 25%. Radiation transmittance was tested on samples of a thermotropic double glazing window,double glazing window and Low-E double glazing window. Results show that thermotropic double-glazed window with the optimum mixing proportion of HPMC,NaCl and pure water of 2:10:100 by mass reduces radiation transmittance at fully turbid state by up to 72% and 32%,respectively,compared to the ordinary double-glazed window and Low-E double-glazed window which do not have adjustable radiation transmittance,and its radiation transmittance changed from transparent state to light scattering state is up to 60%,indicating a high performance on switching solar radiation and a great potential for energy efficient windows.