Study On The Preparation Of Temperature Sensitive Materials For Smart Windows And Their Modulation Properties Of Sunlight

With the improvement of living standard,plenty of devices were invented to create comfortable indoor environment,such as fans,air conditioners and refrigerators.There’s no doubt that these inventions can make a more enjoyable life for human beings.But they ineluctably consume too much electricity,which entails serious environmental problems,like greenhouse effect,atmospheric pollution and resourcedepletion.The report shows that nearly 10%of the electricity used for indoor temperature regulation in developed countries is consumed each year,which is a very large energy consumption problem that needs to be solved urgently.Smart window is a kind of modified windows based on the common glass,make it to respond the appropriate external stimuli,such as heat,electricity,light,to change the light transmittance of equipment.With this device,people can control into the indoor light to achieve the purpose of control the room temperature,which have the effect of reducing energy consumption of temperature control.The research purpose of this paper is to develop smart windows based on two existing thermochromic temperature-sensitive materials,namely,poly N-isopropylamide（PNIPAM）and hydroxypropyl cellulose（HPC）,to reduce the energy consumption of indoor temperature control,so as to achieve the goal of energy saving.The research of the full paper is as follows:（1）Based on PNIPAM,we added W doped VO₂（W-VO₂）,an inorganic thermo-sensitive phase change material,to study the relationship between the content of W-VO₂and the modulation-ability of sunlight,so as to solve the problem of poor regulation performance of PNIPAM in near infrared light.In addition,PNIPAM presented flow dynamics as a polymer microgel,which was not conducive to its practical use.We introduced polyacrylamide as a polymer skeleton to change the bonding state,and systematically studied the relationship between the content of PAM and the gel strength of the prepared thermochromic hydrogel.Finally,the smart window of PAM-PNIPAM/W-VO₂ was constructed with the appropriate PAM content.The sunlight modulation capacity of the smart window is 46.3%,and the smart window shows excellent durability.（2）Based on HPC,a mixture of glycerol and water was used to dissolve the polymer material.Due to the excellent antifreeze property of glycerol,a thermochromic microgel with significant antifreeze property was prepared,and the relationship between phase change temperature,antifreeze property and optical modulation property of the gel and glycerol content was systematically studied.The results showed that with the addition of glycerol,the phase change temperature of HPC microgel decreased,and the antifreeze performance of HPC microgel increased significantly.When the glycerol content was 33%,the phase change temperature of the gel decreased by 9℃and the freezing point decreased to-15℃.（3）The HPC gel with antifreeze performance was introduced into which the electrolyte LiClO₄ with high conductivity was introduced to prepare the electrolyte with thermochromic characteristics,which was integrated with the WO₃ nanofiber membrane with electrochromic properties prepared by hydrothermal method,and the thermoelectric composite response multi-functional intelligent window was successfully constructed.The effect of LiClO₄ on the phase change temperature and light modulation performance of the gel was systematically studied,and the light modulation property of the composite smart window was tested.The smart window can achieve the indoor full privacy protection without curtains.