Preparation And Optical Properties Of Starch Based Thermochromic Smart Windows

Smart window is a device which can respond to the external environment and may adjust the different bands of the light spectrum through it.Thermochromic smart window has been widely studied by many researchers due to its advantage of not requiring any additional energy for its working and lower cost.Sensitive polymers are very important part of smart windows.These polymers can respond to small stimuli and changes in the external environment,leading to changes in their physical or chemical properties.Below the Lowest Critical Solution Temperature(LCST),it remains homogeneous,and over the LCST,the phase separation solution becomes turbid.Synthetic polymers and hydrogels have many biocompatibility and biodegradability problems in practical applications.Many studies are now focused on the synthesis of biocompatible thermosensitive polymers and gels with natural polymers that can be degraded by enzymes,so natural polymers will be used as ideal materials for the preparation of thermosensitive polymers and gels.In this work,temperature responsive starch(HIPS)and its hydrogel have been successfully prepared as temperature responsive polymer,and these materials have been used in the application of smart window,its optical properties have been analyzed and studied.The main research content is divided into two parts:(1)Thermoresponsive starch was successfully prepared through the graft polymerization of Glycidyl Isopropyl Ether.Structure of the obtained samples have been characterized by proton nuclear magnetic resonance spectroscopy(1HNMR)and Fourier transform infrared spectroscopy(FTIR).The results show that the desired product has been successfully prepared By using variable temperature UV test the LCST of the sample,the influence of HIPS and NaCl concentration on the LCST has been studied,and the LCST can be regulated from 34? to 50?.Then we use the obtained materials for the use of smart window,the variation of concentration on its optical performance has been explored.Through the recycle test and other experiments,the application of the prepared materials in the field of smart window has been studied.(2)By changing the dosage of crosslinking agent in the synthesis process,different kinds of hydrogel have been prepared.Structure of the hydrogel was characterized by 1HNMR,FTIR and SEM.And the materials were used for the application of smart window,its effect on the optical performance have been studied.