Study On Preparation And Properties Of Anti-freezing And Ultrastretchable Cellulose Hydrogel Composites

At present,the thermal control of on-skin electronics focuses on solving overheating.The lack of supercooling service has become a technical bottleneck limiting the application of winteroriented electronic skin and emerging on-face electronics.In this paper,we focused on the study of the supertensile strength,freezing resistance and infrared barrier properties of cellulose hydrogel composite film for on-skin electrons.The main research results are as follows:The hydrogel(Gel-PiC)was prepared by metal ion coordination bond and free radical polymerization,which was first physically cross-linked and then chemically cross-linked.When the amount of extra water was added,the supertensile rate was 259%,which was higher than the known literature at present.The water vapor transmittability(WVTR)was234.0 g/m2/day,and the water content only decreased by 0.2% when placed at 30 ? and 55%relative humidity(RH)for 12 h.The freezing point is as low as-97?,and the superelongation is still maintained at-30?.The hygroscopicity of the prepared zinc oxide(ZnO)gel can reach 79.3% in 60 min at90%RH and 30?,which is better than the common commercial desiccant.The initial freezing problem of ZnO gel was successfully solved by the introduction of glycerol.The hygroscopicity of ZnO gel reached 85.4% in 60 min at 90%RH and 30?.The freezing point increased from-47.5? to-27.6?,and the hygroscopicity was not affected.The maximum hygroscopicity of(ZnO Gel/glycerin-water film/Gel-PiC)composite film is 342% at 90%RH and 30?,which shows excellent hygroscopicity.Under-30?,the infrared transmittance was less than 5% within 2.5 h.When the ambient temperature is-30?,it only takes 3.5 hours for the internal temperature to reach the skin temperature.The insulation effect is excellent,and it can be used for on-skin electronic supercooling service in winter.