Preparation And Properties Of Phase Change Energy Storage Microcapsules With Photochromic Function

Phase change materials(PCM)are energy materials that can be stored and released in the process of phase transformation,which can regulate the outside temperature.Phase change materials have gradually become a hot topic in scientific research because of recycling,regulation and relieving energy shortage.Because of the apparent phase change of the solid-liquid phase change material before and after the phase change process,encapsulation technology is used to encapsulate phase change materials with specific melting point and crystallization point into the capsule to prepare heat storage capsule,which has become a hot research topic in recent years.In this paper,phase change material microcapsule with polyurethane resin as wall material,eighteen alkane and ethyl palmitate as core material,and a photochromic spiroxazine compound added into the capsule core was prepared by interfacial polymerization reaction with Isophorone diisocyanate(IPDI),diethylenetriamine(DETA)and polyethylene glycol 400(PEG400)reaction.Surface morphology,heat storage properties,chemical structure and thermal stability of microcapsule phase change material were studied and analyzed by optical microscopy and scanning electron microscopy(SEM),differential scanning calorimetry(DSC),infrared spectroscopy(FTIR)and thermogravimetric analysis(TGA).Microencapsulated phase change materials with polyurethane resin as wall material was prapared by polymerized with eighteen alkyl as core material,styrene maleic anhydride copolymer(SMA)as emulsifier,diethylenetriamine(DETA)and polyethylene glycol 400(PEG400)and isophorone isocyanate(IPDI)and studied the influence of the emulsification time on the emulsifying effect.The results showed that the emulsion after emulsification was homogeneous and stable under the emulsifying speed was 5000rpm and the emulsifying time was 5min.The influence of the rate of dripping amine on the preparation of microcapsules was discussed,and there was no adhesive phenomenon between capsules of microcapsules with the size and the particles dispersed uniformly when diethylenetriamine was completely dripped for 2h.The effect of emulsification speed on the particle size of microcapsules was discussed,and the results showed that within a certain range,the particle size of inner microcapsules decreased with the increase of emulsification speed and the particle size distribution was narrowed.The effect of fourteen alcohol as nucleating agent on the supercooling of eighteen alkane phase change materials in microcapsules and the mass ratio of eighteen alkanes and fourteen alcohols were studied.DSC results showed that with the addition of fourteen alcohol,the crystallization peak temperature of microencapsulated phase change material increased and homogeneous nucleation increased and TG results showed that the addition of fourteen alcohol did not affect the thermal stability of microcapsules.The mass ratio of ethyl palmitate and spirooxazine photochromic compounds was studied.DSC results showed that the mass ratio of ethyl palmitate and spirooxazine photochromic compounds was 10:5,the phase transition temperature of the prepared microcapsules was close to the comfort temperature of the human body,and the phase transition temperature of core material ethyl palmitate microcapsules decreased along with spirooxazine photochromic compounds increased.The quality of the addition of ethyl orthosilicate(TEOS)was studied.The heat resistance results showed that with the increase of the content of TEOS,the heat resistance of core material ethyl palmitate microcapsules was improved.TG results showed that the heat resistance of core material ethyl palmitate microcapsules increased with the increase of TEOS content,and the final weightlessness rate of microcapsule decreased from 10.75%to 7.34%.When the addition of TEOS was 6g,the thermal stability of the microcapsule was increased to 15.6?.