Preparation And Characterization Of N-octadecane Microcapsule/Phase Change Energy Storage Composite

In this study,phase change energy storage wood was prepared by vacuum impregnation method using n-octadecane microcapsule as energy storage material and wood as matrix.Through the microencapsulation of n-octadecane,the problems of leakage and volume change during the phase transition of n-octadecane were solved;the microcapsules were modified with graphene to improve the thermal conductivity of n-octadecane microcapsules.Performance;The energy storage thermal performance,thermal stability,durability and thermal conductivity of n-octadecane microcapsules and phase change energy storage wood were comprehensively characterized,and the possibility of using phase change energy storage wood for indoor temperature regulation was investigated.This study mainly draws the following conclusions:(1)Melamine-modified urea-formaldehyde resin(MUF)coated n-octadecane microcapsules were successfully prepared by in-situ polymerization.The surface morphology and particle size were mainly affected by the emulsification speed and the core/wall material ratio.The faster the emulsification speed,the smaller the particle size,the more uniform the size distribution,and the tighter and smoother the surface;the n-octadecane after MUF still has good heat storage ability,and the phase transition temperature range is consistent with the comfortable temperature range of the human body;When the speed and core/wall material ratio are 4000 r/min and 2/1,respectively,the microcapsule enthalpy and cladding rate are the highest,and the melting enthalpy and crystallization enthalpy can reach 153.9 and 151.4 J/g.The rate can reach 69.8%;after being coated with MUF,the thermal stability of octadecane has been greatly improved(2)Graphene modified n-octadecane microcapsules were prepared using graphene as a modifier.Graphene was successfully combined with microcapsules.The problem of undercooled crystallization of the modified microcapsules was solved,and the thermal conductivity was significantly improved.When the graphene content is 0.1 wt%,the thermal conductivity and thermal diffusion coefficient of the microcapsules are increased by 144.3%and 107.3%,respectively.(3)Compared to natural wood,the porosity of delignified wood has increased by.18.2%,and microcapsules are mainly filled in wood ducts;the melting and crystallization enthalpy of phase change energy storage wood can reach 44.3 and 42.5 J/g.The temperature change is within the comfortable range of the human body,and has good thermal stability and durability;the heat storage capacity of phase change energy storage wood can be adjusted by changing the solid content of the microcapsule emulsion;the heat conduction of phase change energy storage wood after adding graphene The coefficient has increased by 773%.