| Green energy development and utilization,efficient storage and other issues have gradually become the focus of scientific research to solve the increasing world energy contradiction.The latent heat storage technology based on phase change materials can store and release energy in the form of phase change latent heat,which can effectively balance the supply and demand of energy and realize the efficient application of energy.However,when the solid-liquid phase change material absorbs heat and melts,it will corrode the surrounding medium due to leakage.This morphological instability will affect the application prospect of the solid-liquid phase change material.Therefore,composite phase change materials prepared from porous materials,such as Ceramsite,Aerogel,Diatomaceous Earth and Stereotyped show huge application advantages.In this paper,conductive polymer polypyrrole(PPy)was added into the shaped composite phase change material and used as a conductive filler to prepare antistatic temperature-regulating mortar.PPy hydrogels were prepared by chemical oxidation using anionic surfactant oleic acid,sodium dodecylbenzene sulfonate and non-ionic surfactant Span 80,and then lyophilized in vacuum to obtain PPy aerogel.The PPy aerogel composite phase change material was prepared by impregnating the organic phase change material paraffin.The results show that the PPy aerogel composite doped with oleic acid has the best adsorption performance,with a maximum adsorption rate of 59.81%(the molar ratio of pyrrole monomer to oleic acid is 7:1).When the paraffin wax mass fraction is 55%,the resistivity of PPy aerogel composite phase change material is about 40Ω·cm,which meets the requirements of resistivity of conductive materials.When the polypyrrole aerogel composite phase change material is used to replace part of the fine aggregate to prepare the cement-based material,due to the high porosity and strong water absorption of the polypyrrole aerogel composite phase change material,there will be a strong interface effect with water.That is,water will cross the interface between the cement slurry and the aggregate and enter the interior of the aggregate,thereby reducing the effective water-to-binder ratio and fluidity of the cement-based material,which has a greater impact on the working performance and mechanical properties of the cement-based material.Diatomite was modified by microwave acid(DEm)to enlarge the pore.PPy/DEm composite was prepared by chemical oxidation method.PPy/DEm composite was used as carrier material to absorb paraffin in vacuum,and paraffin/PPy/DEm composite phase change material was prepared.When the PPy loading rate of diatomite is 30%,and the paraffin content in Paraffin/PPy/DEm composite phase change material is 60%,the melting latent heat of Paraffin/PPy/DEm composite phase change material is 78.9J/g,the resistivity is 207 Ω·cm.The change of melting latent heat after200 melting and freezing cycles is less than 5%,so Paraffin/PPy/DEm composite phase change material has good thermal stability.The antistatic temperature regulating mortar was prepared by Paraffin/PPy/DEm composite phase change material to replace part of sand with equal volume.The results show that after curing for 28 days,the resistivity of the antistatic temperature regulating mortar can reach480Ω·m,which can meet the resistivity requirements of the antistatic mortar,and its compressive strength is 23.7Mpa.In addition,the temperature regulating test of the antistatic temperature regulating mortar shows that the heating rate and cooling rate of the phase change energy storage mortar board are lower than that of the cement mortar board at the same initial temperature and heating time.Hence,the antistatic temperature regulating mortar prepared by the test has excellent temperature regulating performance. |
