Preparation And Properties Of Silica/Chitosan/Paraffin Phase Change Microcapsules

The development of the society closely related to energy.With the constant progress of the society, human activities expend more and more energy.In terms of development and utilization of new energy, composite phase change materials(PCM or PCMs) has attracted more and more attention. Microcapsule technology can solve the leakage and interface bonding problem of PCM perfectly.This paper mainly study on a kind of double shell microcapsule phase change material (MEPCM) with good heat storage properties, heat-conducting property, heat storage stability.In this paper, a combination of monophase coagulation and crosslink emulsification process was used to prepare a kind of MEPCM with chotisan as shell material and paraffin as core material named CS/MEPCM. Then a layer of SiO2 was coated outside the CS/MEPCM through the hydrolysis reaction of tetraethyl orthosilicate (TEOS). The experimental results shows that when Span-80 and OP-80 mixture with quality ration 3:1 as emulsifie, the Hydrophilic Lipophilic Balance (HLB) of compound emulsifier is 12.2.At this time, the paraffin emulsion has good stabilityThe optimal technological parameters of the formulation were obtained. Mass ratio of emulsifier-paraffin-chotisan-crosslinking agent is 0.1:2:1:2. Durgin the monophase coagulation process, when pH is 7.5, temperature is 50?, stirring speed 1200r/min, the CS/MEPCM has good spherical shape with smooth surface.The thermal conductivity of CS/MEPCM is 0.159 W/(m, K), latent heat is 47.44 J/g, encapsulation rate of paraffin is 71.7%.When pH is 4, mass ratio of TEOS/MEPCM 2:1, the silica-chitosan-double hull microcapsules (SiO2/CS/MEPCM) has good spherical shape and slightly rough surface. The thickness of SiO2 shell is about 15?m.The thermal conductivity of SiO2/CS/MEPCM has improves by 29.56%. Meanwhile and the breakage has reduced by34.86%?The effect of MEPCM on the thermal performance and macro-performance of phase change energy storage foam concrete were investigated. The results show that the addition of MEPCM causes a certain degree reduction in respect of compressive strength, porosity and bibulous rate. With the increase of the content of mierocapsule,the dry density and thermal transmission improved. The application effect of phase change energy storage foam concrete as wall materials was observed by simulation. It turned out that the incorporation of MEPCM can significantly slow down the indoor temperature changes, and the temperature can be digested within the comfort range.