Synthesis And Characterization Of Paraffin/TiO₂-P?MMA-co-BA? Phase Change Material Microcapsules For Thermal Energy Storage

Phase change material microcapsules are a potential candidate for applications in solar energy storage and recovery,architectural materials,intelligent textiles or fabrics for warming underwear,heat transfer slurry due to their advantages,such as their anti-corrosion,anti-leakage and good durability.Such microcapsules have become a research hotpot in the field of energy storage and thermal regulation.In this thesis,a novel phase change microcapsule was successfully prepared by a Pickering emulsion method.Simultaneously,a microcapsule-based multi-functional intelligent building thermal insulation coating and a microcapsule-based self-healing hydrophobicity coating were prepared.The microcapsules and coatings were characterized by scanning electron microscopy?SEM?,fourier transform infrared spctroscopy?FT-IR?,differential scanning calorimetry?DSC?,Thermogravimetric analysis?TGA?,Ultraviolet-visible near-infrared spectrophotometer?UV-Vis-NIR?and Standard type contact angle meter?STCAM?.The main content and result are as follow:1.Microcapsules based on a phase changing paraffin core and TiO₂-P?MMA-co-BA?hybrid shell were prepared via a Pickering emulsion method.The grafting of KH570 onto the surface of TiO₂ particles plays an important role in the formation of the microcapsules.The microcapsules exhibit an irregularly spherical morphology with the size range of 3-24?m.The addition of BA can enhance the toughess of the brittle polymer poly?methyl methacrylate?and improve the thermal reliability of the phase change microcapsules.The ratio of BA/MMA is in the range of 0.09-0.14,the ratio of the monomer/paraffin is varied from 0.45 to 0.60 and the emulsification rate is higher than 10000 rpm.These microcapsules exhibit a well-defined morphology and good thermal stability.The actual core content of the microcapsules reaches36.09%,with an encapsulation efficiency of 73.07%.Furthermore,the prepared microcapsules present the high thermal reliability for latent-heat storage and release after2000 thermal cycles.The output of samples was 32 times,and the results of amplificatory experiments proved that the microcapsules remain a good morphology and high thermal stablity.The microcapsules have the potential to a future megascopic experiments.2.The multi-functional intelligent building thermal insulation coating was prepared by adding rutile TiO₂ and MCPCM in waterborne silicone emulsion.The solar reflectance of MCPCM is 91.08%less than 92.28%of TiO₂.When the ratio of MCPCM is below 10 wt%,the reflectance of coating is 90.75%.The results show that the temperature difference is in the range of 9.7-12.7?when the amount of MCPCM is between 0 wt%and 4 wt%.The coating has a good solar reflectivity and temperature control performance.3.A multifunctional smart coating for antifouling and anticorrosion applications was developed using self-healing and self-cleaning mechanism by dispersing an epoxy with MCPCM exhibited a good antiflouling effect because of their superhydrophobic characteristics.The paraffin inside the MCPCM will spontaneous transfer to the surface of MCPCM.The formation of paraffin coat in the surface of MCPCM will enhance the hydrophobic of MCPCM.When the content of BA is in the range of 12-20%,the water contact angle of MCPCM is in the range of 150-154°?The MCPCM exhibited excellent resistance to a variety of less polar and nonpolar organic solvents.With the depositing of MCPCM in the surface of coating,the coating shows a good self-cleaning performance after the antifouling experiment.