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纤维素纳米晶和氧化石墨烯共稳定皮克林乳液制备光热相变材料微胶囊用于太阳能和热能储存(英文)
Photothermal phase change material microcapsules via cellulose nanocrystal and graphene oxide co-stabilized Pickering emulsion for solar and thermal energy storage
【摘要】 相变材料(PCM)在相变过程中可以储存或释放大量的热能,因此在热管理领域备受关注.然而,PCM的泄漏问题严重限制了其应用.将PCM封装在聚合物壳层的微胶囊中是一种有效防止PCM泄漏的方法,同时也增加了PCM与基体的传热面积.具有光热转换性能的PCM微胶囊可以将太阳能转为热能进行存储,是一种有效利用太阳能的方法.本研究以纤维素纳米晶(CNC)和氧化石墨烯(GO)共稳定的PCM皮克林乳液为模板,制备了以密胺树脂(MF)为壳层的,具有光热转换性能的PCM微胶囊.CNC具有优异的皮克林乳化能力,可促进GO在油水界面的固定,从而可制备出CNC和GO共稳定的PCM皮克林乳液.然后通过多巴胺的氧化自聚合、MF前驱体的原位聚合和交联,在CNC和GO共稳定的PCM皮克林乳液表面原位形成聚多巴胺(PDA)层和MF壳层.由于多巴胺的还原作用,GO被还原为还原氧化石墨烯(rGO).所制备的PCM@CNC/rGO/PDA/MF微胶囊具有均匀的微米级尺寸、优异的防漏性能、高相变焓(175.4 J g-1)和高PCM芯材含量(84.2%).而且rGO和PDA的存在使PCM微胶囊具有出色的光热转换性能.在1 Wcm-2的光照下,PCM@CNC/rGO/PDA/MF微胶囊浆料(15wt%)的温度可高达到73℃.因此,光热PCM@CNC/rGO/PDA/MF微胶囊可应用于太阳能收集、热能储存和释放,在节能建筑和智能纺织品等领域具有广泛的应用前景.
【Abstract】 Phase change materials(PCMs) have attracted significant attention in thermal management due to their ability to store and release large amounts of heat during phase transitions.However,their widespread application is restricted by leakage issues.Encapsulating PCMs within polymeric microcapsules is a promising strategy to prevent leakage and increase heat transfer area with matrices.Moreover,photothermal PCM microcapsules are particularly desirable for solar energy storage.Herein,we fabricated photothermal PCM microcapsules with melamine-formaldehyde resin(MF)as shell using cellulose nanocrystal(CNC) and graphene oxide(GO) co-stabilized Pickering emulsion droplets as templates.CNC displays outstanding Pickering emulsifying ability and can facilitate the fixation of GO at the oil-water interface,resulting in a stable CNC/GO co-stabilized PCM Pickering emulsion.A polydopamine(PDA) layer was coated in-situ on the emulsion droplets via oxidization self-polymerization of dopamine.Meanwhile,GO was reduced to reduced GO(rGP)due to the reducing ability of PDA.The outmost MF shell of the PCM microcapsules was formed in-situ through the polymerization and crosslinking of MF prepolymer.The resulted PCM@CNC/rGO/PDA/MF microcapsules exhibit uniform sizes in the micrometer range,excellent leakage-proof performance,high phase change enthalpy(175.4 J g-1) and PCM encapsulation content(84.2%).Moreover,the presence of rGO and PDA endows PCM@CNC/rGO/PDA/MF microcapsules with outstanding photothermal conversion performance.The temperature of PCM@CNC/rGO/PDA/MF microcapsule slurries(15wt.%) can reach 73℃ after light irradiation at1 W cm-2.Therefore,photothermal PCM@CNC/rGO/PDA/MF microcapsules are promising for solar energy harvesting,thermal energy storage,and release in various applications,such as energy-efficient buildings and smart textiles.
【Key words】 graphene oxide; cellulose nanocrystal; Pickering emulsion; phase change material microcapsule; photothermal;
- 【文献出处】 Science China(Materials) ,中国科学:材料科学(英文) , 编辑部邮箱 ,2024年10期
- 【分类号】TB34
- 【网络出版时间】2024-08-13 16:35:00
- 【下载频次】187