PVA/PAN包覆石蜡的相变胶囊的制备和应用

Preparation and application of PVA/PAN coated paraffin phase change capsule

为了制备能应用于太阳能水蒸馏中的相变胶囊,首先制得直径为3 mm左右、形状为球体的石蜡粒子,然后根据不同聚合物的特性,先涂覆上一层15%聚乙烯醇(PVA),再涂覆上一层聚丙烯腈(PAN),制备得到双层相变胶囊;利用光学显微镜、红外光谱仪、差示扫描量热仪(DSC)和扫描电子显微镜(SEM)等技术对双层相变胶囊进行表征,并以泄漏量测试和对水蒸馏量提升效果来评价双层相变胶囊的应用效果。结果表明:PVA和PAN成功地涂覆在石蜡粒子表面;双层相变胶囊能够实现零泄露;双层相变胶囊的相变焓为111.5 J/g,并且水接触角为69.4°,为亲水性,用于水蒸馏中,可与水充分接触;加入质量分数分别为4%、8%、12%的相变胶囊分别使水蒸馏量提高了5.8%、11.6%、17.1%,表明制备所得的双层相变胶囊在太阳能水蒸馏上具有一定的应用价值。

In order to prepare the phase change capsules that can be used in solar water distillation,paraffin particles with a diameter of about 3 mm and a shape of sphere were prepared firstly.Then,according to the characteristics of different polymers,a layer of 15%polyvinyl alcohol(PVA)was coated,and then a layer of polyacrylonitrile(PAN)was coated to prepare a double-layer phase change capsule.The double-layer phase change capsule was characterized by optical microscope,infrared spectrometer,differential scanning calorimeter(DSC)and scanning electron microscope(SEM).The application of the double-layer phase change capsule was evaluated by leakage test and improvement effect on water distillation.The results showed that PVA and PAN were successfully coated on the surface of paraffin particles;double-layer phase change capsule can realize zero leakage;the phase change enthalpy of the double-layer phase change capsule is 111.5 J/g and the water contact angle is 69.4°.It is hydrophilic and can be fully contacted with water when it is used in water distillation;adding phase change capsules with mass ratio of 4%,8%and 12%increased the amount of water distillation by 5.8%,11.6%and 17.1%respectively,indicating that the prepared double-layer phase change capsules have certain application value in solar water distillation.