Concurrent Superhydrophobicity and Thermal Energy Storage of Microcapsule with Superior Thermal Stability and Durability
作者：Gang Wu*, Congjin Hu, Junyi Cui, Si-Chong Chen, and Yu-Zhong Wang*
關鍵字：Superhydrophobicity，Thermal Energy Storage， Microcapsule
論文來源：期刊
具體來源：ACS Sustainable Chem. Eng.
發表時間：2017年
Despite considerable success in design and preparation of superhydrophobic particles, a facile and low-cost approach to develop multifunctional particles, especially microcapsules with the integrated performances of intrinsically long-lasting and highly stable superhydrophobicity and other passive/active functionalities, remains extremely challenging and is still in its infancy. Herein, we report a microcapsule (MC) with a micro/nano-hierarchical shell and a phase change material (PCM) core by a low-cost one-pot method. The resulting microcapsules (MCs) possess concurrent features of superhydrophobicity and thermal energy storage. Against thermal attack up to approximately 240 °C, the microstructure of MCs is nearly intact to avoid an obvious leakage of encapsulated PCM at high temperature, and meanwhile superhydrophobicity of MCs is enhanced unexpectedly to a static contact angle (CA) of 167.4 ± 0.3° and slide angle (SA) of 5 ± 0.5°. After conventional storage of 80 days, MCs still show a good superhydrophobicity with a nearly constant CA and slightly increasing SA. In addition, encapsulated PCM has high enthalpy up to 176 J/g, nearly unchanged Tm, Tom, and Tos, and negligible change (less than 0.1%) of normalized melting and solidified enthalpies over 100 melting/solidification cycles, indicating high latent heat, low effect of shell on thermal diffusion, and excellent durability during phase transition cycling, respectively. An isothermal stage at around 28 and 26 °C being close to human comfort temperature appears separately in heating-up and cooling-down processes of the epoxy matrix with embedded MCs, revealing a good temperature-regulated property of MCs. Accordingly, the MCs as a promising candidate with all-in-one features of superhydrophobicity, temperature-regulated properties, thermal-resistance, and durability would stimulate wide applications in self-cleaning/energy-saving smart buildings and facilities.