Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7885806 | Ceramics International | 2018 | 35 Pages |
Abstract
Expanded graphite (EG), as a new kind of functional carbon-based material, is a vital supporting material and heat transfer enhancer for preparing highly conductive form-stable composite phase change materials (PCMs). However, the hydrophobic nature of EG makes it difficult to incorporate with inorganic PCMs. In this work, we intended to solve this drawback and a modified EG named Al2O3-coated EG which was characterized by enhanced hydrophilicity was developed via a heterogeneous nucleation technique and subsequent heat treatment. Experiments found that the Al2O3 layer on the surface of EG was uniform and essentially amorphous, and was well-bonded to EG via chemical interactions between oxygen atoms from Al2O3 and carbon atoms from EG. The hydrophilicity and oxidation resistance of Al2O3-coated EG could be enhanced by increasing the amount of Al2O3. Most importantly, compared with EG, the water contact angle of Al2O3-coated EG dropped from 90.7° to 33.9° when only 4.4â¯wt% Al2O3 was used, indicating that the hydrophilicity of EG could be greatly enhanced by low cost. Moreover, molecular dynamics (MD) simulation of the hydrophilicity of EG and Al2O3-coated EG proved that the preparation of Al2O3-coated EG was an efficient and feasible method to improve the hydrophilicity of EG.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Zhongping Li, Zhaowen Huang, Ning Xie, Xuenong Gao, Yutang Fang, Zhengguo Zhang,