Ultrahigh specific surface area of graphene for eliminating subcooling of water
Ultrahigh specific surface area of graphene for eliminating subcooling of water
复制标题
石墨烯超高比表面积消除水的过冷
DOI：
10.1016/j.apenergy.2014.02.032
复制
发表时间：
2014-10-01
期刊：
影响因子：
11.2
通讯作者：
Liu, Zhuowei
中科院分区：
文献类型：
--
作者：
Li, Xing;Chen, Ying;Liu, Zhuowei
石墨烯具有机械强度强、重量轻、近乎光学透明、导热导电性好等优异性能，因此得到了广泛的应用。在这项研究中，我们使用石墨烯的超高比表面积，因为它固有的二维性质，以减少相变材料冻结的过冷。这一结果为石墨烯利用相变潜热进行储能提供了可能。由于悬浮的石墨烯的质量分数(0.020+/-0.001 wt%)或表面积浓度(0.070+/-0.003 m(2)/ml)非常低，完全不需要过冷来冻结水。与相同质量分数的二氧化硅和二氧化钛纳米颗粒悬浮在水中相比，片状石墨烯使水在更小的过冷度下冻结，总冻结时间更短。表面活性剂的加入可以改善悬浮液的稳定性，进一步降低过冷度，但也略微增加了总冻结时间。石墨烯鳞片比球形氧化物纳米粒子更适合用作水中的成核添加剂。(C)2014爱思唯尔有限公司。保留所有权利。
Graphene is widely utilized because of its exceptional properties, such as strong mechanical strength, low weight, nearly optical transparency, and excellent conductivity of heat and electricity. In this study, we used the ultrahigh specific surface area of graphene due to its inherently two-dimensional nature to reduce the subcooling of freezing of a phase change material. The results enable graphene's application in energy storage using the latent heat of phase transition. The need for subcooling to freeze water was eliminated completely with the suspension of a very low mass fraction (0.020 +/- 0.001 wt%) or surface area concentration (0.070 +/- 0.003 m(2)/ml) of graphene. Compared to nanoparticles of SiO2 and TiO2 with the same mass fraction suspended in water, flakes of graphene led to freeze water at a much smaller subcooling degree, and shorter total freezing time. The addition of surfactants can improve suspension stability and further reduce the degree of subcooling, but it also slightly increases the total freezing time. Graphene flakes are more suitable than spherical oxide nanoparticles for use as nucleating additives in water. (C) 2014 Elsevier Ltd. All rights reserved.