Hydrophobic modification of silica/exfoliated graphite nanoplatelets aerogel and its application as supporting material for form-stable phase change materials

Autor: Yu-Hao Ning, Lin-Ping Yu, Hao-Nan Zhou, Yang Feng, Ju-Lan Zeng, Ping Hu, Ni Tan, Chuan-Huang Lin, Qi Li, Zhong Cao
Rok vydání: 2021
Předmět:
Zdroj: Journal of Industrial and Engineering Chemistry. 99:396-406
ISSN: 1226-086X
DOI: 10.1016/j.jiec.2021.04.054
Popis: Hydrophobic modified silica/exfoliated graphite nanoplatelets aerogel (M-SiO2/xGnP) were successfully prepared via surface modification of silica/xGnP alcogel and followed by ambient pressure drying. Afterwards, form-stable PCMs in which capric–palmitic acids eutectic (CA–PA) was confined in the prepared aerogels were obtained by vacuum infiltration. Characterization of the prepared form-stable PCMs revealed that both the hydrophobic modification and the doping of xGnP could effectively improve the loading of CA–PA in the aerogel. The unmodified silica aerogel could not adsorb CA–PA, while the loading of CA–PA in the surface modified pure silica aerogel supported form-stable PCM and the unmodified silica/xGnP aerogel supported form-stable PCM were 24.2 wt% and 44.4 wt%, respectively. Besides, the hydrophobic modification and the doping of xGnP showed significant synergistic effect. The loading of CA–PA in the M-SiO2/xGnP supported form-stable PCM (FPCM/xGnP-20-48) could attain 78.9 wt% when the M-SiO2/xGnP was obtained by modifying the alcogel with 20 vol% trimethyl chlorosilane for 48 h. The FPCM/xGnP-20-48 not only had high latent heat and good thermal reliability, but also exhibited significantly improved thermal conductivity and alleviated supercooling due to the effective thermal conductive network formed by xGnP and the promoted heterogeneous nucleation of CA–PA at interfaces with aerogel.
Databáze: OpenAIRE
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