The surface and interlayer modification of montmorillonite and its potential application for thermal energy storage

Phase change materials (PCMs) could take full advantage of clean and renewable energy, because of their ability to convert and store various energy. However, due to the leakage and low heat storage capacity, the large-scale commercial application of PCMs is seriously limited. In this work, natural montmorillonite (MMT) was modified by organic amine coupling agent that was assembled into the interlayer of MMT. The energy storage performance and the stability of composite PCMs were significantly improved by using a novel frame of MMT encapsulated Paraffin (PA). The MMT-KH550-HAc/PA composite PCMs prepared by organic intercalation provides suitable pore structure and hydrophilicity to encapsulate more PA, resulting in the highest latent heat capacity (150 J/g) that is significantly increased by 144.1% from 60 J/g. Meanwhile, the energy storage stability of MMT-KH550-HAc/PA is also improved, and the latent heat of phase change is reduced by 3.2% after 100 cycles. The present MMT-KH550-HAc/PA has remarkable latent heat capacity and energy storage stability, which can be potentially applied to the solar water heaters.