OPTIMIZATION OF SYNTHESIS OF SHAPE - STABILIZED PHASE CHANGE MATERIALS CONTAINING NaCl - NaBr - Na₂M_oO₄ AND MESOPOROUS SILICA

Fossil fuels are a limited resource, as they formed over millions of years in the Earth's crust. Their use also has significant environmental impacts such as air , water pollution, greenhouse gas emissions and habitat destruction. Renewable energy sources must be developed as soon as possible. Solar energy is a renewable energy source, which can be harvested through concentrated solar power plant into a thermal energy storage system. Shape - stabilized phase change materials are suitable in such power plants as thermal energy storage (TES) batteries. In this study, obtaining of phase change material (PCM) composites based on NaCl-NaBr- Na2MoO4 eutectic and mesoporous silica (MS) is optimized. Several eutectic-MS compositions are obtained and characterized. The resulted materials are shape - stabilized, thermally stable up to 650 degrees C and have a total enthalpy in the range of 100 - 211 Jg-1. PCM composites have a lower melting point than that of the salt eutectic suggesting the nanoconfinement of the eutectic into MS. Some samples exhibit a better thermal reliability and show more evidence of nanoconfinement effect. The obtained shape - stabilized PCMs could act as thermal batteries.