Study on Preparation and Performance Testing of Silica-Composite Organic Phase Change Material Microcapsules.

This study employs a mono-caprylate waterborne polyurethane microencapsulation technique to construct a core-shell phase-change microcapsule system with a structured composite core material. By integrating a silica network with phase change materials (ethyl palmitate/paraffin), a stable core material is formed. The silica not only acts as a physical framework to prevent leakage but also regulates the phase change temperature and latent heat through molecular interactions at its surface active sites. The shell layer polyurethane, derived from a fatty acid monoglyceride prepolymer, exhibits a structure highly similar to that of the core material, ensuring efficient and complete encapsulation, while the aqueous system aligns with green manufacturing requirements. The system successfully achieves two types of performance-tunable microcapsules: the silica-ethyl palmitate type exhibits a broad phase change temperature range near room temperature, while the silica-paraffin type demonstrates high latent heat of phase change in the medium-temperature range. This diversity in performance broadens the material's application scenarios. Its broad temperature range characteristic is particularly suitable for building energy efficiency and electronic thermal management fields, effectively mitigating temperature fluctuations and reducing energy consumption, demonstrating significant application value and innovative potential.