Development and thermal performance of porous PDMS composites with microencapsulated phase change materials for enhanced thermal insulation

This work presents a novel strategy for constructing flexible material by integrating microencapsulated phase change materials (MPCMs) into a porous polydimethylsiloxane (PDMS). The resulting composite exhibits stable MPCMs within the abundant distributed internal pore network, confirmed by scanning electron microscopy. Differential scanning calorimetry reveals a well-defined phase transition temperature and a high latent heat of fusion of 44.3 kJ/kg, enabling efficient thermal energy storage and release. Furthermore, the composite demonstrates remarkable mechanical resilience (tensile strength: 0.59 MPa) and superior hydrophobicity (water contact angle: 110°), ensuring durability and resistance to moisture. Thermal insulation evaluations under both constant heat and direct solar exposure showcase the materials exceptional performance, achieving temperature differentials of 9.4 and 6.2 °C, respectively. This superior insulating capability stems from the synergistic effect of the low thermal conductivity of the porous PDMS matrix and the latent heat storage/release properties of the MPCMs.Graphical AbstractGraphical abstract illustrating the preparation of a flexible PDMS material containing microencapsulated phase change particles using a particle-template method