Enhanced Thermal Conductivity of Phase Change Microcapsules Based on Boron Nitride/Graphene Oxide Composite Sheets

Abstract

Large energy storage capacity and high heat conduction are very important for phase change materials. Phase change microcapsules (PCMCs) were synthesized through in situ polymerization by using paraffin as the core material. The melamine− formaldehyde (MF) polymer shell of PCMCs was modified with boron nitride/graphene oxide composite sheets (BN/GO CSs) to improve thermal conduction. The preparation condition of BN/GO CSs through the self-assembly process and the synthesis process of composite PCMCs (CPCMCs) in the presence of BN/GO CSs were systematically investigated. The thermal conductivity of CPCMCs synthesized under the optimized condition significantly increased about 190% relative to the incorporated paraffin. Promisingly, the introduction of BN/GO CSs hardly influenced the encapsulation process, allowing high encapsulation rate (>93%) and high phase change enthalpy (∼200 J•g −1 ). This work is an enlightening complementarity to the very limited research attempts that incorporating multiple fillers in PCMCs. We postulated and proved the synergistic effect of BN/GO CSs and their advantages in improving the thermal conductivity of the resultant PCMCs without scarifying the essential heat storage capacity. We envision that the insights and the CPCMCs synthesized can be applied in a range of material designs for energy and electronic applications.

Copolymerization of Phase Change Materials with Water Resistance Poly(Acrylamide‐Co‐Polyacrylic Acid) Copolymer Encapsulation: Photothermal Conversion and Storage Performance Under Solar Conditions

“…For PRP, the major peaks of RHTC, PAAAM, and PEG all existed in PRP composites. [ 36,46 ] The location of diffraction peaks were basically the same, indicating that PRP was successfully prepared. In addition, the intensity of the diffraction peak of PRP at 23.4° was significantly enhanced due to the presence of the RHTC diffraction peak at 23.1°.…”

“…), can be added to PCM to effectively improve the heat transfer rate of PCM and accelerate its heat storage/heat release performance to achieve efficient utilization of solar energy. [ 35–38 ] However, the inherent chemical inertia of boron nitride (BN) makes it difficult to interact with other substances, and difficult to distribute evenly, and accumulate on its own, resulting in its difficulty to fully exert its thermal conductivity. [ 39,40 ] Therefore, suitable materials are needed to assist it in forming a thermal conductivity network.…”

Self-Healing Properties of Water Tree Damage in Multilayered Shell–Core-Structured Microcapsules/Cross-Linked Polyethylene Composites

“…When the repaired material is damaged, the microcapsule ruptures under certain conditions, and the internal repair material is released to fix the defective structure, thus restoring the material properties to a certain extent [ 11 ]. Therefore, the viscosity of the repair solution must be low enough to allow an easy flow out of the ruptured capsule within a reasonable time, followed by the repair of the damaged area and the filling of the cavity [ 12 ]. The shell wall of the microcapsules should be constructed well and strong enough to withstand the impact of the core material [ 13 ].…”

Self-Healing Properties of Water Tree with Microcapsule/Cross-Linked Polyethylene Composite Material Based on Three-Layer Core-Shell Structure

“…When the insulating material undergoes water tree aging, the microcapsule will rupture under the action of the electric field, and the repair material inside it will react with the water in the water tree branches under the action of the catalyst to produce organic matter [ 26 , 27 ]. However, most of the current self-repair methods based on microcapsule systems use single-layer shell nucleus microcapsules, which will limit the water tree repair effect due to the different positions of the repair solution and the catalyst [ 28 , 29 ]. Moreover, when the microcapsules are mixed with XLPE, agglomeration easily occurs, and the microcapsules cannot be ruptured and cannot repair aged areas in time, resulting in a decrease in repair rate.…”