High internal phase-phase change composites for customized thermal management and anti-counterfeiting

Abstract

Organic phase change composites (PCCs) research focuses on the trade-off between loading capacity and leakage-proof ability/flexibility. However, practical applications require high energy storage density, thermal cycling stability, and mechanical durability at the same time. Herein, we report the development of an innovative high internal phase PCCs (HIP-PCCs), which is based on the integration of deformable and polydisperse phase change materials (PCMs) capsules densely embedded within a chitin nanofibril matrix that is healable and reconfigurable. The form-stable HIP-PCCs not only possess unexpectedly high PCMs loading capacity of over 95 vol% and phase change enthalpy up to 209 J/g, but also show satisfied thermal cycling stability with negligible leakage (<5%) after 200 phase change cycles. Moreover, HIP-PCCs possess exceptional mechanical robustness (tensile strength of 9.3 MPa), flexibility, and self-adhesive properties. These attributes allow HIP-PCCs to be processed into customized shapes, so they can be tightly integrated with targets to achieve their full potential. Combining the above advantages and newly-acquired switchable optical properties, HIP-PCCs start a new scenario of exploiting PCMs for versatile smart devices with flexibility, sustainability and recyclability, and thereby extent their applications in more broad fields, such as cold-chain transportation, data security protection and temporary information recording.