With the development of polymer-based composite materials technologies and the continuous expansion of its application scale, the research focus has shifted from performance and quality to multifunctionality. Conventional thermally conductive composites are static and passive. Thermoresponsive polymeric composites are dynamic and active; they are able to perceive changes in ambient temperature and exhibit simple and direct responses, which have attracted considerable attention. Herein, thermoresponsive polymeric composites were achieved using an elastic boron nitride framework (BNF) as the architecture and a phase-transition matrix for "freezing" temporary shapes. We use molecular simulation guiding to control the dual-cross-linked network that is based on its stable chemical bond as permanent cross-linking and tunable composition of the hydrogen bond as recoverable cross-linking. The resulting BNF exhibited attractive elasticity and high compressive strength (0.04 MPa). In addition, we optimized the design of the thermal conductive network to obtain thermoresponsive polymeric composites with their own good thermal conductivity and thermal transfer capability. The obtained thermoresponsive polymeric composites have good heat dissipation (ΔT max = 10 °C), indicating temperature capability through the self-shape change. This study paves the way to fabricate multifunctional composites and, through materials structural design and performance regulation, promote the development of heat dissipation materials.

SummaryIn the present study, our aim is to investigate the preferential binding mode and encapsulation of the flavonoid fisetin in the nano-pore of β-cyclodextrin (β-CD) at the molecular level using various theoretical approaches: molecular docking, molecular dynamics (MD) simulations and binding free energy calculations. The molecular docking suggested four possible fisetin orientations in the cavity through its chromone or phenyl ring with two different geometries of fisetin due to the rotatable bond between the two rings. From the multiple MD results, the phenyl ring of fisetin favours its inclusion into the β-CD cavity, whilst less binding or even unbinding preference was observed in the complexes where the larger chromone ring is located in the cavity. All MM- and QM-PBSA/GBSA free energy predictions supported the more stable fisetin/β-CD complex of the bound phenyl ring. Van der Waals interaction is the key force in forming the complexes. In addition, the quantum mechanics calculations with M06-2X/6-31G(d,p) clearly showed that both solvation effect and BSSE correction cannot be neglected for the energy determination of the chosen system.

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