Highly thermally conductive phase change composites with excellent solar-thermal conversion efficiency and satisfactory shape stability on the basis of high-quality graphene-based aerogels

Graphene/Graphitized Polydopamine/Carbon Nanotube All-Carbon Ternary Composite Films with Improved Mechanical Properties and Through-Plane Thermal Conductivity

“…As shown in Figure d, the pure GFs still showed a weak D band even after the graphitization, and the I D / I G decreased with the introduction of PDA@CNTs. When the PDA@CNT mass fraction was more than 5%, the D band almost disappeared, which was owing to that the linkage of adjacent graphene sheets by the gPDA@CNTs, which reduced the edge defects between the graphene sheets. − The pure GFs showed a 2D band at about 2700 cm –1 , which contains a higher ratio of turbostratic-stacking graphene. , With the increase of PDA@CNTs, the 2D band of the G-gPDA-CNT films gradually shifted to 2720 cm –1 , which represents a higher ratio of the order AB Bernal stacking graphene with a higher interlayer binding energy, benefiting the phonon transfer in the through-plane direction. , As shown in Figure e, the G-gPDA-CNT-7.5% film exhibited a silver gray metallic appearance due to the complete restoration of structure defects. The cross-sectional image of the G-gPDA-CNT-7.5% film showed entangled CNTs and wavy fringes, which might be the surface trace of the inner tightly stacked gPDA-CNTs (Figure f), which might effectively promote the transfer of energy, electrons, and phonons, especially in the through-plane direction.…”

Efficient Preconstruction of Three-Dimensional Graphene Networks for Thermally Conductive Polymer Composites

“…In other situations (e.g., battery system and space conditioning), the system temperature should be kept within a certain range and dynamic thermal management by PCMs or thermal switches are typically needed. PCMs can reduce temperature variation by absorbing and releasing heat via the phase change processes, and thermal switches can continuously tune the thermal transfer/dissipation behaviors by varying their own thermal conduction properties [ 118 , 267 – 269 ] (Fig. 18 ).…”

“…The graphene network in the PCMs can not only enhance the heat transport properties but also serve as a supporting framework to improve structural robustness of the PCMs, which enables high shape stability even at temperatures above the melting points of PCMs. For example, Liu et al reported that the combination of an air-dried RGO/GNP hybrid network with 1-octadecanol PCM can result in a great enhancement of thermal conductivity from 0.21 W m −1 K −1 for the 1-octadecanol to 9.50 W m −1 K −1 and the resultant composite has a high melting enthalpy of 196.2 J g −1 [ 267 ]. Notably, typical pristine PCMs, such as PEG, paraffin wax, n-hexadecane, and 1-octadecanol, possess favorable fluidity at elevated temperatures.…”

“…Optimization of PCCs can be achieved by structural/compositional designs of graphene networks. The embedded graphene skeletons can effectively prevent the leakage of PCMs due to the capillary forces, which significantly improves the shape stability of PCCs and ensures outstanding durability for practical applications [ 267 , 275 – 277 ].…”

Preparation, thermal, and mechanical properties of polyethylene glycol/expoxy resin composites as form‐stable phase change materials

“…In addition, due to excellent process capability of the polymers, it enables to make composite PCMs with desired shapes easily. In the case of the current research, most scientists focus on the macroscopic properties of the composite PCMs, such as form‐stability, thermal conductivity, thermal reliability, and flexibility, [ 45–47 ] and few reports are available in the literature with regard to the macro/micro mechanic properties of those polymer composite PCMs.…”