With the rapid development of science and technology, electronic devices are moving towards miniaturization and integration, which brings high heat dissipation requirements. During the heat dissipation process of a heating element, heat may spread to adjacent components, causing a decrease in the performance of the element. To avoid this situation, the ability to directionally transfer heat energy is urgently needed. Therefore, thermal interface materials (TIMs) with directional high thermal conductivity are more critical in thermal management system of electronic devices. For decades, many efforts have been devoted to the design and fabrication of TIMs with high-directional thermal conductivity. Benefiting from the advantage in feasibility, low-cost and scalability, compositing with thermal conductive fillers has been proved to be promising strategy for fabricating the high-directional thermal conductive TIMs. This review summarizes the present preparation technologies of polymer composites with high-directional thermal conductivity based on structural engineering of thermal conductive fillers, focusing on the manufacturing process, mechanisms, achievements, advantages and disadvantages of different technologies. Finally, we summarize the existing problems and potential challenges in the field of directional high thermal conductivity composites.

The proliferation of high-power, highly informationized, and highly integrated electronic devices and weapons equipment has given rise to increasingly conspicuous issues about electromagnetic (EM) pollution and thermal accumulation. These issues, in turn, impose constraints on the performance of such equipment and jeopardize personnel safety. Carbon materials, owing to their diverse and modifiable structures, offer adjustable thermal and electric conductivity, rendering them highly promising for applications in fields such as thermal management and EM protection which have garnered extensive research and review. The pursuit of integrated device and equipment development has elevated the demand for multifunctional materials, prompting significant research into carbon-based composite materials that include both thermal management and EM protection functionalities. Notably, there are no relevant reviews on this topic at present. Consequently, this work consolidates research findings from recent years on carbon matrix composites exhibiting dual attributes of thermal management and EM protection. These attributes include thermally conductive electromagnetic interference (EMI) shielding materials, thermally insulating EMI shielding materials, thermally conductive EM wave (EMW) absorbing materials, and thermally insulating EMW absorbing materials. The paper elucidates the fundamental principles underpinning thermal conduction, thermal insulation, EMW absorbing, and EMI shielding. Additionally, it engages in discussions surrounding areas of contention, design strategies, and the functional properties of various material designs. Ultimately, the paper concludes by presenting the challenges encountered and potential research strategies about composites endowed with both thermal management and EM protection functionalities, while also envisaging the development of novel multifunctional EM protection materials.

Layered double hydroxides (LDHs) are widely used owing to their unique alternating anionic and cationic layered two-dimensional (2D) structures. However, studies on the preparation of 2D LDH nanosheets with uniform thickness and their photodetectors are limited. In this study, two novel ultrathin LDH (Ca-In and Ca-Al LDH) nanosheets are peeled off from precursor bimetallic phosphides through the original precursor method. Both Ca-In and Ca-Al LDH nanosheets demonstrate a uniform thickness distribution with an average thickness of 3–4 nm, micron-level lateral sizes, and moderate bandgap. Owing to its broad light absorption range, hydrophilicity, and stability, Ca-In and Ca-Al LDH nanosheets are applied for the first time in photoelectrochemical photodetectors, realizing a wide range of light detection from ultraviolet (365 nm) to visible light (635 nm). Moreover, the fabricated photodetectors exhibit excellent cycle stability, and the average photocurrent density shows no reduction after 70 days. Therefore, this study provides an effective method to prepare 2D Ca-In and Ca-Al LDH nanosheets with uniform thickness and photoelectric application prospects.