A new class of 2D materials named “MXene” has recently received significant research interest as they have demonstrated great potential for the applications in batteries, supercapacitors, and electronic devices. However, the research on their thermal properties is still very limited. In this work, Ti₃C₂T_x films were prepared by the vacuum-assisted filtration of delaminated nano-flake Ti₃C₂T_x MXenes. The thermal and electrical conductivity of the Ti₃C₂T_x films were measured by the state-of-the-art T-type method. The results showed that the effective thermal conductivity of the films increased from 1.26 W·m⁻¹·K⁻¹ at 80 K to 2.84 W·m⁻¹·K⁻¹ at 290 K, while the electrical conductivity remained at 12,800 Ω⁻¹·m⁻¹ for the same temperature range. Thermal resistance model was applied to evaluate the inherent thermal conductivity of the Ti₃C₂T_x flakes, which was estimated to be in the range of tens to hundreds W·m⁻¹·K⁻¹.

Filled high thermal conductivity epoxy composite solves the problem of the low thermal conductivity of the epoxy resin itself, but the addition of the thermal conductive filler reduces the mechanical properties of the composite, which limits its application in the field of high voltage insulation. In this work, carboxyl-terminated butadiene nitrile liquid rubber (CTBN) was used to toughen the boron nitride-epoxy hybrid system, and the effects of different contents of CTBN on the mechanical properties, thermal conductivity, glass transition temperature, thermal stability, and dielectric properties of the composites were investigated. The results showed that when the content of CTBN was 5–15 wt.%, the CTBN formed a dispersed island structure in the epoxy resin matrix. The toughness of the composite increased by about 32%, the breakdown strength was improved, and the thermal conductivity was about 160% higher than that of pure epoxy resin. As the CTBN content increased, the glass transition temperature and thermal stability of the composite decreased and the dielectric constant and the dielectric loss increased. When the CTBN content is 10–15 wt.%, a toughened epoxy composite material with better comprehensive properties is obtained.

PEDOT-PSS is a widely used hole extraction layer in polymer solar cells (PSCs). However, its acidic and hygroscopic nature usually affects the long-term stability of photovoltaic devices. Herein, we report an effective method to enhance the conductivity and stability of the PEDOT-PSS film by doping with an amphiphilic perfluorosulfonic copolymer, Nafion. The highly hydrophobic fluorocarbon backbone of Nafion preferentially interacts with the hydrophobic PEDOT of PEDOT-PSS, while the highly hydrophilic –SO₃H groups preferentially interact with hydrophilic PSS chains, inducing the PEDOT chains to separate from the PSS chains by Nafion. The conductivity and surface morphology of the Nafion-doped PEDOT-PSS layer were investigated by using a four-point probe and an atomic force microscope, respectively. The optical properties of the Nafion doped PEDOT-PSS film and the photoactive layer spin-coated on it were studied by transmittance and reflection spectra. With the Nafion doped PEDOT-PSS hole extraction layer (HEL), the power conversion efficiency of the PSCs based on poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM) reaches 4.63%, increased by 14.3% in comparison with that of the control devices. Furthermore, the lifetime of the devices with Nafion doped PEDOT-PSS HEL is greatly enhanced.

Mussel-inspired approach was attempted to non-covalently functionalize the surfaces of boron nitride (BN) with self-polymerized dopamine coatings in order to reduce the interfacial thermal barrier and enhance the thermal conductivity of BN-containing composites. Compared to the polypropylene (PP) composites filled with pristine BN at the same filler content, thermal conductivity was much higher for those filled with both functionalized BN (f-BN) and maleic anhydride grafted PP (PP-g-ma) due to the improved filler dispersion and better interfacial filler-matrix compatibility, which facilitated the development of more thermal paths. Theoretical models were also applied to predict the composite thermal conductivity in which the Nielsen model was found to fit well with the experimental results, and the estimated effective aspect ratio of fillers well corresponded to the degree of filler aggregation as observed in the morphological study.

High breakdown strength and low dielectric loss are necessary for the outdoor insulator using silicone rubber (SR) composites. In this work, polydopamine coated mica (mica-PDA) was synthesized via bioinspired dopamine self-polymerization, and mica-PDA-filled SR composite (SR/mica-PDA-VTMS) was prepared using vinyl tri-methoxysilane (VTMS) as a silane coupling agent which serves as the molecular bridges between the organic rubber and the inorganic filler. The SR/mica-PDA-VTMS composite demonstrated dense and uniform morphology where the filler was well dispersed. Due to the strong interfacial interactions between filler and rubber, the SR/mica-PDA-VTMS composite exhibits much lower dielectric loss compared to the other mica-filled SR composites, which was comparable to the prepared alumina-tri-hydrate-filled SR composites. Moreover, the breakdown strength of ~31.7 kV/mm and tensile strength of 5.4 MPa were achieved for the SR/mica-PDA-VTMS composite, much higher than those of the other as-prepared SR composites.