Multifunctional HDPE/CNTs/PW composite phase change materials with excellent thermal and electrical conductivities

Flame-retardant and leakage-proof phase change composites based on MXene/polyimide aerogels toward solar thermal energy harvesting

Rational design of two-dimensional nanofillers for polymer nanocomposites toward multifunctional applications

Flame-retardant and form-stable phase change composites based on MXene with high thermostability and thermal conductivity for thermal energy storage

MXenes are currently one of the most widely studied two-dimensional materials due to their properties. However, obtaining highly dispersed MXene materials in organic solvent remains a significant challenge for current research. Here, we have developed a method called the tuned microenvironment method (TMM) to prepare a highly concentrated Ti3C2Tx organic solvent dispersion by tuning the microenvironment of Ti3C2Tx. The as-proposed TMM is a simple and efficient approach, as Ti3C2Tx can be dispersed in N,N-dimethylformamide and other solvents by stirring and shaking for a short time, without the need for a sonication step. The delaminated single-layer MXene yield can reach 90% or greater, and a large-scale synthesis has also been demonstrated with TMM by delaminating 30 g of multilayer Ti3C2Tx raw powder in a one-pot synthesis. The synthesized Ti3C2Tx nanosheets dispersed in an organic solvent possess a clean surface, uniform thickness, and large size. The Ti3C2Tx dispersed in an organic solvent exhibits excellent oxidation resistance even under aerobic conditions at room temperature. Through the experimental investigation, the successful preparation of a highly concentrated Ti3C2Tx organic solvent dispersion via TMM can be attributed to the following factors: (1) the intercalation of the cation can lead to the change in the hydrophobicity and surface functionalization of the material; (2) proper solvent properties are required in order to disperse MXene nanosheets well. To demonstrate the applicability of the highly concentrated Ti3C2Tx organic solvent dispersion, a composite fiber with excellent electrical conductivity is prepared via the wet-spinning of a Ti3C2Tx (dispersed in DMF) and polyacrylonitrile mixture. Finally, various types of MXenes, such as Nb2CTx, Nb4C3Tx, and Mo2Ti2C3Tx, can also be prepared as highly concentrated MXene organic solvent dispersions via TMM, which proves the universality of this method. Thus, it is expected that this work demonstrates promising potential in the research of the MXene material family.

High Concentration of Ti3C2Tx MXene in Organic Solvent.

Novel light-driven and electro-driven polyethylene glycol (PEG)/two-dimensional MXene composite (PEG@MXene) with enhanced thermal conductivity and electrical conductivity as form-stable phase change material (FSPCM) is first obtained via the simple vacuum impregnation by employing MXene as the supporting skeleton as well as thermally conductive and electrically conductive filler and PEG as the phase change working substance. Fourier transform infrared spectroscopy (FT-IR) indicates that no chemical reaction occurred between PEG and MXene during adsorption process, but X-ray diffraction (XRD) results show the crystalline regions of PEG was decreased by the incorporation of MXene. The differential scanning calorimetry (DSC), polarizing microscope (POM), as well as XRD results demonstrate that the MXene nanosheets act as heterogeneous crystal nuclei and promote the crystallization of PEG. The melting and freezing latent heats of PEG@MXene are as high as 131.2 and 129.5 J/g, respectively, the relative enthalpy efficiency is 80.3%, and the thermal conductivity and electrical conductivity are 2.052 W/mK and 10.41 S/m, respectively. The obtained PEG@MXene has excellent light-to-thermal conversion, electro-to-thermal conversion and thermal energy storage performance. All these results demonstrate that the obtained PEG@MXene will have a great potential application for thermal energy storage.

Novel light-driven and electro-driven polyethylene glycol/two-dimensional MXene form-stable phase change material with enhanced thermal conductivity and electrical conductivity for thermal energy storage

Pengcheng Lin

Papers

Novel light-driven and electro-driven polyethylene glycol/two-dimensional MXene form-stable phase change material with enhanced thermal conductivity and electrical conductivity for thermal energy storage