High-Thermal-Stability and High-Thermal-Conductivity Ti₃C₂T_x MXene/Poly(vinyl alcohol) (PVA) Composites

Abstract

MXenes, a new family of two-dimensional materials, have recently attracted increasing attention due to their unique properties for a wide range of potential applications. Herein, we synthesize Ti 3 C 2 T x /poly(vinyl alcohol) (PVA) composites and investigate the effects of the thermal properties of MXene by temperature-dependent Raman spectroscopy and polarized-laser power-dependent Raman spectroscopy. Compared to the Ti 3 C 2 T x MXene, the PVA significantly improves the thermal stability of Ti 3 C 2 T x by reducing the thermal coefficient of the E g 1 mode from −0.06271 to −0.03357 cm –1 /K, which is attributed to the strong Ti–O bonds formed between the MXene and PVA polymer confirmed by the X-ray photoelectron spectroscopy results. Meanwhile, the thermal conductivities of Ti 3 C 2 T x and Ti 3 C 2 T x /PVA composites reach as high as about 55.8 and 47.6 W/(m K), respectively. Overall, this work will contribute to extend the MXene applications in terms of polymer-based nanocomposites and improve the reliability of the related devices effectively.

Surface Modification of a MXene by an Aminosilane Coupling Agent

“…To confirm the presence and protonation state of amine groups on the surface of the AEAPTMS‐Ti 3 C 2 T x , the N 1s high resolution XPS spectrum was obtained (Figure 3B, and Tables S1 and S2, Supporting Information). The spectrum was deconvoluted into two peaks corresponding to free and protonated amines at binding energies of 400.2 and 402.0 eV, respectively . The ratio of free to protonated amines was found to be ≈1.72:1 based on the ratio of the relative sensitivity factor (RSF) adjusted integral area of the two deconvoluted N 1s region peaks.…”

“…The spectrum was decon voluted into two peaks corresponding to free and protonated amines at binding energies of 400.2 and 402.0 eV, respec tively. [37][38][39] The ratio of free to protonated amines was found to be ≈1.72:1 based on the ratio of the relative sensitivity factor (RSF) adjusted integral area of the two deconvoluted N 1s region peaks. Furthermore, the small peak at ≈397.2 eV is attributed to nitrogen coordinated with a metal which in this case is Ti, thereby forming TiN covalent bonds.…”

Two-dimensional metal carbides and nitrides (MXenes): preparation, property, and applications in cancer therapy

“…MXenes have higher thermal conductivity due to low concentration defects and large size. In 2018, Liu et al tested the thermal properties of Ti 3 C 2 T x and its films using temperature-and polarization-sensitive Raman spectroscopy [72]. The thermal conductivity of Ti 3 C 2 T x and Ti 3 C 2 T x /polyvinyl alcohol (PVA) was experimentally determined to be 55.8 and 47.6 W (m K) −1 , which is higher than that of metals and other 2D materials, such as MoS 2 [73] and BP [74].…”

“…Ti 3 C 2 -based PTT of cancer. (A) Photothermal heating curves of pure water and different concentrations(72,36,18, and 9 ppm) of Ti 3 C 2 nanosheets dispersed in water suspension under irradiation with 808 nm laser (1.5 W cm −2 )[79]. (B) Effective PTT ablation of tumors guided by MRI/PA imaging with MnOx/ Ti 3 C 2 -SP composite nanosheets[80].…”

Ti3C2 MXene Paper for the Effective Adsorption and Controllable Release of Aroma Molecules

“…So far, the control release of the aroma molecules is commonly applied in the field of food science, [7,8] indoor air quality improvement, [9,10] and olfactory display. [11,12] Among the MXene family, the most investigated MXene, Ti 3 C 2 , demonstrates attractive properties including high electric conductivity (≈9800 S cm −1 ), [43] thermal conductivity (≈60 W mK −1 ), [44] and high surface area (≈100 m 2 g −1 ), [45] which underlines the potential of Ti 3 C 2 MXene as a functional material for the controlled release and adsorption of aroma molecules. Additionally, the hydrophilic nature of Ti 3 C 2 MXene not only allows their easy processing with aqueous solution but also shows the well dispersion stability in several polar solvents, which suggests the strong affinity between polar molecules and the surface functional groups of Ti 3 C 2 MXene.…”