Surface-modified MXene/TLCP nanocomposites with enhanced electrical and thermal conductivity via in situ grafting polymerization

Abstract

MXenes, an emerging class of two-dimensional transition metal carbides and nitrides, have garnered significant attention due to their exceptional electrical, thermal, and mechanical properties. However, achieving uniform dispersion of hydrophilic MXene nanosheets within a hydrophobic thermotropic liquid crystal polyester (TLCP) matrix presents a formidable challenge that limits their practical applications. In this study, we address this challenge through a direct surface modification approach to enhance the interfacial interaction between MXene and TLCP. The effects of modified MXene on TLCP performance were investigated through comprehensive material characterization. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analyses reveal that 6-aminohexanoic acid effectively mediates the interfacial interaction between MXene and TLCP molecules, preventing the aggregation of MXene nanosheets and facilitating their uniform dispersion throughout the TLCP matrix. The incorporation of modified MXene (Am-MXene) significantly enhances the thermal stability of the resulting nanocomposites, with the Am-50 %MXene/TLCP demonstrating a 27 C increase in the 5 % weight loss temperature compared to pristine TLCP. The nanocomposite achieves a notable electrical conductivity of 5.99 S/m while preserving the TLCP's intrinsic microstructure. Moreover, MXene incorporation enhances the orderliness and alignment of liquid crystal textures. The nanocomposite exhibits substantial improvements in thermal diffusivity (67 %), thermal conductivity (25 %), dielectric constant (318 %), and photothermal conversion temperature (84 %). These findings advance our understanding of designing multifunctional composite materials with enhanced performance characteristics.