Preparation and High-Sensitivity Thermochromic Performance of MXene-Enhanced Cholesteric Liquid Crystal Microcapsule Textiles

To mitigate the attenuation of color-change sensitivity in cholesteric liquid crystals (CLCs) post-microencapsulation, this study developed MXene-reinforced thermochromic textiles. Monolayer/few-layer MXene nanosheets were fabricated via an etching-intercalation-dispersion approach, while cholesteric liquid crystal microcapsules (CLCMs) were synthesized through a solvent evaporation method. Cotton fabrics were pretreated with polydopamine (PDA), followed by the fabrication of poly(diallyldimethylammonium chloride) (PDAC)/MXene composite coatings via layer-by-layer (LbL) self-assembly and subsequent hydrophobic modification. Systematic characterizations (scanning electron microscopy, SEM; atomic force microscopy, AFM) and performance evaluations revealed that MXene nanosheets have an average thickness of 1.54 nm, while CLCMs display a uniform spherical morphology. The resultant textiles exhibit a reversible red-green-blue color transition over the temperature range of 26.5-29.5 °C, with sensitivity comparable to pristine CLCs and excellent hydrophobicity. This work overcomes the long-standing bottleneck of inadequate color-change sensitivity in conventional liquid crystal microcapsule textiles, offering a novel strategy for the advancement of smart wearable color-changing materials.