Liquid crystal epoxy resins (LCERs) with high thermal conductivity have been drawing significant attention to overcome the thermal conductivity limitation of polymeric composites. Nonetheless, the strategy to enhance the thermal conductivity of LCERs has been primarily focused on improving the well-ordered molecular structure originated from LC phases to reduce phonon scattering. Furthermore, other important factors for the enhancement of thermal conductivity such as intermolecular interaction, fine-tuning of the polymer chain structure, and interchain conjugation have been rarely investigated for LCERs. Here, we introduce a dual-functional LCER enabling the creation of well-ordered microstructures as well as intermolecular π-conjugation networks synergistically suppressing the phonon scattering. As a key design functional group, the diphenyldiacetylene (DPDA) mesogen was employed to assemble a highly ordered lamellar microstructure and create interchain π-conjugation networks via topochemical polymerization of well-organized diacetylenes. The thermal conductivity of cured DPDA epoxy resin with a highly ordered lamellar structure (∼0.43 W m −1 K −1 ) was 194% compared to a commercial epoxy resin (∼0.22 W m −1 K −1 ). Thermal conductivity was further increased up to 227% (∼0.50 W m −1 K −1 ) via post-topochemical polymerization of diacetylenes, leading to π-conjugation and interchain π−π stacking. Furthermore, the thermal conductivity of the composites prepared with hexagonal boron nitride fillers was also increased by 19% after simple heat treatment of the composites, inducing topochemical polymerization of diacetylenes. Finally, a striking thermal conductivity increase from 10.3 W m −1 K −1 to 18.3 W m −1 K −1 was observed by simply replacing the matrix from the commercial one to DPDA epoxy resin (DPDAER), clearly revealing the superiority of our DPDAER in the development of high-thermalconductivity composites.

Microfiber fabrication via wet-spinning of lyotropic liquid crystals (LCs) with anisotropic nanomaterials has gained increased attention due to the microfibers' excellent physical/chemical properties originating from the unidirectional alignment of anisotropic nanomaterials along the fiber axis with high packing density. For wet-spinning of the microfibers, however, preparing lyotropic LCs by achieving high colloidal stability of anisotropic nanomaterials, even at high concentrations, has been a critically unmet prerequisite, especially for recently emerging nanomaterials. Here, we propose a cationically charged polymeric stabilizer that can efficiently be adsorbed on the surface of boron nitride nanotubes (BNNTs), which provide steric hindrance in combination with Coulombic repulsion leading to high colloidal stability of BNNTs up to 22 wt %. The BNNT LCs prepared from the dispersions with various stabilizers were systematically compared using optical and rheological analysis to optimize the phase behavior and rheological properties for wet-spinning of the BNNT LCs. Systematic optical and mechanical characterizations of the BNNT microfibers with aligned BNNTs along the fiber axis revealed that properties of the microfibers, such as their tensile strength, packing density, and degree of BNNT alignment, were highly dependent on the quality of BNNT LCs directly related to the types of stabilizers.