Wet spinning of the graphene oxide composite liquid crystals toward graded utilization of waste heat

Thermal conductive composite materials (TCCMs) applied in the thermal management are of ever-rising significance with the rapid development of a variety of thermal-related industrial products. Previously, the demand for TCCMs with differential thermal conductivity is generally met by using two strategies, tuning the material composition and designing the composite microstructure. However, the miscibility between different components is usually poor, resulting in the uniformity of thermal conductivity of TCCMs. In this work, the flexible reduced graphene oxide@calcium alginate (RGO@CA) composite fibers are fabricated by wet spinning of the lyotropic graphene oxide composite liquid crystals and wet chemical reduction. The resulted RGO@CA composite fibers exhibit high tensile strength of about 200 MPa. The graded utilization of the waste heat can be realized by using RGO@CA composite fibers with different compositions. The displayed utilizations of the waste heat include thermal energy storage, optical sensor, thermal source for chemical reaction. The proposed liquid crystal spinning demonstrates a novel strategy for developing advanced materials toward the thermal management and waste heat recovery of electronic devices and systems. Graphical abstract