Research On The Thermal Conductivity Of Iron Oxide Modified Carbon Nanotubes/Cellulose Microcrystalline Composite

Carbon materials such as carbon nanotubes and graphene are widely used in high thermal conductivity composites.They can provide many phonon transport paths in the composites and improve the thermal conductivity of the composite.But there are still some problems such as a large interface thermal resistance between fillers and matrix.It is necessary to add a large amount of high thermally conductive fillers to effectively improve the thermal conductivity of composites.However,the addition of high content thermally conductive fillers will cause the reduction of the overall mechanical properties and processing properties of the composite,which limits the practical application of thermally conductivity composites.Therefore,how to reduce the interface thermal resistance of the interface between the filler and the matrix and reduce the content of the thermally conductive filler is the key and challenge to improve the thermal conductivity of high-performance thermally conductive composite materials.In this paper,the Fe2O3-CNT as a high thermally conductive filler was prepared by the hydrothermal method.Fe2O3 nanoparticles were used as a bridge between CNT to reduce the thermal resistance between CNT.The Fe2O3-CNT and cellulose microcrystalline were linked selfassembly through electrostatic adsorption in the solution and improve the thermal conductivity of the composite material.The main work done in this subject is as follows:1)A high thermally conductive filler,Fe2O3-CNT,was prepared by the hydrothermal method.The Fe2O3-CNT hybrid fillers with different compositions were prepared by changing the ratio of reagents in the hydrothermal process.The influence of Fe content on the structure of Fe2O3-CNT was explored through SEM,TEM and.It is proved that Fe2O3 and CNT are connected through strong covalent bonds through XPS and other characterization methods.Phonons can propagate through the interface between CNT at these covalent bonds,which reduces the interface thermal resistance between CNTs and improves the thermal conductivity of the filler.2)Fe2O3-CNT and CMC can be adsorbed together by a liquid selfassembly method to obtain Fe2O3-CNT/CMC composite.Besides,there are many H bonds between Fe2O3-CNT and CMC,which can make Fe2O3CNT and CMC have good compatibility of interface and effectively reduce the thermal resistance of the composite.Among the fillers,the 8-Fe2O3CNTs/CMC composite has a higher in-plane thermal conductivity(4.67 W·m-1·K-1)at a lower filler content(5 wt%),which is 540.1%of pure CMC;and 360.2%higher than the CNT-COOH/CMC composite with the same filler content.Such high thermal conductivity is ascribed to the threedimensional thermal network composed of Fe2O3 nanoparticles and CNTs which reduced interface thermal resistance between Fe2O3 nanoparticles and CNTs.