Polymers are widely used in industry and in our daily life because of their diverse functionality, light weight, low cost and excellent chemical stability. However, on some applications such as heat exchangers and electronic packaging, the low thermal conductivity of polymers is one of the major technological barriers. Enhancing the thermal conductivity of polymers is important for these applications and has become a very active research topic over the past two decades. In this review article, we aim to: 1). systematically summarize the molecular level understanding on the thermal transport mechanisms in polymers in terms of polymer morphology, chain structure and inter-chain coupling; 2). highlight the rationales in the recent efforts in enhancing the thermal conductivity of nanostructured polymers and polymer nanocomposites. Finally, we outline the main advances, challenges and outlooks for highly thermal-conductive polymer and polymer nanocomposites.

Thermal conductivity of polymers and polymer nanocomposites

Singly dispersed carbon nanotube/aluminum composites fabricated by powder metallurgy combined with friction stir processing

Cement based composite materials (CBCM) with superior mechanical strength and excellent durability are always desirable in practical applications. Although considerable research has been reported in the past decades about the use of Nano materials (NMs) for strength and durability enhancement of cement matrix, there is little information available on the use of graphene nano-sheets and their derivatives (GND) in cement-based materials. Particularly the role of GND in hydration processes and their mechanisms of strengthening in cement matrix are unclear. In this paper, a critical review on recent research findings about GND modified cement-based materials was conducted. The review mainly discussed the influence of GND on properties of cement matrix including microstructure, hydration, mechanical properties, etc. The information revealed in this paper would not only provide a comprehensive understanding of the effect of GND on cement composites, but also provide valuable ideas and guidance for similar studies in the future.

A critical review on research progress of graphene/cement based composites

Carbon nanotubes (CNTs) have been considered as a new promising reinforcement for ceramic matrix composites (CMCs) over the last decade, owing to their exceptional properties. CNT-reinforced CMCs posses a unique microstructure, nanoscale objects dispersed throughout ceramic matrix grain boundaries, which allows tailoring physical properties with an unprecedented combination of remarkable engineered transport properties as well as superior mechanical properties. However, gaining further control over challenging CNTs dispersion is still an important issue with the aim of tailoring multifunctional properties of CNT-reinforced CMCs. This paper reviews the current status of the research and describes all different approaches used to effectively disperse CNTs throughout ceramic matrices, providing an overview of composites microstructure and mechanical, electrical and thermal properties. Besides, all findings reported till date point out a promising approach towards physical properties tailoring of CNT-reinforced ceramic CMCs.

H. Zhao

Papers

Multi-walled carbon nanotubes reinforced Al2O3 nanocomposites: Mechanical properties and interfacial investigations