Dispersion and alignment of carbon nanotubes in polymer matrix

Carbon nanotubes (CNTs) have been demonstrated ideal alternative fillers in polymer matrix to endow its excellent electrical and thermal conductivity, improve the mechanical and thermal properties (strength, stiffness, toughness, thermal stability, flame resistance, etc.), and decrease the gas permeability. The effective dispersion level of CNTs and their good compatibility with the matrix are critically important in determining the final performance of polymer nano-composites. However, random dispersion of CNTs in polymer matrix hardly produces the expected performance for the polymer nanocomposites according to both the theoretical predictions and experimental results. The effective alignment of CNTs in polymer matrix induced by external force enables to remarkably enhance their performance. In this chapter, we mainly focus on reviewing the previous work in the processing techniques of CNTs dispersion (mechanical dispersion process and surface functionalization) and understanding the dispersion mechanisms. Further, the chapter highlights the progress on the processing design and strategies for adjusting the alignment of CNTs in the polymer matrix. Finally, the outlook towards the challenges and opportunities on the dispersion and alignment of CNTs in the polymer matrix are also discussed and illustrated.