To maximize the advantage of CNTs as effective reinforcement for high strength polymer composites, the CNTs should not form aggregates, and must be well dispersed to enhance the interfacial interaction with the matrix. Several processing methods available for fabricating CNT/polymer composites based on either thermoplastic or thermosetting matrices have been described in past review articles [13], [203] and [204]. They mainly include solution mixing, in situ polymerization, melt blending and chemical modification processes. Although inherently different processing routes have been attempted, they all address important issues that affect composite properties, such as exfoliation of CNT bundles and ropes, homogeneous dispersion of the individual tubes into the matrix, alignment and interfacial bonding.
The effective utilization of CNT material in composite applications depends strongly on their ability to be dispersed individually and homogeneously within a matrix. An optimized interfacial interaction between the CNT sidewalls and the matrix should result in an efficient load transfer to the “hard” component of the composite. All processing methods known thus far for CNT-based composites are described below. Due to the huge volume of related literature, only the seminal works will be discussed for each processing method.