Preparation of aramid nanofiber and its application in polymer reinforcement: A review

In recent years, aramid nanofibers (ANFs) have been widely used in polymer reinforcement and toughening fields, due to their large specific surface area, high aspect ratio and retaining the excellent strength, modulus and high temperature resistance of aramid micron fibers (AMFs). It is considered that ANFs have excellent reinforcement effects for polymer composites and much attention has been focused on them. ANFs have excellent water dispersibility, which provides convenience for their reinforced polymers. ANF-reinforced polymers could also impart excellent properties such as high temperature resistance, flame retardancy, and tear resistance. Therefore, it is necessary to find a simple and efficient preparation method of ANFs. However, there is almost no literature review on the research progress of the fabrication of ANFs and ANF-reinforced polymer composites. This article reviews the recent research progress of the preparation of ANFs and the advantages and disadvantages of different preparation methods, and presents the applications in reinforcing various polymer matrices such as epoxy, rubber and composites. Finally, we proposed our own opinions on the issues of ANF-reinforced polymers.