Effect of Carbon Nanofiber‐Matrix Adhesion on Polymeric Nanocomposite Properties—Part II

Abstract

A successful integration of two independent phases with good adhesion is imperative for effective translation of superior carbon nanofiber filler properties into a physically superior carbon nanocomposite. Carbon nanofibers were subjected to electrochemical oxidation in 0.1 M nitric acid for varying times. The strength of adhesion between the nanofiber and an epoxy matrix was characterized by flexural strength and modulus. The surface functional groups formed and their concentration of nanofibers showed a dependence on the degree of oxidation. The addition of chemical functional groups on the nanofiber surface allows them to physically and chemically adhere to the continuous resin matrix. The chemical interaction with the continuous epoxy matrix results in the creation of an interphase region. The ability to chemically and physically interact with the epoxy region is beneficial to the mechanical properties of a carbon nanocomposite. A tailored degree of surface functionalization was found to increase adhesion to the matrix and increase flexural modulus.

Polyester composite water uptake and organic contaminant release affected by carbon nanofiber reinforcements

“…Unsaturated polyester resin (Cook Composites & Polymers, Product ID: CI–1001–25), 0.005 mass fraction MEKP, eight layers of E–glass random fiber mats sized with an undisclosed silane coupling agent (Saint–Gobain Vetrotex America, M113 random chopped strand mat) and 0.01 mass fraction of CNF (Pyrograf, PR–24 LHT, 150 nm average diameter, range of 70–200 nm diameter, 50–200 µm length, density of 1.9 g/mL) were used. Because of their high surface area, oxidized CNFs can be dispersed easily into polar polymer matrices such as epoxy, polyester and vinyl ester and show significant improvements in their mechanical properties . In this study, oxidized CNFs were mixed with polyester resin and sonicated in a cold water bath for 45 min.…”

Processing and Characterization of Space-Durable High-Performance Polymeric Nanocomposite

“…One of the possible explanations of achieving better results could be the better fiber-matrix interface. Proper adhesion between fiber and matrix is essential in order to ensure optimum stress transfer across the resulting interfaces [17,18]. Another possible explanation could be the higher cross-linking of polymer films manufactured in this study.…”

Use of Carbon Nano-Fibers in Cementitious Mortar

“…The elastic modulus of individual nanofibers ranges from 25 to 200 GPa, depending on their diameter (Lawrence et al, 2008). Given their relatively low cost compared to carbon nanotubes, development of carbon nanofiber reinforced polymer nanocomposites is actively pursued (Shofner et al, 2003;Hammel et al, 2004;Lafdi et al, 2008). Efforts to assess the value of carbon nanofibers to inorganic (including cementitious) matrices have also been initiated; uniform dispersion and effective interfacial interactions are key to their reinforcement efficiency in cementitious materials (Sadiq et al, 2012a ;Sadiq et al, 2012b ;Sadiq et al, 2012c;Xie et al, 2005).…”