Interfacial properties and self-sensing of single carbon fiber reinforced CNT-phenolic nanocomposites using electro-micromechanical and wettability tests

Interfacial and other properties along with self-sensing were investigated for single carbon fiber/neat phenolic resins and carbon nanotube (CNT)-phenolic nanocomposites by electro-micromechanical and wettability tests. The apparent modulus was higher for samples with a single carbon fiber in CNT-phenolic nanocomposite than for samples with a single carbon fiber in neat phenolic resin, indicating better stress transfer. In water droplet contact angle measurements the contact angle increased form slightly less than 90° on neat phenolic resin to more than 90° on CNT-phenolic nanocomposites. This behavior was attributed to hydrophobic domains randomly distributed on the surface as a result of the heterogeneous microstructure of CNT. The work of adhesion between a single carbon fiber and CNT-phenolic nanocomposites was greater than for neat phenolic resin which is attributed to an increase in viscosity by adding CNT. Micro-failure patterns and interfacial adhesion between CNT-phenolic nanocomposites and single carbon fibers were consistent with these other results.