Fabrication and properties of dense thin films containing functionalized carbon nanofibers

In this study, dense thin films containing carboxylic acid-functionalized carbon nanofibers (O-CNFs) are fabricated by a two-step approach involving solution filtering and mechanical compression through a rolling process. Optical images reveal a notable change from porous to dense in the surface morphology of the rolled O-CNF thin film. Moreover, test results show that the tensile strength and electrical conductivity of the rolled thin film are improved by approximately 400% in comparison to the non-rolled thin film. Upon fracture, electron microscope image shows significant pull-out and alignment of O-CNFs parallel to the direction of the applied load due to interlocking mechanism within the highly entangled O-CNF network.

► Carbon nanofiber (CNF) thin films are studied.
► Dense CNF thin films are made by solution filtration and mechanical compression.
► Surface of rolled CNF thin film changed from porous to dense.
► Strength and conductivity of rolled CNF thin film are improved by ~ 400%.
► CNF pull-out mechanism and alignment are observed in rolled CNF thin film.