TY - JOUR
T1 - Controlling the wettability and adhesion of carbon fibers with polymer interfaces via grafted nanofibers
AU - Hong, Seokjin
AU - Minary-Jolandan, Majid
AU - Naraghi, Mohammad
N1 - Funding Information:
MN and MMJ acknowledge the support from NSF by NSF-CMMI award numbers 1450110 and 1450107 . MN also acknowledges the supports from TAMU , through startup funds.
Publisher Copyright:
© 2015.
PY - 2015/9/9
Y1 - 2015/9/9
N2 - Interfacial properties in carbon fiber composites is one of the key parameters controlling their structural functionality. Here, we introduce a novel method to engineer carbon fiber-epoxy interfaces, via inclusion of nanofibers, towards higher interfacial strength and energy dissipation. In our method, thermally stabilized polyacrylonitrile (PAN) nanofibers are grafted onto carbon fibers via electro-spinning process, followed by nanofiber consolidation via solvent vapor and thermal treatment. These treatments partially dissolves nanofibers along the nanofiber-fiber interface and trigger entropic elasticity in nanofibers, thus, increasing the nanofiber-fiber interactions. The hybridization of carbon fibers with PAN nanofibers increased the interfacial shear strength (IFSS) by ~48%, from 10.8±2.6 to 15.9±4.9MPa. Postmortem fractography points to mechanical interlocking between nanofibers and epoxy and reinforcing effects of nanofibers in matrix as root causes of IFSS enhancement. As a result of adding nanofibers to carbon fiber, junction failure mode changes from a dominantly adhesive failure (at epoxy-fiber interface) to dominantly cohesive failure, and failure plane slightly shifts away from epoxy-fiber interface to within the epoxy. Compared to other types of whiskers grown on carbon fibers, such as CNTs, the method proposed here requires low temperatures (below 300°C), during which no surface damages are expected to accumulate on carbon fibers.
AB - Interfacial properties in carbon fiber composites is one of the key parameters controlling their structural functionality. Here, we introduce a novel method to engineer carbon fiber-epoxy interfaces, via inclusion of nanofibers, towards higher interfacial strength and energy dissipation. In our method, thermally stabilized polyacrylonitrile (PAN) nanofibers are grafted onto carbon fibers via electro-spinning process, followed by nanofiber consolidation via solvent vapor and thermal treatment. These treatments partially dissolves nanofibers along the nanofiber-fiber interface and trigger entropic elasticity in nanofibers, thus, increasing the nanofiber-fiber interactions. The hybridization of carbon fibers with PAN nanofibers increased the interfacial shear strength (IFSS) by ~48%, from 10.8±2.6 to 15.9±4.9MPa. Postmortem fractography points to mechanical interlocking between nanofibers and epoxy and reinforcing effects of nanofibers in matrix as root causes of IFSS enhancement. As a result of adding nanofibers to carbon fiber, junction failure mode changes from a dominantly adhesive failure (at epoxy-fiber interface) to dominantly cohesive failure, and failure plane slightly shifts away from epoxy-fiber interface to within the epoxy. Compared to other types of whiskers grown on carbon fibers, such as CNTs, the method proposed here requires low temperatures (below 300°C), during which no surface damages are expected to accumulate on carbon fibers.
KW - Electro-spinning
KW - Fiber/matrix bond
KW - Hybrid composites
KW - Interface
KW - Polymer-matrix composites (PMCs)
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U2 - 10.1016/j.compscitech.2015.06.008
DO - 10.1016/j.compscitech.2015.06.008
M3 - Article
AN - SCOPUS:84933513436
SN - 0266-3538
VL - 117
SP - 130
EP - 138
JO - Composites Science and Technology
JF - Composites Science and Technology
ER -