# Interfacial Pull-Out Properties of Surface-Grown Carbon Nanotubes (gCNTs) on Para-Aramid Fabric Material by Chemical Vapor Deposition (CVD)

## TL;DR

Carbon nanotubes grown on aramid fabric improve strength and friction, offering a new way to reinforce flexible materials.

## Contribution

A low-temperature CVD method is introduced to grow MWCNTs on para-aramid fabrics for interfacial reinforcement.

## Key findings

- CNT-functionalized fabrics showed a 66.19% increase in maximum pull-out force.
- Friction coefficients increased by 26.67% (static) and 16.67% (kinetic) due to surface roughness.
- Energy dissipation and fracture toughness improved up to 1769 J/m² in single-yarn tests.

## Abstract

Carbon nanotubes (MWCNTs) were synthesized in situ on para-aramid fabrics (gCPO) via a low-temperature (450 °C) chemical vapor deposition (CVD) process to enhance interfacial pull-out, frictional, and fracture toughness characteristics. FESEM analysis confirmed CNT coverage on fiber surfaces, while FTIR, Raman, and XRD results indicated limited structural modification without significant polymer degradation. The CNT-functionalized fabrics exhibited a 66.19% increase in maximum pull-out force, 55.32% improvement in interlacement rupture strength, and a three-fold rise in intra-yarn shear resistance compared with control fabrics (KPO). The static and kinetic friction coefficients increased by 26.67% and 16.67%, respectively, due to CNT-induced surface roughness, enhancing inter-fiber load transfer and reducing slippage. Single-yarn pull-out tests revealed notable gains in energy dissipation and fracture toughness (up to 1769 J/m2), whereas multi-yarn pull-out performance decreased due to excessive friction surpassing filament strength. The study demonstrates that low-temperature MWCNT growth enables effective interfacial reinforcement of soft para-aramid fabrics, establishing a novel framework for meso-scale mechanical screening of flexible nano-ballistic composites.