Covalently modified Kevlar fabric incorporating graphene oxide with enhanced antibacterial properties and preserved strength

This work describes a multi-step modification process for the covalent transformation of Kevlar fabric en route the incorporation of graphene oxide (GO) nanosheets. Spectroscopic, thermal and microscopy imgaing techniques have been employed to follow step-by-step the modification of Kevlar and the formation of the corresponding Kevlar-GO hybrid fabric. The level of Kevlar's functionalization can be controled with the nitration time, the first reaction in the multi-sequence organic transformations, for obtaining the hybrid fabric with a content of GO up to 30%. Most importantly, the covalent post-modification of Kevlar does not occur in the expense of the other otherwise excellent mechanical properties of the fabric. Under optimal conditions, the Kevlar-GO hybrid fabric shows a 20% enhancement of the ultimate strengh. Notably, when the Kevlar-GO hybrid fabric exposed to cyanobacterial Synechococcus the bacteria growth was fully inhibited. Overall, the covalently modified fabric demonstrated significant antibacterial behavior, excellent strength and stability under common processes. Due to its simplicity, the methodology presented in this work not only promises to result in a standard procedure to functionalize the mer units of Kevlar with a variety of chemicals and nanomaterials but it can be also extended for the modification and hybridization of other fabrics.