Surface carboxylation of hydrophobic synthetic fibers for enhancing deposition of reduced graphene oxide to create highly conductive and bactericidal textiles

The surface functionality of three synthetic fibers including polyethylene terephthalate (PET) fiber, polypropylene (PP) fiber and polytetrafluoroethylene (PTFE) fiber was obviously hindered by their high hydrophobicity. In this work, the three fibers were carboxylated by different surface modification methods to introduce carboxyl groups for increasing the deposition of reduced graphene oxide (RGO) on their surface. High surface carboxyl group content further enhanced RGO deposition, thus increasing electrical conductivity of these fibers. Carboxylated PET and PP fibers deposited more RGO, and show higher electrical conductivity and antibacterial activity than carboxylated PTFE fiber. Increasing temperature, acidic pH or the addition of NaCl or anionic surfactant improved RGO deposition on PTFE fiber. The increasing number of GO deposition cycles increased electrical conductivity of RGO deposited PTFE fiber and its washing resistance. Glucose was used as an environmentally benign substitute of Na2S2O4 to improve the transformation of GO into RGO on these fibers.