Facile synthesis of copper/ reduced single layer graphene oxide as a multifunctional nanohybrid for simultaneous enhancement of antibacterial and antistatic properties of waterborne polyurethane coating

Development of a surface with simultaneous antibacterial and antistatic properties is necessary for some special environments like operating rooms and high-tech industries. Multifunctional copper/ reduced single layer graphene oxide (Cu/ rSLGO) nanohybrid has been developed to induce these simultaneous properties in waterborne polyurethane coatings (WPU). The Cu/ rSLGO nanohybrid was synthesized through the in-situ reduction of Cu+2 ions and single layer graphene oxide nanosheets without using any secondary reducing reagent. FESEM, TEM, FTIR, XRD, EDX, UV-vis, and TGA analyses were used to characterize morphological, structural, crystallographic, and thermal properties of the prepared nanohybrid, and the modified WPU coatings were studied by SEM, AFM, contact angle, TGA, DLS, and mechanical properties analyses. The results of the colony counting method exhibited that the Cu/ rSLGO nanohybrid has a strong antibacterial activity with 92% and 80.66% of the loss of viability for S. aureus and E. coil bacteria, respectively. Moreover, adding 3%wt Cu/ rSLGO nanohybrid and the creation of sufficient conductive pathways throughout the WPU matrix lead to the electrical surface resistance of the modified coating reaches 4.8 x 10(+9) Omega/sq which falls into the electrical surface resistance range of commercial antistatic coatings. Furthermore, utilizing the Cu/ rSLGO in the WPU coating not only provided thermal resistance but also, enhanced its mechanical properties compared with the coating made of pristine waterborne polyurethane.