# rGO/PAN Composite Membranes Obtained In Situ Using Hydrothermal Reduction of GO in the Polymer Bulk

## TL;DR

This paper introduces a new method to create rGO/PAN composite membranes using hydrothermal reduction, which changes the membranes' physical and transport properties.

## Contribution

The novel in situ hydrothermal reduction method for producing rGO/PAN composite membranes is introduced.

## Key findings

- Hydrothermal reduction significantly alters the physicochemical properties of the membranes.
- The water flux of the membranes decreases by up to ~348 dm3/m2 × h after reduction.
- FTIR, Raman, WAXS, and TGA confirmed the successful reduction of GO to rGO.

## Abstract

A new method of in situ hydrothermal reduction of graphene oxide (GO) to reduced graphene oxide (rGO) in polymer bulk was developed, which involves heating GO/polyacrylonitrile (PAN) composite membranes (0.5; 1.0; 2.0% w/w of GO/PAN) in the presence of water vapor at a temperature of 120 °C and a pressure of 0.2 MPa. As a result of this process, membranes containing rGO were obtained, as confirmed by FTIR, Raman, WAXS and TGA studies. The composite membranes obtained after hydrothermal reduction of GO to rGO (B60, C60, D60) were substantially different from the initial membranes containing unreduced GO (B0, C0, D0). The hydrothermal reduction process clearly influenced the physicochemical properties (reduction of apparent density, water sorption, and increase in the contact angle) and transport properties of the B60, C60, and D60 membranes (decrease in water flux by ~104 [dm3/m2 × h] and even ~348 [dm3/m2 × h] compared to the initial membranes).