Pressure-assisted assembly of Tris-phenol-intercalated graphene oxide membranes for efficient isopropanol dehydration

Rigid triphenol intercalation regulates GO nanochannels and interlayer interactions. • Pressure-assisted assembly builds compact, ordered lamellar membranes with few defects. • Optimal membrane delivers separation factor ∼ 3568 and flux of 0.67 kg·m −2 ·h −1 . • DFT calculations confirm diffusion selectivity governs separation via lower water barrier. Isopropanol (IPA) dehydration is a critical industrial process, yet it remains challenged by the energy-intensive nature of conventional distillation; however, graphene oxide (GO) membranes often suffer from the trade-off between flux and selectivity, as well as limited structural stability. Herein, a Tris-phenol-intercalated GO (TG) membrane was fabricated via a pressure-assisted filtration strategy. The rigid Tris-phenol molecules served as interlayer spacers to regulate the nanochannel structure, while their abundant hydroxyl groups enhanced water adsorption and hydrogen-bonding interactions. Meanwhile, pressure-assisted assembly promoted the formation of a compact and highly ordered lamellar architecture with well-connected transport pathways. Under the selected fabrication conditions, the TG membrane achieved a separation factor of >3.6 × 10 3 with a water flux of 0.67 kg m −2  h −1 for the dehydration of 90 wt% IPA at 60 °C, significantly outperforming the membrane prepared by conventional vacuum filtration method. First-principles calculations revealed that Tris-phenol intercalation enhanced selective water transport by lowering the diffusion energy barrier for water while maintaining a relatively high barrier for IPA, indicating that diffusion selectivity dominates the separation process. The membrane also maintains a separation factor above 6000 during 40 h of continuous operation. This work demonstrates that coupling molecular intercalation with pressure-assisted assembly is an effective strategy for constructing high-performance two-dimensional GO membranes and provides valuable guidance for the design of energy-efficient membranes for solvent dehydration. Download: Download high-res image (167KB) Download: Download full-size image