Engineering Multinanochannel Polymer-Intercalated Graphene Oxide Membrane for Strict Volatile Sieving in Membrane Distillation

Abstract

Graphene oxide (GO) membranes enabled by subnanosized diffusion channels are promising to separate small species in membrane distillation (MD). However, the challenge of effectively excluding small volatiles in MD persists due to the severe swelling and subsequent increase in GO interlamination spacing upon direct contact with the hot feed. To address this issue, we implemented a design in which a polymer is confined between the GO interlaminations, creating predominantly 2D nanochannels centered around 0.57 nm with an average membrane pore size of 0.30 nm. Compared to the virginal GO membrane, the polymer-intercalated GO membrane exhibits superior antiswelling performance, particularly at a high feed temperature of 60 °C. Remarkably, the modified membrane exhibited a high flux of approximately 52 L m −2 h −1 and rejection rates of about 100% for small ions and 98% for volatile phenol, with a temperature difference of 40 °C. Molecular dynamics simulations suggest that the sieving mechanisms for ions and volatiles are facilitated by the narrowed nanochannels within the polymer network situated between the 2D nanochannels of GO interlaminations. Concurrently, the unrestricted permeation of water molecules through the multinanochannel GO membrane encourages high-flux desalination of complex hypersaline wastewater.

Bubble Turbulent Gas-Permeable Membrane for Ammonia Recovery from Swine Wastewater: Mass Transfer Enhancement and Antifouling Mechanisms

“…As a result, accelerating mass transfer and controlling contamination are crucial to driving the development of gas-permeable membranes. Interface disturbance is a practical approach to attenuate the interaction between pollutants and membrane surfaces, manifested in micropatterned structure, self-vibration, , microbubbles, , ultrasound, and others. , Membrane fouling is alleviated to a certain extent by these means, but their contribution to mass transfer efficiency is insignificant and the structural design is cumbersome. , …”

Surface Microstructure Drives Biofilm Formation and Biofouling of Graphene Oxide Membranes in Practical Water Treatment

“…Water scarcity, particularly the lack of available safe and reliable drinking water has become a fundamental challenge facing humanity in the 21st century in the context of rapid population expansion, industrial production, and environmental pollution. , Membrane-based separation technologies, characterized by a high purification capability, low carbon emission, and chemical free, are considered an attractive technology for producing high-quality water from conventional and unconventional water resources. , Graphene oxide (GO) membrane, as a novel two-dimensional membrane, has been of particular interest owing to its extraordinary chemical stability, ultrahigh permeance, precise sieving performance, and tunable microstructure. − Based on these excellent features, GO membranes have been extensively investigated and successfully used for desalination, removal of heavy metals, micropollutants, and natural organic matter. , …”