Hot-pressed polymer nanofiber supported graphene membrane for high-performance nanofiltration

Abstract

Graphene oxide (GO) sheets can be readily surface-overlaid on hot-pressed electrospun polyacrylonitrile (PAN) nanofiber membrane to form a continuous and crack-free layer; upon thermal reduction at 150 °C for 12 h, the resulting reduced GO (rGO) layer can reject ∼90% MgSO with high water flux (due to the size exclusion mechanism), making the prepared PAN-rGO membranes promising nanofiltration media for water purification. It is important to note that no delamination of GO/rGO sheet layers has been observed throughout this study. We highlight that a simple processing method (i.e., hot pressing) is critical for the successful preparation of 2D materials (e.g., GO/rGO) based membranes/media. It is envisioned that the reported study can benefit many groups working on various membrane applications of 2D materials; in other words, the hot-pressed electrospun nanofiber membranes could be generally utilized as an innovative type of platform to support various 2D sheets for different separation applications such as highly efficient and cost-effective removal of dissolved components (e.g., organic molecules) and even (hydrated) ions from water.

The relative insignificance of advanced materials in enhancing the energy efficiency of desalination technologies

“…The blue dashed line is a proxy for complete salt exclusion. Novel materials assessed were nanotubes, 139-142 2-D laminates, 29,[143][144][145][146][147][148] biomimetic channels, [149][150][151][152][153][154] and nanoporous sheets. 155,156 Energy & Environmental Science Perspective Open Access Article.…”

State‐of‐the‐Art and Future Prospects for Atomically Thin Membranes from 2D Materials

“…Electrospun fiber membranes are often employed as supports for thin film composite membranes for RO and NF desalination but the high surface roughness of electrospun membranes can complicate their utilization as supports for NATMs . For example, when Wang et al prepared multilayer GO membranes by vacuum deposition of GO flakes onto electrospun poly‐acrylonitrile membranes, they observed that GO layers developed multiple cracks upon drying. Hot pressing of the electrospun poly‐acrylonitrile membranes prior to GO deposition allowed mitigating the surface roughness and, as a result, uniform GO layers were obtained …”

“…For example, when Wang et al prepared multilayer GO membranes by vacuum deposition of GO flakes onto electrospun poly‐acrylonitrile membranes, they observed that GO layers developed multiple cracks upon drying. Hot pressing of the electrospun poly‐acrylonitrile membranes prior to GO deposition allowed mitigating the surface roughness and, as a result, uniform GO layers were obtained …”

Polyacrylonitrile-based nanocomposite fibers: A review of current developments

“…Specifically, research on PAN nanocomposite fibers in sensors, supercapacitor, batteries, electromagnetic interference (EMI) shielding, metal ion removal, and antimicrobial relevance is reviewed. 8–10 These applications need to optimize the nanofiber chemical composition, surface porosity, hydrophobicity, absorption capacity, and wettability. And future scenarios in the technological development of these nanocomposite fibers are presented.…”