Realizing small-flake graphene oxide membranes for ultrafast size-dependent organic solvent nanofiltration
Authors: Jaewoo Lee
Michael D Guiver
Yu Wang
Kunli Goh
H Enis Karahan
Kun Zhou
Tae-Hyun Bae
Lina Nie
Yinjuan Huang
Journal: Science advances (2020)
Discipline: Multidisciplinary
Keywords: Membranes; Organic solvent nanofiltration; Solvent-resistant nanofiltration; Graphene oxide; La3+ cross-linker
Affiliations: School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore., Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore., Environmental Process Modelling Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore., School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore., State Key Laboratory of Engines, School of Mechanical Engineering, Tianjin University, Tianjin 300072, China., Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China., Department of Chemical and Biomedical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-338, Republic of Korea.

Abstract:  Membranes for organic solvent nanofiltration (OSN) or solvent-resistant nanofiltration (SRNF) offer unprecedented opportunities for highly efficient and cost-competitive solvent recovery in the pharmaceutical industry. Here, we describe small-flake graphene oxide (SFGO) membranes for high-performance OSN applications. Our strategy exploits lateral dimension control to engineer shorter and less tortuous transport pathways for solvent molecules. By using La3+ as a cross-linker and spacer for intercalation, the SFGO membrane selective layer was stabilized, and size-dependent ultrafast selective molecular transport was achieved. The methanol permeance was up to 2.9-fold higher than its large-flake GO (LFGO) counterpart, with high selectivity toward three organic dyes. More importantly, the SFGO-La3+ membrane demonstrated robust stability for at least 24 hours under hydrodynamic stresses that are representative of realistic OSN operating conditions. These desirable attributes stem from the La3+ cross-linking, which forms uniquely strong coordination bonds with oxygen-containing functional groups of SFGO. Other cations were found to be ineffective. 

Retracted: No

PubPeer comments:
 This paper has features suggestive of [what has elsewhere been labeled as  Papermill #2 ] , characterised by stylised geometrical WBs that are reduced to black blobs on a featureless grey background, reminiscent of a Miro painting:  ...and by a small repertoire of recurring flow cytometry plots,  slightly modified by artisanal stippling on each of their occurrences.  Other examples are listed in a Google document. https: docs.google.com spreadsheets d 1qBqQMXgzxoBd5bTbqdMuapGheupE5bdIopypju417NM edit?usp=sharing , 
 Retracted [6 August 2021] . ---------------------------- Cancer Biotherapy and Radiopharmaceuticals officially retracts the paper entitled, u201cThe Effect of PTCH1 on Ovarian Cancer Cell Proliferation and Apoptosis,u201d by Fang Zheng, Xinyi Xiao, and Chunmei Wang (Cancer Biother Radiopharm 2019;34:2;103u2013109; doi: 10.1089 cbr.2018.2626) due to the discovery that the paper was submitted from a paper mill which is a violation of the journal s proper protocols, and is considered an infraction against the rigorous standards of scientific publishing. The Editor and Publisher of *Cancer Biotherapy and Radiopharmaceuticals* are committed to preserving the scientific literature and the community it serves and does not tolerate any violations of scientific misconduct. ,