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Owing to intrinsic perm-selectivity, cell membranes have attracted considerable attention in the field of biomimetic membranes. Herein, largest possible cell membranes of E.coli were prepared and then used as two-dimensional (2D) materials to fabricate high-performance nanofiltration (NF) membranes. The structure parameters of the selective layer of the E.coli -NF membrane could be finely tailored through the loading mass of cell membranes and the applied pressure during vacuum filtration. The E.coli- NF membrane exhibited a high rejection towards dyes (98.5%, brilliant blue R), antibiotics (91.1%, erythromycin), and divalent ions (64.8%, sodium sulfate). The membrane effective pore size was found to be significantly smaller than the interlayer spacing because of the small intrinsic nanochannels inside the E.coli cell membranes, which is distinct from GO and MXene-based 2D membranes. Moreover, the membrane water permeance was 52.6 L m−2 h−1 bar−1, higher than that of most of the reported 2D materials-based NF membranes. The E.coli -NF membrane exhibited the typical separation behavior of the negatively charged NF membranes governed by Donnan effect and size exclusion. This work gives some insights into the fabrication of the selective membranes using cell membranes as 2D materials with intrinsic nanochannels and fruitful choices in nature. [Display omitted] • Cell membranes from E.coli were used to fabricate selective membranes. • The membrane effective pore size was smaller than the interlayer spacing. • Nanofiltration membranes were fabricated for fast molecular separation. • The water permeance of the membrane was 52.6 L m−2 h−1 bar−1. [ABSTRACT FROM AUTHOR]

In order to solve the problems of poor mechanical property, non-antibacterial and low flux of calcium alginate (CaAlg) membrane, silver nanoparticles (AgNPs) were synthesized with bovine serum albumin (BSA) and carboxymethyl chitosan (CMCS) for improving CaAlg membrane in this paper. Meanwhile, the dispersion property of silver nanoparticles and the mechanical property, thermal stability, antibacterial property and filtration efficiency of the composite membrane were explored. The results illustrated CMCS observably strengthened the mechanical property and thermal stability of the composite membrane, and AgNPs endowed the composite membrane with excellent antibacterial property. The flux of the BSA/CMCS/AgNPs/CaAlg composite membrane was raised compared to CaAlg membrane. Finally, the viscose fiber/polyethylene terephthalate fiber (VF-PET) nonwoven fabric was introduced as the support layer to further improve the filtration flux and mechanical property of the composite membrane. VF-PET/BSA/CMCS/AgNPs/CaAlg membrane had a rejection rate of over 99.0 % for dye molecules and <9.0 % for salt ions, while the flux maintained 38.5 L·m−2·h−1. Furthermore, VF-PET/BSA/CMCS/AgNPs/CaAlg membrane also had excellent separation effect on actual dye wastewater. The separation of dye and salt by the membrane mainly depended on the screening mechanism of membrane pore size, rather than adsorption. The composite membrane had an outstanding performance on the separation of dye molecules and inorganic salt ions. [Display omitted] • Stable and uniformly dispersed BSA/CMCS/AgNPs was prepared. • BSA/CMCS/AgNPs/CaAlg membrane showed high mechanical property and excellent antibacterial property. • BSA/CMCS/AgNPs/CaAlg membrane had excellent separation efficiency of dye/salt. • Nonwovens with hydrophilic and hydrophobic sides improved the membrane flux and was expected to industrialize the membrane. [ABSTRACT FROM AUTHOR]

This work reports a composite film using (3-Aminopropyl)triethoxysilane-modified boron nitride nanosheets (BNNS) incorporated in the aramid nanofibers (ANF) network via sol–gel method. High-resolution TEM, SEM, XPS, and XRD outcomes confirmed the imitation pearl layered structure—BNNSs as thermal conductive fillers were layer-by-layer overlapped on ANF. The reasonable coordination between interfaces and fillers stimulated the thermal conductivity (35.4 W/(m·k)) of composite film i.e., 338.43% higher than that of ANF. The composite film exhibited good cyclic thermal stability, high tensile strength (65.9 MPa), and high volume resistivity (2.424×1015 Ω∙cm). [Display omitted] • BNNS@APTES/ANF with imitation pearl layered structure was prepared via sol–gel method. • BNNS as thermal conductive fillers were layer-by-layer overlapped on the ANF. • High thermal conductivity of BNNS@APTES/ANF was 35.4 W/(m·k) higher than pure ANF. • BNNS@APTES/ANF exhibited excellent tensile property and high volume resistivity. • The thermal conductivity of BNNS@APTES/ANF did not decay during 8 cooling/heating cycles. This work reports a composite film using (3-Aminopropyl)triethoxysilane-modified boron nitride nanosheets (BNNS) incorporated in the aramid nanofibers (ANF) network via sol–gel method. High-resolution TEM, SEM, XPS, and XRD outcomes confirmed the imitation pearl layered structure—BNNSs as thermal conductive fillers were layer-by-layer overlapped on ANF. The reasonable coordination between interfaces and fillers stimulated the thermal conductivity (35.4 W (m·k)-1) of composite film i.e., 338.43 % higher than that of ANF. The composite film exhibited good cyclic thermal stability, high tensile strength (65.9 MPa), and high volume resistivity (2.424 × 1015 Ω∙cm). [ABSTRACT FROM AUTHOR]

To improve the mechanical strength, antimicrobial and anti-swelling ability of calcium alginate hydrogel membrane, the graphene oxide/calcium alginate hybrid (GCA-H) hydrogel filtration membrane was prepared by ion cross-linking without organic solvent in this study. Meanwhile, the morphology, structure, and chemical bonding mechanism of membranes were characterized. Furthermore, we also investigated the mechanical strength, swelling behaviors, anti-bacterial, and anti-fouling properties of the GCA-H membrane. Since the excellent hydrophilicity, the GCA-H membrane showed high flux recovery rate (>97 %) based on the alternating filtration tests without cleaning the membrane. It was mentioned that the maximum stress-strain of the GCA-H membrane could reach 1.53 MPa, which was 2.34-fold more than that of the unmodified membrane. Due to the enhanced structure, it was beneficial to design the thinner membrane for further application. Moreover, we evaluated the impact of the operating parameters on dye/salt separation performance in this work. Generally, the rejections of Coomassie brilliant blue (CBB) and NaCl of GCA-H membrane were approximately 99 % and 8 %, respectively. Finally, we summarized the separation factor and nominalized flux for the dye/salt separation. The GCA-H membrane still maintained a good separation efficiency after being placed for 45 days. So the GCA-H membrane has a great potential in the selectivity separation process, which may provide a sustainable strategy for dye recycle. Graphene oxide/calcium alginate hybrid hydrogel (GCA-H) membrane was prepared by ion-crosslinking and applied for the separation of dye/salt. The GCA-H membrane exhibited high selectivity for salt and dye and the selectivity coefficient was 230.5. The GCA-H membrane showed high antimicrobial property. [Display omitted] • A graphene oxide/calcium alginate hybrid (GCA-H) hydrogel filtration membrane was fabricated in water. • The chemical bonding mechanism of GO and NaAlg was investigated. • The GCA-H membrane has excellent antimicrobial and anti-fouling properties. • The selectivity coefficient of GCA-H membrane for dye/salt was 230.5. [ABSTRACT FROM AUTHOR]

Membrane fouling is the major obstacle to hinder the extensive application of polyamide thin-film composite reverse osmosis (PA TFC RO) membranes in the water purification and reclamation fields. In this study, a series of hydrophilic and charge-tuned antifouling RO membranes were fabricated by grafting three kinds of small molecules of multi-grade amines N , N -dimethylethylenediamine (DMEDA), (2-aminoethyl) guanidine (AEGu) and (2-aminoethyl)triethylenediamine (AEDABCO) via layer-by-layer interfacial polymerization (LbL-IP). Detailed characterizations revealed that the three tailored membranes presented obviously diminished surface negative charge and reduced PA layer thickness, the water permeability increased by 67.4 %, 34.7 % and 75.6 % compared to the pristine membrane, reached 4.05 L m−2 h−1 bar−1, 3.26 L m−2 h−1 bar−1, and 4.28 L m−2 h−1 bar−1, respectively, meanwhile kept high NaCl rejection > 98.5 %. The dynamic fouling tests indicated that the tailored membranes exhibited much improved antifouling performance towards most of the model organic foulants. Meanwhile the membranes assembled with cationic groups exhibited an enhanced antibacterial property against E. coli. These functional small charged molecules and the convenient modification method provide a valuable pattern for designing antifouling PA TFC RO membranes, which is important for sustainable water purification. [Display omitted] • Small molecular muti-grade amines were tailored onto the TFC RO membrane surface by facile LbL-IP method. • The three modified membranes exhibited much enhanced hydrophilicity and charge-tuned pseudo-zwitterionic surface. • Their water fluxes were significantly elevated meanwhile kept admirable NaCl rejection. • The modified membranes showed much improved antifouling properties and also antibacterial attachment. [ABSTRACT FROM AUTHOR]