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• Monovalent selective AEMs were prepared by electrodeposition of PDA and Fe-PAA. • The electrostatic repulsion between PDA and PAA was reduce byorientation of PDA. • Fe3+ promoted the stability of PDA layer by oxidation and complexation. • The elution of Fe3+ released electronegative groups in PAA. Monovalent selective anion exchange membranes were efficiently prepared by two-steps electrodeposition. Firstly, a polydopamine (PDA) interlayer was formed onto the surface of a commercial anion exchange membrane (AEM), followed by the deposition of a top layer of Fe3+ complexed polyacrylic acid (Fe-PAA). The PDA interlayer formation was investigated by reversing the polarity of the electric field applied. In particular, modified membrane prepared with PDA layer facing the cathode (labeled as FC-PDA-M) exhibited lower negative charge surface density compared to the membrane prepared with DA solution close to the anode (labeled as FA-PDA-M). This effect resulted in an increased deposition of PAA, due to the diminished electrostatic repulsion, when a solution of Fe3+ complexed polyacrylic acid with a Fe/PAA ratio of 1/4 was electrodeposited on the PDA layer. After eluting the Fe3+ with EDTA, the two manufacture membranes, labeled as FC-PDA/(Fe)PAA-M and FA-PDA/(Fe)PAA-M, were characterized. The former exhibited a higher Cl−/SO 4 2− permselectivity than the latter, although the latter demonstrated better performance compared to both the pristine AEM and a PAA-PDA-M obtained without applying any current during the deposition process. The effect the Fe3+ addition and varied the Fe/PAA ratio was also investigated. The membranes obtained using the Fe/PAA ratio of 1/4 exhibited best separation performance. Finally, the stability of this membrane was assessed by conducting ten consecutive electrodialysis (ED) experiments, revealing consistent Cl−/SO 4 2− permselectivity values within the 5–6 range. [ABSTRACT FROM AUTHOR]

This study aims to fabricate monovalent cations selective membranes through Layer-by-Layer (LbL) assembly with ion-imprinting introduced. Nickel ions (Ni2+) were introduced into the polycation of polyethyleneimine (PEI) as template and then modified the ultrafiltration membrane through LbL assembly followed by glutaraldehyde (GA) crosslinking and reduction. After eluting the template, ion-imprinting channels with specific size were formed in the modified layer. These channels enhanced the water flux with the selectivity for Na+/Mg2+ improved 2.25 times simultaneously compared to the non-imprinted membrane. Besides, the membrane preparation conditions were optimized and the optimum selectivity of 4.16 was achieved. We analyzed the mechanism of improving separation performance via ion-imprinting technology and believed that this environmental-friendly method provides a new road to fabricate monovalent selective membrane for seawater softening and lithium extraction from magnesium-rich brine. • Monovalent cations selective membranes were prepared by combining LbL and ion-imprinting. • Ni2+ was coordinated with PEI as template ions and induced to LbL self-assembly. • The ion-imprinting formed channels improved the water flux and monovalent selectivity simultaneously. [ABSTRACT FROM AUTHOR]

Highlights: [•] Amyloidogenic segments have distinct physico-chemical properties. [•] A new biophysical insight amyloidogenic segments have lower average flexibility. [•] Amyloidogenic segments in disorder proteins do not contradict the new insight. [ABSTRACT FROM AUTHOR]

Prion protein, encoded by the prion protein gene ( PRNP ), plays a crucial role in the pathogenesis of transmissible spongiform encephalopathies (TSEs). Several polymorphisms within the PRNP are known to be associated with influencing bovine spongiform encephalopathy (BSE) susceptibility in cattle, namely two insertion/deletion (indel) polymorphisms (a 23-bp indel in the putative promoter and a 12-bp indel in intron 1), the number of octapeptide repeats (octarepeats) present in coding sequence (CDS) and amino acid polymorphisms. The domestic buffaloes, Bubalus bubalis , are a ruminant involved in various aspects of agriculture. It is of interest to ask whether the PRNP polymorphisms differ between cattle and buffalo. In this study, we analyzed the previously reported polymorphisms associated with BSE susceptibility in Chinese buffalo breeds, and compared these polymorphisms in cattle with BSE, healthy cattle and buffalo by pooling data from the literature. Our analysis revealed three significant findings in buffalo: 1) extraordinarily low deletion allele frequencies of the 23- and 12-bp indel polymorphisms; 2) significantly low allelic frequencies of six octarepeats in CDS and 3) the presence of S4R, A16V, P54S, G108S, V123M, S154N and F257L substitutions in buffalo CDSs. Sequence alignments comparing the buffalo coding sequence to other species were analyzed using the McDonald–Kreitman test to reveal five groups ( Bison bonasus , Bos indicus , Bos gaurus , Boselaphus tragocamelus , Syncerus caffer caffer ) with significantly divergent non-synonymous substitutions from buffalo, suggesting potential divergence of buffalo PRNP and others. To the best of our knowledge this is the first study of PRNP polymorphisms associated with BSE susceptibility in Chinese buffalo. Our findings have provided evidence that buffaloes have a unique genetic background in the PRNP gene in comparison with cattle. [ABSTRACT FROM AUTHOR]

• Individual effect of acid blocking AEM and monovalent selective CEM in selective ED was studied. • The recovered acid concentration increased by using acid blocking AEM, but limited by high Cu2+ flux. • Monovalent selective CEM further improved the acid concentration by breaking the H+ transfer balance. • Acid concentration was increased with electric current and dilute volume in SED. • H+ concentration difference plays crucial role in improving the current efficiency of SED. Electrodialysis (ED) could concentrate salt solutions, but the leakage of H+ ions across the anion-exchange membrane (AEM) obstructed their application in waste acid recovery. Selective electrodialysis (SED) with acid blocking AEM and monovalent selective cation-exchange membrane (CEM) has the ability of reclaiming acid with high concentration efficiently. This study investigated the individual effect of the two selective ion-exchange membranes by comparing the acid reclamation performance of configurations with standard AEM and CEM (A-C), acid blocking AEM and standard CEM (SA-C) and acid blocking AEM and monovalent selective CEM (SA-SC) for etching solution treatment after diffusion dialysis. Substituting acid blocking AEMs for the standard ones could significantly increase the recovered acid concentration. An acid concentration plateau was reached quickly, but Cu2+ ions transfer through the CEMs continuously due to the low H+/Cu2+ ratio in the dilute of SA-C configuration. The monovalent selective CEM obstructed the migration of Cu2+ through the CEM and broke the balance of H+ migration into and out of the dilute through CEM and selective AEM individually. The configuration of SA-SC has the highest current efficiency and the configuration of A-C has the lowest. The utilization of selective membranes increased the purity of the recovered acid, and decreased the specific energy consumption simultaneously. The acid concentration could be further improved by higher current or enlarged dilute volume in SA-SC configuration. During the ED process, H+ concentration difference between the concentrate and the dilute plays a crucial role on the current efficiency for acid recovery. [ABSTRACT FROM AUTHOR]

Exploring green, renewable, and low-cost raw materials has great significance on developing high-performance loose nanofiltration (LNF) membranes using a scalable fabrication approach. Lignin is the second most abundant biomacromolecule in the botanic field. In this report, a lignin-based LNF membrane is successfully fabricated using alkaline lignin and sodium ligninsulfonate as raw materials and dopamine (DA) as a surface modifier by a brush assisted layer-by-layer assembly. The driving forces for the assembly are hydrogen bonds between hydrophilic groups and π-π stacking in phenyl groups. The experimental results show that the membrane possesses ultrahigh pure water permeability (65.2 LMH bar−1), and high dye rejections (100% for brilliant blue R (BBR), 96.1% for congo red (CR)) and salt permeations (85.1% for NaCl, 96.7% for MgCl 2), exhibiting satisfactory dye/salt separation performance. The separation process is dominated by the synergistic action of the size exclusion and Donna repulsion between charged dye clusters and the membrane surface. The separation selectivity of the membrane can keep stable accompanied by a small permeate-flux fluctuation during immersed in HCl solution for 7 days. The membrane also shows low flux decline and excellent flux recoverability during a three-cycle CR fouling process. Moreover, the separation capability and permeate flux only show small fluctuations under 5500 ppm·h chlorination strength (pH = 5). The DA surface modification can significantly enhance the membrane permeability, fouling and chlorine resistances. The membrane possesses satisfactory performance stability on a long-term running process for the CR/NaCl separation. [Display omitted] • A loose NF membrane is fabricated using low-cost lignin-based raw materials. • The membrane has high water permeance due to suitable pore size and hydrophilic surface. • The membrane exhibits high dye rejection, salt permeation, and dye/salt selectivity. • The membrane shows good acid, chlorine, and dye fouling resistances, and stability. • Dopamine modification improves the water permeance, chlorine and fouling resistances. [ABSTRACT FROM AUTHOR]