Tight Membrane Research Articles

High-flux, antifouling and highly hydrophilic tight ultrafiltration membranes based on crosslinked PEEKWC/PEI containing positively charged water channel for dyes removal

For the removal of textile dyes, an effective alternative to fabricate tight ultrafiltration membrane was adopted. A series of tight ultrafiltration membranes based on PEEKWC/PEI covalent crosslinking structure were prepared by phase inversion method and showed high-flux and good antifouling performance attributed to the enhancement of hydrophilicity by PEI. The top-surface of the UF membranes was with a water contact angle in range of 24.33° and 40.10° indicating the excellent hydrophilicity. These membranes containing PEI-based positively charged water channel showed high permeability for pure water and salt solutions. As the content of PEI in membrane reaching 20 wt%, the pure water permeability and pure water flux at 3 bar could reach 308 L·m−2·h−1·bar−1 and 925 L·m−2·h−1, respectively. The pure water flux could even reach 1526 L·m−2·h−1 at 5 bar. At the operation pressure of 3 bar, all the UF membranes showed good single-component BBR rejection between 94.87 % and 97.73 %. The rejection of membranes for BBR in dye/salt mixtures was substantially higher than 94.0 % even at a high salt concentration of 60 g/L. The UF membranes with high-flux of pure water and dye solution were discussed, which could be a promising alternative for sustainable textile wastewater treatment and natural water recovery.

Membrane-organic solute interactions in asymmetric flow field flow fractionation: Interplay of hydrodynamic and electrostatic forces

The structure and size characterization of organic matter (OM) using flow field-flow fractionation (FFFF) is interesting due to the numerous interactions of OM in aquatic systems and water treatment processes. The estimation of hydrodynamic and electrostatic forces involved in the fractionation of OM over different molecular weight cut-off (MWCO) membranes is vital for a better understanding of the FFFF process. This work aims to understand the membrane-OM interactive forces with respect to membrane MWCO, solute molecular weight, flow rates, solution pH and ionic strength. Polystyrene sulfonate sodium salt (PSS) of molecular weights 10, 30 and 65 kDa were used as model organic solutes for fractionation over ultrafiltration (UF) membranes of MWCO 1–30 kDa. Maximum fractionation of PSS was achieved by using a tight membrane of 1 kDa MWCO at the conditions of high permeate flow rate (1.5–2.0 mL·min−1), low concentrate flow rate (0.2–0.3 mL·min−1) and low ionic strength (10 mM). The better fractionation corresponds to high permeate drag force and low concentrate drag force. A low membrane-solute DLVO interaction is favourable for the retention of a small solute. This study illustrated that FFFF characteristics can be analyzed based on membrane-solute interactive forces controlled by selected flow, size and charge parameters.

Integrated electrocoagulation-tight ultrafiltration for river water decontamination: The influence of electrode configuration and operating pressure

Most rivers have been contaminated by household and industrial wastes that are harmful to human health. In this research, electrocoagulation (EC) and tight ultrafiltration (tight UF) processes were integrated and used to treat the contaminated river water. The EC reactor was designed and equipped with an agitator system. The EC system was operated in continuous mode at a constant flow rate of 500 mL.min −1 . Meanwhile, the tight UF membrane was polysulfone-based, which had a tight structure in the surface layer. The influence of applied current in two configurations of electrodes and the operating pressure of the membrane system was investigated. It was found that a high effluent quality was achieved when 4 anodes and 2 cathodes were used in the EC reactor at a current density of 7.4 mA.cm −2 and operating pressure of 15 psig in the tight UF membrane. The removal efficiency of the integrated EC-tight UF in reducing TDS, turbidity, BOD, and COD was 72.20%, 99.11%, 94.35%, and 81.55%, respectively. Operating cost of 0.83 US$.m −3 was achieved when the water production capacity of the EC-UF plant was designed for 150 m 3 .d −1 , a current density in EC system of 7.4 mA.cm −2 , and permeate flux in the tight UF membrane system was 50 L.m −2 .h −1 . The operating cost was decreased to 0.49 US$.m −3 when the production capacity was increased to 600 m 3 .d −1 .

A hybrid nanofiltration and reverse osmosis process for urine treatment: Effect on urea recovery and purity

Human urine can be treated and concentrated using reverse osmosis (RO), but this process also concentrates pharmaceuticals and undesirable salts along with valuable nutrients such as urea. The final fertilizer product, therefore, has limited use on salt-sensitive crops or edible crops as the effects of pharmaceuticals remain a concern.Tight and loose nanofiltration (NF) pre-treatment was investigated as a method to recover urea in the permeate (which could then be further concentrated using RO), whilst pharmaceuticals and undesirable salts would be removed in the brine. Both NF options removed pharmaceuticals (NF90 – 99%, NF270 – 70%). Using a loose NF membrane, 78% of the urea was recovered in the permeate (80% water removal), however, the salt removal was poor (44%), and the urea purity only increased from 37 to 56%. Tight NF membranes provided better rejection of salts and organics (96% and 90% removed respectively). The urea purity in the permeate (75% water removal) from the tight NF process was 89%, however, the urea recovered was lower (48%). The tight NF permeate was then further concentrated with RO. At an overall water removal of 80%, 32.7% of the urea could be recovered with a purity of 85%. A decision tree was also developed to determine the optimum treatment process based on the desired final product. This decision tree could be used to determine the economic feasibility of each treatment process based on the final product choice and product value.

Preparation of highly selective PSf/ZnO/PEG400 tight ultrafiltration membrane for dyes removal

AbstractTight ultrafiltration (UF) has increasingly been developed to overcome the low selectivity of conventional UF membranes towards soluble contaminants. In this work, a tight structure of polysulfone‐based (PSf) UF membrane was prepared by blending PSf with polyethylene glycol (PEG400), ZnO nanoparticle (ZnO‐Np), and acetone (Ac) in dimethylacetamide (DMAc). The influences of Ac/DMAc ratio (1: 15 to 1:25) and PEG400 concentration (0–25 wt%) on the binodal curve of the polymer solution, characteristics, and performances of the UF membrane were studied. The membrane performances were investigated by observing the permeate flux and dye rejection during real textile wastewater treatment. The binodal curves are close to the polymer line, which means that rapid demixing occurred after the casted solution was immersed in the coagulation bath. Based on FTIR analysis, PEG400 and ZnO‐Np were partially entrapped in the UF membrane structure. Over 90% of color removal at a permeate flux of 72 L.m−2.h−1 could be achieved when the Ac/DMAC ratio was 1:12. The tight‐UF membrane removed TDS and Naphthol AS by 74.5% and 92.8%, respectively. Since the experimental result showed a high contaminants removal, the tight‐UF could be used as clean technology to produce clean water for water reuse purposes at low energy requirements.

Fabrication of high performance carboxylated poly (aryl ether nitrile) membrane for dye/salt selective separation

Membrane with high performance for dye/salt mixed solutions effective separation is desired for textile wastewater treatment. In this paper, a carboxylated poly(aryl ether nitrile) (PEN-COOH) tight ultrafiltration membrane was prepared to fractionate dye/salt by non-solvent induced phase separation with PEG6000 as additive. Due to the synergistic effect of the strong electricity absorption of inherent -CN on poly(aryl ether nitrile) and the ionization of -COOH, PEN-COOH membrane surface showed a strong electronegativity, which was beneficial to the efficient dyes removal by electrostatic repulsion effect. Meanwhile, it was conducive to moderately reducing the membrane denseness to improve permeability. Dextran solute retention experiment showed that PEN-COOH membrane had a molecular weight cut-off of 31,000 Da, corresponding to an effective surface average pore of 7.7 nm. It had a hydraulic permeability of 2.9 L m−2 h−1 bar−1. Compared with those membranes prepared by commercially available materials, PEN-COOH membrane showed unparalleled separation performance advantages. Its pure water flux reached 401.2 L m−2 h−1, while maintaining high retention efficiency of electronegative dyes (> 99%) and low rejection rate of salts (< 10%) under 0.1 MPa driving pressure. PEN-COOH membrane also showed good anti-dye-fouling durability and excellent dye separation performance under varied pH, temperature and pressure, making it a promising membrane for textile wastewater treatment.

ZO‐2 Protein But Not ZO‐1 Protein Limits Occludin Lateral Mobility in MDCK Type II Renal Epithelial Cells

The tight junction‐associated Zonula Occludens proteins, ZO‐1 and ZO‐2, possess binding sites for multiple tight junction membrane proteins, including occludin, multiple tight junction‐associated proteins, and F‐actin filaments. It is believed that these ZO proteins function as scaffolding proteins that crosslink tight junction membrane and associated proteins to the actin cytoskeleton to form a supramolecular complex. Fluorescence Recovery After Photobleaching (FRAP) studies reveal the existence of subpopulations of tight junction membrane proteins with limited lateral mobility (immobile fractions). It is hypothesized that the immobile proteins represent those tight junction membrane proteins tethered to the actin cytoskeleton via scaffolding proteins, including ZO‐1 and ZO‐2. To examine the roles of ZO‐1 and ZO‐2 in limiting the lateral mobility of the tight junction membrane protein occludin, we compared the FRAP behavior of GFP‐occludin constructs with and without the Ca‐terminal cytoplasmic domain or the ZO binding region contained in the C‐terminal cytoplasmic region. Wild type MDCK Type II renal epithelial cells were transduced with a viral vector containing full‐length GFP‐occludin, C terminal‐deletion GFP‐occludin, or ZO binding region‐deletion GFP‐occludin. In cells expressing the full‐length GFP‐occludin construct, approximately half (44.5 + 18.8%, n=31) of the GFP‐occludin was not mobile in the plane of the plasma membrane (immobile fraction). Deletion of virtually the entire C‐terminal region of GFP‐occludin decreased the immobile fraction (30.3 + 11.8%, n=23; p=0.0024 versus full‐length GFP‐occludin). Deletion of the ZO binding region produced a more dramatic decrease in the occludin immobile fraction (immobile fraction = 21.0 + 9.4%, n=26; p=3.4085 X 10‐7 versus full‐length GFP‐occludin). These results support the hypothesis that binding of occludin to ZO proteins limits occludin lateral mobility. To investigate whether this reflects binding to ZO‐1, ZO‐2, or both proteins, we examined the effect of knockdown of either ZO‐1 protein content or ZO‐2 protein content in MDCK II cells on the FRAP behavior of full‐length GFP‐occludin. Full‐length GFP‐occludin expressed in ZO‐1 knockdown MDCK Type II cells exhibited an immobile fraction similar to the value obtained in wild type MDCK Type II cells (immobile fraction = 44.4 + 14.2%, n=28; p=0.9711). In contrast, full‐length GFP‐occludin expressed in ZO‐2 knockdown MDCK Type II cells exhibited a decreased immobile fraction (25.9 + 11.2%, n=27; p=3.4713 X 10‐5 versus wild type MDCK II cells) similar to the immobile fraction observed in wild type MDCK Type II cells expressing ZO binding region‐deletion GFP‐occludin. These results indicate that about half of the immobile occludin protein is tethered to ZO‐2 protein in MDCK Type II renal epithelial cells. The other half of the immobile occludin fraction is tethered via a non‐ZO protein mechanism. ZO‐1 protein does not appear to tether any of the immobile occludin fraction in these cells. These results point to an unexpected complexity to the organization of the tight junction supramolecular complex.

Claudin‐23 Strengthens the Colonic Epithelial Barrier by Regulating Claudin‐3 and ‐4 proteins in the Tight Junction Plasma Membrane

Colonic epithelial barrier function is controlled by differential expression of Claudin (CLDN) proteins in the crypt‐luminal axis. We recently identified the expression of a CLDN family member, CLDN‐23, in intestinal epithelial cells (IECs). However, the role of CLDN‐23 in regulating epithelial barrier function has not been identified. Analysis of the human and murine intestinal crypt‐luminal axis revealed increased CLDN‐23 expression in differentiated IECs facing the lumen compared to the proliferative crypt‐base IECs. Similarly, CLDN‐23 expression was higher in differentiated human and murine IECs cultured as a monolayer on permeable supports compared to proliferative IECs cultured in a 3D matrigel matrix. To investigate the contribution of CLDN‐23 in regulating IEC barrier function in vivo, we generated inducible intestinal‐epithelia specific (Villin‐CreERT2) Cldn23 knockout mice (Cldn23ERΔIEC). Functional analysis displayed increased intestinal mucosal permeability to 4kDa FITC dextran, indicating compromised epithelial barrier function. To confirm this observation, we created human IECs in which CLDN‐23 expression was either silenced or enhanced in vitro. CLDN‐23 loss increased paracellular permeability to 4kDa FITC dextran and reduced transepithelial electrical resistance (TEER) consistent with a leaky barrier. Conversely, CLDN‐23 overexpression resulted in improved barrier function. Altogether, these data suggest that CLDN‐23 controls the IEC barrier function.Evaluation of CLDN protein interactions employing co‐culture of HeLa cells expressing CLDN‐23 with those expressing either CLDN‐2, CLDN‐3, or CLDN‐4 showed that CLDN‐23 interacts in trans with barrier‐forming CLDN‐3 and CLDN‐4, but not with pore‐forming CLDN‐2. Using in situ proximity ligation assay, we observed close association in cis between CLDN‐23 and barrier‐forming CLDN‐3 and CLDN‐4 in the TJ plasma membrane, but not with CLDN‐2. These findings suggest that CLDN‐23 interacts in both cis and trans with barrier‐forming CLDN‐3 and CLDN‐4 in differentiated IECs. Interestingly, the overexpression of CLDN‐23 in human IECs revealed up‐regulation of barrier‐forming CLDN‐3 protein expression in the TJ while decreasing the pore‐forming CLDN‐2 protein at this site. In conclusion, we identified that CLDN‐23 strengthens the colonic barrier properties by orchestrating the composition of CLDN protein interactions in epithelial TJs.

Tight junction membrane protein's role in neural tube defects

More than 300,000 infants worldwide are born with neural tube defects (NTD), making it the second most common birth defect in the world. Many genetic and environmental factors have been identified as drivers of NTDs, some of which have been tied to damage of tight junctions (TJ), which are critical for the success of neural tube folding. Claudins (CLDN), occludin (OCLN) and junctional adhesion molecules (JAMs) are essential components of the TJ and are key players in its function. In the chicken embryo, clostridium perfringens enterotoxin (CPE) induces NTDs, by interacting broadly with CLDN3, ‐4, and ‐8. These interactions increase TJ permeability to an influx of calcium ions, causing cell death. There is no information for the role of OCLN or JAMs in NTDs. Our laboratory has created Synthetic Biology approaches to produce soluble CLDNs, OCLN and JAMs. These are detergent independent proteins that result in molecules that retain structure and adhesive properties of the native membrane protein. We present evidence that specific interactions, rather than the broad specificity of CPE, can be used to identify specific mechanisms leading to NTD formation. Our approach expands to the role of OCLN and JAMs in the formation of NTDs. These new tools may be used in developmental research as an alternative for genetic manipulation with equal value.

Improved permeability of tight acid resistant nanofiltration membrane via citric acid post-treatment

Development of acid resistant nanofiltration membranes (ARNFMs) with high metal rejection, high flux and low molecule weight cut-off (MWCO) remains a big challenge. The separation performance of polyamine ARNFM is partially limited by the dense structure caused by the high concentration of organic phase solution. Herein, in this work, a novel effective post-treatment of citric acid (CA) was utilized to further improve the separation property of dually charged polyamine ARNFMs with low MWCO. An appropriate CA post-treatment (1.5 mol/L, 30 min, 65 °C) could gently remove off the oligomers and CA molecules would react with the redundant protonated/non-protonated amino, imine and hydroxyl groups of the polyamine NFM. Therefore，after the post-treatment, the membrane flux was enhanced 7.1 times with a high MgCl 2 rejection (97.6%) and a low MWCO around 220 Da. Furthermore, CA post-treatment not only had no significant influence on the acid stability of this membrane, but would also protect the membrane from the drastic effect of HCl (hydrolyze -Cl into –OH) in turn. All the results indicated that CA post-treatment has positive effects on polyamine ARNFMs, and the resulted dually charged polyamine ARNFMs have a good application potential for acidic wastewater treatment. • A novel post-treatment was applied in polyamine nanofiltration membrane (NFM). • Citric acid (CA) post-treatment vastly enhanced flux with high MgCl 2 rejection (98%). • CA would remove off oligomers and react with active groups of the polyamine NFM. • The Janus polyamine NFM exhibited good acid resistant stability in 3 wt% HCl.

Loss of CLDN5 in podocytes deregulates WIF1 to activate WNT signaling and contributes to kidney disease

Although mature podocytes lack tight junctions, tight junction integral membrane protein claudin-5 (CLDN5) is predominantly expressed on plasma membranes of podocytes under normal conditions. Using podocyte-specific Cldn5 knockout mice, we identify CLDN5 as a crucial regulator of podocyte function and reveal that Cldn5 deletion exacerbates podocyte injury and proteinuria in a diabetic nephropathy mouse model. Mechanistically, CLDN5 deletion reduces ZO1 expression and induces nuclear translocation of ZONAB, followed by transcriptional downregulation of WNT inhibitory factor-1 (WIF1) expression, which leads to activation of WNT signaling pathway. Podocyte-derived WIF1 also plays paracrine roles in tubular epithelial cells, as evidenced by the finding that animals with podocyte-specific deletion of Cldn5 or Wif1 have worse kidney fibrosis after unilateral ureteral obstruction than littermate controls. Systemic delivery of WIF1 suppresses the progression of diabetic nephropathy and ureteral obstruction-induced renal fibrosis. These findings establish a function for podocyte CLDN5 in restricting WNT signaling in kidney.

Formulation of Chitosan-Coated Apigenin Bilosomes: In Vitro Characterization, Antimicrobial and Cytotoxicity Assessment.

We prepared apigenin (APG)-loaded bilosomes (BLs) and evaluated them for vesicle size, zeta-potential and encapsulation efficiency. The formulations were prepared with cholesterol (CHL), sodium deoxy cholate (SDC), Tween 80 (T80) and phosphatidylcholine (PC) using solvent evaporation method. The prepared formulations showed the optimum result was coated with much mucoadhesive polymer chitosan (CH, 0.25 and 0.5% w/v). The chitosan-coated bilosomes (CH-BLs) were further evaluated for surface morphology, drug–polymer interaction, mucoadhesion, permeation, antimicrobial activity and cell viability. The prepared APG-BLs showed nano-metric size (211 ± 2.87 nm to 433 ± 1.98 nm), polydispersibility index <0.5, negative zeta potential (−15 to −29 mV) and enhanced encapsulation efficiency (69.5 ± 0.93 to 81.9 ± 1.3%). Based on these findings, selected formulation (F2) was further coated with chitosan and showed a marked increase in vesicle size (298 ± 3.56 nm), a positive zeta potential (+17 mV), superior encapsulation efficiency (88.1 ± 1.48%) and improved drug release (69.37 ± 1.34%). Formulation F2C1 showed significantly enhanced permeation and mucoadhesion (p < 0.05) compared to formulation F2 due to the presence of CH as a mucoadhesive polymer. The presence of CH on the surfaces of BLs helps to open the tight membrane junctions and leads to enhanced permeation. A TEM study revealed non-aggregated smooth surface vesicles. The antimicrobial and cell viability assessment revealed better effects in terms of zone of inhibition and cell line assessment against two different cancer cell line. From the study, it can be concluded that APG-CHBLs could be a superior alternative to conventional delivery systems.

The Daily Expression of ABCC4 at the BCSFB Affects the Transport of Its Substrate Methotrexate.

The choroid plexuses (CPs), located in the brain ventricles, form an interface between the blood and the cerebrospinal fluid named the blood-cerebrospinal barrier, which, by the presence of tight junctions, detoxification enzymes, and membrane transporters, limits the traffic of molecules into the central nervous system. It has already been shown that sex hormones regulate several CP functions, including the oscillations of its clock genes. However, it is less explored how the circadian rhythm regulates CP functions. This study aimed to evaluate the impact of sex hormones and circadian rhythms on the function of CP membrane transporters. The 24 h transcription profiles of the membrane transporters rAbca1, rAbcb1, rAbcc1, rAbcc4, rAbcg2, rAbcg4, and rOat3 were characterized in the CPs of intact male, intact female, sham-operated female, and gonadectomized rats. We found that rAbcc1 is expressed in a circadian way in the CPs of intact male rats, rAbcg2 in the CPs of intact female rats, and both rAbcc4 and rOat3 mRNA levels were expressed in a circadian way in the CPs of intact male and female rats. Next, using an in vitro model of the human blood–cerebrospinal fluid barrier, we also found that methotrexate (MTX) is transported in a circadian way across this barrier. The circadian pattern of Abcc4 found in the human CP epithelial papilloma cells might be partially responsible for MTX circadian transport across the basal membrane of CP epithelial cells.

Contributions of the microbiome to intestinal inflammation in a gut-on-a-chip

The intestinal microbiome affects a number of biological functions of the organism. Although the animal model is a powerful tool to study the relationship between the host and microbe, a physiologically relevant in vitro human intestinal system has still unmet needs. Thus, the establishment of an in vitro living cell-based system of the intestine that can mimic the mechanical, structural, absorptive, transport and pathophysiological properties of the human intestinal environment along with its commensal bacterial strains can promote pharmaceutical development and potentially replace animal testing. In this paper, we present a microfluidic-based gut model which allows co-culture of human and microbial cells to mimic the gastrointestinal structure. The gut microenvironment is recreated by flowing fluid at a low rate (21 μL/h) over the microchannels. Under these conditions, we demonstrated the capability of gut-on-a-chip to recapitulate in vivo relevance epithelial cell differentiation including highly polarized epithelium, mucus secretion, and tight membrane integrity. Additionally, we observed that the co-culture of damaged epithelial layer with the probiotics resulted in a substantial responded recovery of barrier function without bacterial overgrowth in a gut-on-a-chip. Therefore, this gut-on-a-chip could promote explorations interaction with host between microbe and provide the insights into questions of fundamental research linking the intestinal microbiome to human health and disease.

Membrane diafiltration for enhanced purification of biologically active compounds from goji berries extracts

• The recovery of phenolic compounds from aqueous goji berries extract was investigated. • Three tight ultrafiltration membranes with different cut-off (1, 2.5 and 3.5 kDa) were studied. • Diafiltration was implemented to improve the separation of phenolic compounds from sugars. • Membrane performance was evaluated in terms of productivity and selectivity towards target compounds. • All selected membranes allowed high recovery of phenolic compounds into the retentate. Goji berries represent a valuable source of phenolic compounds with a strong antioxidant and free radical scavenging activity combined to huge quantities of small sugars. This study was aimed at evaluating the potential of three tight ultrafiltration (UF) membranes with molecular weight cut-off (MWCO) from 1.0 to 3.5 kDa in the fractionation of phenolic compounds from sugars in the aqueous extract of dried goji berries. The aqueous extract produced in optimized conditions of water-to-solid ratio and temperature (6.66 mL/g and 65 °C, respectively) was preliminarily clarified by UF in order to remove suspended solids and colloidal particles. A membrane diafiltration (DF) process was developed in order to fractionate phenolic compounds from sugars with selected UF membranes from the clarified extract. The membrane performance was evaluated in terms of productivity and selectivity towards target compounds. All selected membranes allowed high recovery (more than 80%) of phenolic compounds into the retentate. On the other hand, the yield of carbohydrates increased in the permeate by increasing the diafiltration volume. Among the selected membranes, the 2.5 kDa membrane allowed to reduce the concentration of total carbohydrates from 26.5 up to 2.2 g glucose/L (a reduction of 91.7%) in a diafiltration/batch concentration process producing a concentrated extract enriched in phenolic compounds of interest for pharmaceutical or nutraceutical applications.

Charged modified tight ceramic ultrafiltration membranes for treatment of cationic dye wastewater

Tight ceramic ultrafiltration membranes have been proven to exhibit good rejection performance for reactive dye wastewater at high temperatures because of their high thermal and chemical resistance. However, the application of ceramic membranes for the treatment of cationic dye wastewater is challenging because of their surface charge. In this study, a ceramic membrane is modified by grafting aminosilane (KH-551) to enhance the positive charge of the membrane surface. The rejection performance of the charged modified ceramic membrane toward the methylene blue solution is significantly improved. The modification substance is bonded to the ceramic membrane surface via covalent bonding, which imparts good thermal stability. The modified ceramic membrane exhibits stable separation performance toward the methylene blue solution. Overall, this study provides valuable guidance for the adjustment of the ceramic membrane surface charge for treating industrial cationic dye wastewater.

Low Temperature Preparation of High-Flux Α-Alumina Tight Ultrafiltration Membrane by Modified Co-Sintering Process

Low Temperature Preparation of High-Flux Α-Alumina Tight Ultrafiltration Membrane by Modified Co-Sintering Process

Purification of Gastrodin from Microbial Fermentation Broth by High Anti-Fouling Tight Ultrafiltration Membrane

Purification of Gastrodin from Microbial Fermentation Broth by High Anti-Fouling Tight Ultrafiltration Membrane

Improved Permeability of Tight Acid Resistant Nanofiltration Membrane Via Citric Acid Post-Treatment

Improved Permeability of Tight Acid Resistant Nanofiltration Membrane Via Citric Acid Post-Treatment

Facile Negative Modification of Tight Ceramic Ultrafiltration Membranes for Protein-Resistant and Easy-Cleaning Performance

Facile Negative Modification of Tight Ceramic Ultrafiltration Membranes for Protein-Resistant and Easy-Cleaning Performance