Preparation and Characterization of Regenerated Cellulose Membrane Blended with ZrO2 Nanoparticles

It is of great significance to search for efficient, renewable, biodegradable and economical membrane materials. Herein, we developed an organic-inorganic hybrid regenerated cellulose membrane (ZrO2/BCM) with excellent hydrophilic and anti-fouling properties. The membrane was prepared by introducing ZrO2 particles into an N-Methylmorpholine-N-oxide(NMMO)/bamboo cellulose(BC) solution system by the phase inversion method. The physi-chemical structure of the membranes were characterized based on thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (ATR-FTIR), field emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD). The modified regenerated cellulose membrane has the excellent rejection of bovine serum albumin (BSA) and anti-fouling performance. The membrane flux of ZrO2/BCM is 321.49 (L/m2·h), and the rejection rate of BSA is 91.2%. Moreover, the membrane flux recovery rate after cleaning with deionized water was 90.6%. This new type of separation membrane prepared with green materials holds broad application potential in water purification and wastewater treatment.

Improvement of Properties and Performances of Polyethersulfone Ultrafiltration Membrane by Blending with Bio-Based Dragonbloodin Resin

Polyethersulfone (PES) is the most commonly used polymer for membrane ultrafiltration because of its superior properties. However, it is hydrophobic, as such susceptible to fouling and low permeation rate. This study proposes a novel bio-based additive of dragonbloodin resin (DBR) for improving the properties and performance of PES-based membranes. Four flat sheet membranes were prepared by varying the concentration of DBR (0–3%) in the dope solutions using the phase inversion method. After fabrication, the membranes were thoroughly characterized and were tested for filtration of humic acid solution to investigate the effect of DBR loading. Results showed that the hydrophilicity, porosity, and water uptake increased along with the DBR loadings. The presence of DBR in the dope solution fastened the phase inversion, leading to a more porous microstructure, resulted in membranes with higher number and larger pore sizes. Those properties led to more superior hydraulic performances. The PES membranes loaded with DBR reached a clean water flux of 246.79 L/(m2·h), 25-folds higher than the pristine PES membrane at a loading of 3%. The flux of humic acid solution reached 154.5 ± 6.6 L/(m2·h), 30-folds higher than the pristine PES membrane with a slight decrease in rejection (71% vs. 60%). Moreover, DBR loaded membranes (2% and 3%) showed an almost complete flux recovery ratio over five cleaning cycles, demonstrating their excellent antifouling property. The hydraulic performance could possibly be enhanced by leaching the entrapped DBR to create more voids and pores for water permeation.

Study of the stability of lipid nanoemulsions with oleic acid

This work presents the results of a study on the effect of ionic surfactant cetriltrimethylammonium chloride (CTAB) on the size and ζ-potential of lipid nanoemulsions composed of oleic acid, prepared by temperature phase inversion method and stabilized by nonionic surfactants — Tween 60, Span 60

Vascular Polyurethane Prostheses Modified with a Bioactive Coating—Physicochemical, Mechanical and Biological Properties

This study describes a method for the modification of polyurethane small-diameter (5 mm) vascular prostheses obtained with the phase inversion method. The modification process involves two steps: the introduction of a linker (acrylic acid) and a peptide (REDV and YIGSR). FTIR and XPS analysis confirmed the process of chemical modification. The obtained prostheses had a porosity of approx. 60%, Young’s Modulus in the range of 9–11 MPa, and a water contact angle around 40°. Endothelial (EC) and smooth muscle (SMC) cell co-culture showed that the surfaces modified with peptides increase the adhesion of ECs. At the same time, SMCs adhesion was low both on unmodified and peptide-modified surfaces. Analysis of blood-materials interaction showed high hemocompatibility of obtained materials. The whole blood clotting time assay showed differences in the amount of free hemoglobin present in blood contacted with different materials. It can be concluded that the peptide coating increased the hemocompatibility of the surface by increasing ECs adhesion and, at the same time, decreasing platelet adhesion. When comparing both types of peptide coatings, more promising results were obtained for the surfaces coated with the YISGR than REDV-coated prostheses.

Study on the separation of phospholipids from crude palm oil using a polyethersulfone ultrafiltration membrane

Crude Palm Oil (CPO) extracted from the palm fresh fruit bunches (FFB) should be refined to meet the specified quality for edible oils. One of the components that are removed in the CPO refining process is a phospholipid. Phospholipids are undesirable because they form mucus (gum) in CPO and enhance the emulsion formation during oil processing. As one of the emerging separation processes, membrane technology could be proposed on phospholipid removal in CPO. The research objectives are to synthesize polyethersulfone (PES) ultrafiltration (UF) membrane and evaluate its performance on phospholipids removal in CPO. Besides, the effects of temperature and pressure on UF-PES membrane performance in phospholipid removal were also studied. The UF-PES membrane was prepared by phase inversion method with the composition of PES polymer of 17.5%; Polyethylene Glycol (PEG) polymer as much as 2.5% as pore-forming agent; and 80% (w/w) of N-Methyl Pyrrolidone (NMP) as a solvent. Two types of the UF-PES membrane have been synthesized, namely M1 and M2 membranes. Furthermore, the M1 membrane was selected for the filtration process due to its high resistance to pressures up to 3 bar. The result indicated that the pressure (T) and temperature (S) significantly affected phospholipid removal. The lowest phospholipid removal was obtained in the S2T2 treatment, about 78%. Moreover, the S3T1 and S3T2 treatments gave a stable permeation flux in comparison to the others treatment.

New Understanding of the Difference in Filtration Performance between Anatase and Rutile TiO2 Nanoparticles through Blending into Ultrafiltration PSF Membranes

The blending of nanomaterials into a polymeric matrix is a method known for its ability, under certain circumstances, to lead to an improvement in membrane properties. TiO2 nanoparticles have been used in membrane research for the last 20 years and have continuously shown promise in this field of research. Polysulfone (PSf) membranes were obtained through the phase inversion method, with different TiO2 nanoparticle concentrations (0, 0.1, 0.5, and 1 wt.%) and two types of TiO2 crystalline structure (anatase and rutile), via the addition of commercially available nanopowders. Research showed improvement in all studied properties. In particular, the 0.5 wt.% TiO2 rutile membrane recorded an increase in permeability of 139.7% compared to the control membrane. In terms of overall performance, the best nanocomposite membrane demonstrated a performance index increase of 71.1% compared with the control membrane.

Novel Dopamine-Modified Cellulose Acetate Ultrafiltration Membranes with Improved Separation and Antifouling Performances

Cellulose derivatives are the earliest and most widely used membrane materials due to its many excellent characteristics, especially chemical activity and biodegradability. However, the hydrophobic properties of cellulose acetate (CA) limited its development to some extent. To improve the inherent hydrophobic and antifouling properties of the CA membrane, CA was successfully modified with dopamine (CA-2,3-DA) through selective oxidation and Schiff base reactions in this work, which was confirmed by 1H NMR and FTIR measurements. And then, the CA-2,3-DA membrane with high water permeability and the excellent antifouling property was prepared by the phase inversion method. Compared with the primordial CA membrane, the CA-2,3-DA membrane maintained a higher rejection rate for BSA (92.5%) while greatly increasing the pure water flux (167.3 L/m2h), which could be overcome the trade-off relationship between selectivity and permeability of the traditional CA membrane to a certain extent. According to the three-cycles dynamic ultrafiltration and static protein adsorption experiments, the CA-2,3-DA membrane showed good long-term performance stability and superior antifouling performance, which was supported by the experiment results including filtration resistance, flux decline ratio and flux recovery ratio. It is expected that this approach can greatly expand the high-value utilization of modified natural organic polysaccharides in separation engineering.

Preparation Optimization and Performance Evaluation of Waterborne Epoxy Resin for Roads

To further improve the road performance of waterborne epoxy resin, it was prepared by using the phase inversion method. The tensile properties, bending properties, impact resistance, and storage stability of waterborne epoxy resin were determined. The bonding properties of waterborne epoxy resin were analyzed. At the same time, their properties were compared with those of waterborne epoxy resin prepared by using the curing agent emulsification method. The performance of waterborne epoxy resin was comprehensively evaluated based on multi-index grey target decision model. The results show that the optimum preparation parameters for the preparation of waterborne epoxy resin by phase inversion method are shear time 1.5 h, shear temperature 60°C, and shear rate 1300–1500 r/min. The suitable contents of emulsifier A and B are 18% and 16%, respectively. The tensile strength, elongation at break, bending strength, bending deformation, and impact strength of waterborne epoxy resin prepared by emulsifier A can reach 34.46 MPa, 12.96%, 85.37 MPa, 19.42 mm, and 15.66 kJ/m2, respectively. It shows improved mechanical strength, deformation ability, impact resistance, and bonding performance. The comprehensive properties of waterborne epoxy resin prepared by emulsifier A are the best. It is suggested to use phase inversion method to prepare waterborne epoxy resin for roads.