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As an efficient, safe, and environmentally friendly technology, semiconductor photocatalysis has been widely used in the removal of antibiotics from wastewater. In this work, a novel Ag/BiOI/g‐C3N4 composite photocatalytic material, BiOI/g‐C3N4, g‐C3N4, and BiOI are prepared as the photocatalysts. The morphologies, chemical properties, and photocatalytic performances of the photocatalysts are characterized using scanning electron microscope, transmission electron microscope, X‐ray diffraction, X‐ray photoelectron spectroscopy, Fourier‐transform infrared spectrometer, ultraviolet–visible spectroscopy (UV–Vis) diffuse reflectance spectra, and photoluminescence spectra. In addition, tetracycline hydrochloride (TC) and ceftiofur sodium aqueous solutions are used to simulate wastewater and the photocatalytic degradation performances of the photocatalysts are investigated and compared under visible light. Compared to g‐C3N4, BiOI, and BiOI/g‐C3N4, the Ag/BiOI/g‐C3N4 demonstrates superior performance, increasing the removal rates of TC and ceftiofur sodium to 85.6% and 90.2%, respectively. The photocatalytic mechanism of the Ag/BiOI/g‐C3N4 may involve the promotion of the visible light–harvesting ability and inhibition of the recombination of photogenerated electron/hole pairs. Furthermore, the primary active groups in the system are identified as superoxide radicals (·O2−) and hydroxyl radicals (·OH). Herein, some valuable insights into the development of innovative photocatalytic materials are offered for the effective removal of antibiotics from water. [ABSTRACT FROM AUTHOR]

In this study, a novel "three-layer sandwich" composite loose nanofiltration (NF) membrane structure by mussel bionic technology was constructed on a porous polyvinylidene fluoride (PVDF) substrate membrane, with a mussel bionic coating as the middle layer and the complex network of polyphenols and metal ions as the top layer. The new composite NF membrane had comprehensive properties such as excellent separation performance, good hydrophilicity and strong antifouling ability. The experimental results showed that the combination of tannic acid (TA) and iron ion (Fe3+) could significantly improve the comprehensive performance of the composite NF membrane, with water flux of more than 3000 L/(m2∙h), and the retention rate of dyes and bovine serum protein (BSA) exceeded 90 %, and contact angle was up to 30°. The combination of TA and copper ion (Cu2+) can greatly enhance the antifouling performance and interception ability of methylene blue. The complexation activity of metal ions and polyphenols was related to the oxidation of metal ions. The PVDF/DA-PEI/TA-M+ composite structure scheme of "three-layer sandwich" NF membrane provides a new idea and future development direction for the development of novel NF membranes with excellent comprehensive performance. [ABSTRACT FROM AUTHOR]

Fluorinated polyimide and PVA blending membranes were prepared by aqueous solution casting. We chose a poly (amic acid) ammonium salt (PAAS) in aqueous solution based on a novel green strategy as the PI precursor. The blending membranes were characterized by ATR-FTIR, DSC, TGA and gas permeation measurement. The ATR-FTIR analysis revealed that the imidization reaction of 6FPI based on aqueous precursor was completed at 180°C and hydrogen bonds formed between PVA and 6FPI. 6FPI showed good compatibility with PVA segment in blending membranes without obvious separated phase structure. The blending membranes showed high separation properties, for blending with 6FPI the gas separation performance stability was improved due to the hydrogen bonds between hydroxyl groups of PVA and carbonyl groups of 6FPI, and the rigid structure of 6FPI. At high operating pressure 10 bar, the CO2 permeability and CO2/N2 selectivity remained rather high. Using water as the solvent in the PAAS synthesis and membrane preparation is more environmentally friendly and less costly. [ABSTRACT FROM AUTHOR]

A novel method for preparing Ni2P/Al2O3(L) catalysts in an N2 atmosphere by decomposition of hypophosphites was proposed, and Ni2P/Al2O3(T) catalyst was synthesized by the temperature programmed reduction method in a H2 atmosphere for comparison. These prepared catalysts were washed with deionized water to remove impurities. The X-ray diffraction, N2-adsorption specific surface area measurements, CO uptake, and X-ray photoelectron spectroscopy were applied to characterize these catalysts. The activities of the Ni2P/Al2O3 catalysts prepared with the two different methods were tested in the dibenzothiophene hydrodesulfurization reaction. [ABSTRACT FROM AUTHOR]

Poly(arylene ether sulfone) (PES)–titanium dioxide (TiO2) hybrid membranes were prepared via solution blending method using TiO2 nanoparticles as inorganic filler. The chemical structure and thermal stability of the matrix polymer were characterized by proton nuclear magnetic resonance, Fourier transform infrared, differential scanning calorimetry, and thermogravimetric analysis. The crystal structure, morphology, mechanical properties, and gas separation performance of hybrid membranes were characterized in detail. As shown in scanning electron microscopic images, TiO2 nanoparticles dispersed homogeneously in the matrix. Although the mechanical properties of hybrid membranes decreased certainly compared to the pure PES membranes, they are strong enough for gas separation in this study. All gas permeability coefficients of PES-TiO2 hybrid membranes were higher than pure PES membranes, attributed to the nanogap caused by TiO2 nanoparticles, for instance, oxygen and nitrogen permeability coefficients of Hybrid-3 (consists of PES with 4-amino-phenyl pendant group and hexafluoroisopropyl (Am-PES)-20 and TiO2 nanoparticles, 5 wt%) increased from 2.57 and 0.33 to 5.88 and 0.63, respectively. In addition, the separation factor increased at the same time attributed to the stimulative transfer effect caused by the interaction of hydroxyl groups on the TiO2 nanoparticle and polar carbon dioxide molecules. [ABSTRACT FROM AUTHOR]

A series of asymmetric membranes based on a trifluoromethylphenylated poly(ether ether ketone) (CF3-PEEK) were prepared using a dry–wet phase inversion method. To obtain the asymmetric membranes with defect-free skin, the type and concentration of internal nonsolvent and the evaporation time were carefully investigated. The cross-section of membranes was characterized by scanning electron microscopy. The gas separation performance of asymmetric membranes was tested in terms of gas permeabilities and selectivities for helium, carbon dioxide (CO2), oxygen (O2), and nitrogen by the constant volume method. It was found that the permeabilities of asymmetric membranes were obviously higher than that of CF3-PEEK dense membrane. The membranes in series 2 showed higher permeability for each gas while the separability for gas pair CO2/O2 increased from 3.78 to about 6 comparing with that of the dense membrane. [ABSTRACT FROM PUBLISHER]

A series of triple-layer membranes were prepared based on a sulfonated polyimide (SPI) and a traditional sulfonated poly(ether ether ketone) (SPEEK) polymer matrix. Compared with the single-component membranes (pure SPI and SPEEK), the multicomponent membranes exhibited better comprehensive performance. Interestingly, the triple-layer membranes possessed improved mechanical properties, lower water uptake, and swelling ratio than those of the corresponding blend membranes. When the contents of SPI were 30 and 40%, the triple-layer membranes even had lower methanol permeability (3.42 and 2.61 × 10−7 cm2 s−1, respectively) than that of the pure SPI membrane (3.51 × 10−7 cm2 s−1). The proton conductivity of the triple-layer membranes was in the range of 0.117–0.149 S cm−1 at 100°C. All the results suggest that the triple-layer membranes have sufficiently excellent performance to be applied in fuel cells. [ABSTRACT FROM AUTHOR]

AbstractIn this study, a novel type of organosilicone fluoride modified acrylate emulsion was developed using the semi-continuous pre-emulsification method. The emulsion was synthesized by incorporating organic fluorine monomer and three types of organosilicone monomers. The effects of the organosilicon types, the amount of organosilicon and organofluorine on the performance of the emulsions were investigated. The structure of the organosilicon fluorine modified acrylate was characterized using infrared spectroscopy, and the properties of the emulsion and coating films were evaluated through thermal analysis, contact angle, and conventional tests. The results demonstrated that the optimal comprehensive performance of the organosilicon fluorine-modified acrylate emulsion was achieved when the reaction was conducted at 80 °C for 4 h with the MMA/BA ratio of 0.7:1. The addition amounts of A-171 silicone, organic fluorine, and electrolyte were determined to be 3, 1.25, and 0.25% of the total monomer, respectively. The contact angle of the emulsion coating reached 89° and the pencil hardness reached 6H. Furthermore, the thermal stability of the newly modified acrylate emulsion showed significant improvement, indicating its potential for broad applications. [ABSTRACT FROM AUTHOR]

In this study, a novel composite membrane was developed by casting the mixed aqueous solution of chitosan (CS) and polyvinyl alcohol (PVA) on a glass fiber microporous membrane. The polymeric coating of a composite membrane containing amino groups and hydroxyl groups has a favorable CO 2 affinity and provides an enhanced CO 2 transport mechanism, thereby improving the permeance and selectivity of CO 2 . A series of tests for the composite membranes were taken to characterize the chemical structure, morphology, strength, and gas separation properties. ATR-FTIR spectra showed that the chemical structure and functional group of the polymer coating had no obvious change after the heat treatment under 180 °C, while SEM results showed that the composite membranes had a dense surface. The gas permeance and selectivity of the composite membrane were tested using single gases. The results showed that the addition of chitosan can increase the CO 2 permeance which could reach 233 GPU. After a wetting treatment, the CO 2 permeance (454 GPU) and gas selectivity (17.71) were higher than that of dry membranes because moisture promotes the composite membrane transmission. After a heat treatment, the permeance of N 2 decreased more significantly than that of CO 2 , which led to an increase in CO 2 /N 2 selectivity (10.0).