Abstract:In recent years, spherical particles based on natural bio-based materials have received increasing attention due to their unique properties, including shape, structure，and ability to bond with other materials. As the most abundant aromatic polymer in nature, lignin has antibacterial and antiviral properties and good biocompatibility, which has great potential for applications in the pharmaceutical, cosmetic and food fields. Preliminary research results have been achieved in the using of spherical lignin particles as carriers for encapsulating drugs, including encapsulating active ingredients of drugs for the treatment of diseases such as cancer, encapsulating drugs such as insecticides and antimicrobial agents for application in controlled release formulations of pesticides. This paper reviews the recent research progress related to lignin-based microcapsules. Firstly, the fundamental physicochemical properties and releases influencing factors of lignin-based drug-loaded microcapsules is introduced briefly. Secondly, the preparation methods and corresponding characteristics and advantages of lignin-based drug-loaded microcapsules are outlined in detail to provide more theoretical basis for the preparation of microcapsules. Furthermore, the progress of the application of lignin-based drug-loaded microcapsules with biopharmaceutical application and chemical pesticide application and the key problems that need to be solved are reviewed. Finally, the perspectives for developing of lignin-based drug-loaded microcapsules are thus provided.

Abstract:CO2 reduction and resource utilization is an important means to alleviate Greenhouse Effect. Biocatalysts have high selectivity for reactions and substrates, so they are used to build efficient CO2 reduction systems. Among them, formate dehydrogenase (FDH) especially certain NAD⁺ -dependent/metal-containing (W- or Mo-) FDH are able to reversibly reduce CO2 to formate. This review summarizes the recent advances in reductive activity and catalytic mechanism of FDH for CO2 reduction, enzyme engineering, whole-cell biocatalysis and the application progress based on CO2 reductase. The innovative results summarized in this paper provide a great enlightenment and guidance for the future research of FDH for CO2 reduction, and provide a theoretical basis for the construction of feasible CO2 refining systems with abundant, cheap and sustainable CO2 as raw materials to produce value-added fuels and chemicals.

Abstract:Sulfur quantum dots are outstanding because of high luminous intensity, low toxicity and stable photochemical properties, and they are widely used in cell imaging, photoelectric conversion and chemical catalysis. Synthesis methods, optical properties and application background of sulfur quantum dots are systematically reviewed in this article. The synthesis method of sulfur quantum dots can be divided into "bottom-up method" and "top-down method", and the latter could afford sulfur quantum dots with higher fluorescence quantum yield than the former. It is reviewed that the optical properties of sulfur quantum dots. The characterization of optical properties shows that sulfur quantum dots possess ultraviolet absorption characteristics, fluorescence characteristics, Photoluminescence, electrochemiluminescence, and optical stability. Finally, it is introduced about the important application of sulfur quantum dots in the fields of fluorescent probes, biological imaging and light-emitting devices. Based on the above analysis, the problems are deeply discussed and need to be solved urgently in the cutting-edge application of sulfur quantum dots. Moreover, the future development direction of sulfur quantum dots is forecasted in new industries and fields such as biomedicine and photoelectric.

Abstract:The selective hydrogenation of the benzene ring of phenyl derivatives with complex substituent groups is an atom-economic reaction. It can not only eliminate the potential harm of benzene ring to human health, but also endow the synthesized materials with special functions. In this paper, the research progress of catalysts, operating conditions and reaction properties for selective hydrogenation of benzene rings with retained substituent groups was reviewed, mainly including the catalytic hydrogenation of benzene rings of aromatic diamines, aromatic esters, aromatic methyl carbamate, polystyrene, biphenyls and bisphenol A. In order to retain the substituent group on the reactant, the catalyst used in the above reaction was noble metals such as ruthenium, rhodium, palladium, and platinum. The activity and selectivity of non-precious metal catalysts such as Ni need to be further improved. Therefore, the future research should focus on the development of high performance catalysts with reduced or alternative noble metals.

Abstract:Solid adsorption technology for capturing carbon dioxide has the advantages of excellent adsorption and desorption performance, portable and flexible equipment, environmental protection and low cost. It is considered to be one of the most promising technologies for capturing carbon dioxide in the flue gas of power plants. Domestic and foreign scholars have carried out a lot of research and made some progress on solid adsorption materials that can be applied to capture carbon dioxide in the flue gas of power plants. In this paper, the research status of adsorption materials such as zeolite molecular sieve, metal organic framework (MOFs) and activated carbon (ACs) in recent years is reviewed. The application advantages and problems of various adsorption materials in engineering application are summarized and analyzed. The main influencing factors and adsorption mechanism of adsorption properties of various materials are concluded. Finally, the development direction of solid adsorption materials is prospected.

Abstract:Purely organic long-persistent luminescent materials are widely used in the fields of anti-counterfeiting, information security, biological imaging, and other applications due to their benefits of ease of synthesis, low cost, flexibility, and environmental friendliness. Among them, organic long-persistent luminescence materials based on doping systems have become a current focus of research for long-persistent luminescence materials because they enable the adjustment of luminescent time and color by controlling the coordination relationship between host and guest. This article reviews the developments in the disciplines of micromolecular, macromolecular, and polymer matrix research, as well as the uses of related materials in fields such as information security and counterfeit prevention, biological imaging, flexible fiber film, and others. Finally, some problems existing in the research area are pointed out, and their development prospects are prospected.

Abstract:Using H2SO4 and KMnO4 as the oxidant, the ultrathin oxygen-doped g-C3N4 nanosheets was prepared through ultrasonic assisted oxidative exfoliation of original graphite phase carbon nitride (g-C3N4) synthesized by thermal polymerization. Based on the characterization of HRTEM, XRD, AFM and XPS, the effect of ultrasound assisted oxidative exfoliation on the morphology and structure of pristine g-C3N4 was investigated; the photocatalytic performance of ultrathin oxygen-doped g-C3N4 nanosheets was analyzed by photocatalytic degradation of Congo red under visible light; and the enhancement mechanism of photocatalytic performance of ultrathin oxygen-doped g-C3N4 nanosheets was also explored by means of UV-vis-DRS, EIS and PL analysis. The results showed that, the ultrathin oxygen-doped g-C3N4 nanosheets with a specific surface area of 58.45 cm2 g-1 and thickness of 1.08 nm was obtained after 6 h of ultrasound assisted oxidative exfoliation of pristine g-C3N4; The ultrathin oxygen-doped g-C3N4 nanosheets（200 mg L-1）degraded Congo red (20 mg L-1) by 83% within 120 min, showing a good photocatalytic performance; Compared with pristine g-C3N4, the ultrathin oxygen-doped g-C3N4 nanosheets is more conducive to the exposure of catalytic active site, but also the separation and transportation of photogenerated carriers, which has better photocatalytic performance.

Abstract:As the core component of controlling the water vapor transmission of proton exchange membrane fuel cell (PEMFC), gas diffusion layer (GDL) has an important influence on the performance of PEMFC.After soaking the carbon paper (CP) with Polytetrafluoroethylene (PTFE) , the carbon paper treated with alternating hydrophilic and hydrophobic pressing by mold filling was obtained, and the hydrophilic and hydrophobic alternating gas diffusion layer (GDL) was prepared by microporous layer (MPL) coating process, in order to improve the water management ability of proton exchange membrane fuel cell (PEMFC). The structure and performance of hydrophilic and hydrophobic alternating GDL at the base layer were characterized by the data of appearance, contact angle, SEM, EDS, through plane (TP) resistivity, through plane (TP) permeability and assembled single cell polarization curve. The results show that the carbon paper impregnated with PTFE formed the striped hydrophilic area and hydrophobic area. The GDL assembled with alternating hydrophilic and hydrophobic treatment had a voltage of 0.47 V and power density of 948 mW/cm2. In the same case, the GDL assembled with undifferential hydrophobic treatment had 0.44 V and power density of 884 mW/cm2. Compared with the GDL assembled with undifferential hydrophobic treatment, the voltage and power density at 2 A/cm2 increased by 6.82% and 7.24%, respectively.

Abstract:Responsive polymer gels, which can undergo sol-gel/gel-sol transition by responding to external physical or chemical stimuli, have attracted significant attention over the past decades. However, implementing the sol-gel-sol transition under constant temperature remains a major challenge. Herein, a novel polymer gel (HGX), which can undergo a sequential sol-gel-sol transition upon simply heating at a fixed temperature, was developed based on poly (2-hydroxyethyl methacrylate) (PHEMA) and glyoxal (GX). The gelation and degradation times could be tuned over wide ranges (10-1500 min and 1.5 h ~ 15 days, respectively) by changing GX content and temperature. After gelation, the elastic modulus of HGX was as large as 847 Pa. Before gelation or after degradation, the apparent viscosity of HGX was below 30 mPa·s. This unique transition is mainly ascribed to the dynamic competition between aldolization and hydrolysis of ester.

Abstract:In order to protect and repair fragile silk cultural relics and prolong their life, try to study a new type of biological material to strengthen and protect aging silk, and explore the strengthening mechanism. In this study, silk fibroin/carboxymethyl chitosan (SF/CMCS) composites were prepared using silk fibroin (SF) and carboxymethyl chitosan as raw materials, and transglutaminase as cross-linking agent, and were applied Reinforced protection from aged silk. Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometer (XRD), colorimeter, scanning electron microscope (SEM) and servo tensile tester were used to characterize the effect of aged silk before and after reinforcement. The research results show that the SF/CMCS composite material has good compatibility with the aged silk, the appearance of the reinforced silk has no obvious change, the mechanical properties are significantly improved, and it has certain antibacterial properties. It is proved that SF/CMCS composite material is a safe and effective reinforcement material, which lays a certain foundation for the protection and restoration of silk cultural relics in the later period.

Abstract:A new oxidized corn starch-based antimicrobial material (OI) was successfully produced by linear grafting of indoleacetic acid monomer (IAA) on oxidized corn starch (OCS) through a simple "one-pot" method. OI was then further blended with biodegradable polycaprolactone (PCL) to produce oxidized corn starch-polycaprolactone based antimicrobial film (PO). The chemical structures and performance characteristics of the prepared OI and PO films were characterized by FTIR, UV-vis, and XRD. The results showed that IAA was combined with OCS mainly by esterification reaction, and the substitution degree reached 60%. After compounding OI with PCL, the crystallinity of the prepared PO films was significantly decreased. With the increase of OI content in the composite films, the prepared film materials decreased in light transmission, increased in tensile strength, and slightly decreased in contact angle. Especially, when the OI content was 10% (based on the total mass, the same below), the produced PO-10 showed good biocompatibility, non-leachability, and antibacterial activity. According to the disk diffusion test, the minimal inhibitory concentration of the produced antibacterial material was 0.5 g/L, which was much lower than the dosage of traditional antibiotics and macromolecular chitosan antibacterial materials. Therefore, the obtained PO not only has good functional properties, but also the raw material is green and non-toxic, inexpensive, and easy to obtain, which is a potential biomedical material.

Abstract:A novel fluorescent probe on the basis of Schiff base ((E)-4-((2-(8,9-di(naphthalen-1-yl)-9H- purin-6-yl) hydrazineylidene) methyl)-2-methoxyphenol named as PHM) for detecting Cu2+ and Pd2+ ions were designed and structurally described using biological purine scaffolds. This fluorescent probe can quickly recognize palladium and copper ions in the HEPES buffer solution system without interference from the rest of the metal ions. It’s detection limits in HEPES buffer solution for Cu2+ and Pd2+ ions were 72.97 nmol/L and 839 nmol/L, respectively. Meanwhile, naked eyes can detect a visual hue change, which could be due to its complexation with Cu2+ and Pd2+ ions, generated in the inhibition of photo-induced electron transfer effects. The fluorescence of PHM-Cu2+ was restored after the addition of EDTA, confirming the reversible property of PHM. A density flooding theory (DFT) and Job’s plot analysis backed up the binding processes of the fluorescence probe towards Pd2+ and Cu2+ ions.

Abstract:A layer of polyaniline conductive material was formed on the surface of nylon fabric by low-temperature in situ polymerization, and its morphology and chemical composition were characterized by field emission scanning electron microscopy (FESEM) and micro-Raman imaging spectroscopy. The conductivity of polyaniline nylon fabric was tested by the multimeter and electrochemical workstation. The results showed that polyaniline polymerized on the surface of the nylon fabric imparted better electrical conductivity to the fabric. The electrical conductivity of the fabric was 31.62 S/m.The resistance of polyaniline nylon fabric increases with the increase of strain. when the strain returns to the initial state, the fabric resistance recovers gradually and approaches to the initial value. The polyaniline fabric still has a high cycle stability of 96.2% after 3500 stretching-releasing cycles.As a conductive fabric, polyaniline nylon fabric has good sensing performance, which can accurately monitor the joint movement of the human body in strain range from 0% to 15%. Meanwhile, polyaniline nylon fabric has thermoelectric properties, and the Seebeck coefficient of the fabric is 8.406 μV/K, which is expected to be used as a temperature difference sensor.

Abstract:The chalcone derivatives (E)-3-(4-(allyloxy)phenyl)-1-phenylprop-2-en-1-one (Blank-Cha), (E)-3-(4-(allyloxy)phenyl)-1-(4-hydroxyphenyl)prop-2-en-1-one (Oxhydryl-Cha) and (E)-3-(4-(allyloxy)phenyl)-1-(4-methoxyphenyl)prop-2-en-1-one (Methoxy-Cha) were prepared. Further, polysiloxane UVA filter (WPUF) was prepared by grafting Methoxy-Cha onto polymethylhydrosiloxane chain via silica-hydrogen addition reaction. The chemical structures of the products were identified by NMR, LC-MS and FTIR, and proved that the chalcone derivatives and WPUF were successfully prepared. The effects of different substituents on the UV absorption properties and cytotoxicity of chalcone derivatives were investigated. The results showed that the chalcone derivatives had a molar absorbance coefficient ε > 10000, and Methoxy-Cha was the least cytotoxic. The chemical structure of WPUF did not change after protection from light for 6 months and heating at 90 ℃ for 12 h. The loss of UV absorption capacity was only 30.46% after simulated sunlight exposure for 4 h. Moreover, WPUF did not exhibit cytotoxicity at concentrations of 250 μg/mL and below. In vitro penetration test measured an average penetration depth of 11 μm in the stratum corneum of WPUF. The SPF value of WPUF was determined in vitro to be 36.21, which is comparable to commercial sunscreens.

Abstract:CAR/GEL/PVA active fibrous membranes were prepared by electrospinning using the biodegradable polymer gelatin (GEL) and polyvinyl alcohol (PVA) as substrates and carvacrol (CAR) as an antioxidant to achieve sustained release of CAR and slow down the oxidative deterioration of foods. The effects of CAR addition on the structure and performance of the fibrous membranes were analyzed by test and characterization of SEM, FTIR, XRD, antioxidant activity, sustained release performance, and peroxide value of olive oil. The results showed that with the increase of CAR addition (Based on the mass of GEL in the solution), the viscosity of the spinning solution increased and the electrical conductivity decreased, and the morphology of the prepared fiber membrane changed from a smaller diameter and uniform distribution to a larger diameter and uneven distribution, thus affecting mechanical properties, the antioxidant properties and sustained release effects of the fibrous membranes. The obtained fitting results of the Ritger-peppas and Weibull model were the best, with the correlation coefficient close to 1. The release mechanism followed Fickian"s law and the best sustained release effect was obtained with the addition of 5% CAR. CAR/GEL/PVA fibrous membranes with high CAR addition could release CAR slowly and had strong antioxidant activity in fatty foods. At the moment of 48h, DPPH radical scavenging rate of the fibrous membranes with 20% CAR addition was 82.4%, which was 50.4% higher than the one without CAR. Meanwhile, the increase of CAR addition could effectively reduce the peroxide value of olive oil.

Abstract:Covalent organic frameworks (COFs) are an emerging class of porous crystalline organic materials connected by covalent bonds. Due to the excellent properties of COFs materials, they have a wide range of applications in the environmental field. In this paper, the synthesis and modification of COFs and the application of COFs and their derivatives in the field of environmental remediation are summarized, and the existing problems and future research directions of COFs materials in the field of environmental remediation are discussed and prospected.

Abstract:Two azole silane couple agents TUP and IAP were synthesized from 3-isocyanatopropyltriethoxysilane, 2-aminothiazole and imidazole. Organometallic coatings were obtained by dipping method on copper foil surface using TUP and IAP as main film-forming agents applied in high-frequency PCB, and then compared with brown oxidation film and polymeric coatings containing KH132 and KH580. The structure, surface morphology, flatness and hydrophobicity of the films were characterized by FTIR, SEM, AFM and contact angle measurement, respectively. The corrosion resistance of the layers was evaluated by electrochemical, salt spray and saline immersion tests, and the interfacial adhesion between copper foil and epoxy resin was investigated after laminates process. The results indicated that two azole silane coupling agents were both successfully grafted onto the copper surface, fabricating relatively smooth and compact organic protective films. The organometallic coatings formed by TUP with a concentration of 3% (based on the total mass of ethanol and water) exhibited excellent smoothness with Ra and Rq both below 21 nm，optimal hydrophobicity with water contact angle up to 142°. Furthermore, the corrosion inhibition efficiency could reach 99.2% and salt spray resistance up to 14 d revealing best barrier performance. In addition, the peel strength of copper/resin laminates achieved 5.97 N/cm appropriately, satisfying interfacial adhesion requirement of PCB.

Abstract:Inorder to increase the daptomycin yield of Streptomyces roseosporus AN-126, the strain AN-126 was mutated by ARTP-DES compound mutagenesis combined with sodium decanoate tolerance. A mutant strain RR-447 with a yield of 101.41 mg/L was obtained, which was 2.44 times that of the strain AN-126. The genetic stability experiment showed that the high yield performance of the strain RR-447 was stably inherited. The morphological characteristics and gene fingerprints of strains AN-126 and RR-447 were analyzed. The strain RR-447 was not only different from strain AN-126 in morphological characteristics, but also had a specific band between 1.5 kb and 2.0 kb in its genome DNA. In 5 L fermentation tank, the daptomycin yield of strain RR-447 reached a maximum of 521.39 mg/L by adding sodium decanoate. The results show that ARTP-DES compound mutagenesis combined with sodium decanoate tolerance is an effective breeding method for breeding high-yield daptomycin strains, which provides a technical reference for industrial microbial breeding of daptomycin and other strains improvement.

Abstract:To optimize the ultrasonic extraction auxiliary ionic liquids extraction process for flavonoids from Lotus Leaf and to evaluate the anti-oxidant activity. With ionic liquid concentration，ultrasonic power and ultrasonic time as influencing factors，flavonoids yield as an evaluation index，the extraction process was optimized by response surface method on the basis of single factor test．Subsequently the scavenging effects of flavonoids on DPPH，·OH free radicals were determined．The optimal conditions were determined to be 0.9 mol·L-1 of 1-hexyl-3-methylimidazole tetrafluoroborate([C6mim]BF4）as extraction solvent, 1:25 g·mL-1 for solid- liquid ratio 0.9 mol·L-1 for ionic liquid concentration，186W for ultrasonic power，and 24min for ultrasonic time，and 70℃ for extraction temperature ,total flavonoids demonstrated the extraction rate of 4.65%. When the mass concentration was 1.6 mg·mL-1，the scavenging rates of DPPH and ·OH radical were 63.2% and 55.4%，and the corresponding half inhibitory concentration (IC50) was 1.512 mg·mL-1and 2.140 mg·mL-1，the absorbance of reducing power determination was 0.72Abs. This stable and reliable method can be used for the extraction for flavonoids with significant in vitro antioxidant activity from Lotus Leaf.

Abstract:The Co-Mo2C was prepared by in-situ reduction of ammonium molybdate and cobalt nitrate with isosorbitol-tar at high temperature and characterized by X-ray diffraction (XRD), N2 adsorption (BET), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The prepared Co-Mo2C was used to catalyze the oxidation of dimethyl succinate (DMSS) by O2 to form dimethyl 2,5-dihydroxyterephthalate (DHTA). The effects of calcination temperature, atomic ratio of Co to Mo and oxidation conditions were investigated. The results show that: Co-5Mo2C with a specific surface area of 134 m2/g can be prepared by in situ reduction of ammonium molybdate and cobalt nitrate at 850 ℃ for 4h with isosorbitol-tar. Co-5Mo2C-4, Co:Mo=1:5 (mol. r.), exhibits good performance due to the synergistic effect of Co and Mo2C. Using Co-5Mo2C-4 as a catalyst, under 1.1 MPa O2 at 110 ℃ for 4h, 88.22% yield of DHTA with 99.98% purity can be obtained. The yield of DHTA is decreased by 1.7% and 7.3% after the catalyst reused for 6 times and 9 times, respectively.

Abstract:Carboxyethiosuccinic acid (CETSA) was selected as anion and four kinds of novel ionic liquids were synthesized by one-step method. Their structures were characterized by 1H NMR、13C NMR、TG、MS and FTIR respectively, confirming the successful synthesis of ionic liquid catalysts. β-mercaptopropionic acid was synthesized by Michael addition reaction from acrylic acid and hydrogen sulfide (H2S). The catalytic effect of ionic liquid was investigated. The optimal process conditions are: tetrahydrofuran (THF) of 35 g, acrylic acid of 2.16 g, sufficient hydrogen sulfide in situ to replace the traditional gas cylinder, the ionic liquid of 3mmol, the reaction temperature was 90 ℃, and the reaction time was 4.5 h in the hydrothermal synthesis reaction reactor. At this time, the results showed that 1,5-diazabicyclo[4.3.0]-5-nonene carboxyethyl thioglycoate ([DBNH]CETSA) showed the best catalytic effect, and the conversion rate of acrylic acid was 100% and the selectivity of product was 90.57%. [DBNH]CETSA still has high activityafter repeated use for 7 times, and the conversion rate of acrylic acid still reached 98.97%, indicating that the ionic liquid catalyst was relatively stable in the reaction.

Abstract:A PtNi/CNTs alloy electrocatalyst was prepared by one-pot method using multi-walled carbon nanotubes (CNTs) as the carrier, H2PtCl6·6H2O as the platinum source, Ni(NO3)2·6H2O as the nickel source, sodium borohydride and ethylene glycol as reducing agents. The catalyst was structurally characterized by XRD, SEM, TEM, HR-TEM, XPS, ICP-OES and Raman. The electrochemical activity and stability of the catalyst were evaluated by cyclic voltammetry (CV), time-amperometric method (i-t) and CO-stripping method. The results show that PtNi/CNTs have excellent electrocatalytic properties for methanol oxidation (MOR), and the peak current and steady-state current are 5.89 times and 38.97 times than that of commercial Pt/C, respectively, and PtNi/CNTs also show good stability, mainly due to the unique structure of carbon nanotubes and the synergistic effect of bimetallic alloys.

Abstract:InZrOx oxide was prepared by co-precipitation and hydrothermal methods using indium nitrate tetrahydrate and zirconium nitrate pentahydrate as raw materials, and the effect of calcination temperature on the synthesized oxides was investigated under optimal preparation conditions, and combined with SAPO-34 molecular sieve as a bifunctional catalyst for the catalytic conversion of syngas to high-value products. The texture properties, crystal structure, morphology features, and surface charge of the oxides were characterized by XRD, SEM-EDS, HRTEM, XPS and BET. And the factors affecting the catalytic effect, including pace velocity, hydrogen-carbon mole ratio of feed gas, mass ratio of oxide to molecular sieve, reaction temperature, and reaction pressure, were systematically studied in a fixed bed reactor. The results showed that the oxides obtained by co-precipitation performed better than the hydrothermal method in all aspects, and the optimum calcination temperature was 550 °C.The reaction conditions were optimized as follows: space velocity 2000 mL/(gcat·h), hydrogen-carbon mole ratio 3:1, m(InZrOx):m(SAPO-34)=1:1, 400 °C, and 3 MPa. Under the optimized conditions, the conversion of CO was 67.58%, the selectivity of high-value products was 70.81%(including the selectivity of C2-4= was 37.74%, the selectivity of C5+ was 37.74%), the yield of light olefins reached 23.98%, and the selectivity of by-product CO2 was only 5.99%.

Abstract:It is of great practical significance to design and develop low-cost and high activity hydrogen evolution electrocatalysts in the all-pH (0~14) range for the development and utilization of new energy. Nanowire structured MoS2/Ni3S2/NF electrocatalysts were in situ constructed on nickel mesh (NF) by a simple solvothermal method, which exhibited excellent hydrogen evolution (HER) activity in the all-pH range. The electrochemical test results show that the MoS2/Ni3S2/NF-41 electrode prepared with 41 mg ammonium tetrathiomolybdate has a HER overpotential of 87, 113 and 195 mV in alkaline (1 moL/L KOH, pH=14), neutral (0.5 moL/L PBS, pH=7) and acidic (0.5 moL/L H2SO4, pH=0) media at a current density of 10 mA/cm2, and exhibits a lower Tafel slope. In addition, SEM, TEM, EDX, XPS and other characterization methods show that the catalyst has good structural stability. This study provides a new way for efficient hydrogen evolution of transition metal sulfides in a all-pH environment.

Abstract:GOM/Poly(AAPBA-DMAA-co-AAm) microgels with glucose-sensitive properties are proposed as emulsifiers in Pickering emulsions, providing a wider application for the use of functionalized microgels with specific response behaviors. The morphological structure and elemental composition of the microgels were characterized by Fourier infrared spectroscopy (FT-IR) and scanning electron microscopy-X-ray energy spectroscopy (SEM-EDS). By regulating the content of propylene-based graphene oxide (GOM) in microgels and the content of microgels in the aqueous phase, O/W-type stable Pickering emulsions with uniform particle size distribution and good dispersion were fabricated with glucose sensitivity. The in vitro simulated drug release using insulin as a model loaded drug showed that the cumulative release rate of insulin could reach 44.69% when the concentration of glucose was 6 mM and 94.21% when the concentration of glucose was increased to 40 mM.

Abstract:A method for the synthesis of monodisperse polyethylene glycols by single chain extension strategy using cheap polyethylene glycols with degree of polymerization of 2 to 4 as raw materials based on macrocyclic sulfates is developed. With benzyl as the protecting group, the hydroxyl end of benzylated polyethylene glycols was extended by repeated nucleophilic ring opening of macrocyclic sulfate and subsequent hydrolysis reaction，and the benzylated monodisperse polyethylene glycol derivatives with degree of polymerization of 6 to 16 were obtained in 55%~86% yield. Finally, monodisperse polyethylene glycols with degree of polymerization of 6 to 16 were obtained in 95%~99% yield through debenzylation by catalytic hydrogenation. The structure of the intermediates and the final products were confirmed by NMR and MS. This method has the following advantages: 1) The reaction process is easy to monitor. 2) The reaction efficiency is high, and no polyethylene glycol impurities with degree of polymerization close to that of the target products were generated, so the intermediates and the final products are easy to be separated and purified.

Abstract:Calcium chloride with final mass concentration of 0.05 g/L, 0.11 g/L and 0.22 g/L were added to mass concentration of 120 g/L ginkgo seed protein isolate (GSPI) and 5.0 g/L pectin (with two types of degree of esterification, which was 38% and 76%, respectively) composite solutions. The above prepared solutions were then heated to develop a GSPI/pectin composite gel. The determination of particle size and ζ-potential, rheology, texture profile analysis, protein electrophoresis, spectroscopic and microscopic techniques were employed to detect physiochemical characteristics of gel-forming solutions, gelling and functional properties of the resulting composite gels and their microstructure. The mode of action caused by calcium chloride was also prospected. The results indicated that calcium ions reduced the particle size of GSPI/pectin but not affected their electric charge, degraded rheological properties of the heat induced gels, formed a composite gel with a loosen structure. Accordingly, the textural propertied of the gels was weakened, whereas the water holding capacity was not significantly deteriorated. It was supposed that calcium ions impair the interaction between GSPI and pectin due to competitive binding to pectin and hence disrupt the balance of GSPI/pectin assembly. As the calcium concentration increased, the effects were notably prominent. The pectin with higher degree of esterification was more sensitive to calcium ions.

Abstract:Li2FeSiO4-xSx/C (x=0,0.01,0.02,0.03) nano cathode materials were prepared by solid state reaction. The micro morphology, crystal structure and electrochemical properties of the materials were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (Raman), infrared absorption spectroscopy (FTIR) and constant current charge discharge tests. The results show that the Li2FeSiO3.98S0.02/C morphology is nano spherical, and the average particle size is 45.38nm. The nano particle size is conducive to shortening the diffusion path of Li+; Carbon coating can inhibit the growth of nanocrystals and enhance the conductivity of materials; Sulfur doping can expand the tunnel spacing of materials and improve the magnification performance of materials. Li2FeSiO3.98S0.02/C shows high charge discharge specific capacity, excellent rate performance and cycle stability. The specific capacity of the first discharge at 0.1C is up to 180.1mAhg-1, and the capacity retention rate after 100 cycles at 10C is 91.3%.

Abstract:A magnetic composite CuFe2O4/diatomite (CFD) was prepared by citric acid assisted sol-gel method. The microstructure and elemental valence of the materials were analyzed by SEM, XRD, FTIR and XPS, and the effects of different oxidation systems, mass concentration of CFD, mass concentration of PMS, initial pH of solution, reaction temperature and anion type on the degradation of AO7 by CFD system were discussed. The results show that the spherical CuFe2O4 particles on CFD can be dispersed on diatomite, which reduces the agglomeration of pure CuFe2O4, and the valence cycles among the surface hydroxyl group, Fe3+/Fe2+ and Cu2+/Cu+ on CFD composite are involved in the activation of PMS. Under the optimal conditions of 0.5 g/L mass concentration of CFD, 0.3 g/L mass concentration of PMS, 50 mg/L mass concentration of AO7 and 30 ℃ reaction temperature, the degradation rate of AO7 in 60 min was 96.88%. The degradation process of AO7 in CFD+PMS system was in line with the quasi-first-order kinetic model. Compared with pure CuFe2O4+PMS system, the degradation rate constant of AO7 is increased by 1.98 times. The single factor test results show that the pH range of CFD+PMS system is wide (5~11) and the activation energy is low (Ea=31.77 kJ/mol). The quenching test showed that the main active substances in the degradation process were 1O2 and ?O2-, and SO4-? and ?OH were also produced.

Abstract:In order to solve the problem of insufficient carbon source in actual sewage treatment, the biological nitrogen removal performance of modified nano-pyrite as electronic donor was explored. Natural pyrite was milled to nanometer scale, mixed with dimethyl sulfoxide solution, and then calcined at 600℃ for 2 hours without oxygen to obtain modified nanometer pyrite. XRD, SEM and BET analysis results showed that the pyrite with high crystallinity was transformed into pyrrhotite with low crystallinity (Fe0.95S1.05) through modification and showed a porous honeycomb structure. The specific surface area increased from 0.82 m2/g to 10.54 m2/g, and the pore size increased from 7.70 nm to 22.41 nm. At the same time, VSM results showed that the magnetic strength of modified nano-pyrite was 12 emu/g. The effects of different physical and chemical factors on the biological nitrogen removal performance of modified nano-pyrite were investigated. The results showed that under the experimental conditions of 500 mg/L of modified nano-pyrite, temperature 30~35℃, pH 6.5~7.5, the concentration of NO3--N in the simulated wastewater decreased from 18.5 mg/L to 0.362 mg/L, the reaction time shortened from 4.5 h to 1 h, and the removal rate of NO3--N increased from 42.8% to 98.2% compared with that before the modification, which showed that the modified nano-pyrite could be used as an electronic donor by denitrifying microorganisms efficiently. The analysis of denitrification kinetics showed that the kinetics of autotrophic denitrification (MNPAD) reaction with modified nano-pyrite as electron donor was in line with zero-order reaction characteristics (R2>0.97).

Abstract:The surface active polymer PAS with low relative molecular weight was prepared by free radical polymerization of surfactant monomer N- (hexadecyl) -N- (sulfonyl) acrylamide and acrylamide. The structure of PAS was characterized by FTIR, and the related properties of PAS as an oil displacement agent such as viscosity increase, emulsification, injection and enhanced oil recovery were studied. At 45 ℃ and 2410 mg/L, the viscosity of PAS solution at 1000 mg/L is 32.6 mPa. s, which is higher than partially hydrolyzed polyacrylamide (18.9 mPa. s) with the same relative molecular weight. Under the condition of PAS concentration of 1000 mg/L, the water dissolution rate of the emulsion formed with crude oil is 5% for 120 min, and the viscosity retention rate of three adsorption is 114.11%, which still has good emulsification after adsorption. When the core permeability is 0.025 μm2 and the stable pressure is 1.02 MPa and the core permeability is 0.1 μm2, the PAS flooding can improve the oil recovery by 19.02% on the basis of water flooding, which is 5% higher than partially hydrolyzed polyacrylamide flooding and comparable to the enhanced oil recovery of polyacrylamide-sodium carbonate - sodium petroleum sulfonate system, only 0.58% lower.

Abstract:Abstract:A series of tung oleic acid modified emulsion containing epoxy group polyacrylate emulsion (modified polyacrylate emulsion for short) were prepared by semi-continuous emulsion polymerization with butyl acrylate (BA), methyl methacrylate (MMA), hydroxyethyl acrylate (HEA) as the main monomer ,and tung oil acid and shrinkage glyceride methacrylate (GMA) as the functional monomer.The structure of the films was characterized by FTIR. The properties of the films were analyzed by mechanical properties, acid and alkali resistance test. The results show that when the content(based on the total mass of MMA, BA, HEA and GMA) of tung oleic acid is 4%, with the increase of GMA content(that is, the mass of GMA as a percentage of the total acrylic monomer mass, the same below), the hardness of the pencil increases, the water resistance, acid and alkali resistance increase, the tensile strength increases, the thermal stability increases, and the adhesion of the film increases. When the mass ratio of GMA is 12% in the total monomer mass, the hardness of the film pencil is 4H. The film coated on tinplate has no change in 5% hydrochloric acid solution for 144 h, no change in 5% sodium hydroxide solution for 72 h. The water absorption rate of 24h is 3.31% and the adhesion level is 0.

Abstract:In order to overcome the disadvantages of difficult recycling, equipment corrosion and environmental pollution, perovskite oxides with abundant acid-base active sites were selected to catalyze n-valeraldehyde self-condensation. The catalysts were characterized by XRD, SEM, NH3-TPD and CO2-TPD. Combined with the activity evaluation, the influences of catalyst preparation conditions and reaction conditions were investigated, and the interaction between acid and base active sites was clarified. The results show that pure phase CaTiO3 with better dispersion and catalytic performance can be obtained by sol-gel method under the optimal condition: a dosage of dispersant polyethylene glycol (PEG-1000) = 2.5%(benchmarked against the quality of calcium nitrate, the following is the same), calcined at 500 ℃ for 1 h. The suitable n-valeraldehyde self-condensation conditions catalyzed by CaTiO3 were determined as follows: a reaction temperature of 190 ℃, a reaction time of 8 h and a weight percentage of catalyst = 15% (benchmarked against the quality of n-valeraldehyde, the following is the same). Under the above conditions, the conversion of n-valeraldehyde and the selectivity of 2-propyl-2-heptenal reached 97.0% and 99.1% separately. After being reused for four times, the catalytic performance of CaTiO3 had no significant decrease. NH3 and CO2 were used as probe molecules to selectively poison the active sites of CaTiO3 catalysts, respectively, and the results indicate that there is an obvious synergistic catalysis between the acid and base active sites.