Abstract:In recent years, with the rapid development of industry, medical treatment, chemical industry and other fields, a large number of pollutants have been produced and discharged, which has gradually affected the ecological environment and human health. Photocatalytic processes have been at the forefront of environmental/catalysis due to their "green" properties and may play an important role in the future of carbon neutrality. Heterojunction piezoelectric photocatalytic materials have become a promising photocatalyst because of their efficient utilization of solar energy. Many kinds of heterojunction piezoelectric photocatalytic materials have been developed to solve the environmental pollution crisis. However, the current research needs to be further deepened, expanded and innovated. This paper reviews the recent progress in the preparation of heterojunction related materials and their applications in water environment. This paper focuses on the synthesis method and construction of heterojunction piezoelectric materials, as well as their degradation effect and mechanism in degrading pollutants in water. In addition, the influence of parameters such as pH value, inorganic anion and material adsorbability on the reaction is also discussed, so as to provide reference and reference for the development of better heterojunction piezoelectric photocatalysts for environmental catalysis. The application prospect of catalyst catalyst is also discussed.

Abstract:This article elaborates in detail the research progress in improving the interfacial interaction between fibers and polymers. Fiber-reinforced polymer composites have broad application prospects in many fields, but the poor interfacial compatibility between fibers and polymer matrices (such as epoxy resin, polyetheretherketone, polyethylene terephthalate, etc.) affects their applications. Modifying fibers through methods such as plasma treatment, silane treatment, and chemical grafting can improve the interfacial compatibility and enhance the performance of composite materials. The article introduces the methods for improving the interfacial compatibility of polymer composites reinforced with carbon fibers, ramie fibers, and basalt fibers, etc. For example, bamboo fibers can improve the interfacial compatibility through plasma treatment and encapsulation processes; the mechanical properties of ramie fibers are enhanced after modification with silane coupling agents, but the influence of the modification on the high-temperature molding process needs further study; basalt fibers can improve their interfacial compatibility with polymers through dual modification and other methods. In addition, the related research on carbon fiber and aramid fiber-reinforced polymer composites is also discussed. In the future, it is necessary to achieve the multifunctionalization of composite materials and adopt new production technologies and modification methods to meet the application requirements in different fields.

Abstract:Thermoplastic polyamide elastomers (TPAEs) have emerged as important elastomer materials, because of their outstanding mechanical properties, entropy elasticity and processability. However, the traditional raw precursors of TPAEs are mainly from fossil materials, which causes high energy consumption and environmental pollution. Therefore, bio-based TPAEs are aligned with the development demands of modern green environmental protection and the "double carbon" goal. The utilization of bio-based platform chemicals for the production of elastomers holds practical value and significance. This study provides a comprehensive summary of biomass platform chemical raw materials used in the preparation of TPAEs, including bio-based diamines, bio-based dicarboxylic acids, bio-based amino acids, and bio-based lactams. Detailed information on the sources, preparation methods, and properties of various bio-based chemicals and their corresponding TPAEs is presented, and the domestic development status and future direction of bio-based chemicals are prospected. The types, preparation mechanisms and performance differences of soft segment compounds for synthetic bio-based TPAEs are summarized, along with a brief outlook on the functional properties and potential applications of bio-based TPAEs. Moreover, the paper discusses the opportunities and challenges associated with bio-based platform chemicals and TPAEs, aiming to drive the further advancement of bio-based elastomer materials in practical applications.

Abstract:Thiols are a class of key compounds containing organic sulfur atoms, playing important physiological roles in living organisms. It can be ingested into organisms through various pathways, including active transport and passive diffusion mechanisms. Thiols participate in regulating various life activities such as antioxidant, detoxification, and protein synthesis in organisms. In recent years, thiol mediated uptake (TMU) has emerged as a cellular uptake mechanism, mainly through the formation of disulfide bonds between substrates and cell surface protein thiol groups, which then enter cells through various methods such as fusion, endocytosis, or direct transmembrane transport. Once inside the cell, the substrate can be released through dynamic exchange of disulfide bonds mediated by active small molecules such as GSH, thereby achieving delivery to some proteins, small molecule probes, and nanomaterials. Meanwhile, this uptake pathway can also be hindered by some thiol inhibitors, thereby hindering the uptake of thiol compounds. The latest research progress indicates that thiol mediated uptake has potential application prospects in the prevention and treatment of various diseases.

Abstract:As an artificial photosynthesis, semiconductor photocatalysis technology can alleviate the current global environmental pollution and energy shortage crisis, and has become a hot research direction in recent years. Graphitic carbon nitride (g-C3N4) is a two-dimensional layered semiconductor material, which has a simple preparation method and good visible light response ability, and is currently the research focus of photocatalytic materials. The photocatalytic performance of g-C3N4 prepared by direct polymerization of nitrogen-containing precursor system is poor, so it is necessary to regulate the performance of g-C3N4. In this paper, several main preparation methods of g-C3N4 are briefly introduced. Then, it focuses on the modification methods of g-C3N4, including improving crystallinity, constructing heterojunction, regulating morphology and defect engineering, and summarizes the application of g-C3N4 in the field of photocatalysis, including degradation of organic pollutants, decomposition of water to produce hydrogen, production of H2O2 and reduction of CO2. Finally, the future development of g-C3N4 is prospected, and it is suggested that while continuously improving the photocatalytic performance of g-C3N4, more consideration should be given to the design problems faced by actual industrial production. Further research on the preparation of highly crystalline g-C3N4 by molten salt method, the construction of g-C3N4-based heterostructure system, the clear separation mechanism of photogenic carrier in g-C3N4, the mechanism analysis of adsorption and REDOX reaction of reactants on g-C3N4 surface, and the research of recoverable g-C3N4-based photocatalyst are taken as the key development directions. The study on the modification of g-C3N4 has deepened our understanding of the mechanism of photocatalysis, and provided an efficient and stable photocatalyst candidate material for practical applications such as environmental purification and energy conversion, showing a broad application prospect.

Abstract:Petroleum-based phthalate plasticizers have successfully occupied more than 80% of the polyvinyl chloride (PVC) plasticizer market due to their high cost performance and good plasticizer performance. However, due to the negative impact of petroleum-based plasticizers on human health and the environment, the use of petroleum-based plasticizers has been restricted in developed countries in Europe and the United States, so it is imperative to replace petroleum-based plasticizers with environmentally friendly and renewable bio-based plasticizers. Because of its wide source, low cost and rich chemical structure, biorenewable resources provide a broad market for the development of new bio-based PVC plasticizers. This paper reviews the research progress of different types of bio-based PVC plasticizers in recent years, mainly introduces the research and application of plant oils (soybean oil, castor oil, cashew nut oil), citrate esters and other types of bio-based plasticizers (vanillic acid, lactic acid, cashew phenol, tartaric acid, isosorbate, succinate, etc.). The development trend of bio-based plasticizers was also prospected.

Abstract:Photosensitizers are the core substances in photodynamic therapy, which play a crucial role in improving the effect of photodynamic therapy and reducing side effects. However, traditional photosensitizers are prone to aggregation in vivo, which leads to the ACQ (aggregation-caused quenching) effect, resulting in a decrease in the fluorescence intensity and active oxygen generation efficiency of the photosensitizer. Meanwhile, the light absorption and emission wavelength range of traditional photosensitizers also has limitations. AIE (aggregation-induced emission) red-light emitting photosensitizers with high active oxygen production rate in the aggregated state, strong light tissue penetration ability, small background interference, low or even no toxicity to normal cells, etc. have broad application prospects in the field of photodynamic therapy. This review summarizes the design principles of AIE red-light emitting photosensitizers based on cyano, benzothiadiazole, and dipyrromethene fluoroborate electron-withdrawing groups and their relevant applications in photodynamic therapy, with the aim of providing reference for the more efficient and safer molecular design and application research of red-light emitting AIE photosensitizers.

Abstract:The sandwich-structured PMMA-ANF-PMMA (P-A-P) composite film was constructed using vacuum impregnation method based on aramid nanofibers (ANF) and poly(methyl methacrylate) (PMMA) for preparing high dielectric breakdown strength polymer materials over a wide temperature range. The results showed that the P-A-P composite film exhibited a distinct three-layer structure, and the thickness of PMMA layer increases gradually with increment of PMMA concentration. Additionally, the dielectric constant and dielectric loss of the P-A-P composite film decreased with the increase of PMMA concentration. Due to the reduced surface roughness, enhanced Young"s modulus, and the special spatial electric field distribution mechanism in the multilayer structure, the dielectric breakdown strength of P-A-P composite film continuously increased with enhancement of PMMA concentration. When the PMMA solution concentration was 10 wt%, the dielectric breakdown strength of P-A-P composite film at 25°C and 120°C were 262.4 MV/m and 232.8 MV/m, respectively, which were 87.8% and 134.0% higher than that of single-layer P-A-P-0 (ANF film), providing a new approach for preparing polymer materials with high dielectric breakdown strength over a wide temperature range.

Abstract:Silicon-based anodes are the most promising anode materials for lithium-ion batteries (LIBs) due to their high theoretical specific capacity (4200 mAh g_^-1), but their inherent low electrical conductivity and the problem of large volume expansion during cycling limit their applications. In this study, three-dimensional silicon-carbon composites were successfully prepared as anode materials for lithium-ion batteries by a simple ball milling method and high-temperature calcination method. Nanosilica and graphite were used as the active materials, and clay was used as the binder. The three-dimensional silicon-carbon anode materials were obtained by calcination at high temperatures. The electrochemical performances of three-dimensional silicon-carbon anode materials with different silicon dopant amounts were separately investigated. The results show that the prepared 3D silicon-carbon anode material has a high reversible specific capacity of 1757.5 mAh g_^-1 with 96.7% capacity retention after 100 cycles at 100 mA g_^-1 current density when the silicon doping is 20%. A multiplication test was conducted, and the specific capacity of the electrode was restored to 91.6% of the initial multiplication rate, therefore, the 3D silicon-carbon anode material with 20% silicon doping has the best performance.

Abstract:Using an anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), and a silane coupling agent, γ-aminopropyltriethoxysilane (KH550), as modifiers, 4A zeolite was modified to prepare two types of modified 4A zeolites (zeolite-SDBS and zeolite-KH550). Subsequently, poly(butylene adipate-co-terephthalate) (PBAT) was used as the matrix to prepare PBAT/modified 4A zeolite composite films via the solution casting method. The structures and properties of the two modified 4A zeolites were analyzed using FTIR, particle size, Zeta potential, and TGA tests. The effects of the content of the two modified 4A zeolites (based on the mass of PBAT) on the mechanical properties, thermal properties, water vapor permeability, and hydrophilicity of the PBAT/modified 4A zeolite composite films were investigated through tensile tests, TGA and DSC tests, water vapor transmission rate, and water contact angle measurements.The results indicated that, compared to 4A zeolite (median particle size 4.7 μm, Zeta potential 23.6 mV), the median particle sizes of zeolite-KH550 and zeolite-SDBS decreased (4.4 and 4.6 μm, respectively), and the surface negative charge increased (Zeta potential -46.2 and -45.8 mV, respectively). Compared to PBAT/4A zeolite composite films, the tensile strength, elongation at break, and initial decomposition temperature of PBAT/modified 4A zeolite composite films were improved. When the content of zeolite-KH550 and zeolite-SDBS was 20%, the tensile strength of PBAT/modified 4A zeolite composite films (15.4 and 13.5 MPa) increased by 22.2% and 7.1%, respectively, compared to PBAT/4A zeolite composite films (12.6 MPa). When the content of zeolite-KH550 and zeolite-SDBS was 30%, the elongation at break of PBAT/modified 4A zeolite composite films (331% and 303%) increased by 24.4% and 13.9%, respectively, compared to PBAT/4A zeolite composite films (266%). When the content of zeolite-KH550 and zeolite-SDBS was 40%, the initial decomposition temperature of PBAT/modified 4A zeolite composite films (370.9 and 370.7 ℃) increased by 1.3% compared to PBAT/4A zeolite composite films (366.1 ℃). Zeolite-SDBS was more conducive to inducing crystal nucleation but hindered crystal growth; the crystallization temperature of PBAT/modified 4A zeolite composite films prepared with zeolite-KH550 was relatively lower, but the crystallinity was relatively higher. Compared to zeolite-SDBS, PBAT/modified 4A zeolite composite films prepared with zeolite-KH550 exhibited better mechanical properties, thermal degradation performance, and water vapor barrier properties.

Abstract:A series of anion exchange membranes (xPip-30%18PBP) containing both long hydrophobic (with an octadecyl grafting degree of 30%) and flexible hydrophilic (with an alkyl piperidine grafting degree of x) side chains were prepared by introducing octadecyl side chains and flexible hexyl piperidine cationic side chains synthesized with the main raw materials of 1-(6-bromohexyl)-1-methylpiperidine ionic salt (Br-6-Pip) and 1-bromooctadecane into the molecular structure of poly(biphenylpyridine) polymer through Menshutkin reaction. Their chemical structure was characterized by 1HNMR, and the microstructure was observed using SEM and TEM. The effects of the alkyl piperidine grafting degree on the performance of the xPip-30%18PBP membrane were investigated through various tests, including physical property measurements, TGA, mechanical properties, ion conductivity, vanadium ion permeability, and vanadium redox flow battery performance. The results indicate that the xPip-30%18PBP membrane exhibits a well-defined microphase separation structure. As the grafting degree of the flexible alkyl piperidine side chains increases from 40% to 70%, the significance of the microphase separation structure within the membrane also progressively enhances. With the increase in flexible piperidine grafting degree (from 40% to 70%), the ion exchange capacity of the xPip-30%18PBP membrane increases from 2.26 mmol/g to 2.88 mmol/g, the water uptake at 20 ℃ rises from 53.8% to 82.6%, and the swelling ratio increases from 9.9% to 23.4%. The ionic conductivity improves from 28.9 mS/cm to 41.9 mS/cm, while the membrane surface resistance decreases from 0.76 Ω·cm2 to 0.39 Ω·cm2. The tensile strength gradually decreases from 9.6 MPa to 5.7 MPa, while the elongation at break gradually increases from 19.8% to 35.5%. The vanadium ion permeability range from 1.32×10-6 cm2/min to 2.16×10-6 cm2/min. At a grafting degree of 60%, the 60%Pip-30%18PBP membrane demonstrates optimal comprehensive performance. A vanadium redox flow cell assembled with this membrane achieves an energy efficiency of up to 80.0% at a current density of 40 mA/cm2. After 200 charge-discharge cycles at a current density of 100 mA/cm2, the coulombic efficiency remains around 91% to 92%, while the energy efficiency decreases by only 4.2%.

Abstract:The extraction of calcium resources from high-calcium fly ash and the preparation of nano-CaCO3 were conducted in order to realize high value utilization of high-calcium fly ash. NH4Cl was used as an extractant to extract calcium from the high-calcium fly ash. About 50% ammonia in the extraction solution was separated and used to prepare NH4HCO3 solution, and then nano-CaCO3 was prepared with a microchannel reactor by separated nucleation/crystallization technology using NH4HCO3 and extraction solutions as raw materials. The obtained nano-CaCO3 was modified by sodium stearate and subsequently mixed with polypropylene (PP) to prepare CaCO3/PP composites. FT-IR, XRD and SEM characterizations were conducted to analyse the morphology and structure of the prepared nano-CaCO3 and CaCO3/PP composites. The results showed that CaCO3 with high dispersion, uniform size and an average particle size of 45.0 nm was prepared by using 0.5 mol/L CaCl2 solution and 15% ammonium citrate, nucleating at 30 ℃ and crystallizing for 5 min. The sodium stearate modified CaCO3 nanoparticles were uniformly dispersed in the CaCO3/PP composites, which improved the mechanical properties of the composites. The tensile strength, elastic modulus and breaking elongation of CaCO3/PP composites were about 35.6 MPa, 999.8 MPa and 10.26% when 6 wt% nano-CaCO3 was added in PP, which were about 14.5%, 3.2% and 21.0% higher than those of pristine PP (31.1 MPa、968.7 MPa和8.48%), respectively. The modified nano-CaCO3 particles have a strong interaction with PP, and the modified nano-CaCO3 particles are easy to slide on the molecular chain of PP and can absorb the fracture energy during stretching, resulting in the improved toughness of the composite.

Abstract:MOF-5-NH2 was prepared by using 2-aminoterephthalic acid and zinc nitrate hexahydrate at room temperature. A fluorescent composite MOF-5-NH2@C was prepared by encapsulating 7-N,N""-((7-(diethylamino)-2-oxo-2H-chromen-3-yl)methylene)hydrazinecarbothiohydrazide (C) into the pores of MOF-5-NH2 by impregnation method. The structure and composition of MOF-5-NH2 and MOF-5-NH2@C were characterized by SEM, XRD, FT-IR and XPS. The fluorescence recognition properties of MOF-5-NH2@C for 15 common metal cations (K+, Ca2+, Na+, Mg2+, Fe3+, Co2+, Cu2+, Zn2+, Ag+, Cd2+, Pb2+, Cd2+, Hg2+, Ni2+, Al3+) were investigated. The results show that in ethanol, MOF-5-NH2@C has a fluorescence enhancement of 162 times in the presence of Al3+, and the detection limit is 0.328 μmol/L. It has good anti-interference and naked-eye recognition ability, and can detect Al3+ in actual water samples.

Abstract:In present work, cerium phytate (Ce–PA), a high-performance bio-based anticorrosion pigment was developed through a simple mixing between phytic acid and cerium nitrate. A series of epoxy coatings containing different contents of Ce–PA were prepared in order to investigate the anticorrosion performance for aluminum alloy. The microstructure, mechanical property and anticorrosion property were characterized systematically. Ce–PA exhibits a good mono-dispersity and thermal stability, and its average diameter is about 185 nm. In addition, Ce–PA can disperse homogeneously in epoxy coatings and epoxy coatings containing Ce–PA show good mechanical properties. The extract of Ce–PA shows an excellent corrosion inhibiting effect for aluminum alloy in 3.5% NaCl solution, and the highest protection efficiency is up to 98.7%. Subsequently, Ce–PA was introduced into epoxy resin to construct a composite coating in order to give aluminum alloy a long term protection. Electrochemical impedance spectroscopy(EIS) and salt spray test were used to elvaluate the anticorrosion property of epoxy coating with and without defect. Epoxy coating containing 4% of Ce–PA presents the best protectiveness for aluminum alloy. The coating resistance of intact coating still keeps at 108 Ω cm2 after 50 days of immersion in 3.5% NaCl solution, and the coating resistance of the coating with artificial defect also gets to 7.5×106 Ω cm2 after 14 days of immersion in 3.5% NaCl solution. Ce–PA can hydrolize in water releasing Ce4+ and PAn-, the released Ce4+ and PAn- will transfer to Ce(OH)4 and Aln(PA) which covers on aluminum alloy surface to prevent it from corrosion. A series of study confirms that Ce–PA can be used as a high performance anticorrosion pigment to give epoxy coating a long term protection for aluminum alloy in future.

Abstract:With the continuous development of modern biomedical field, the performance requirements of injectable and self-healing hydrogel are increasing. Improving adhesion property to meet the practical applications while satisfying injectable and self-healing properties is an urgent problem to be solved. Polysaccharide based GA-CS/OKGM hydrogel with injectable, self-healing, and adhesion properties was successfully prepared by modifying chitosan (CS) with gallic acid (GA) and then dynamically crosslinked with oxidized konjac glucomannan (OKGM). The synergistic effect of dynamic imine bonding, hydrogen bonding, and electrostatic interactions in polymer network endows the hydrogel with injectable, self-healing, and shape-adaptability properties. This is structural similiarity between the polyphenol moiety in gallic acid and mussel catechol moiety, endowing adhesive property to the hydrogel. In addition, GA-CS/OKGM hydrogel has excellent biocompatibility, biodegradability, and good mechanical properties, which is a promising smart biomaterial in biomedical fields.

Abstract:Three kinds of coal-based isomeric alkylbenzene sulfonates, including sodium dodecylbenzene sulfonate (SDDBS), sodium C6 dimer alkylbenzene sulfonate (SC6DBS) and sodium dihexylbenzene sulfonate (SDHBS), were used as raw materials to compound with isomeric tridecanol polyoxyethylene ether (9) (IC13EO9) to obtain three compound systems SDDBS/IC13EO9, SC6DBS/IC13EO9 and SDHBS/IC13EO9. Based on UV-Vis, surface tensiometer, dynamic light scattering instrument, drop shape analyzer, vertical decontamination machine and other characterization and testing. The results showed that the compound system of alkylbenzene sulfonate and IC13EO9 with a mass ratio of 5∶5 showed the best synergistic effect. The SDHBS/IC13EO9 exhibited good wettability (water contact angle of 53.0 ° at 30 s), foam properties (foam half-life of 349.2 s) and emulsifying properties (emulsifying time of 1035 s), and had comparable decontamination performance to commercial sodium dodecyl benzene sulfonate (LAS)/IC13EO9 complex system.

Abstract:In order to study the effects of phosphorylation and carboxymethylation on the physicochemical properties and hypoglycemic activity of CSP, P-CSP CM-CSP were prepared by using sodium phosphate and chloroacetic acid method respectively. respectively, and their physicochemical properties and hypoglycemic activity were investigated. The results of IR、NMR showed that P-CSP and CM-CSP were successfully prepared; compared with the CSP before modification, the viscosity was reduced, the solubility, the relative molecular mass were increased, and the surface morphology was changed, and the thermal stability was improved; however, the composition of the monosaccharides and the triple-stranded helical structure did not change; in vitro hypoglycemic study showed that 6 mg/mL of CSP, P -CSP and CM-CSP had IC50 of 3.78 mg/mL, 1.94 mg/mL, and 3.82 mg/mL for α-amylase inhibition, and 3.82 mg/mL, 1.98 mg/mL, and 2.12 mg/mL for α-glucosidase inhibition; IR-HepG2 showed an increase in the glucose consumption and liver glycogen results showed that at 2.0 mg/mL, the glucose consumption of CSP, P-CSP, CM-CSP was 6.61 mmol, 8.23 mmol, 7.62 mmol, and the liver glycogen content was 6.31 mg/g, 7.14 mg/g, and 6.52 mg/g, respectively. suggesting that the phosphorylation and carboxymethylation modifications were able to enhance the physicochemical properties and hypoglycaemic activity of Crataegus songarica polysaccharides, which has good potential for application.

Abstract:In order to improve the hydrothermal stability and acid resistance of the catalyst for the hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) in aqueous system, the Ru/SiC catalyst (Ru3/SiC) with a Ru loading capacity of 3% (mass fraction based on SiC mass) was prepared by a sample impregnation-reduction process. TEM, XRD, XPS, H2-TPR and H2-TPD were used to characterize the structure and surface effects of the catalysts. The catalytic performances of Ru catalysts with different support ( SiC, graphene, TiO2，ZrO2、SiO2、Al2O3) for the hydrogenation of LA were investigated. The influences of reaction conditions (reaction temperature, time, hydrogen pressure and solvent) on the hydrogenation of LA catalyzed by Ru3/SiC were studied. The results show that Ru nanoparticles (0.22 nm) in Ru3/SiC are mainly dispersed uniformly on the SiC surface in the form of Ru0. Compared with other supported Ru-based catalysts, Ru3/SiC showed higher catalytic activity for LA hydrogenation in water under mild conditions of 50 ℃, 0.2 MPa H2 for 2 h, and LA conversion rate and GVL selectivity are close to 100%. Moreover, Ru3/SiC activity did not decrease significantly after 5 cycles. The high catalytic activity of Ru3/SiC is due to the electron transfer through Mott-Schottky junction between Ru and SiC. The electron-rich Ru nanoparticles are favorable for H2 dissociation, thus enhancing the catalytic activity for hydrogenation reaction of LA.

Abstract:This research explored the differences in catalytic activity between MgO and CaO in the transesterification reactions through the combinations of theoretical and experimental studies. A series of transesterification reactions involved cyclic carbonates, straight-chain carbonates, carboxylates, or oxalates was designed systematically. And the results showed that both CaO and MgO exhibited catalytic activity in the transesterification reactions between cyclic carbonates and alcohols, whereas CaO demonstrated superior initial activity when reacting with methanol. In addition, the catalytic efficiency of MgO relatively improved with the increased alcohol chains, such as ethanol and n-butanol. The catalytic efficiency for straight-chain carbonate transesterifications was generally lower compared to cyclic ones over both CaO and MgO. When the carbonates reacted with polyols (such as ethylene glycol), the product selectivity decreased over time, possibly due to the ring-opening reactions between the formed cyclic carbonates and excess ethylene glycol.

Abstract:LTA zeolite adsorbent is considered to be a promising material for capturing carbon dioxide (CO2), but its application faces challenges in terms of economy and adsorption capacity. This paper proposes a sustainable green synthesis strategy to construct the LTA (Na-LTA) zeolite precursor using industrial solid waste titania slag as raw material, and then prepare a series of cation-exchanged M-LTA (M: K, Ca, Ce) zeolite molecular sieves adsorbents through conventional liquid-phase ion exchange (LPIE) to adjust the cationic active sites. The dynamic adsorption test and weight adsorption test show that the saturated adsorption capacity of all M-LTA zeolite molecular sieves has been improved, but the penetration adsorption capacity of K-LTA is significantly reduced, which is related to the lower adsorption rate and pore volume. The Ca-LTA type zeolite significantly improved the CO2 capture capacity and CO2/N2 and CO2/CH4 separation rate, and maintained excellent cyclic stability after five cycles of adsorption/desorption; it accelerated the CO2 adsorption rate, being 4.95 times that of the Na-LTA precursor; and according to the Langmuir-Freundlich isotherm model, the maximum adsorption capacity of Ca-LTA could reach 4.02 mmol/g. The CO2 adsorption process by Na-LTA zeolite is dominated by both physical and chemical adsorption. This study follows the environmental protection concept of "treating waste with waste" and provides important reference value for the resource utilization of solid waste and the improvement of environmental pollution through synergistic CO2 capture.

Abstract:To achieve the regulation of spatial crosslinking degree of gelatin solution system and enhance its gelling properties, addressing the issues of poor gelation and low recycling rates during the resource utilization of gelatin solutions, choline chloride-based deep eutectic solvents (DES) were used to regulate the protein conformation in the gelatin solution system. Using gelatin solution as a control group, five different acidic and alkaline choline chloride-based DES were introduced. The effects of DES acidity on the gelling behavior of gelatin solutions were investigated through transmittance ratio, particle size and Zeta potential measurements, and UV-Vis, FTIR, XPS, circular dichroism spectroscopy characterization, and thermal performance testing. Results indicated that acidic DES (choline chloride + oxalic acid, choline chloride + p-toluenesulfonic acid) mainly exerted a pH effect on gelatin solutions by altering the chemical environment, reducing chemical structure strength and stability. Neutral DES (choline chloride + glycerol, choline chloride + sorbitol) disrupted the original hydrogen bonding network within gelatin, forming a new hydrogen bonds. Under the influence of the choline chloride-glycerol deep eutectic solvent, the total content of α-helix and β-sheet structures in the proteins increased from 44.30% to 70.86%, leading to a more ordered and rigid structural transition, indirectly increasing the folded conformations in the tertiary structure, and altering the spatial cross-linking network, thereby enhancing the gelling action of the gelatin solution.

Abstract:In order to explore the effect of nano-zero-valent iron (nZVI) on the storage and in-situ recovery of aerobic granular sludge (AGS) at room temperature, the sludge-water mixture (mass concentration of mixed liquid suspended solid 7.5 g/L) in a 52.0 L sequencing batch reactor was used as the original AGS, and nZVI was added to 1 L of the original AGS to construct a storage system. Based on the 60 d storage experiment, 6 d recovery experiment and organic carbon source (COD) batch experiment, the effects of nZVI addition on the physicochemical properties and denitrification performance of AGS during storage and recovery were investigated, and the changes of nitrification and denitrification were analyzed. The results showed that in the 60 d storage experiment, the amount of nZVI had little effect on the particle shape of AGS before and after storage. The color of all AGS particles became black in different degrees, and the extracellular polymer content, ammonia oxidation rate and nitrate denitrification rate decreased significantly. In the 6-day recovery experiment, most of the AGS particles returned to yellow after the recovery period. The specific oxygen consumption rate and extracellular polymer content of AGS in S2 and S3 with nZVI addition of 1 and 10 g were significantly reduced. The addition of nZVI had no significant effect on the sedimentation of the particles, but had a significant inhibitory effect on the biological activity of AGS, and the inhibitory effect was positively correlated with the amount of nZVI added. The denitrification performance of S1 with 0 g nZVI was the best, and the removal rates of ammonia nitrogen and total inorganic nitrogen reached 95.1% and 84.8% on the first and second days, respectively. S2 reached 93% and 81.3% on the 2nd and 3rd day, respectively. S3 reached 90% and 80.5% on the 4 th day, respectively. In the COD batch experiment, the nitrification reaction of S2 was not significantly different from that of S1, but the nitrite denitrification rate of S2 increased and the nitrate denitrification rate decreased. COD is the main electron donor in the denitrification process of nitrite nitrogen, and nZVI also provides some electrons to supply nitrite nitrogen denitrification, thus enhancing the denitrification rate of nitrite nitrogen. In the denitrification process of nitrate nitrogen, nZVI reacts with COD and lacks the electrons required by the system, thus reducing the denitrification rate of nitrate nitrogen.