Abstract:In recent years, the advanced oxidation process of activated percarbonate has been applied to treat various organic pollutants in water by many scholars due to its low cost, safety and stability, which is expected to become a new environment-friendly water treatment technology. By reviewing a large number of domestic and foreign literatures in the past decade, the mechanism of activating percarbonate for oxidative degradation of organic pollutants was summarized, and the different activation methods and reaction mechanisms of percarbonate such as homogeneous activation, heterogeneous activation, physical activation, combined activation were systematically reviewed. The research status of activated percarbonate advanced oxidation process applied to the degradation of various organic pollutants in wastewater, membrane pollution control, sludge dewatering and sludge anaerobic digestion were also described. Finally, the problems of activated percarbonate advanced oxidation process in the field of water treatment research were pointed out, and the key research directions in the future were prospected, with a view to providing a reference for the further popularization and application of this technology in water pollution control.

Abstract:Methanol oxidation electrocatalyst is the key to the performance, life and cost of direct methanol fuel cells(DMFCs). In order to obtain DMFCs with high power density and low production cost, the design and synthesis of anode catalysts with controllable composition, structure and morphology have attracted much attention. The particle size, particle size distribution, morphology, stability, dispersion and catalytic activity of anode catalyst are closely related to the support. And carbon-based support materials are wide-ly used in DMFCs because of their excellent properties. This paper introduces the mechanism of methanol oxidation reaction in acidic and alkaline environments, and then reviews the application of different forms of carbon materials, such as carbon black, mesoporous carbon, carbon nanomaterials, graphene, ox-ygen-functionalized carbon, heteroatom-doped carbon, and metal oxide-modified carbon as catalyst sup-port in the field of DMFCs. Finally, the Development trend of direct methanol fuel cells is prospected.

Abstract:With the rapid development of industry, the problem of water pollution is becoming more and more serious and threatening human health.Therefore, the removal and treatment of water pollutants is imminent. With the successful preparation of high-performance adsorbents, adsorption technology has become one of the most promising technologies. β-cyclodextrin polymer not only retains the hydroxyl group and cavity structure with adsorption sites in cyclodextrin structure, but also solves the problems that cyclodextrin monomer is easy to dissolve and has poor stability in water, which has attracted much attention in removing water pollutants. However, β-cyclodextrin polymers have different adsorption properties due to different preparation methods. Based on this, the structural characteristics and preparation methods of four kinds of cyclodextrin polymers, which are cross-linked, star-shaped, linear and immobilized, are described in detail, and the adsorption mechanism and application of heavy metals, dyes, endocrine disruptors and other pollutants in water pollutants in recent years are summarized, and their future development is prospected.

Abstract:Collagen is an important essential tissue protein in creatures with excellent biocompatibility, biodegradability and biological activity. The origin and types of collagen are comprehensive. However, the application of unmodified collagen is not satisfactory. This was attributed to poor physical and chemical properties such as thermal stability, mechanical strength, and enzyme resistance. Hence, improving collagen properties via modification attracts attention of researchers. Amino groups on the side chain of collagen provide strong crosslinking ability and positive charge. The application of collagen can be further expanded by amination, which related to the enhancement of positive sites and surface charge of collagen. In this background, the properties and main modification methods of collagen are introduced detailly. The latest research progress of amino-modified collagen in biomedicine, environmental management and the leather industry is reviewed. Finally, the future development of amino-modified collagen in a clean chrome-free leather tanning system has also been prospected.

Abstract:The sources and bioactivities of phenolic acids are briefly introduced, and the multiple skin care effects of phenolic acids as a natural compound, such as whitening and blemish reduction, anti-ageing, anti-inflammation and barrier repair through scavenging free radicals, inhibiting inflammatory responses, antibacterial, inhibiting tyrosinase activity and accelerating the breakdown of late glycation end products in the skin, are reviewed, and the safety issues of phenolic acids are presented. The practical application problems of phenolic acid compounds such as low bioavailability and low water solubility are presented, and some of the practical application problems can be improved by using bio-based nanoparticles loaded with phenolic acid compounds. Finally, the current problems of phenolic acid compounds in the cosmetic industry are described, with a view to providing a reference for the application of phenolic acid compounds in skin care.

Abstract:Two-dimensional transition metal-carbon/nitride (MXene) is a novel two-dimensional carbonized nanomaterial with unique advantages such as a large lateral ratio, short transport pathways, and many nanochannels. The paper firstly reviews the preparation process of MXene/polyvinylidene fluoride (PVDF) membranes and analyzes the regulatory relationships between the electrical, mechanical, thermal, antibacterial, and chemical stability properties of MXene and PVDF membranes; then reviews the progress of MXene/PVDF composite membranes in separation membranes, high dielectric membranes, electromagnetic shielding membranes, and other applications; finally gives an overview of Finally, the development direction of MXene/PVDF membranes is prospected: in the current research stage, the extraction treatment of PVDF membranes is still an effective way to bring into play the excellent performance of MXene, which is a major research tool; at the same time, further in-depth research on the multifunctionality mechanism of MXene"s directional regulation of PVDF membranes can help better understand the interaction law between MXene and PVDF membranes; in addition, the In addition, application-oriented research should be strengthened to form a better practical application system. This will help to understand better the properties and performance of MXene/PVDF composite membranes and promote the research and practical application of MXene/PVDF composite membranes in various fields.

Abstract:Hydroxylation of benzene to phenol is one of the challenging topics for the transition from C—H bonds to C—O bonds. In this paper, the research progress of the reaction mechanism of benzene hydroxylation catalyzed by vanadium-based catalysts to phenol is discussed. Taking vanadium activity center as the main line, the paper focuses on the detailed analysis and summary of three aspects: free radical, non-radical mechanisms and dual-catalysis mechanism, and covers the nature of the high efficiency of such catalysts and the importance of catalytic microenvironment. Because such catalytic systems and catalytic mechanisms can provide theoretical guidance for solving scientific problems such as inert C—H bond on benzene rings and deep oxidation of phenol. Therefore, it is necessary to focus on phenol synthesis methods that coexist with economy and safety, and at the same time rely on the existing catalytic reaction mechanism to develop more stable and high-performance catalysts to promote the original innovation of abundant hydrocarbon organic compound resource utilization in China.

Abstract:Due to the high chemical inertness of CO₂ molecules, the selective activation and controllable conversion of CO₂ become extremely challenging. Compared with electric- or photo-driven catalytic conversion of CO₂, the thermal-driven heterogeneous catalytic conversion of CO₂ is a simple method with adjustable target products and high product yield. Most importantly, the value-added products obtained from the reduction or non-reduction of CO₂ can effectively promote the utilization of CO₂ and alleviate the greenhouse effect, which is of great significance in the fields of environmental protection, energy, and materials. Based on the author"s research work on CO₂ capture and conversion, this review summarizes the current developments and improvements in the thermal-driven heterogeneous catalytic conversion of CO₂ toward the synthesis of CO, CH₄, formic acid, methanol, hydrocarbons, and other fine chemicals in terms of the reaction mechanism, the improvements of catalyst and reaction process. Besides, the problems and limitations of this research field are discussed and the future development direction is prospected.

Abstract:Phase change energy storage is a kind of thermal energy storage, that is, use the heat storage characteristics of phase change materials to store or release the heat, so as to achieve the effect of temperature regulation. However, phase change materials often do not have the ability to absorb light and cannot collect sunlight in time, resulting in low photothermal conversion efficiency. The combination of phase change material and photothermal conversion material can obtain higher light absorption capacity and store the energy obtained in the phase change material, so that the composite phase change material has the high photothermal conversion ability. This review classified the photothermal conversion materials, their photothermal conversion mechanism and absorption capacity of UV-Vis-NIR light and application in the field of phase transition are introduced. In addition, the composite strategies of photothermal composite phase change materials, including impregnation method, sol-gel method, coating method and modified microcapsule method are described, the analysis shows that the optical absorption capacity, thermal conductivity and photothermal conversion efficiency of photothermal composite phase change materials prepared under different composite strategies are almost improved. Therefore, the expansion of photothermal conversion materials into phase change energy storage will further optimize solar energy resources.

Abstract:This paper introduces the development status of fluorine-containing electronic special gases for chip manufacturing. At present, fluorine-containing electronic special gas can be categorized as the traditional ones and new generations. Among them, the new generations have excellent environmental performance, which can replace the traditional ones in the field of etching and cleaning. In this paper, the main synthetic routes of the new products are summarized, and the best industrialization route is pointed out. At this stage, the main intellectual property rights of fluorine-containing electronic special gases are currently monopolized by foreign developed countries, and the processes are complex and inefficient due to the separate parts of etching and cleaning, making it difficult to meet higher precision needs such as high-end chip integration and yield rate. Therefore, future research should mainly focus on the development of new generations with the dual functions of etching/cleaning synergy, which can not only meet the major strategic needs of the country but also have the advantages of simplifying the process, improving efficiency and the chip manufacturing yield, as well as replacing the current ones that are only used in a step-by-step manner.

Abstract:Proton exchange membrane (PEM) is one of the core components of vanadium redox flow battery (VRFB). Excellent PEMs should solve the current problems of high cost and complicated synthesis process and have key properties such as high proton conductivity, low vanadium ion permeability, high mechanical strength and excellent chemical stability. Herein, a series of poly(fluorenyl ether ketone)s (PFEKs) were synthesized based on tetramethylbisphenolfluorene monomer by condensation polymerization, and the phenylmethyl groups were functionalized to bromomethyl groups followed by SN₂ nucleophilic substitution with sodium 4-hydroxybenzenesulfonate to yield a series of sulfonated poly(fluorenyl ether ketone)s (SPFEKs) with different ion exchange capacities. A series of novel low-cost PEMs were obtained by solution casting SPFEKs into membranes and acidification. The synthetic route is based on a wide and inexpensive source of raw materials, which avoids dangerous sulfonation reactions, making it easy for industrial scale-up. All of the prepared PEMs have good mechanical properties and oxidative stability, among which the SPFEK-40 membrane has the most balanced properties such as high proton conductivity, high ion selectivity, low vanadium ion permeability, and low areal resistance. The energy efficiency of the VRFB assembled with SPFEK-40 membrane was 88.2% at a current density of 80 mA/cm^₂, which is higher than that of the VRFB assembled with Nafion 212 membrane (84.8%). In addition, the discharge capacity of the VRFB assembled with SPFEK-40 membrane only decreased to 84.3% after 30 cycles, which is much higher than that of the VRFB assembled Nafion 212 membrane (66.1%).

Abstract:Three single lithium-ion conductive polymer electrolytes membrane were synthesized using lithium 4-styrenesulfonyl(trifluoromethylsulfonyl)imide (LiSTFSI), polyethylene glycol methyl methacrylate (PEGM), tetrafluoropropyl methacrylate (TFMA), octafluoropentyl methacrylate (OFMA) and dodecafluoroheptyl methacrylate (DFMA) as monomers. The membrane were characterized by FTIR, SEM, EIS and LSV. The results show that the synthesized electrolyte membrane have high ionic conductivity (90 ℃, 10-5 S/cm), wide electrochemical stability window (4.5 V) and high lithium-ion transference number (≈1). The button cell of membrane assembled CR 2025 was tested by constant potential intermittent titration (PITT). The results showed that the electrolyte membrane have a high lithium-ion diffusion coefficient (60 ℃, 10-9 cm2/s). After heat treatment, the interfacial stability between the electrolyte membrane and lithium metal was improved obviously. X-ray photoelectron spectroscopy shows that this was related to the enrichment of fluorine-containing side chain groups on the surface of the polymer electrolytes.

Abstract:A metal-cobalt organic framework-derived fibrous rod-like carbon material (Co-DM) with peroxidase-like properties was prepared by a room-temperature synthesis-pyrolysis method in order to achieve a simple, rapid, low-cost and visual detection of L-cysteine (L-Cys). Its morphology, structure and elemental composition were characterized by SEM, TEM, XRD and XPS. The catalytic mechanism of reactive oxygen species was investigated, and Co-DM catalyzed H2O2 to release superoxide anions (O2·?) and hydroxyl radicals (·OH), thereby oxidizing the colorless chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB) to blue oxTMB, performing UV-vis spectrophotometer detection at 652 nm, and recording the colorimetric signal. L-Cys has antioxidant properties and can reduce oxTMB to fade the blue color of the solution. Based on this principle, a colorimetric detection method for the detection of L-Cys was established. Under the optimal conditions, the concentration of L-Cys has a linear relationship with the absorbance in the range of 0.1~15.0 μmol/L, and the detection limit (LOD) is 0.35 μmol/L. In addition, the quantitative relationship between the relative activity of L-Cys and the color characteristic values was established by recording the characteristic values R (red), G (green), and B (blue) values of color change in the range of white (0,0,0) to black (255,255,255) for solutions at different concentrations of L-Cys with the aid of a homemade smartphone optical device and Color Garb software. The detection range was 0.1~70.0 μmol/L and the LOD was 0.27 μmol/L. This method was successfully applied to the detection of L-Cys in clinical human serum, and the recovery rate exceeded 96%. The results show that colorimetric sensing based on Co-DM catalyzed TMB-H2O2 system has broad prospects for the determination of L-Cys, which is sensitive, fast and does not require expensive equipment.

Abstract:The α-Fe2O3@C is used as a carbon source and is calcined at high temperature with titanium and aluminum powders to form FeO@C/MAX (noted as FCM). The FCM charge storage mechanism is explored by kinetic analysis to quantify the pseudocapacitance percentage of the FCM. The compositional and morphological changes of FCM at different Ti/C ratios and Al/C ratios were investigated by characterization with XRD and SEM. The results show that the content of the MAX phase (Al2Ti4C2-Ti3AlC2 mixture) in the FCM product increases with increasing Ti/C ratio as well as Al/C ratio, and that α-Fe2O3 transforms into unstable FeO. According to electrochemical tests, when the molar ratio of Ti, Al and C is 3:1:2, the maximum specific capacitance of FCM is 168.37 F/g at a sweep rate of 10 mV/s, which is approximately 8 times higher than that of α-Fe2O3. Through kinetic analysis, it was found that the MAX phase present in FCM undergoes redox reactions in electrochemistry, providing conditions for rapid electron transport of particles, adding the proportion of FCM pseudocapacitors. The results show that the pseudocapacitance of the FCM-312 is 22.12% at a sweep rate of 10mV/s.

Abstract:Hyperuricemia. The HUA rat model was established with potassium oxonate. Allopurinol was used as positive drug control. Rosa roxburghii tratt extract was divided into low, medium, and high-dose groups. Non-targeted qualitative analysis of rat serum was performed using LC-MS technology, and multivariate statistical methods was used to analyze rat serum data and screen for differential metabolites. Metabolic pathway analysis was performed using the MBRole 2.0 pathway analysis function. The results showed that different rosa roxburghii tratt extract doses could reduce uric acid levels in HUA rats, and 242 metabolites were identified in the serum. Under the criteria of variable importance projection value (VIP>1), P (p-value) value<0.01, and fold change (FC ≥ 2), a total of 44 significantly different metabolites were screened, with a total of 58 metabolic pathways associated with different metabolites. The reduction of uric acid by rosa roxburghii tratt extract may be related to its inhibition of xanthine oxidase activity and regulation of serum lipid and amino acid metabolism. This provides a certain theoretical basis for the prevention or treatment of HUA in rosa roxburghii tratt.

Abstract:The in vitro antioxidant activity of Hippophae rhamnoides L. leaves extracts was evaluated using DPPH? scavenging capacity and total reducing power as indicators, and its ability to be an acetylcholinesterase inhibitor was examined by the inhibition ability of Hippophae rhamnoides L. leaves extracts on acetylcholinesterase. The results showed that five different ethanol volume fractions of (40%, 50%, 60%, 70%, and 80%) Hippophae rhamnoides L. leaves extracts showed good antioxidant activity and acetylcholinesterase inhibitory capacity. The DPPH? scavenging rates, total reducing power, and acetylcholinesterase inhibitory capacity of Hippophae rhamnoides L. leaves extracts with 60% ethanol reached maximum values of (85.80±1.39) %, 3.06±0.18, and (97.14±0.809) % as antioxidants and acetylcholinesterase inhibitors. The screened Hippophae rhamnoides L. leaves extracts showed strong inhibitory ability against acetylcholinesterase with a half inhibitory concentration（IC50） of (1.086±0.144) mg/mL and a mixed reversible type of inhibition against acetylcholinesterase based on the kinetic analysis of enzyme inhibition that was more competitive than non-competitive. The results of AutoDock molecular docking also indicated that the active ingredients of Hippophae rhamnoides L. leaves have a certain docking affinity with acetylcholinesterase. Dose-effect correlation analysis showed a favorable correlation (P<0.05) between the antioxidant and enzyme inhibitory activities of Hippophae rhamnoides L. leaves extracts and the functional components, and it showed that polyphenols played a major role in antioxidant activity and enzyme inhibitors.

Abstract:Nickel-aluminum alloys with different Ni2Al3 contents were prepared by controlling the induction current with intensity of 100 A, 250 A and 400 A. Two kinds of granular Raney nickel catalysts were prepared by pre-etching and two-step etching of the alloy with high Ni2Al3 content. The experimental results show that the catalyst obtained by the secondary etching method can catalyze the hydrogenation of 1,4-butynediol with a conversion rate of 100% and a BDO yield of 92% within one hour, while the pre-etching catalyst takes 3 hours to achieve the same BDO yield. The catalysts were characterized by ICP, BET, XRD, XPS and SEM. The results show that the specific surface area of the catalyst obtained by two-step etching method is larger than that of the pre-etching catalyst, the surface microstructure is more obvious, the content of Ni element is increased, and the dispersion of metal Ni is improved. The surface metal Al completely disappears, while the oxides of Al and Ni increase, which making the skeleton structure of the catalyst surface more stable, thus improving the catalytic activity of the catalyst.

Abstract:Abstract: Porphyrin-based metal organic framework compounds (Al-PMOFs) with cubic columnar crystal structure were synthesized by hydrothermal method. CdZnS nanoparticles were prepared and deposited on the surface of Al-PMOFs cubic columns by chemical coprecipitation, Al-PMOFs/CdZnS nanohybrid materials with good interfacial contact were obtained. The photocatalytic activity of the prepared Al-PMOFs/CdZnS nanohybrids were evaluated by the photooxidative coupling reaction of benzylamine. The results show that Al-PMOFs/CdZnS nanocomposites have excellent photocatalytic activity and stability for the reaction. When N,N-dimethylformamide (DMF) was the solvent at room temperature, after a 7-hour-irridiation of visible light, Benzylamine can be oxidized to form n-benzyl-1-phenylmethylimine (BPMI). The conversion rate of benzylamine can reach 97%, and the selectivity of BPMI is higher than 99%. The photocatalytic activity of Al-PMOFs/CdZnS nanohybrids is 2 times higher than that of each pure component of CdZnS or Al-PMOFs, and photoactivity of the prepared Al-PMOFs/CdZnS nanohybrids can also be extended to the photooxidative coupling of many other benzylamine derivatives. The improvement of the photoactivity of Al-PMOFs/CdZnS nanohybrid materials is mainly due to the formation of Z-scheme heterojunction between Al-PMOFs and CdZnS. After many careful characterizations and analyses, it is proved that the Z-scheme heterojunction can efficiently promote the charge transfer at the interface between Al-PMOFs and CdZnS and inhibit the recombination of the photogenerated carriers on the surface of Al-PMOFs/CdZnS nanohybrids. The probable mechanism as well as the route for the transfer of the photogenerated carriers for this photocatalytic system was proposed by free radical trapping experiment.

Abstract:Acetyl bromide-α-D-glucose(I) as a sugar donor reacted with isoeugenol (II) to synthesize isoeugenol-2,3,4,6-tetra-O-acetyl-β-D-glucoside (Ⅲ) and isoeugenol-β-D-glucoside (Ⅳ). Phase transfer catalysis method and ionic liquid method were explored in the synthesis of compound III. The structures of the intermediates and target products were confirmed by 1HNMR, 13CNMR, IR and HRMS. Compound IV was added into cigarettes, and its transfer rate in the cigarette mainstream smoke was determined by gas chromatography-mass spectrometry (GC/MS). The results show that compound III can be obtained by the above two methods, and the ionic liquid method is better than the phase transfer catalysis method. The reaction conditions of ionic liquid method are as follows: 1-butyl-3-methyl-imidazonium bromide as catalyst, chloroform as solvent, sodium hydroxide aqueous solution as acid binding agent, n (I) : n (II) = 0.8 : 1, n (I) : n (1-butyl-3-methyl-imidazonium bromide) = 1 : 1, reaction at room temperature for 8 hours, yield of compound III is 56.8%. Compound III reacted in sodium methoxide/methanol solution to remove the tetraacetyl group to obtain compound IV in 87.6% yield. During cigarette smoking, the transfer rate of isoeugenol from the thermal decomposition of compound IV to the mainstream smoke particle phase is 3.2%.

Abstract:Ten novel chalcone derivatives bearing thieno[3,2-d]pyrimidine moiety were successfully designed and synthesized based on the principle of drug molecular fragment and splicing principle and evaluate their antiproliferative activities. The structures of the target compounds were confirmed by 1H NMR, 13C NMR and MS. A549, HepG2 and PC-3 cell lines were employed to evaluate anticancer activities of the target compounds using MTT assay in vitro．All the target compounds showed excellent antiproliferative activities against all tested cancer cell lines. Among them, compound Ⅶh exhibited remarkable inhibitory activity against A549, HepG2 and PC-3 cell lines with IC50 value of 0.87 μmol/L, 2.43 μmol/L and 2.02 μmol/L, respectively, which were more potent than that of the positive control sorafenib. Chalcone derivatives bearing thieno[3,2-d]pyrimidine moiety showed excellent antiproliferative activities, and could serve as a scaffold for anticancer drug development.

Abstract:N,O-二-(4,6-dichloro-1,3,5-triazinyl)-glucosamine (CG) was synthesized from cyanuric chloride (TCT) and glucosamine. The structure of the synthesized product was characterized by FTIR and _¹HNMR. And it was used in the leather tanning experiment. Taking the pickled sheepskin as the material, the proper tanning process conditions were determined by single factor experiment: the dosage of CG tanning agent was 7.5% (based on the mass of the limed skin, the same below), and the tanning process was carried out in a step temperature control mode of 30, 40, and 45℃. The tanning time was 1, 1.5, and 2h, respectively; the pH of the bath solution was finally maintained at 6.0-6.5 by basification. The experimental results showed that the shrinkage temperature of the CG tanned crust leather can reach 78.9℃, the leather surface was white and delicate, and the body and bones were soft. This tanning agent is a new organic synthetic tanning agent with good tanning effect and application prospect.

Abstract:A fluorine-containing nanoemulsion (FPA) was prepared with methyl methacrylate, butyl acrylate, γ-methylacryloxy propyl trimethoxy silane and perfluoroalkyl ethyl acrylate (PEA) as raw materials, which can change reservoir wettability and prevent reservoir water lock. The structure and stability of FPA emulsion were characterized by FT-IR, SEM, XRD and particle size. The results showed that PEA was successfully introduced into the polymer chain, and the particle size of the emulsion increased with the increase of PEA mass fraction. When PEA mass fraction was greater than 1.5 %, the emulsion was stratified. When the mass fraction of PEA was 1.5 % (FPA-3), the emulsion stability was the best. The influence of FPA-3 solution mass fraction on core wettability was investigated by surface tension, discharge rate, capillary imbibition and contact Angle. The results show that with the increase of FPA-3 solution mass fraction, the surface tension of FPA-3 solution decreases, the discharge rate increases, the capillary imbibition height decreases, and the contact Angle with water increases. When the mass fraction of FPA-3 emulsion is 2.0 %, the surface tension decreases from 46.01 mN/m to 22.68 mN/m, and the surface tension decreases by 50.7 %. The discharge rate increased from 19.89 % to 29.47 %, and the discharge rate increased by 48.16 %; The capillary imbibition height decreased from 42 mm to 30 mm, and the capillary imbibition height decreased by 28.6 %. The surface free energy of core decreases from 73.2 mN/m to 8.7 mN/m, and the surface free energy of core decreases by 88.11 %. Change the core from hydrophilic (θ=69.8 °) to hydrophobic (θ=125.1 °). Therefore, nano-emulsion containing fluorine can be used as wetting inversion agent to change reservoir wettability and improve gas well recovery.

Abstract:A kind of polyacrylamide polymer RDTA was prepared by free radical aqueous solution polymerization with acrylamide (AM), hydrophobic monomer allyl group dodecylamine and salt tolerant monomer H-66 as raw materials. The polymer structure was characterized by 1H NMR and FTIR, and the association effect of RDTA in different solutions and the relationship between the association behavior and temperature changes were studied through apparent viscosity, SEM, and rheological properties tests. The experimental results indicate that the critical association mass fraction (W*) of RDTA is between 0.25% and 0.3%. The stimulation effect of salt ions on RDTA polymer chains can enhance the structural viscosity of the molecular chain. The elastic modulus G" increases with the increase of RDTA mass fraction, and the solution system exhibits elasticity, resulting in a more dense spatial structure. At 70℃, 90℃, and 120℃, under 170 s-1 shear, when the shear time of 0.5% RDTA in 6% NaCl salt solution is less than 300 s, the viscosity of the solution shows a slow upward trend, indicating that RDTA has a phenomenon of salt stimulating RDTA solution thickening in NaCl salt solution. After further shear for 1 hour, the remaining viscosity after shear is still above 60 mPa·s.

Abstract:Hydroxyethyl ethylenediamine(AEEA) was synthesized from ethylenediamine(EDA) and ethylene oxide(EO) by ethoxylation in a continuous flow microreactor with special microstructure. The effects of material ratio, water content of ethylenediamine, reaction temperature and residence time on the reaction were investigated. The optimal process conditions were determined: n(EDA): n(EO) = 3:1, the water content of ethylenediamine should be controlled within 5% (mass fraction), reaction temperature was 80 °C, and residence time was 60 s. Under these conditions, the conversion of EO is close to 100%, the selectivity of AEEA was 87.4% and the selectivity of dihydroxyethyl ethylenediamine was 9.2%. In the batch kettle reactor, the selectivity of AEEA is 83.5% and the selectivity of dihydroxyethyl ethylenediamine is 15.9% under the same material ratio and reaction temperature. Compared with that, the continuous flow microreactor can effectively improve the selectivity of AEEA, reduce the occurrence of side reactions, greatly shorten the reaction time and improve the reaction efficiency.