• Volume 40,Issue 6,2023 Table of Contents
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    • >Review and monographs
    • Research progress of organic corrosion inhibitors in marine corrosion protection

      2023, 40(6).

      Abstract (644) HTML (0) PDF 7.16 M (901) Comment (0) Favorites

      Abstract:The marine environment (sea water, marine atmosphere, and sea mud) is a naturally corrosive environment with extremely harsh conditions. Steel structures, such as shipping and offshore engineering, which have been used in the marine environment for a long time, are prone to corrosion. Organic corrosion inhibitors have the advantages of excellent design ability of molecular structure, high corrosion inhibition efficiency, and long actuation duration, which can effectively prevent or slow down the corrosion of metals. Therefore, adding an organic corrosion inhibitor to marine anti-corrosion coatings is an effective strategy to improve corrosion resistance. Based on the latest research status at home and abroad, this review summarized the characteristics of organic small molecule corrosion inhibitors and polymer corrosion inhibitors and their applications in marine anti-corrosion coatings, including the molecular structure and performance influencing factors of various organic corrosion inhibitors, analyzing the characteristics and mechanism of organic corrosion inhibitors, and discussing the application of organic corrosion inhibitors in anti-corrosion coatings by different fortification technology. Finally, the future development of organic corrosion inhibitors is prospective.

    • Advances in photocatalytic treatment of microplastics in water

      2023, 40(6).

      Abstract (277) HTML (0) PDF 5.95 M (767) Comment (0) Favorites

      Abstract:In recent years, the environmental problems caused by microplastics (MPs) as new pollutants have received widespread attention. And the aqueous environment, which is the main pool of microplastics, has become a hot research area for its management. Due to their stability, ease of migration, and toxic effects caused by adsorption of other pollutants, etc., conventional water treatment technologies are not able to remove them efficiently and completely. However, photocatalysis can convert MPs to water-soluble hydrocarbons and CO2 at laboratory scale, showing great potential for complete degradation of MPs. This paper reviews the mechanism of MPs removal by photocatalysis and the main factors affecting catalysis to provide a reliable basis for the study of MPs removal in the aqueous environment. At the same time, it prospects the development trend of photocatalytic degradation of MPs and catalysts in complex aqueous environment.

    • Solar-driven atmospheric water harvesting: progress and prospect

      2023, 40(6).

      Abstract (365) HTML (0) PDF 1.81 M (866) Comment (0) Favorites

      Abstract:Solar-driven atmospheric water harvesting (SAWH), inspired by solar interface evaporation and passive radiation cooling, produces freshwater in a green and sustainable manner. It has the advantages of being free from geographical constraints and has great potential in solving the crisis of freshwater resources. In recent years, in order to better realize the application of SAWH, researchers have continuously optimized the moisture absorption materials, the core component of solar-driven atmospheric water harvesting technology, and developed a variety of moisture absorption materials such as moisture absorption salts, zeolites, silica gel, and MOFs. At the same time, new progress has been made in the design and improvement of water gathering devices. In this paper, SAWH is comprehensively reviewed, and different moisture absorption materials suitable for solar-driven atmospheric water harvesting are combed, and the properties of the materials are compared. Different solar-driven atmospheric water gathering systems are analyzed, and the potential applications of water gathering systems under different climatic conditions are discussed. The development direction of this technology is prospected, which provides theoretical guidance and technical support for the application and promotion of SAWH.

    • Field-assisted photocatalysis mechanism and degradationof organic pollutants: A review

      2023, 40(6).

      Abstract (237) HTML (0) PDF 5.95 M (903) Comment (0) Favorites

      Abstract:Photocatalysis can generate free radicals to degrade and mineralize organic pollutants by absorbing solar energy, which has the advantages of green, energy saving, and pollution-free. Photocatalysis is considered to be the most promising advanced oxidation technology. The current research focuses on improving the degradation efficiency of photocatalytic technology. The use of external field-assisted methods, such as electric field and ultrasonic field, can further improve the photocatalytic efficiency by improving the mass transfer efficiency of the solution, suppressing the carrier recombination, and improving the free radical yield. The research progress and application status of the five external fields assisted in photocatalytic degradation of organic pollutants are reviewed, including electric field, thermal field, microwave field, ultrasonic field and magnetic field. The main mechanism of external field to improve photocatalytic degradation efficiency is highlighted. The advantages and disadvantages are summarized, and the problems faced in practical applications are presented. The future research and development directions are prospected.

    • Progress in the synthesis, structure and application of UiO-66

      2023, 40(6).

      Abstract (1594) HTML (0) PDF 8.29 M (1275) Comment (0) Favorites

      Abstract:Metal-organic frameworks (MOFs) materials are widely used in various research fields due to their large specific surface area, high porosity, easy adjustment of pores and easy functionalization. However, the chemical stability and hydrothermal stability of most MOFs are poor, which greatly limits the application of MOFs. Zirconium-based MOFs material UiO-66 has attracted much attention due to its skeleton collapse temperature higher than 500 ℃, withstands 1.0 MPa mechanical pressure and has ultra-high stability. This paper systematically introduces the research progress of various synthesis methods of UiO-66, and it is believed that the dry gel conversion method has the advantages of high product yield, small reaction volume and continuous production. The effects of organic ligands, metal nodes and doping on the structure of UiO-66 were introduced in detail. The research results show that the modification of UiO-66 structure can further improve its performance. The application of UiO-66 in catalysis, gas storage and separation is summarized. The future development direction of UiO-66 is also prospected.

    • Synthesis and application of formyl-substituted BODIPY-based probes

      2023, 40(6).

      Abstract (160) HTML (0) PDF 8.79 M (690) Comment (0) Favorites

      Abstract:Fluorescent probes are widely used in biomedicine, information storage, chemical analysis and other fields due to their high sensitivity, real-time detection, accurate diagnosis and imaging visualization. Among them, borondipyrromethene (BODIPY)-based fluorescent probes are widely designed and developed because of their excellent photophysical and chemical properties. In this review, the molecular design strategies and functional applications of formyl substituted BODIPY fluorophores were summarized and discussed, including α/β-formyl substituted BODIPYs, meso-formyl BODIPYs and 1,7-formyl BODIPYs with different positions, and their applications in anions detections, biological thiol recognition and biological imaging. Design of new formyl substituted BODIPY-based probes shows great development potential in precise diagnosis and treatment in the future.

    • Functional modification strategies of layered double hydroxide adsorbents

      2023, 40(6).

      Abstract (132) HTML (0) PDF 5.14 M (751) Comment (0) Favorites

      Abstract:The study of economic, green, and efficient sewage treatment methods has been a major challenge for the water treatment industry due to the complex nature of wastewater and the increasing demand for clean water supply. Layered double hydroxides (LDHs) are a kind of anionic clay with strong anion exchange capacity, good adjustability, high thermal stability, and rich active sites. As a class of adsorption materials, it has been widely used to adsorb various pollutants in wastewater and shows excellent removal performance. However, the defects in functional groups and structural components severely limit the adsorption performance and application range of pristine LDHs. The functionalization of LDHs with different modification strategies can significantly enhance the pollutant adsorption capacity and selectivity, stability, recyclability, as well as application scope. Based on the optimization of the performance of LDHs in the treatment of pollutants in wastewater, this review focuses on the commonly used functional modification strategies of LDHs, such as intercalation, surface modification, calcination, composite assembly, entrapment, and membrane preparation. The intercalation and surface modification treatment increases the number of special functional groups and promotes the selective adsorption of LDHs for target pollutants. The calcination treatment increases the adsorption efficiency of LDHs for anionic pollutants. And the efficient separation and recovery of LDHs can be realized by other methods, such as composite assembly, entrapment, and membrane preparation. Subsequently, the interaction mechanism between functionalized LDHs and various inorganic non-metallic anions, heavy metal ions, organic dyes, and antibiotic pollutants in wastewater was summarized. In addition, the regeneration methods of functionalized LDHs were also described. Finally, the advantages and the possible obstacles of functionalized LDH adsorbents in the next study were briefly proposed, and its broad application prospects were provided.

    • >Functional materials
    • Synthesis and properties of a series of highly soluble polyimides containing phenolphthalein structures

      2023, 40(6).

      Abstract (113) HTML (0) PDF 629.85 K (661) Comment (0) Favorites

      Abstract:A new aromatic diamine monomer which contains phenolphthalein structure, isopropyl and methyl groups was prepared by thymolphthalein and 4-fluoronitrobenzene through aromatic nucleophilic substitution and oxidation-reduction reaction. Furthermore, a series of high soluble polyimides (PI-1, PI-2 and PI-3) were prepared through one step high temperature condensation polymerization with the new diamine monomer and three commoditized aromatic dianhydrides (4,4’-oxydiphthalic anhydride, 4,4’-arbonyldiphthalic anhydride and 4,4’-biphthalic anhydride). The obtained polyimides were not only dissolved in high boiling point solvents, such as NMP、 DMAc、DMF and DMSO at room temperature, but also could dissolve in low boiling point solvents, such as CHCl3, CH2Cl2 and THF. The polyimides could be easily prepared for film materials by solution casting method. The prepared polyimide films have better optical transparency. Their cut-off wavelengths were between 324 nm to 365 nm, and their transmittance at the wavelength of 450 nm was in the range of 56%~78%. Their glass transition temperatures were between 265 ℃ and 288 ℃, and their temperatures of 10% weight loss were both beyond 430 ℃ in N2 and O2. Meanwhile, these polyimides exhibited good mechanical and dielectric properties. Their tensile strength and elongation at break ranged from 77 MPa to 95 MPa and 9.1% to 13%, and their dielectric constants were in the range of 2.79~3.01 at 1MHz.

    • Preparation and photophysical properties of red region dual-state emission BODIPY

      2023, 40(6).

      Abstract (100) HTML (0) PDF 2.41 M (657) Comment (0) Favorites

      Abstract:Meso-unsubstituted and methyl group substituted BODIPYs and their ligands have been obtained with indole derivatives and 1, 8-naphthalenimide by condensation and coordination reactions. Structures were characterized by NMR, HRMS, single crystal and electronic spectra. The results indicated that the solid emission spectra red-shifted 34 nm by the introduction of methyl group at meso-position. BODIPYs show high intensity fluorescence in dual state (solution and solid state). The liquid and solid fluorescence quantum yields of Ⅳ are as high as 66% and 76.3% respectively. Its solid fluorescence quantum yield is 4.2 times higher than that of Ⅱ (14.6%). The excellent optical properties of Ⅳ can be attributed to the absence of C—H…π interaction and different “head to tail” π-π stacking between layers. Excellent dual state emission luminogens glowing at red region have been obtained by the introduction of methyl group, which is different from other strategies and enriches the types of dual state organic luminescent materials.

    • Preparation and properties of two-dimensional accordion-like MXene/palmitic acid composite phase change materials

      2023, 40(6).

      Abstract (232) HTML (0) PDF 2.80 M (684) Comment (0) Favorites

      Abstract:With the emphasis on environmental protection, the development and utilization of solar energy has become the focus of current research, and the development of latent heat storage technology based on phase change materials (PCM) is one of the important measures to improve the development and utilization of solar energy. In this paper, MXene composites (PA/MXene) were prepared by melt blending method using two-dimensional transition metal carbide and/or carbon nitride (MXene) as the support skeleton and palmitic acid (PA) as the phase change material, and the composites with different Mxene additions were structurally characterized and thermally characterized. Compared with pure palmitic acid, the light absorption range of PA/MXene-20% [MXene mass fraction of 20% (based on the mass of PA/MXene composite)] is increased from 200-263.2 nm to 200-679.3 nm, the degradation temperature is increased by 13%, the thermal conductivity can be increased to 200%, and the photothermal conversion efficiency reaches 84.5%, which can realize integrated application of solar photothermal conversion and thermal energy storage.

    • Preparation and properties of functionalized nanocellulose PLA/PBAT composite film

      2023, 40(6).

      Abstract (366) HTML (0) PDF 6.59 M (962) Comment (0) Favorites

      Abstract:CNF-PPG nanoparticles were prepared by functionalized cellulose nanofibers (CNF) with γ-aminopropyltriethoxysilane (KH550) as a modifier and using polypropylene glycol (PPG) to coat the modified CNF. CNF-PPG were added as fillers to a polylactic acid (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) polymer matrix and PLA/PBAT/CNF-PPG composite films were prepared using the solution casting method. The films were characterized by FTIR, XPS, SEM, DSC and TG, and the effects of the ratio of PLA to PBAT and the addition of CNF-PPG nano-fillers on the mechanical strength, thermal stability and barrier properties of the films were investigated. The results showed that the PLA/PBAT films had higher toughness and thermal stability than the pure PLA films. When m(PLA):m(PBAT)=90:10, the tensile strength of the composite films reached 33.38 MPa and the elongation at break was 39.97% with the addition of 10% (based on the mass of PLA/PBAT, as below) of CNF-PPG nano-fillers. Compared with pure PLA, the final degradation temperature of the composite film was increased from 394 ℃ to 435 ℃; the water vapor and oxygen permeability coefficients were 4.98×10-14 g·cm/cm2·s·Pa and 8.86×10?14 cm3·cm/cm2·s·Pa, which were reduced by 33.6% and 23.5% compared with pure PLA, respectively.

    • Preparation and properties of castor oil-based double cross-linked anticorrosion waterborne polyurethane

      2023, 40(6).

      Abstract (303) HTML (0) PDF 3.21 M (679) Comment (0) Favorites

      Abstract:Castor oil (CO) was introduced as a cross-linking agent into a water-based polyurethane (WPU) capped with pentaerythritol triacrylate (PETA), and the double bonds were cross-linked by ultraviolet light to construct a dual cross-linking system. CWPU coatings with different CO contents were prepared, and the effects of CO content on various properties of CWPU coatings were explored. The test results show that when the CO content is 4 %, the 24 h water absorption of the film is 4.5 %, the surface hardness is 2 H, and the adhesion to the Q235 steel plate substrate is 0. Subsequently, the anti-corrosion performance was tested and analyzed by polarization curve test and impedance spectrum test. The results showed that the protection efficiency of the CWPU coating with 4 % CO content on the Q235 steel plate substrate could reach 99.05 %.

    • Preparation of boron carbonitride nanotubes using as targeted delivery vehicle for DOX and the antitumor performance

      2023, 40(6).

      Abstract (90) HTML (0) PDF 2.46 M (669) Comment (0) Favorites

      Abstract:Using nanomaterials as delivery vehicles of chemotherapeutic drugs enable to reduce their side effects. In this work, BCNNTs were prepared via an improved solid-state reaction method, which were then functionalized by folate (FA) to load doxorubicin (DOX), thereby building a targeted drug delivery system of FA-BCNNTs-DOX. FTIR and UV-Vis analysis results revealed the loading of DOX on FA-BCNNTs, accompanied with the capacity of 87.11 μg/mg. In vitro cytotoxicity test indicated that the antitumor activity of FA-BCNNTs-DOX is significantly higher than those of free DOX and BCNNTs-DOX. Furthermore, FA-BCNNTs-DOX and BCNNTs-DOX were found to possess pH-responsive release characteristic, which helps to improve the bioavailability of DOX and reduce the damage to healthy cells. In addition, cellular uptake research indicated that FA-BCNNTs-DOX entered cancer cells through folate receptor-mediated endocytosis, which greatly enhanced the drug delivery efficiency.

    • Blue emitting 3-bromo-5-pyrazolamide material with aggregation-induced emission for latent fingerprint detection

      2023, 40(6).

      Abstract (85) HTML (0) PDF 2.30 M (731) Comment (0) Favorites

      Abstract:A new blue emitting 3-bromo-(3-chloropyridinyl)-N-[4-(3,6-ditertbutylcarbazolyl)phenyl]- pyrazole-5-carboxamide (compound 1) with D-π-A type was designed and synthesized by using 3-bromo-(3-chloropyridinyl)pyrazole-5-carbonyl chloride and 4-(3,6-ditertbutylcarbazolyl)aniline. Aggregation-induced emission (AIE) and photophysical properties of compound 1 were tested by UV-vis absorption spectrum, fluorescence emission spectra and dynamic light scattering. Based on density-functional theory calculation, compound 1 shows intramolecular charge transfer property, agreeing with its solvent effect. Quantum yield of the compound increased with molecular aggregation 〔Φ(DCM)=60.1%; Φ(powder) = 67.5%; Φ(crystal) = 70.2%〕. Notably, compound 1 exhibited good AIE properties with increasing water fraction in the mixture solution of acetonitrile and water. The maximum emission wavelength (λmax) of crystal compound 1 is 439 nm, which is blue emission. Compared with the crystal state, λmax of compound 1 in powder is redshifted by 17 nm. In addition, compound 1 can accurately detect latent fingerprints including the first level, the second level and even the third level, and also has a good recognition effect on the aged fingerprints.

    • Construction and Property of Oxidized Sodium Alginate/Cellulose Nanocrystal/Polyacrylamide-Gelatin Composite Hydrogel Based on Interpenetrating Network Technology

      2023, 40(6).

      Abstract (130) HTML (0) PDF 1.41 M (672) Comment (0) Favorites

      Abstract:To improve the bio-applicability of alginate hydrogel, the composite hydrogels of oxidized sodium alginate (OSA)/cellulose nanocarrier (CNCs)/ polyacrylamide-gelatin (PAM-GT) were constructed from combination of interpenetrating network technology, CNCs reinforcement and GT surface deposition with OSA. The effects of CNCs dosage on the structure and properties of OSA/CNCs/PAM-GT composite hydrogels were analyzed by FTIR, TGA, XRD, SEM, swelling and degradability experiments as well as cytocompatibility tests. The results showed that CNCs could interact with the polymers in the matrix. As the dosage of CNCs increased, the composite hydrogel exhibited a decreased porosity, enhanced mechanical strength and biodegradability, and a slightly reduced swelling, indicating that CNCs could regulate the physicochemical properties of the composite hydrogels to a certain extent. Meanwhile, the composite hydrogels displayed good cell adhesion, proliferation and differentiation properties. When the dosage of CNCs was 0.5%(based on the mass of OSA solution, the same below), the composite hydrogel showed the best cell proliferation activity for MG63 cells, while displayed the most significant cell differentiation activity when the dosage of CNCs was 1.5%.

    • Rapid detection of sulfide based on the chromogenic reaction of iron (III) ion and o-phenylenediamine

      2023, 40(6).

      Abstract (174) HTML (0) PDF 1.19 M (642) Comment (0) Favorites

      Abstract:A Fe3+-OPD chromogenic system was developed based on the formation of yellow and fluorescent product from direct oxidation of OPD via Fe3+, which was selected from investigation on the oxidation ability of different metal ions (Fe2+, Fe3+, Cu2+, Zn2+, Al3+, Na+, Ca2+, Mg2+, K+, Ag+, Cr3+) towards o-phenylenediamine (OPD). A colorimetric method for selective detection of sulfide was then developed combining the reducibility of sulfide and its strong affinity towards metal ions. The results showed that, in NaAc-HAc buffer solution at pH 4.0, the absorbance and fluorescence intensity of Fe3+-OPD chromogenic system showed a good linear relationship with NaHS concentration ranging 10~ 200 μmol/L and 5~150 μmol/L, respectively. The fluorescence method exhibited a detection limit of 0.1 μmol/L with no observed interference from other reducing substances and thiols. The paper-based colorimetric system, constructed from Fe3+-OPD chromogenic system in combination with test paper, displayed a good linear relationship between blue color value (B value) and the concentration of NaHS in the range of 20~150 μmol/L, and a detection limit of 2 μmol/L. The paper-based colorimetric system was further applied for sulfide quantification in spiked tap water and fetal calf serum.

    • >Catalysis,separation and purification technology
    • Process optimization and functional characteristics analysis of euglena protein foam separation

      2023, 40(6).

      Abstract (81) HTML (0) PDF 4.41 M (676) Comment (0) Favorites

      Abstract:In this study, euglena protein solution was used as raw material, and euglena protein was extracted by foam separation method. With the recovery and enrichment ratio as indexes, the effects of pH, liquid volume, temperature and dilution ratio on the recovery and enrichment ratio of euglena protein were investigated by single factor and response surface design. At the same time, the functional characteristics of euglena protein were studied, and the structure of the protein was analyzed by Fourier transform infrared spectroscopy and dual-beam ultraviolet-visible spectrophotometer. The secondary structure of the protein was identified by Peakfit Version software, and the amino acid composition of euglena protein was determined by amino acid analyzer. The results showed that the optimum conditions for foam separation of Euglena protein were as follows: pH5.5, liquid volume 300 mL, temperature 30 ℃, and 15 times of dilution. Under these conditions, the protein recovery rate was 94.27% and the enrichment ratio was 4.18. The maximum water holding capacity of protein was 7.27 g/g at 60 ℃, and the maximum oil holding capacity was 14.74 g/g at 40 ℃. The emulsifying ability, emulsifying stability, foaming property and foam stability of euglena protein increased at first and then decreased with the increase of mass fraction.. FT-IR and UV showed that euglena sp. protein had a typical protein peak, and its secondary structure indicated that euglena sp. protein was mainly β-folded. The contents of essential amino acids and hydrophobic amino acids in protein are 35.28% and 50.81%. The results provide experimental basis for the study of euglena protein.

    • Adsorptive separation of acetophenone and 1-phenylethanol by β-cyclodextrin-cellulose based hypercrosslinked microspheres

      2023, 40(6).

      Abstract (317) HTML (0) PDF 834.40 K (677) Comment (0) Favorites

      Abstract:The mixture of acetophenone (AP) and 1-phenylethanol (PE), usually produced in petrochemical and biochemical processes, are difficult to be separated by the traditional distillation, crystallization, etc. It is of great significance to separate AP and PE by physical adsorption. A kind of b-cyclodextrin-cellulose based hypercrosslinked microspheres (HCCM) was prepared and used to adsorb and separate AP/PE. The structure of HCCM was characterized by FT-IR, N2 adsorption desorption, scanning electron microscopy and transmission electron microscopy. The results showed that HCCM was a biomass based polymer microsphere with hierarchically porous structure formed by interweaving a large number of sugar units and phenyl rich units. The performance of HCCM for the adsorption and separation of AP/PE was studied. It was found that the equilibrium could be reached quickly, and the adsorption capacity of AP was higher than that of PE. Furthermore, PE, broke through much earlier than AP, with a long breakthrough interval and a high separation factor, which indicate that HCCM can separate AP and PE effectively. The recycling experiment proved that the material possessed excellent reusability.

    • >Perfumes and essences
    • Preparation and thermal properties of two new carbonyl furan flavor precursors

      2023, 40(6).

      Abstract (250) HTML (0) PDF 552.81 K (623) Comment (0) Favorites

      Abstract:In order to develop carbonyl furan flavor precursors, 2-acetylpyridine, 2-acetylthiophene and furfuryl alcohol were used as raw materials to synthesize 1-(furan-2-yl)-1-(Pyridin-2-yl) propan-1-one (Ⅲa) and 1-(furan-2-yl)-1-(thiophen-2-yl) propan-1-one (Ⅲb) in one step via dehydrogenative coupling reaction using iprPNP pincer manganese catalyst. The structure of the compounds Ⅲa and Ⅲb was characterized by 1H NMR, 13C NMR and HRMS, and its thermal properties were identified. The results showed that the target compound Ⅲa began to degrade from 99.9 °C, the main weightlessness interval was 99.9-875 °C, and the weightlessness rate was the largest at 259 °C, with a total weightlessness of 97.31%. The target compound Ⅲb began to degrade from 116.2 °C, the main weightlessness interval was 116.2~875 °C, and the maximum weightlessness rate at 274 °C was 98.41%. Under the aerobic cracking atmosphere of 300~900 °C, a total of 9 volatile products were identified after the cracking of the target compound Ⅲa, mainly including alkyl furans, alkyl pyridines, 2-acetylpyridine and other characteristic fragrance substances; After the cracking of the target compound Ⅲb, a total of 13 volatile products were identified, mainly including alkyl furans, alkyl thiophenes, 2-acetylfurans and other characteristic fragrance substances. According to the changes in the types and relative contents of the main cleavage products, the cracking mechanism was preliminarily revealed. The most suitable addition amount of target compound Ⅲb in a single cigarette is 3mg/kg through the evaluation of incense effect.

    • >Food and feedstuff chemicals
    • Effect of phenolic acid structure on antioxidant activity of phenolic acid-g-polymanturonic acid

      2023, 40(6).

      Abstract (54) HTML (0) PDF 1002.58 K (598) Comment (0) Favorites

      Abstract:Eight kinds of graft copolymers phenolic acid-g-polymanturonic acid (PA-g-PM) were prepared by graft copolymerization of eight phenolic acids (PA) and intermediate PM-EDA, which was synthesized from the reaction between the carboxy group of polymanuronic acid (PM), a hydrolysate of sodium alginate, and the amino group of ethylenediamine (EDA). The preparation conditions of PM-EDA were optimized, and the influence of PA structure on the antioxidant activities of PA-g-PM were investigated. The results showed that under the conditions of n(PM) ∶ n(EDA) =1 ∶ 1.5, n(PM) ∶ n(carbodiimide) ∶ n(N-hydroxysuccinimide)= 1∶2∶1, pH 8.0, and reaction time of 24 h, PM-EDA with the highest substitution degree of 17.27% was obtained. Data from UV-Vis, FTIR and XRD analyses showed that phenolic acids were successfully graft onto PM, with grafting rates ranging from (4.171±0.16) to (8.880±0.32) mg gallic acid/g for the eight copolymers. Compared with PM, all eight PA-g-PM copolymers exhibited significantly enhanced 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging rate and iron reducing power. The antioxidant performance of PA-g-PM was positively correlated with the number of phenolic hydroxyl groups contained, with that of PA-g-PM possessing para-phenolic hydroxyl group superior to that of possessing ortho-phenolic hydroxyl group. Meanwhile, PA-g-PM with methoxy group in replacement of phenolic hydroxyl group showed weakened antioxidant activity.

    • >Water treatment technology and environmental protection
    • Porous Co3O4 Modified with Sulfur in Activating Peroxymonosulfate for Degradation of Methylene Blue

      2023, 40(6).

      Abstract (108) HTML (0) PDF 1.95 M (667) Comment (0) Favorites

      Abstract:Using Na2S2O3 as sulfur source, a series of sulfur-modified porous Co3O4 catalysts with different sulfur contents were prepared by an improved oxalate-pyrolysis method (Sx@Co3O4, x=0.25, 0.5, 0.75, 1, where x represented the added ratio of sulfur and was calculated by the amount of Co(NO3)2?6H2O). Their properties for activating peroxymonosulfate (PMS) to degrade methylene blue (MB) were compared and the catalyst with the best catalytic performance was screened out. On this basis, the influences of treatment parameters including catalyst dosage, PMS concentration, reaction temperature and common anion species on MB degradation ratios under Sx@Co3O4-PMS system were investigated. Besides, the cyclic stability of catalyst was evaluated. Results showed that the performance of Co3O4 was boosted with the increase of sulfur content in the range of this study, and S1@Co3O4 exhibited the best catalytic performance. Moreover, it was confirmed that sulfur element was uniformly bonded on the surface of Co3O4 in the form of SO42-. The modification of S increased the specific surface area, oxygen vacancy content of Co3O4 and enhanced the polarization effect for HSO5-, which was considered as a key reason for improving the catalytic activity of Co3O4. Under the optimal reaction conditions: catalyst dosage of 0.04 g/L, PMS concentration of 0.6 mmol/L, reaction temperature of 25 ℃, and reaction time of 25 min, a degradation rate of 98.35% for MB (500 mL 10 mg/L) could be reached in the S1@Co3O4-PMS advanced oxidation system. S1@Co3O4 was recycled in a simple way and the degradation ratio of MB could reach 68.57% after four consecutive cycles. Furthermore, electron paramagnetic resonance spectroscopy (EPR) confirmed that the degradation of MB in S1@Co3O4-PMS system was the result of co-action of free radicals (?SO4-, ?OH and ?O2-) and non-free radicals (1O2).

    • >Fine chemical intermediates
    • Preparation of Bromomethylimidazole/Melamine Oligomer Composite Catalyst and Its Catalytic Performance for CO2 Cycloaddition Reaction

      2023, 40(6).

      Abstract (209) HTML (0) PDF 1.04 M (605) Comment (0) Favorites

      Abstract:Bromomethylimidazole modified melamine oligomer catalyst(CN MIm) was prepared by two-step method. The structure, morphology and thermal stability of catalyst were characterized by FTIR, XRD, SEM, TG and XPS. The results showed that the imidazole based ionic liquid was successfully loaded on the oligomer of melamine and had good thermal stability. The effects of reaction conditions on the cycloaddition performance of epichlorohydrin(ECH)and CO2 were investigated. Using CN MIm as catalyst, under the conditions of reaction temperature of 120 ℃, reaction time of 1.5 h, CO2 pressure of 2.0 MPa and mass ratio of catalyst to ECH of 0.036, the conversion of ECH and the yield of chloropropylene carbonate(CPC) were 99% and 98%, respectively. Meanwhile, CN MIm had good universality for different epoxides. In addition, the synergistic catalytic reaction mechanism of cycloaddition of epoxide and CO2 by bromine ion in hydroxyl, amino and imidazole based ionic liquids contained in melamine oligomers was proposed.

    • High dispersion Pd/Ni-A-CA nanocatalysts for catalytic hydrogenation of quinoline

      2023, 40(6).

      Abstract (274) HTML (0) PDF 1.89 M (602) Comment (0) Favorites

      Abstract:The amorphous metal-organic compounds (Ni-A-CA) were prepared by combining nickel node with organic ligands (adenine (A) and citric acid (CA)) via solvothermal method. Then, highly dispersed Pd/Ni-A-CA catalysts developed were fabricated by dispersing PdCl2 on amorphous support and reducing PdCl2 solution via freshly prepared NaBH4. The microstructure, morphology, and compositions of the obtained Pd/Ni-A-CA catalysts were comprehensively investigated by XRD, FT-IR, TEM, and XPS, etc. The results showed that Pd NPs were in high dispersed state and Pd NPs size diameter was 2.2 ± 0.3 nm. Besides, there existed a strong interaction effect between Pd NPs and amorphous Ni-A-CA support. The optimal temperature and hydrogen pressure were 90 °C and 2 MPa H2, respectively. Under this condition, the conversion of quinoline and the selectivity of 1,2,3,4-tetrahydroquinoline were about 99% over 3% Pd/Ni-A-CA catalyst for 70 min reaction duration. Furthermore, the Pd/Ni-A-CA catalyst also exhibited good catalytic stability and catalytic performance basically kept unchanged after 5 cycles.

    • Green synthesis of symmetric thiourea compounds

      2023, 40(6).

      Abstract (150) HTML (0) PDF 443.98 K (715) Comment (0) Favorites

      Abstract:Ethylene thiourea (ETU), with both yield and HPLC purity over 99%, was synthesized with ethylenediamine and CS 2 as raw materials and water as solvent in one pot, and characterized by NMR and FTIR. The effects of CS 2 dropping temperature, molar ratio of ethylenediamine to CS 2 , reflux reaction temperature, reflux heating rate, and NaOH dosage in NaOH reaction section on the yield and purity of ETU were then investigated. The results showed that the optimum synthesis conditions were as follows: CS 2 dropping temperature of 25~30 ℃, n(ethylenediamine)∶n(CS 2 )=1∶1.20, reflux reaction temperature of 65~70 ℃, reflux heating rate of 0.17 ℃/min, and NaOH dosage in NaOH reaction section being 3.0% of the mass of ethylenediamine. 1,3-diethylthiourea (DETU) and tetrahydro-2(1H)-pyrimidine thioketone (PUR) were then synthesized under the optimized process conditions, and the pilot test indicated that the process was stable and reliable with the yield and HPLC purity of products obtained >99%, and the mother liquor could be recycled.