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10 June 2022, Volume 43 Issue 6

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Content

Cover and Content of Chemical Journal of Chinese Universities Vol.43 No.6(2022)

2022, 43(6):  1-10. 

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Review

Application of DNA Silver Nanoclusters in the Fluorescence Biosensors based on Functional Nucleic Acids

WANG Junyang, LIU Zheng, ZHANG Qian, SUN Chunyan, LI Hongxia

2022, 43(6):  20220010.  doi:10.7503/cjcu20220010

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DNA silver nanoclusters（DNA-AgNCs） are a kind of fluorescent nanoprobes obtained by reducing Ag⁺ with NaBH₄ using DNA as template， because the N atoms on the base heterocyclic are combined with Ag⁺. Due to the advantages of simple synthesis method， good biocompatibility and adjustable fluorescence emission wavelength， DNA-AgNCs have been widely used in the fields of analysis and detection. In this paper， the application of DNA-AgNCs as label-free fluorescent probes in functional nucleic acids biosensing detection is classified and summarized. In addition， conclusive views on the deficiencies and application potential are put forward， which provide references for future research and application.



Application of Mineralocorticoid Receptor Antagonists with Different Chemical Structures in Cardiovascular Diseases

LIN Zhongqiao, CHEN Peipei, WANG Lei

2022, 43(6):  20220059.  doi:10.7503/cjcu20220059

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Over-activation or over-expressions of mineralocorticoid receptors lead to cardiovascular disease and di-sease progression. Antagonizing mineralocorticoid receptor， inhibiting its over activation and blocking the biological effects mediated by mineralocorticoid receptor， which is effective treatment of those diseases. The different chemical structures of mineralocorticoid receptor antagonists determine the strength of antagonistic effect and clinical targeted application. With the development of the times， optimization of the chemical structure of mineralocorticoid receptor antagonists improves the pharmacological properties， increases the selectivity and reduce the side effects. At the same time， there are different emphases in the treatment of cardiovascular diseases. This paper summarizes the action mechanisms， pharmacological characteristics and clinical application advantages of different kinds of mineralocorticoid receptor antagonists： spironolactone， eplerenone and finerenone， in order to provide new ideas in subsequent clinical application and future new drug research and development.



Electron Transfer on the Semiconductor-microbe Interface and Its Environmental Application

LI Yidi, TIAN Xiaochun, LI Junpeng, CHEN Lixiang, ZHAO Feng

2022, 43(6):  20220089.  doi:10.7503/cjcu20220089

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Semiconductors are widely detected in the natural environment， and microbes are one of the most abundant living organisms on the earth. Semiconductor-microbe hybrid system plays a key role in many fields， such as deeply degradation and mineralization of refractory pollutants， synthesis of value-added chemicals， and bio- geochemical cycles of elements. The key factor between semiconductors and microorganism centers on the electron transfer mechanism and pathway on the abiotic/biotic interface. Therefore， this review focused on the electron transfer on semiconductor-microbe interface， and summed up the functional types of microorganisms， types of semiconductors and photocatalytic mechanism on the biotic/abiotic hybrid system. Direct and indirect electron transfer pathway on the semiconductor-microbe interface were summarized. Methods of enhancing electron transfer methods were also introduced， including direct electron transfer enhanced by semiconductor modification， reducing photo-electrons and holes recombination， and indirect electron transfer enhanced by electron shuttles and carriers. At last， this paper introduces the application of the semiconductor-microbe hybrid system in the environmental field over recent years， including refractory pollutants synergistic degradation， value-added chemical synthesis， and elemental bio-geochemical cycling on the earth. We hope this review will help researchers to strengthen the understanding of the semiconductor-microbe interface， and propose solutions for the design and applications of the hybrid semiconductor-microbe system in the environmental field.



Articles:Inorganix Chemistry

Preparation of Organic Hybrid Mesoporous Beta Zeolite for Alkylation of Mesitylene with Benzyl Alcohol

CHEN Weiqin, LYU Jiamin, YU Shen, LIU Zhan, LI Xiaoyun, CHEN Lihua, SU Baolian

2022, 43(6):  20220086.  doi:10.7503/cjcu20220086

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Through the dual strategy by introducing a hierarchical pore structure and an organic hybrid modification in zeolites， an existing problem of low catalytic selectivity， caused by quantities of side reaction of benzyl alcohol self-etherification in micropores， and the low catalytic activity in the alkylation reaction of benzyl alcohol and mesitylene has been solved. We developed an organic hybrid mesoporous Beta zeolite with high activity and high selectivity to alkylation products， which has greatly increased the number of accessible active centers on external specific surface， effectively reduced the self-etherification side reaction of benzyl alcohol in micropores， and immensely improved its alkylation catalytic activity and selectivity to alkylation product in the reaction of benzyl alcohol and trimethylbenzene. Eventually， we realized the increasing conversion of benzyl alcohol from 66.8% to 99.7% and the increasing selectivity to 2-benzyl-1，3，5-triethyl benzene from 14.8% to 50.7%. This work will provide a new thinking of the development of catalysts with high activity and selectivity in Friedel-Crafts alkylation.



Preparation of Modified Gadolinium/Boron/Polyethylene Nanocomposite and Its Radiation Shielding Performance for Neutron and Gamma-ray

ZHAO Sheng, HUO Zhipeng, ZHONG Guoqiang, ZHANG Hong, HU Liqun

2022, 43(6):  20220039.  doi:10.7503/cjcu20220039

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The surface of nano-sized gadolinium oxide（nanoGd₂O₃） was modified by the coupling agent， 3-（trimethoxysilyl）propyl methacrylate（KH570）， and a new type of nanocomposite（modified-gadolinia/boron carbide/polyethylene， M-nanoGd₂O₃/B₄C/HDPE） was prepared by the hot-pressing method. The results of Fourier transform infrared spectroscopy（FTIR）， scanning electron microscopy（SEM） and energy dispersive X-ray energy spectroscopy（EDS） show that the nanoGd₂O₃ was successfully modified by _{coupling reagent and the surface modification of nanoGd2O3 significantly improved the interfacial compatibility and dispersion in the polyethylene matrix. Thermogravimetric analysis（TGA）， differential scanning calorimetry（DSC） analysis and mechanical tensile tests showed that the modification of nanoGd2O3 improved the thermal stability， tensile strength， elongation at break and Young’s modulus of the composites. The neutron and gamma-ray shielding performance of the M-nanoGd2O3/B4C/HDPE was studied by real tests and Monte Carlo simulation. The results showed that the modified nanoGd2O3 with excellent interfacial compatibility and dispersion could enhance the neutron and gamma-ray shielding rate effectively. The square shape M-nanoGd2O3/B4C/HDPE material could achieve a neutron shielding rate of 90% at thickness of 11.7 cm and a gamma-ray shielding rate of 70% at thickness of 13.5 cm.}



Synthesis， Structure and Fluorescence Detection Properties of a New Lanthanide Metal-Organic Framework Material

LU Cong, LI Zhenhua, LIU Jinlu, HUA Jia, LI Guanghua, SHI Zhan, FENG Shouhua

2022, 43(6):  20220037.  doi:10.7503/cjcu20220037

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A new lanthanide metal-organic framework material， ［Tb₂（bpt）₂（H₂O）₂］·（DMA）_4.5， with Tb³⁺ ion as the metal center was synthesized by solvothermal method. The material was further characterized by single crystal X-ray diffraction（SXRD）， powder X-ray diffraction（PXRD）， elemental analysis（EA）， thermogravimetric analysis（TGA）， Fourier transform infrared spectroscopy（FTIR） and fluorescence spectroscopy（FS）. The results of single crystal diffraction analysis show that the compound has a three-dimensional structure containing a one-dimensional straight channel with a channel window of ca. 1.23 nm×1.10 nm. Fluorescence test results demonstrate that the detection limit for Cr³⁺ ions is as low as 0.22 mg/L， indicating that the compound has superior selectivity. It is expected to have potential application in the field of fluorescent detection of Cr³⁺ ions.



Synthesis and Luminescence Properties of Gd₂ZnTiO₆∶Dy³⁺， Eu³⁺ Single Phase White Light-emitting Phosphors

JIANG Xiaokang, ZHOU Qi, ZHOU Hengwei

2022, 43(6):  20220029.  doi:10.7503/cjcu20220029

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Dy³⁺，Eu³⁺ codoped Gd₂ZnTiO₆ white light-emitting phosphors were prepared by a facile sol-gel method. The phase， morphology and optical properties of these phosphors were characterized by X-ray diffraction（XRD）， scanning electron microscopy（SEM） and photo-luminescence（PL） spectroscopy. The results showed that the obtained Dy³⁺，Eu³⁺ codoped perovskite Gd₂ZnTiO₆∶Dy³⁺，Eu³⁺ phosphors crystallized in the monoclinic space group P2₁/n and were composed of irregular particles with the size of 2—5 μm. Under the excitation of 392 nm near-UV light， Gd₂ ZnTiO₆∶Dy³⁺，Eu³⁺ phosphors exhibited not only yellow and blue luminescence of Dy³⁺， but also characte-ristic red emissions of Eu³⁺. Besides， the obtained samples achieved warm white-light emissions with lower correlated color temperature values by changing the doping concentration of Dy³⁺ and Eu³⁺ ions. Based on their excellent fluorescence properties， Gd₂ZnTiO₆∶Dy³⁺， Eu³⁺ phosphors have potential application in UV-pumped white light-emitting devices．



Analytical Chemistry

Role of Catalyst Acidity in Glucose Conversion over Sn-Al-β Zeolite as Studied by Solid-state NMR

LI Zhiguang, QI Guodong, XU Jun, DENG Feng

2022, 43(6):  20220138.  doi:10.7503/cjcu20220138

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A series of β zeolite catalysts with different acidic properties were prepared. The acidity of these catalysts was characterized by solid-state nuclear magnetic resonance（NMR） probe molecule technique. These catalysts were tested for the conversion of glucose to methyl levulinate. ³¹P NMR of trimethyl phosphine adsorbed on Sn-Al-β zeolite showed that the introduction of framework Sn and Al atoms resulted in both Br?nsted and Lewis acidity. Three Br?nsted acid sites with different acidic strength were distinguished by ¹³C NMR of 2-¹³C-acetone probe molecule， with one being close to “super acid”， which is most likely generated by the synergistic effect between the spatially adjacent Br?nsted and Lewis acid sites. The catalytic reaction of glucose to methyl levulinate showed that Sn-Al-β was superior in catalytic activity and selectivity to methyl levulinate as compared to Sn-β containing only Lewis acid sites， Al-β containing only Br?nsted acid sites and the mixed sample of Sn-β and Al-β. This can be accounted by the synergy of Br?nsted and Lewis acid sites and stronger Br?nsted acidity of Sn-Al-β.



¹H NMR Study on the Conformation of Aromatic Amides Limited by Three-center Hydrogen Bonds

MIN Jing, WANG Liyan

2022, 43(6):  20220084.  doi:10.7503/cjcu20220084

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We designed and synthesized nine N-aryl aromatic amides that could form three-center hydrogen bonds， and six N-aryl aromatic amides that could form two-center hydrogen bonds. Based on their one-dimensional ¹H nuclear magnetic resonance（NMR） spectra in chloroform and dimethye sufoxide（DMSO）， the de-shielding effects of carbonyl groups on βH and γH were analyzed separately. The conformational restriction of aromatic amides by three-center hydrogen bonds was evaluated by combining Δ（δ_βH） and Δ（δ_γH）. It was disclosed that three aromatic amides ［2-fluoro-N-（2-methoxyphenyl）benzamide， N-（2-fluorophenyl）-2-methoxybenzamide and 2-fluoro-N-（2-fluorophenyl）benzamide］ display excellent planarization of molecular comformations at both sides of their carbonyl groups， which would have greater potential in constructing new foldamers. Furthermore， it was inferred that， when an NH group forms hydrogen bond with the second hydrogen-bond acceptor， the hydrogen bond between the NH group and the first hydrogen-bond acceptor would be weakened. In other words， for an aromatic amide with a three-center hydrogen bond， two hydrogen-bond acceptors contend with each other for the NH group， resulting in a balanced situation.



A 3-Hydroxythalidomide-based Ratiometric Fluorescent Probe for the Detection of H₂O₂

LIU Xiaolei, LU Yongqiang, YOU Qi, LIU Guohui, YAO Wei, HU Riming, YAN Jixian, CUI Yu, YANG Xiaofeng, SUN Guoxin, JIANG Xuchuan

2022, 43(6):  20220070.  doi:10.7503/cjcu20220070

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Off-label use of 3-hydroxythalidomide draws more and more attentions due to its known biocompatibility， the metabolic pathway and the unique binding mode to CRBN protein. However， there is rare report about the application in analysis field. Herein， the off-label use of 3-hydroxythalidomide in the field of chemosensor was investigated. We designed and synthesized a H₂O₂ probe 2-（2，6-dioxopiperidin-3-yl）-4-｛［4-（4，4，5，5-tetramethyl-1，3，2-dioxaborolan-2-yl）-benzyl］oxy｝isoindoline-1，3-dione with fluorescent properties， using the old drug 3-hydroxythali-domide as parent compound. Based on the analysis， the probe has high selectivity and sensitivity for H₂O₂ over other analysts based on the exited state intramolecular proton transfer mechanism. Furthermore， the probe has good selectivity towards other analysts with a limit of detection（LOD） of 9.8 nmol/L， and it was successfully used in the detection of H₂O₂ in cosmetics samples， water samples and sewage samples. Meanwhile， we revealed the sensoring mechanism through the spectrum technology and the theoretic calculations.



Measurement of Particle Size Distribution of Battery Slurries Using Ultrasonic Attenuation Spectroscopy

HUANG Mingxin, ZHOU Lei, WANG Xuezhong

2022, 43(6):  20220040.  doi:10.7503/cjcu20220040

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The particle size distribution and dispersion uniformity of the granular active material in the battery slurries have a direct impact on the important properties of the battery such as internal resistance， voltage， local surface current， and total polarization degree. It is of great significance for the quality control of the battery if its present line can be measured in real time. Based on the characteristics of high solid content， high viscosity and low transmittance of battery slurry， this paper investigates the measurement of its particle size distribution by ultrasonic attenuation spectroscopy. The biggest difficulty in applying to the particle size distribution measurement of battery slurries is that its model for predicting the particle size distribution using the ultrasound attenuation spectroscopy requires difficult-to-obtain physical parameters of the dispersed and continuous phases. In this paper， principal component analysis（PCA） combined with error back propagation（BP） neural network is proposed to establish a prediction model to solve the difficulties of ultrasonic attenuation spectroscopy method， and genetic algorithm（GA） is introduced to optimize the initial weights and thresholds of the BP network. Combined with the battery slurry with LiCoO₂ as the active material for validation， the results show that the PCA-GA-BP neural network can effectively predict the particle size distribution of battery slurry with different solid contents， and the predicted values have high peak shape overlap with the real values and small peak height deviation， with the mean square error of 0.1358 and the degree of fit（R²） of 0.9816， indicating that ultrasonic attenuation spectroscopy can be used as an important way to measure the particle size distribution of battery slurry.



SERS Nanoprobe for the Detection of Reactive Oxygen Species in Cells Produced by Electrostimulus

CHEN Jiamin, QU Xiaozhang, QI Guohua, XU Weiqing, JIN Yongdong, XU Shuping

2022, 43(6):  20220033.  doi:10.7503/cjcu20220033

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Electrostimulus（ES） is an important therapeutic method for diseases caused by abnormal intracellular electrical activity. Also， ES can induce apoptosis of cells， which is a potential tumor treatment method. At present， there are no relevant studies on the intracellular reactive oxygen species（ROS） levels produced in the process of ES， and what effects will be brought by the simultaneous implementation of conventional antioxidant inhibitor drugs and ES therapy. In this study， a kind of gold/silver core-shell nanorod-based surface-enhanced Raman（SERS）-active probe with good biocompatibility was designed for the detection of intracellular ROS generated during ES. The sensing mechanism realized the quantitative analysis of ROS based on the principle that ROS could etch the silver shell， leading to a decrease of the SERS signal of the SERS probe. The probe was co-incubated with cells and was internalized into cells. The cells were then electrically stimulated for different periods of time. Finally， the signal of the SERS probe was detected in vivo. The experimental results show that the SERS signal weakens with the extension of ES time， indicating that the amount of ROS produced in cells increases significantly. In addition， two antioxidation inhibitors， ascorbic acid（AA） and glutathione（GSH）， were studied when combined with ES. It was observed that they could eliminate reactive oxygen species（ROS） produced by electrical stimulation. This study developed a new method for intracellular ROS detection and suggests a combination of drugs for abnormal oxidative stress and tumor therapy. Also， ES can induce apoptosis of cells， which is a potential tumor treatment method.



Preparation and Chromatographic Performance of Mixed-mode Silica Stationary Phase Modified by Double Cationic Ionic Liquid and Octadecyl Group

JI Shuangqi, JIN Zhao, GUAN Wenna, PAN Xiangyu, GUAN Tong

2022, 43(6):  20220008.  doi:10.7503/cjcu20220008

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In this paper， a mixed-mode silica chromatography stationary phase（Sil-C18-IL-C4） modified by imidazole-based double cationic ionic liquid and octadecyl group was prepared by a step-by-step bonding reaction. The stationary phase was characterized by elemental analysis and infrared spectroscopy. The chromatographic separation performance of the stationary phase in reversed-phase mode（RPLC）， hydrophilic mode（HILIC） and RPLC/HILIC mixed-mode were evaluated， respectively， and 6 base nucleosides were separated in HILIC mode. The influence of the volume fraction of the organic phase and the concentration of ammonium formate in the aqueous phase on the separation effect was also investigated. In addition， the repeatability of stationary phase separation was investigated. Elemental analysis and characterization of the prepared Sil-C18-IL-C4 stationary phase show that the nitrogen content was 1.65%， the carbon content was 11.16%， and the hydrogen content was 2.44%. In the characterization results of infrared spectroscopy， the asymmetric and symmetric stretching vibration peaks of —CH appeared at 2928 and 2856 cm^?1， and the stretching of C=C on the imidazole ring appeared at 1440 and 660 cm^?1. The vibration peaks and the bending vibration peaks of C=N indicate that both octadecyl and 1，5-bis（imidazol-1-yl）pentane were grafted onto the silica surface. The chromatographic performance evaluation results showed that the Sil-C18-IL-C4 mixed-mode silica stationary phase could simultaneously exhibit reversed-phase and hydrophilic-interaction chromatogra-phic separation performance， and could completely separate 6 kinds of base nucleosides. Moreover， under certain chromatographic conditions， the RPLC/HILIC mixed separation mode can be realized in a single run of a single chromatographic column. It has good application potential for solving hydrophilic substances such as base nucleosides in complex samples.



Organic Chemistry

Synthesis and Topochemical Polymerization Study of Naphthalene/perylene Imides Substituted Diacetylene Derivatives

LIU Qingqing, WANG Pu, WANG Yongshuai, ZHAO Man, DONG Huanli

2022, 43(6):  20220091.  doi:10.7503/cjcu20220091

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Naphthalene/perylene imide substituted terminal alkyne and iodide monomers were prepared by a five-step reaction. Two new symmetric diacetylene monomers， pale yellow powder 2-（2-ethylhexyl）-7-｛4-［7-（2-ethylhexyl）-1，3，6，8-tetraoxo-1，2，3，3a，5a，6，7，8-octahydroisoquinolino［6，5，4-def］isoquinolin-2-yl］buta-1，3-diynyl｝- 1，2，3，6，7，8-hexahydroisoquinolino［6，5，4-def］isoquinoline-1，3，6，8-tetraone（diNDI） and deep red powder 9-｛4-［1，3，8，10-tetraoxo-9-（tricos-12-yl）-1，2，3，8，9，10-hexahydroisoquinolino［6'，5'，4'：9，1，2］anthra［6，5，10-def］isoquinolin-2-yl］buta-1，3-diynyl｝-2-（tricos-12-yl）-1，2，3，8，9，10-hexahydroisoquinolino［6'，5'，4'：9，1，2］anthra［6，5，10-def］isoquinoline-1，3，8，10-tetraone（diPDI）， were synthesized by the Sonagashira coupling reaction with yields up to 60% and 70%， respectively. Due to the strong electron-withdrawing of NDI and PDI side groups， they exhibited deeper lowest unoccupied molecular orbital energy levels of -3.80 and -3.70 eV， respectively. The single crystal data of diNDI showed that the intermolecular hydrogen bonding and π-π interaction of naphthalene imide units mediated the intermolecular assembly of diNDI， showing a layer packing model. The differential scanning calorimetry results indicated that diNDI polymerized in solid-state under heating. The changes in the UV-Vis absorption and in situ Raman spectra of diNDI under heating and 532 nm-10% laser irradiation condition indicated that diNDI microcrystals might react to form a distorted structure instead of a fully conjugated backbone that usually resulted from the regular 1，4-addition. The laser irradiation conditions were found to facilitate the polymerization reaction.



Combined PGC-Triple-Tof-MS Enables the Separation， Identification of Sugar Beet Pectin Derived Oligomers

ZHU Kai, LI Jie, WU Xiaoyi, HU Weiwei, WU Dongmei, YU Chengxiao, GE Zhiwei, YE Xingqian, CHEN Shiguo

2022, 43(6):  20220023.  doi:10.7503/cjcu20220023

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Sugar beet pectin（SBP） was extracted by high-temperature acid method， the water-eluted components（SBPW） and salt-eluted components（SBP3） were obtained by strong anion exchange chromatography. The results of monosaccharide composition and molecular weight analysis showed that SBPW was mainly composed of galactose（Gal）， arabinose（Ara） and galacturonic acid（GalA）， with a molecular weight of 1100， while SBP3 was dominated by GalA and weighted 41450. Combined sequential enzymatic degradation and porous graphitized carbon column-quadrupole-time-of-flight mass spectrometry（PGC-Triple-Tof MS）， the fine structure of SPPW and SPP3 oligosaccharides was analyzed. The results showed that the main chain of SPBW was ［→4）-α-GalA-（1→2）-α-Rha-（1→］ repetitive units composed of RG-Ⅰ pectin， and neutral sugar side chain ［α-（1→5） arabinan and β-（1→4） galactan］ were substituted for Rha at the O-4 position. SBP3 consisted of HG and RGⅠ with a molar of 3：2， HG was a linear structure of α-1，4-linked GalA， HG and RG-Ⅰ domains were connected directly by α-1，4 glycoside bonds. New characteristic structures of oligosaccharide have also been found， similar to α-GalA（1→2）α-Rha（1→4）α-Rha（1→4）α-GalA（1→2）α-Rha.



Physical Chemistry

Effects of Thermodynamic Data on Combustion Characters of 1，3-Butadiene

REN Nana, XUE Jie, WANG Zhifan, YAO Xiaoxia, WANG Fan

2022, 43(6):  20220151.  doi:10.7503/cjcu20220151

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In this work， thermodynamic data for 102 species in a skeletal reaction mechanism for combustion of 1，3-butadiene were calculated based on the G4 method. Effects of anharmonic vibration， scaling factor for frequencies and internal rotations on these thermodynamic data of these species were investigated. The results show that effects of internal rotations are sizeable on thermodynamic data， while the anharmonic effect and different scaling factor for frequencies do not have a much effect on these thermodynamic data. Agreement between available experimental results and the present thermodynamic data will be improved when the internal rotations are considered. Effects of thermodynamic data obtained in this work on adiabatic combustion temperature and ignition delay time of 1，3-butadiene were also studied. The results indicate that experimental thermodynamic data for small molecules such as CO and CO₂ should be adopted to obtain reliable adiabatic combustion temperatures. On the other hand， ignition delay times with the original thermodynamic data diff considerably from those using thermodynamic data obtained in this work. The results indicate that effects of ignition delay times are affected by thermodynamic data through their effect on rate constants of reverse reactions. Furthermore， species whose thermodynamic data has large impact on ignition delay times are also identified. These works will be important in obtaining reliable thermodynamic data and kinetic mechanism for combustion.



Preparation of CuO/BiVO₄ Photocatalyst and Research on Carbon Dioxide Reduction

SONG Yingying, HUANG Lin, LI Qingsen, CHEN Limiao

2022, 43(6):  20220126.  doi:10.7503/cjcu20220126

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The CuO/BiVO₄ heterojunction photocatalyst was constructed based on decahedral bismuth vanadate （BiVO₄） and copper oxide（CuO） nanoparticles. The morphology， structure and optoelectronic properties of the catalysts were analyzed by X-ray diffractometer（XRD）， X-ray photoelectron spectroscopy（XPS）， scanning electron microscope（SEM）， ultraviolet-visible absorption spectroscopy（UV-Vis）， photocurrent response spectroscopy（I-t）， electrochemical impedance spectroscopy（EIS） and fluorescence emission spectroscopy（PL）. The results show that CuO nanoparticles are uniformly supported on the surface of BiVO₄， and the content of CuO can be adjusted by controlling the amount of copper source. The content of CuO has a great effect on the visible light absorption capacity and the separation efficiency of photogenerated carriers of the CuO/BiVO₄ heterojunction. The photocatalytic CO₂ reduction performance of CuO/BiVO₄ heterojunction under gas-solid reaction system was investigated. The results showed that the main products of photocatalytic reduction of CO₂ were CO and CH₄. With the increase of CuO content， the yield of CO decreased gradually， while the yield of CH₄ increased first and then decreased. The CO and CH₄ yields of the optimized catalyst CuO/BiVO₄ were 0.62 and 1.81 μmol·g^-1·h^-1， respectively， and the selectivity to CH₄ reached the maximum value（93%）. Band structure analysis and electron paramagnetic resonance（EPR） test results show that the transfer of photogenerated charges in CuO/BiVO₄ conforms to the Z-type transfer mechanism. The formation of the Z-type heterostructure promotes the separation of photogenerated electrons and holes and enhances the redox capacity of the catalytic system.



Uniaxial Negative Thermal Expansion and Mechanism in Zn（NCN）

SHI Naike, ZHANG Ya, SANSON Andrea, WANG Lei, CHEN Jun

2022, 43(6):  20220124.  doi:10.7503/cjcu20220124

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As an abnormal physical phenomenon， negative thermal expansion（NTE） has been observed in some materials like alloys and framework structure materials. However， the types of NTE materials are still limited. In this study， a uniaxial NTE material Zn（NCN） was synthesized. The coefficient of thermal expansion of the c-axis is -3.35×10^?6 K^?1 of 100—475 K， while the a and b axes show low thermal expansion. The volume of Zn（NCN） has a low coefficient of thermal expansion（α_vca. 6.13×10^?6 K^?1， 100—475 K）. The NTE mechanism was revealed by joined methods of synchrotron X-ray diffraction， extended X-ray absorption fine structure spectroscopy， and Raman spectra. It is found that the Zn—N exhibits obvious transverse vibration. Some low frequency vibration modes show negative Grüneisen parameter. The direct experimental evidence reveals that the transverse vibration of N=C=N linkage and coupling rotation and twist of quasi rigid ZnN₄ tetrahedra result in the NTE in the c-axis.



Experimental Optimization and Theoretical Simulation of High Performance Field-effect Transistors Based on Multilayer Tungsten Diselenide

ZHANG Yichao, ZHAO Fulai, WANG Yu, WANG Yaling, SHEN Yongtao, FENG Yiyu, FENG Wei

2022, 43(6):  20220113.  doi:10.7503/cjcu20220113

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The field-effect transistors（FETs） were prepared based on high-quality WSe₂ nanosheets of different thicknesses by mechanical exfoliation method and the influencing factors of their performance were investigated. By regulating the WSe₂ nanosheet and dielectric layer substrate thickness， testing temperature， annealing treatment， combined with theoretical simulation analysis， the best electrical performance of WSe₂-FETs was obtained. Finally， the obtained 7-layer WSe₂ nanosheets exhibit the most excellent electrical properties with carrier mobility up to 93.17 cm²·V^?1·s^?1 at room temperature and 482.78 cm²·V^?1·s^?1 at low temperature of 78 K.



Pickering Emulsion Stabilization and Interfacial Catalytic Oxidation by Janus Nano-Au

WANG Hong, SAN Khin Nyein Ei, FANG Yun, ZHANG Xinyu, FAN Ye

2022, 43(6):  20220105.  doi:10.7503/cjcu20220105

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Structural design and facile synthesis of Janus nanoparticles are crucial to Pickering emulsion interfacial catalysis. By manipulating self-assembly and self-crosslinking activities and weak reducibility of conjugated linoleic acid（CLA）， Janus self-crosslinked admicelle-decorated nano-Fe₃O₄（SCA-Fe₃O₄） was synthesized under protection by Pickering emulsions， and then Janus nano-Au catalyst（Au-SCA-Fe₃O₄） was prepared by in-situ reduction of Au on the particle surface. Subsequently， Au-SCA-Fe₃O₄ was investigated to act as both emulsifier and catalyst in the emulsion interfacial catalytic oxidation of benzyl alcohol to benzaldehyde. Experimental results show that Au-SCA-Fe₃O₄ is only with 0.66%（mass fraction） of Au content， but shows emulsifying， catalytic activities and magnetic response simultaneously. It creates a Pickering emulsion with appearance stability（uniform size of about 100 μm） and thermal stability（up to 90 ℃）， and improves the catalytic activity to be two fold of the fully-modified counterpart and three times as high as the coarse dispersion， which is ascribed to significantly increased contact between insoluble reactants and the catalyst. Moreover， the selectivity of benzaldehyde is higher than 99.9%， which depends on the non-rotational property of Au-SCA-Fe₃O₄ at the benzyl alcohol/water interface avoiding the excessive oxidation of benzaldehyde into benzoic acid. It would offer a new approach for green synthesis and application of Janus nano-catalysts.



Construction of Dual-functional 2D/3D Hydrid Co₂P-CeO _x Heterostructure Integrated Electrode for Electrocatalytic Urea Oxidation Assisted Hydrogen Production

YANG Lijun, YU Yang, ZHANG Lei

2022, 43(6):  20220082.  doi:10.7503/cjcu20220082

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A high catalytic activity and stable dual-functional hierarchical 2D/3D hybrid Co₂P-CeO _x integrated electrode（Co₂P-CeO _x /NF） for electrocatalytic urea oxidation assisted hydrogen production was prepared by multi-step electrodeposition and low-temperature phosphating on nickel foam（NF）. Through the strong interfacial interaction and electron synergistic coupling between 3D CeO _x nanoflower and 2D Co₂P nanosheet， the as-prepared Co₂P-CeO _x /NF exhibited high conductivity， catalytic activity and stability， and enhanced the electrocatalytic hydrogen evolution reaction（HER） and urea oxidation reaction（UOR） performance. Assembling an electrolyzer with a straight substitution of UOR for oxygen evolution reaction（OER）， it needed only 1.42 V to achieve a current density of 30 mA/cm²， which was 0.17 V less than that required for water splitting. After 10 h of electrocatalysis， the degradation efficiency of urea reached 76.4%， realizing the preparation of clean energy hydrogen and synchronous wastewater purification， opening up a new path for green energy development and environmental governance. Based on the comprehensive analysis above， the electron transfer at the heterogeneous interfaces between 2D Co₂P nanosheet and 3D CeO _x nanoflower would cause the rearrangement of surface/interfacial charges； the formed oxygen vacancies provided coordination unsaturated sites， exposed more active sites， optimized the adsorption energy of reactant molecules on the catalyst surface and promoted molecular activation， making it have higher catalytic activity. In this study， a 2D/3D hybrid Co₂P-CeO _x heterojunction was constructed to regulate the charge states at the surface/interface of the electrocatalyst and thus improve the catalyst activity， providing a new idea for the construction of other efficient electrocatalysts.



Analysis of Gating Characteristics of TRPM8 Channel Based on Molecular Dynamics

GAO Zhiwei, LI Junwei, SHI Sai, FU Qiang, JIA Junru, AN Hailong

2022, 43(6):  20220080.  doi:10.7503/cjcu20220080

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Physiological functions of TRPM8 channel， such as temperature sensing， depend on normal gating. Due to the lack and insufficient number of existing crystal structures， the gating characteristics of TRPM8 channels need to be further explored. Therefore， 11 TRPM8 channels with different conformations were constructed， basing on the existing crystal structure and AlphaFold algorithm. It was found that there were two different architectural in the S6 transmembrane helical bundle crossing domain（gating）： loop state and helix state. At the loop state， multiple amino acids participated in the formation of pore regions that hinder ion permeability， while in the helical architecture. Only the key amino acid V956 played a gating role. Because the flexibility of the gated loop architecture was greater than that of the helical， and the number of key amino acids involved in gating was different. The secondary structure prediction showed that the loop architecture could change to the helical. In this process， the flexible loop domain moved upward to the outside of the cell， and the gated amino acids twisted to the outside of the pore lining. At the same time， the interaction with the adjacent transmembrane S5 helix was enhanced， and a rigid， stable and orderly helical architecture was formed. This promoted the coordination between the various domains of TRPM8 channel， enabled energy and information to be transmitted to the bundle crossing more efficiently， which was conducive to channel opening.



Preparation of Ethyl α⁃Cyanocinnamate Catalyzed by Nitrogen-rich Porous Organic Polymers

GAO Wenxiu, LYU Jieqiong, GAO Yongping, KONG Changjian, WANG Xueping, GUO Shengnan, LOU Dawei

2022, 43(6):  20220078.  doi:10.7503/cjcu20220078

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Ethyl α-cyanocinnamate， an electron-deficient olefin containing various functional groups， is a highly suitable substrate for organic synthesis reactions. It is mainly obtained by catalytic Knoevenagel condensation reaction. Nitrogen-rich porous organic polymer mPMF was prepared by the solvothermal method using paraformaldehyde and melamine as substrates， and K₂CO₃-mPMF-X（X=1， 10， 50） was obtained by K₂CO₃ treatment. The catalytic performance of mPMF in the Knoevenagel condensation reaction of benzaldehyde and ethyl cyanoacetate was discussed. To investigate the effect of basicity on the Knoevenagel condensation reaction by comparing the catalytic activity of mPMF and K₂CO₃-mPMF-X. The catalytic reaction mechanism was initially explored. The experimental performance indicates that the abundance of nitrogen species in the catalyst provides a basic environment and a lot of basic active sites for the reaction. Control of catalyst basicity is an essential factor in the catalytic synthesis of ethyl α-cyanocinnamate. The reaction of mPMF in methanol solvent at 60 ℃ for 3 h resulted in 97% conversion of benzaldehyde and over 99.9% selectivity of the target product.



Biomass Derived Nitrogen Doped Porous Carbon Materials as Adsorbents for Removal of Methylene Blue in Water

HAO Honglei, MENG Fanyu, LI Ruoyu, LI Yingqiu, JIA Mingjun, ZHANG Wenxiang, YUAN Xiaoling

2022, 43(6):  20220055.  doi:10.7503/cjcu20220055

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A series of biomass（willow leaves） derived nitrogen doped porous carbon materials（WNC） were prepared by a sol-gel route， and were characterized by a variety of means. The results show that the WNC materials possessed high surface areas（528—618 m²/g） as well as large number of oxygen-containing and nitrogen-containing groups （molar fraction of nitrogen 8.9%—9.9%）. The WNC materials exhibit excellent adsorption capacity for Methylene blue（MB） in wastewater. The pseudo-second-order kinetic model and Langmuir isothermal model fit the adsorption data well and the adsorption process of MB was spontaneous and endothermic， the maximum monolayer adsorption capacity calculated from Langmuir model was 263.2 mg/g（pH=5，T=298 K）.WNC-2 material can be easily recycled for many times without obvious loss in adsorption capability. Furthermore，two other samples of WNC-2-R and WNC-2-MB， which were obtained through the high-temperature calcination of the fresh WNC-2 and the used WNC-2 （after adsorption of dye MB），show much higher adsorption capacity for MB （1.3 and 1.6 times of the fresh sample）， respectively， possibly related to the significant increase of the zeta-potential and surface alkalinity. Combined with various characterization results， it can be concluded that the high specific surface area and the hierarchical porous pore structure of WNC materials are beneficial to the transport of the MB ions，while the abundant carbonyl，quinone and pyridine nitrogen groups existed on the surface of WNC materials could strongly interact with the adsorbate， thus resulting in a higher adsorption rate and adsorption capacity for MB.



Heterostructure Construction of Noble-metal-free Ternary Composite Ni（PO₃）₂-Ni₂P/CdS NPs and Its Visible Light Efficient Catalytic Hydrogen Production

WANG Guangqi, BI Yiyang, WANG Jiabo, SHI Hongfei, LIU Qun, ZHANG Yu

2022, 43(6):  20220050.  doi:10.7503/cjcu20220050

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The development of visible-light-driven efficient， stable， and inexpensive photocatalysts for water- splitting hydrogen production is an important topic to address global energy and environmental challenges. In this work， a highly efficient， stable， and non-noble metal CdS-based photocatalytic composite Ni（PO₃）₂-Ni₂P/CdS NPs was synthesized by combining cocatalyst modification and heterostructure construction strategy. Binary cocatalyst Ni（PO₃）₂-Ni₂P nanosheet arrays were prepared using flower bulb Ni（OH）₂ as precursor by gas-phase sintering phosphating process， and CdS NPs were combined with them to form a new type of ternary composite photocatalyst ［Ni（PO₃）₂-Ni₂P/CdS NPs］ by sonochemical. The photocatalytic hydrogen production rate of 8%（mass fraction） Ni（PO₃）₂-Ni₂P/CdS NPs reaches 4237 μmol·g^?1·h^?1 with Na₂S-Na₂SO₃ as sacrificial agent under the irradiation of visible light（λ>420 nm）， which is about 19 times for CdS NPs（217 μmol·g^?1·h^?1）. In the cycling experiment， the hydrogen production rate of reaction is about 89% of the initial value after sixth cycles（18 h）， which demonstrates excellent catalytic stability. Compared with CdS NPs， the absorption edge of Ni（PO₃）₂-Ni₂P/CdS NPs is obviously red-shifted， the forbidden band width is reduced to 1.86 eV， and the overpotential of H⁺ reduction is reduced， which exhibits strong light absorption properties and a suitable band gap structure. The photogenerated electrons of CdS NPs are transferred to Ni（PO₃）₂-Ni₂P through the synergistic effect between Ni（PO₃）₂-Ni₂P and CdS NPs， which effectively promotes the separation of photogenerated carriers and improves the activity and stability of hydrogen production. This noble-metal-free composite photocatalyst may provide a way to design very efficient water splitting catalysts， which will promotes the practical industrial application of CdS visible photocatalytic water splitting.



Theoretical Investigations on the Electronic Structures and Reactivity of Heptafluoro-iso-butyronitrile Anion

DAI Wei, HOU Hua, WANG Baoshan

2022, 43(6):  20220044.  doi:10.7503/cjcu20220044

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Heptafluoro-iso-butyronitrile（C4） has attracted considerable interest for its use as a novel eco-friendly dielectric gas in various high-voltage applications. Electronic structures， photoelectron spectra， lifetime， reaction mechanisms， and kinetics for the C4^- anion formed by electron attachment to C4， together with the C4^-+CO₂ reaction， were calculated using various high-level ab initio methods. The electron in the π^* anti-bond orbital of C≡N leads to the bent C—C=N geometry of C4^- anion， and best theoretical adiabatic electron affinity is 0.30 eV. Photodetachment spectrum of C4^- anion exhibits significant absorption in the range 0—2 eV peaked at 1.63 eV. C4^- anion prefers to decompose via C—F bond fission， surmounting a barrier of ca. 9 kJ/mol， to form the long-lived ［F...（CF₃）₂CCN］^- intermediate， in which the C...F distance is as long as around 0.2 nm. The C4^-+CO₂ reaction takes place via three stepwise association/elimination mechanisms， namely， F， C or N of CN site-specified attacking by CO₂， resulting in energetically feasible electron-transfer from CN to CO₂. The present theoretical results shed new light on the high dielectric strength of C4 and the synergistic effect of the C4/CO₂ gas mixture.



Research on Co₃O₄/UiO-66@α-Al₂O₃ Ceramic Membrane Separation and Catalytic Spraying Industry VOCs Waste Gas

JIANG Hongbin, DAI Wenchen, ZHANG Rao, XU Xiaochen, CHEN Jie, YANG Guang, YANG Fenglin

2022, 43(6):  20220025.  doi:10.7503/cjcu20220025

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Co₃O₄/UiO-66@α-Al₂O₃ ceramic membranes were constructed with α-Al₂O₃ as the support layer， UiO-66 as the separation layer， and Co₃O₄ as the catalytic layer. The ceramic membrane exhibits outstanding separation performance of benzene/pyridine. The molar concentration ratio of pyridine to benzene in the gas on the permeate side can be increased from 1 to 17 on the feed side. After O₃ was introduced into the system， the concentration of benzene on the feed side was significantly reduced， and its removal rate can reach 89%. The removal rate of pyridine on the permeate side was only 27%， which was retained to a large extent， and the remaining pyridine could be collected for separate advanced treatment. The Co₃O₄/UiO-66@α-Al₂O₃ ceramic membrane can effectively solve the emission problem of nitrogen oxides in the waste gas treatment process of the spraying industry， and is expected to be an ideal choice for the waste gas pretreatment process of the spraying industry.



Preparation of Potassium Doped g-C₃N₄ Thin Film Photoanode and Its Application in Photoelectrocatalytic Oxidation of Diclofenac Sodium in Water

GONG Yanxi, WANG Jianbing, CHAI Buyu, HAN Yuanchun, MA Yunfei, JIA Chaomin

2022, 43(6):  20220005.  doi:10.7503/cjcu20220005

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The difficulty in preparing thin film photoelectrodes with high optical quality and excellent electro- chemical property limited the application of photoelectrocatalytic oxidation process in water treatment. In this paper， g-C₃N₄ thin film electrodes loaded on indium tin oxide（ITO） glass was prepared by in situ calcination method and used potassium doping to improve their photoelectrocatalytic activity. The electrodes were characterized， the photoelectrocatalytic degradation of diclofenac sodium（DCF） in water with them was studied， and the DCF degradation pathways were investigated. The results showed that the in situ calcination method could prepare high-quality K⁺/g-C₃N₄ thin film photoelectrodes， and the doping of K⁺ insignificantly changed the crystalline shape， valence state， and porous morphology of g-C₃N₄ on the electrode. However， it could increase the loading of g-C₃N₄ on ITO glass and enhance the photocurrent response of the electrode to visible light. The optimal doping concentration of K⁺ was 0.002 mol/L. The rate constant of DCF degradation in photoelectrocatalytic oxidation process with the K⁺/g-C₃N₄ thin film electrode was 1.86 times higher than that with the pure g-C₃N₄ film electrode. The DCF removal rate from water in 2 h reaction time reached 70% with the initial pH of 4， applied potential of 1 V， and light intensity of 0.96 W/cm². For the photoelectrocatalytic oxidation of DCF with the K⁺/g-C₃N₄ film electrode， there was a synergy between photocatalytic oxidation and electrochemical oxidation. They could optimize each other and enhance the concentration of the photogenerated holes（h⁺） and hydroxyl radicals（·OH） produced in the reaction process. Under the action of these two active substances， DCF in water was oxidized by h⁺ into carbazole derivatives， reacted with ·OH to form polyhydroxy aromatic compounds， and finally occurred reaction of ring opening to form small molecules.



Effects of Ag，Zn，Pd-doping on Catalytic Performance of Copper Catalyst for Selective Hydrogenation of Dimethyl Oxalate

SONG Youwei, AN Jiangwei, WANG Zheng, WANG Xuhui, QUAN Yanhong, REN Jun, ZHAO Jinxian

2022, 43(6):  20210842.  doi:10.7503/cjcu20210842

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The active crystal planes of Cu（111） and Cu₂O（111） doped with Ag， Zn and Pd atoms were constructed using a density functional theory to investigate the effects of different metal doping on the activity and selectivity for dimethyl oxalate（DMO） hydrogenation to methyl glycolate（MG）. The results showed that Zn-doping can prohibit the deep hydrogenation of MG effectively， and Ag additves could effectively improve hydrogenation activity for DMO. Conversely， the addition of Pd increased the energy barrier of MG generation， thus reduced MG selectivity. The Ag-Cu（111） surface has a suitable d-center and has the highest activity to generate CH₃OOCCH₂OH. On the surface of Ag， Zn， Pd atom doped Cu₂O（111）， Ag-Cu₂O（111） has a small band gap and high valence band strength， and has the best catalytic activity in DMO hydrogenation reaction. Based on the above results， theoretical methods for structural modulation and performance regulation of copper-based catalysts are proposed， which provide reliable theoretical guidance for the design of highly efficient catalysts.



Polymer Chemistry

Preparation and Properties of Novel Optical and Thermal Dual Response Shape Memory Polymers

YU Pengdong, GUAN Xinghua, WANG Dongdong, XIN Zhirong, SHI Qiang, YIN Jinghua

2022, 43(6):  20220085.  doi:10.7503/cjcu20220085

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Glass microsphere was modified by the surface in situ polymerization reaction of dopamine. The chemical composition of the glass microsphere before and after modification was characterized by X-ray photoelectron spectroscopy（XPS） and Fouried transform infrared spectroscopy（FTIR）， its thermal stability was tested by thermogravimetry（TG） and its morphology was observed by transmission electron microscope（TEM） and scanning electron microscope（SEM）； the effects of the modified glass microsphere on the thermal， mechanical and shape memory properties of the shape memory composite polycaprolactone and polyurethane（PCL/TPU） were investigated. The results show that the surface-coated polydopamine glass microsphere（PHGM） was successfully prepared， and the addition of modified glass microsphere not only enhanced the mechanical properties of the materials（the tensile strength increased to 53.3 MPa and the Young’s modulus increased to 178.4 MPa at 3% of modified glass microsphere）， but also imparted excellent photothermal effects to the materials. When the composites were exposed to 808 nm near infrared（NIR） light， they can reach their switching temperature and return to their permanent shape within a short time （7 s）.



Synthesis and Application of Modified Low Molecular Weight Polyisoprene

YAN Zhixuan, MA Ji, QU Jinlei, LIU Li, SUN Chong, LIU Jiwen, LIU Guangye, SUN Lishui, HE Lixia

2022, 43(6):  20220066.  doi:10.7503/cjcu20220066

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Low molecular weight 3，4-polyisoprene（LPI） was prepared by anionic solution polymerization and then it was modified to prepare siloxane modified functionalized low molecular weight 3，4-polyisoprene（MLPI）， including three end group-modified materials， LPI-propyl methyldimethoxysilane（LPI-CMDS）， LPI-propyl trimethoxysilane（LPI-CTMS）， LPI-propyl trimethoxysilane（LPI-CTES） and one graft-modified material， 3-mercaptopropyl triethoxy silane graft modification LPI（LPI-g-MTS）. The influences of LPI and MLPI on dispersion of silica and properties of solution polymerized styrene butadiene rubber（SSBR） composites were studied. Improvement of interaction between the filler and the polymer and dispersion of silica in the composites was domenstrated by strain scanning and bound rubber content results. Due to the more active sites， LPI-g-MTS had the best effect. Compared to the unmodified LPI filled composite， the physical and mechanical properties of the LPI-g-MTS filled composites increased， especially the modulus at 300% elongation increased by 89.66% and the tensile strength increased by 27.15%. This work provides a new method to improve the dispersion of silica in rubber/silica composites.



Effects of Muco-inert and Acid-sensitive Modification on Mucosal Penetration of Nanoparticles

JI Fa, LIU Ling, YU Linling, SUN Yan

2022, 43(6):  20210837.  doi:10.7503/cjcu20210837

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Gastric cancer， cervical carcinoma， lung cancer are occurred in mucosa， and the nanoparticles provided a competitive way for the diagnosis and therapy of these diseases. However， the mucus layer which contains mucus and other viscous substances could adsorb and remove the foreign substance， resulting the hindered penetration of nanoparticles. In this paper， a pH-responsive mucus-inert nanoparticle was designed for penetrating mucus and entering mucosal epithelial cells. In brief， mesoporous silica nanoparticles with surface amination（MSNs-NH₂） was prepared by sol-gel method. Then， the zwitterionic polymer was modified to the surface of MSNs-NH₂ by atom transfer radical polymerization to form mucus-inert particles（MSNs-pCBMA）. Acid-sensitive molecule DMMA was modified onto MSNs-pCBMA through amino groups on the particle surface to obtain pH-responsive mucus-inert nanoparticles（MSNs-pCBMA-DMMA）. The results of transmission electron microscopy（TEM）， proton nuclear magnetic resonance（¹H NMR），Fourier transform infrared spectrophotometer（FTIR） and Zeta potential measurements showed that four nanoparticles were synthesized successfully， and MSNs-pCBMA-DMMA exhibited sensitive pH response at pH= 7.4—5.7. A mucus-containing Transwell^? model was used to study the permeability of nanoparticles in mucus. The penetration results showed that within 4 h， the mucus permeability of MSNs-pCBMA-DMMA reached 16.3%， 1.9 times that of MSNs-pCBMA and 3 times that of MSNs-NH₂， and its relative apparent permeability coefficient reached 2.96 calculated with the apparent penetration coefficient（P_app） of MSNs-NH₂ as the reference. In addition， the grafting pCBMA improved the penetration rate of nanoparticles in mucus and the modification of DMMA further improved the penetration rate. Cytotoxic test showed that the viability of cells cultured with 100 μg/mL MSNs- pCBMA-DMMA was 78.3% in 24 h， indicating its good biosafety. The cellular uptake experiment showed that MSNs-pCBMA-DMMA could be endocytosed effectively at 4 h， and exhibited better endocytosis performance compared with other particles. The work proved that the combination of mucus inertia and acid sensitivity can effectively promote the mucosal permeability of nanoparticles， and MSNs-pCBMA-DMMA has excellent mucus permeability. The experimental results would benefit the design of nanoparticles for the diagnosis and therapy of mucosal diseases.



Reduction Performance and Mechanism of Liquid Terminated-carboxyl Fluoroelastomers Using NaBH₄/MCl _x Reduction System

CHANG Yunfei, LIAO Mingyi, WEN Jiaming

2022, 43(6):  20210835.  doi:10.7503/cjcu20210835

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Using a simple one-pot method， direct transformation of liquid terminated-carboxyl fluoroelastomers（LTCFs） to the corresponding liquid terminated-hydroxyl fluoroelastomers（LTHFs） was easily realized with sodium borohydride（NaBH₄） in the presence of metal chloride（MCl _x ）. The structure and functional group content of LTCFs and LTHFs were analyzed by Fourier transform infrared spectroscopy（FTIR）， ¹H nuclear magnetic resonance（¹H NMR） spectrocopy， ¹⁹F nuclear magnetic resonance（¹⁹F NMR） spectrocopy and chemical titration. The results showed that —C=C— and carboxyl groups of LTCFs were reduced efficiently. The effect of different rare-earth chlorides（LaCl₃， CeCl₃， NdCl₃ and SmCl₃） and transition metal chlorides（MnCl₂， NiCl₂， CoCl₂ and CuCl₂） on the performances of the LTCFs reduction was discussed. The NaBH₄/SmCl₃ system was the best and the reduction rate reached 92% under optimum reaction conditions. Mechanism research showed that the stronger binding force of metal ion and carbonyl oxygen was beneficial to the reduction of LTCFs.



Materials Chemistry

Preparation and Performance of Paraffin/Expanded Graphite/Graphene Composite Phase Change Heat Storage Material

YAN Jiasen, HAN Xianying, DANG Zhaohan, LI Jiangang, HE Xiangming

2022, 43(6):  20220054.  doi:10.7503/cjcu20220054

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The paraffin/expanded graphite/graphene aerogel composite phase change material was prepared by using paraffin（PA） as the phase change heat storage material， expanded graphite（EG） as the main thermal conductive material and support material， and graphene aerogel（GA） as the thermal conductivity enhancement material and auxiliary support material. The effects of the amount of GA added on the phase transition temperature， latent heat of phase transition， thermal conductivity and cycling stability of the composite material were investigated. The results show that the phase change material with composition of 80%PA-17%EG-3%GA has good thermal conductivity and excellent cycling stability. Compared with 80%PA-20%EG composite material， it exhibits almost the same phase transition temperature， latent heat of phase transition and cycling stability， but increased thermal conductivity from 4.089 W/（m·K） to 5.336 W/（m·K）， showing good application prospects.