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    10 December 2020, Volume 41 Issue 12
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    Cover and Content of Chemical Journal of Chinese Universities Vol.41 No.12(2020)
    2020, 41(12):  0-8. 
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    Volume Contents of Chemical Journal of Chinese Universities to Vol.41(2020)#br#
    2020, 41(12):  1-12. 
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    Construction of Hetero⁃hollow Structure Micro⁃/Nanomaterials
    SHEN Minghui, WEI Yanze, XU Nan, WANG Zumin, YANG Nailiang, YU Ranbo, WANG Dan
    2020, 41(12):  2561-2576.  doi:10.7503/cjcu20200708
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    Hetero-hollow structures refer to a kind of hollow micro-/nanostructures which composed of shells with distinct components. By controlling the interface and mass transfer behavior through hetero-structure， the energy and mass conversion in hollow structures would be modified. Thus， the hetero-hollow structures exhibit enhanced properties and gigantic potentials in various fields like solar energy conversion， gas sensing， electrochemical energy storage and drug delivery. To date， the design and construction of hetero-hollow structures is a charming research topic in material frontiers. In this work， the hetero-hollow structures are classified， and the characters， advantages， and especially the fabrication methods are introduced in detail. In the last， the challenges and perspectives on the future research and development of hetero-hollow structures are also discussed.

    Recent Advances in Lanthanide-titanium-oxo Clusters
    LI Guanjun, LONG Lasheng, KONG Xiangjian, ZHENG Lansun
    2020, 41(12):  2577-2586.  doi:10.7503/cjcu20200414
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    As a new branch of cluster chemistry， lanthanide-titanium-oxo clusters not only integrate the cha-racteristics of lanthanide and titanium ions， but also often show a synergistic effect of the two elements， so they usually have excellent optical， electoral， magnetic and catalytic properties. The lanthanide-titanium-oxo cluters attract more attention because its accurate structure model is more conducive to understand the relationship between structure and activity. In this paper， the synthesis and structures of lanthanide-titanium-oxo clusters are outlined based on different ligands and the representative properties are introduced. The synthetic strategies and development prospects of lanthanide-titanium-oxo clusters are prospected. It is hoped that this review can provide insight into future research on lanthanide-titanium-oxo clusters.

    Recombinase Polymerase Amplification： from Principle to Performance
    LI Xianming, ZHENG Ting, GAO Lu, LI Feng, HOU Xiandeng, WU Peng
    2020, 41(12):  2587-2597.  doi:10.7503/cjcu20200592
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    DNA amplification is essential to most nucleic acid testing（NAT）. There is no doubt that polymerase chain reaction（PCR） is the benchmark technology for DNA amplification， but is mainly performed in centralized laboratories. Recombinase polymerase amplification（RPA）， as one of the most promising isothermal amplification technologies， can break through laboratory boundaries for nucleic acid testing， since it is less instrument-dependent and easier access to resource-limited areas， namely， suitable for point-of-care testing（POCT） applications. As a developing technology， RPA also has several defects， which hind its widespread applications and development. Here， we make a summary on the principle and performance of RPA， with particular interest on the key process of the primer recombination and the dynamic balance of ATP that guide the eventual performance. Besides， several critical issues and potential points for further improving the performance of RPA were also summarized.

    Development and Applications of Mass Spectrometry in Reaction Monitoring
    AI Wanpeng, SONG Shiyao, BAI Yu, LIU Huwei
    2020, 41(12):  2598-2609.  doi:10.7503/cjcu20200505
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    Mass spectrometry has been widely used in reaction monitoring research due to its distinguishing advantages in resolution， sensitivity， speed and structure identification ability in recent years. At first， the applications of mass spectrometriconline sampling in real-time reaction monitoring are introduced. Then the development and applications of ambient mass spectrometry in the reaction monitoring are summarized， inclu-ding the short-time reaction monitoring using ambient mass spectrometry， the long-time organic reaction monitoring using microdroplet acceleration， and the applications of other ambient mass spectrometry in the reaction monitoring. Finally， the challenges and development of mass spectrometry in the field of reaction monitoring are summarized and prospected.

    Frequency Domain Density Matrix Renormalization Group
    JIANG Tong, REN Jiajun, SHUAI Zhigang
    2020, 41(12):  2610-2628.  doi:10.7503/cjcu20200767
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    Density matrix renormalization group（DMRG） has been developed for electron correlation in low-dimensional system and has been quickly applied to quantum chemistry as a powerful method for electronic structure calculation and for quantum dynamics of complex system. After more than 20 years of development， a series of effective methods for calculating dynamic response properties within DMRG have been developed and have been extensively applied for spectroscopy. We will first briefly describe the main features of DMRG， including its matrix product state（MPS） formulation. Based on the linear response theory， we focus on descri-bing the DMRG algorithms in frequency domain to solve the response properties both for zero temperature and finite temperature. We then introduce several most relevant applications in electronic correlation problems and electron-phonon correlation problems.

    Progress of Charge Transport Through Self-assembled Monolayers by Employing Eutectic Gallium-Indium Technique
    LIU Tianshuo, LONG Shichuan, YAO Zhiyi, SHI Jia, YANG Yang, HONG Wenjing
    2020, 41(12):  2629-2637.  doi:10.7503/cjcu20200725
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    Electron transport through organic molecular layers is an essential issue in molecular electronics. The electrical testing by employing gallium-indium alloy（EGaIn） electrodes is well recognized because of its high junction formation rate， reliability， and user-friendly operation. It thus has been extensively adopted in analyzing the charge transport through self-assembled monolayers（SAMs）. This review outlines the principle and experimental operation of the EGaIn technique， introduces the recent progress in molecular electronics using the EGaIn technique， and finally gives a prospect.

    Research Advance of Polymer Anti-fouling Coatings
    WANG Dagui, CHEN Yajie, JIAN Qi, GAO Pengcheng, XIA Fan
    2020, 41(12):  2638-2647.  doi:10.7503/cjcu20200396
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    Preparing polymer anti-fouling surface is an effectivel strategy to solve the problem of biological fouling. Polymer has some advantages such as anti-acid and anti-alkali， easy to functionalization and modification， and polymer anti-fouling coatings play an important role in reducing the effects of biological fouling and economic losses. This review summarizes the strategies of anti-adhesion biological fouling and research advance and introduces the representative achievements of new-type polymer coatings. In addition， it also prospects the challenges of future in the fields.

    Progress on Aptamer for Cancer Theranostics
    DONG Qian, LI Zhaoqian, PENG Tianhuan, CHEN Zhuo, TAN Weihong
    2020, 41(12):  2648-2657.  doi:10.7503/cjcu20200436
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    Aptamers are single-stranded oligonucleotides selected through a process known as Systematic Evolution of Ligands by Exponential enrichment（SELEX）， showing a high selectivity towards their target molecules. The selectivity and affinity of aptamers are comparable to antibodies and even higher. They have the advantages of multiple targets， low immunogenicity， ease of accurate synthesis and modification， flexible and controllable design， which endow them as new molecular tools for early screening， diagnosis and targeting therapy. Therefore， aptamers have attracted extensive attention and have been applied in the field of cancer diagnosis and treatment. This review focused on the applications of aptamers in cancer diagnosis and treatment， and summarized systematically the research progresses made in recent years and discussed the prospective of the future development.

    Proximity Labeling in Cell-cell Interaction Detection
    MA Weiyi, LIU Shibo, CHEN Peng
    2020, 41(12):  2658-2666.  doi:10.7503/cjcu20200371
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    Cell-cell interactions play an important role in many physiological processes. Elucidating these interactions is current interest in the frontier of interdisciplinary studies integrating of chemistry and life sciences. Enzymatic intercellular proximity labeling has become one of the most promising detection methods for cell-cell interactions， enabled by the rapid advancement of protein engineering techniques， including protein function manipulation， directed evolution of enzymes， and precise spatiotemporal regulation on enzymatic activities. We here describe some of the current proximity labeling designs， highlight key advantages and limitations of each method， and discuss the potential applications of proximity labeling.

    2D Mesoporous Covalent Organic Framework with High Iodine Capture Capability
    XU Guojie, CHANG Jianhong, FANG Qianrong
    2020, 41(12):  2667-2672.  doi:10.7503/cjcu20200624
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    As a typical contaminant of nuclear waste， the research and development of iodine-capture materials has been great concern and challenge. Here， a novel two-dimensional mesoporous covalent organic framework（JUC-573） was reported. Powder X-ray diffraction， nitrogen adsorption and desorption isotherm， TGA and other characterizations indicated that the synthesized covalent organic frameworks（COFs） has high crystallinity， high specific surface area and good thermal stability. Under 333 K and ambient pressure， JUC-573 exhibited a good adsorption capacity to iodine vapor， and high adsorption capacity was up to 4.15 g/g. The regular 1D mesoporous vertical channel in JUC-573 can effectively avoid the blockage after iodine adsorption， thus optimizing the adsorption capacity of material. In addition， JUC-573 can be reused at least 5 times and retains its crystallinity.

    Investigation of Lipid Distributions by Trifluoroacetic Acid-enhanced Desorption Electrospray Ionization Mass Spectrometry Imaging
    WANG Xiaoqun, HUANG Guangming
    2020, 41(12):  2673-2680.  doi:10.7503/cjcu20200448
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    A large number of lipids play an important role in the process of life， so it is important to simultaneously visualize multiple lipids by mass spectrometry imaging. By adding trifluoroacetic acid into the spray solvent of desorption electrospray ionization（DESI）， the number of detectable lipids was increased from 59 to 71 in the mouse brain tissue sagittal section. This method could not only improve the detection sensitivity， but also suppress the formation of sodium and potassium adducts of lipids， to simplify spectrum interpretation and facilitate quantitative analysis. Furthermore， the result also revealed the spatial correlation among the lipids in the whole mouse brain tissue section as well as specific brain regions. The present protocol provides a new research method for exploring potential metabolic pathways between lipids， suggesting the potential application in neuroscience， clinical， and other fields.

    Structure， Nature and Activity of Ga Species for Propane Aromatization in Ga/ZSM-5 Revealed by Solid-state NMR Spectroscopy
    ZHAO Xingling, QI Guodong, WANG Qiang, CHU Yueying, GAO Wei, LI Shenhui, XU Jun, DENG Feng
    2020, 41(12):  2681-2689.  doi:10.7503/cjcu20200474
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    A series of Ga-modified ZSM-5 zeolites were prepared by different methods. The structure and aci-dity of these catalysts were characterized by solid-state NMR（ssNMR）. The catalytic reactions for propane aromatization were also investigated. With the help of 71Ga NMR and trimethylphosphine（TMP） probe 1D 31P and 2D 1H-31P HETCOR NMR， it was found that the Ga2O3/ZSM-5 sample prepared by physical mixing only contains Ga2O3 species with weak Lewis acidity， and the samples prepared by impregnation（Ga/ZSM-5-ox） and impregnation followed by reduction-oxidation treatment（Ga/ZSM-5-redox） contain both highly dispersed ga- llium clusters and cationic Ga species. Cationic Ga species was favored on Ga/ZSM-5-IE prepared by ion exchange. Both dispersed gallium clusters and cationic Ga exhibited stronger Lewis acidity. The results of propane aromatization over Ga-modified ZSM-5 showed that the speciation and acidity of Ga have significant effect on the propane conversion. The conversion and selectivity to aromatics followed the order of Ga/ZSM-5-IE > Ga/ZSM-5-redox > Ga/ZSM-5-ox > Ga2O3/ZSM-5 > H-ZSM-5. The synergic active sites composed of Br?nsted acid site（BAS） and Lewis acid sites（cationic Ga and dispersed Ga species） on Ga/ZSM-5 zeolite were identified by 2D 1H-31P HETCOR NMR spectroscopy， which were correlated to the catalytic activity.

    Review
    Biomedical Applications of Single-atom Catalysts
    YUAN Zhongwen, HE Lizhen, CHEN Tianfeng
    2020, 41(12):  2690-2709.  doi:10.7503/cjcu20200388
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    Single-atom catalysts（SACs）， which have 100% atomic utilization and fully exposed atomic metal active sites， show distinct advantages in catalytic activity and selectivity， thus have been widely applied in the fields of chemistry， energy， environment and so on. Since the concept of SACs was proposed， the studies about different monometallic atoms loaded on various supporting materials were reported continuously. As the research of nanozyme has attracted increasing attention， SACs were also explored for their enzyme-like activities. Therefore， SACs attract extensive attention in the biomedical domain in recent years， among that， ancho- ring monatomic metals on nitrogen-doped carbon materials by pyrolysis were the most widespread studied. The M-Nx-C site formed after pyrolysis is similar to the M-Nx site of natural metal enzymes， which endows the materials superior enzyme-like activity. Importantly， compared with natural enzymes and nanozymes， SACs own the advantages of simpler synthesis steps， controllable active center and morphology， adjustable coordination environment， better catalytic activity， lower cost， easier commercial application and more convenience to invest relative catalytic reaction mechanism. It is worth mentioning that， metal atoms with enzyme-like activity（such as Au， Pt， Pd） dispersed on supporting materials（like carbon points， metal oxides， 2D material） can also obtain higher enzyme-like activity than nanoparticles or supporting materials themselves. In short， the excellent enzyme-like activity is mainly due to the maximum exposure of monodisperse metal atoms in the biocatalysis reaction. Meantime， the strong interaction between these metal atoms and the supporting materials makes the whole system more stable to achieve long-term catalysis. This paper reviews the application and research progress of SACs in the fields of tumor therapy， antibacterial， antioxidation and biosensor， and some examples will be introduced in detail， including material preparation method， enzyme-like activity， catalytic mechanism and practical application effect. At the end of the review， we briefly summarize the challenges and opportunities about the future application of SACs， so as to provide strategies for the rational design of SACs with multiple properties.

    Inorganic Chemistry
    Preparation of Sn-doped MFI Molecular Sieve Membrane by CVD Method and Its Separation Performance for Ethanol/water System
    PENG Li, WU Zhengqi, WANG Xing, WANG Boxuan, GU Xuehong
    2020, 41(12):  2710-2716.  doi:10.7503/cjcu20200465
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    Sn-modified MFI zeolite membranes were prepared by chemical vapor deposition（CVD） method using anhydrous SnCl4 as Sn source， and were applied for the separation of alcohol-water mixture by pervaporation. SEM， XRD， 29Si NMR and UV-Vis analyses showed that Sn can be introduced into the framework of MFI zeolite membranes by CVD process with their structure remained. The surface Si—OH groups can be effectively reduced after the incorporation of Sn， and the obtained membranes showed improved stability. The zeolite membrane prepared with 3 mL of SnCl4 at autoclave bottom and the reaction time of 1 h had the best separation performance and also showed a long-term stability for the separation of 5% ethanol/water mixture at 60 ℃. After 50 h， the permeation flux slightly decreased from 1.52 kg·m-2·h-1 to 1.38 kg·m-2·h-1， and the separation factor decreased from 18 to 16.

    Synthesis of an Orange-red-emitting Cationic Iridium（III） Complex Containing a Triphenylamine-triazole Bipolar Unit and Its Application in LEDs
    CHEN Qiuhong, YE Yanchun, REN Mengran, WANG Kaimin, TANG Huaijun, WANG Zhengliang, ZHOU Qiang
    2020, 41(12):  2717-2724.  doi:10.7503/cjcu20200384
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    A novel orange-red-emitting cationic organic iridium（Ⅲ） complex， ［（npy）2Ir（DPPTA）］PF6， containing a triphenylamine-triazole bipolar unit was synthesized using 2-naphthyl pyridine（npy） as main ligand and N，N-diphenyl-4-［4-phenyl-5-（pyridin-2-yl）-4H-1，2，4-triazol-3-yl］aniline（DPPTA） as ancillary ligand. The thermal decomposition temperature of the complex was 345 ℃， from 20 ℃ to 100 ℃， its relative photoluminescent emission intensity reduction was 28.0%， however the light color was unchanged， suggesting that the complex can be well used in LEDs. Mainly due to the bipolar unit， the complex can efficiently absorb and be excited by the blue light（λem，max=455 nm） of GaN chips. Excited by blue-emitting GaN chips， orange-red LEDs can be fabricated by only using ［（npy）2Ir（DPPTA）］PF6 as down-conversion luminescent material， and efficient neutral and warm white LEDs can be obtained when yellow-emitting Y3Al5O12∶Ce3+（YAG∶Ce3+） was used together.

    Coligand Induced Luminescent Cd-MOFs： Luminescence Enhancement Toward Acetylacetone and Quenching Toward Cr2O72-
    XIAN Guoxuan, YU Yu’e, CHEN Yuqian, WAN Xiaoyu, WANG Suna, LU Jing
    2020, 41(12):  2725-2735.  doi:10.7503/cjcu20200364
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    Three coordination complexes， ｛［Cd（HL）（bpea）·H2O］·H2O·DMF｝n（1）， ｛［Cd（HL）（bpp）·H2O］·2H2O·DMF｝n（2） and ｛［Cd（HL）（dmbpy）］·DMF｝n（3）， were obtained from the reaction of 5-（3-carboxy-4-methoxybenzylamino） isophthalic acid（H3L） with cadmium nitrate and different nitrogen-containing ligands under solvothermal conditions， and show interesting 2D→2D penetrating and 1D ribbon structures， respectively. The results reveal that these complexes all demonstrate luminescence quenching effect toward Cr2O72?， while only complex 1 shows a significant fluorescence enhancement in DMF solution of acetylacetone. The flexibility of carboxylate ligand and types and structures of nitrogen-containing ligands play an important role in regulating the structures and fluorescence properties of complexes.

    Analytical Chemistry
    Fluorescent Peptide Sensor for Detection of Copper Ions
    A Li, WANG Yong
    2020, 41(12):  2736-2741.  doi:10.7503/cjcu20200447
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    A fluorescent sensor for copper（Ⅱ） ions was developed based on the quenching of rhodamine B-labeled peptide by copper（Ⅱ）. The sensing mechanism was studied using resonance light scattering， UV-Vis absorption spectroscopy， fluorescence lifetime， and circular dichroism. The results showed that copper（Ⅱ） might induced the conformational change of the peptide that make rhodamine B approach each other， resulting in the aggregation-caused quenching effect of copper（Ⅱ） and the rhodamine B-labeled peptide. Moreover， the experimental results displayed that the sensor possessed both linear ranges of 5×10?4—1×10?2 μmol/L and 0.1—7 μmol/L with a detection limit of 0.29 nmol/L. The sensor also had a high selectivity for copper（Ⅱ）， and can be successfully employed for the detection of copper（Ⅱ） ions in lake water samples.

    Detection of Nitroreductase in Living Cells Based on Surface Enhanced Raman Scattering Nanoprobes
    ZHENG Youwei, TIAN Fei, ZHANG Qian, XU Di, YANG Guohai, QU Lulu
    2020, 41(12):  2742-2748.  doi:10.7503/cjcu20200346
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    The expression of nitroreductase（NTR） is closely related to the degree of hypoxic in anoxic tumor cell. Therefore， the development of a highly selective method for the detection of NTR is of great significance for the diagnosis and treatment of cancer. We functionalized p-NTP onto the surface of Au NPs to prepare a highly sensitive SERS probe. Under hypoxic conditions， the reduced nicotinamide adenine dinucleotide（NADH） is used as an electron donor， and NTR can catalyze the reduction of a nitroaromatic compound to an aromatic amine， which results in the SERS spectrum change of the nanoprobe， thus realizing the detection of NTR. The detection limit of the nanoprobe for NTR can reach 18 ng/mL. The probe exhibits low toxicity and good biocompatibility. It can be used for SERS analysis of A549 cells under hypoxia conditions and reveals that the concentration of nitroreductase in tumor cells increases with the increase of hypoxia degree， which provides an effective strategy for evaluating hypoxia in tumor cells.

    Organic Chemistry
    Efficient Synthesis of Pyridine ［2，3-d］pyrimidine Derivatives by Catalyst-free Tandem Cyclization Under Microwave Irradiation
    LIN Junjie, WANG Shuang, LI Weiqiang, CUI Xin, HUANG Chao
    2020, 41(12):  2749-2758.  doi:10.7503/cjcu20200563
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    This work presents a highly efficient and simple method for the synthesis of pyridine ［2，3-d］ pyrimidine derivatives. This method took the α，β-unsaturated ketones compounds and 1，3-dimethyl-6-aminouracil as raw material， 28 pyridine ［2，3-d］pyrimidine derivatives were synthesized by microwave irradiation high-efficiency tandem cyclization in 5―15 min without catalyst， including 21 compounds did not see the literature. This method has the characteristics of simple and easy raw materials， high green efficiency， high bonding efficiency and simple post-treatment.

    Design， Synthesis and Biological Activity of Pyrazole-4-carboxamides Compounds Containing 1，2，4，5-Tetrasubstituted Phenyl
    DONG Xinrui, XIA Zhe, WANG Zhenxue, BIAN Qiang, LI Huabin
    2020, 41(12):  2759-2765.  doi:10.7503/cjcu20200462
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    To find novel fungicidal compounds with potent biological activities， a series of pyrazole-4-carbo- xamide compounds containing tetra-substituted phenyl groups was designed via the method of linking active sub-structures. The structures of all the compounds were confirmed by high resolution mass spectrometer（HRMS） and hydrogen nuclear magnetic resonance（1H NMR）. The bioassay results showed that some compounds have obvious inhibitory activities against Physalospora piricola， Rhizoctonia solani， Sclerotinia sclerotiorum， and Botrytis cinerea. In particular， compound 5c， with 95.5% inhibition rate at a concentration of 50 μg/mL against Physalospora piricola， exhibited a broad spectrum of fungicidal activity. The initial structure-activity relationship indicated that the type of N-substituent on the pyrazole ring would influence the activity and methyl or tert-butyl were more beneficial. The compound 5 with a single benzene ring showed better activity than compound 5′ with a bicyclic structure. Besides， compounds with a benzene ring substituent R2 less than four carbons were favorable to enhance fungicidal activity.

    Synthesis of Aminophosphine Ruthenium Carbene Complex and Its Application in Olefins Metathesis Reaction
    WANG Jinyu, LIU Chunli, CHEN Yanhui
    2020, 41(12):  2766-2773.  doi:10.7503/cjcu20200420
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    A series of Grubbs ruthenium carbene catalysts featuring an aminophosphine ligand ［RuCl2·（H2IMes）（R1HNPR22）（=CHPh）］ was synthesized and characterized by means of nuclear magnetic resonance spectrometry and single crystal X-ray diffraction. Under the ambient conditions， these ruthenium complexes were tested as catalyst for the ring-closing metathesis（RCM） reaction of N，N-diallyl-p-toluenesulfonamide， and complex G2?1 was found to have the best catalytic activity. With the catalyst loading in the range of 0.1%—2.0%（molar fraction）， G2?1 was compatible with the RCM reaction of various diene and polyene， and had high catalytic activity（>95% yield of product）. G2?1 could also be used as catalyst for cross metathesis（CM） reaction of different terminal olefin substrates， up to 92% yield was achieved in the CM reaction of styrene and 3-phenoxypropene.

    Physical Chemistry
    Oxygen Evolution Reaction Electrocatalytic Performance Analysis of Electroless Plated Ni-Bx
    JIANG Yuanyuan, LI Boyu, LU Yizhong, WU Tongshun, HAN Dongxue
    2020, 41(12):  2774-2780.  doi:10.7503/cjcu20200667
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    Transition metal borides are one of the most promising electrocatalysts in water splitting reaction for their high electrocatalytic performance and low cost. Through electroless plating method， nickel borides grown on graphene， nickel foam（NF）， Ti mesh（TM） and carbon cloth（CC） were fabricated， in which graphene supported nickel borides exhibits homogeneous and dense nanoparticles structure. The oxygen evolution electrocatalytic performances of these materials are studied in alkaline solution（1.0 mol/L KOH）. The results show that the nickel boride grown on graphene（NiBx/graphene） exhibits the best electrocatalytic performance for water oxidation. An overpotential of only 277 mV is needed to reach the current density of 10 mA/cm2， and the corresponding Tafel slope are 57 mV/dec. The annealed sample shows an overpotential of 330 mV， which means an activity decline compared to the unannealed one. The NiBx/graphene prepared by this facile method exhibits high electrocatalytic activity and stability， which provides new strategy for preparing high-performance and low-cost water oxidation electrocatalysts.

    Solvent Effect for Electron Transition of Alexa Fluor 350 with Linear Response and State-specific Methods
    BI Tingjun, WANG Fan, WANG Zhifan
    2020, 41(12):  2781-2787.  doi:10.7503/cjcu20200546
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    The linear response and two state-specific methods for calculating the difference in the excitation energy and spectral shift of Alexa Fluor 350（AF350） in solution were compared within the framework of pola-rizable continuum model（PCM）. Compared with the experimental values， it is found that both the linear response and the two state-specific methods overestimate the excitation energy. Among them， the excitation energy obtained by IBSF method is the smallest and that by cGSRF method is the largest. As for the spectral shift value， the three methods are relatively small compared with the experimental value， and the LR method has the lar-gest calculated error， while the IBSF method is the most accurate method to predict the excitation energy and spectral shift of AF350. In addition， Marcus’s traditional theory was compared with the new non-equilibrium solvation theory based on constrained equilibrium， and it was found that the latter’s results are more consistent with the experimental values.

    Preparation of Platinum-modified Uniform Gold Nanopillar Electrodes and Photoelectrocatalytic Oxidation of Methanol
    SUN Weixin, LIU Jia, WANG Jiazheng, ZHANG Yimiao, JIN Lei, ZHOU Jianzhang, YANG Fangzu, WU Deyin, TIAN Zhongqun
    2020, 41(12):  2788-2795.  doi:10.7503/cjcu20200512
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    Surface plasmons（SPs） excitation in nanostructured noble metals has been shown to effectively accelerate and drive photochemical reactions. Methanol， as an important alcohol fuel， has the characteristics of high energy density， wide source， low price and convenient storage. It can be used as a raw material in direct methanol fuel cell（DMFC）. At present， studies have shown that surface plasmon resonance（SPR） can effectively enhance the oxidation efficiency of methanol. However， most of the current composite catalysts are core-shell structure nanoparticles， and their stability and repeatability have become a problem to be overcome， especially the thickness of the catalytic metal on the surface of the core-shell structure is not uniform and difficult to control， which has caused many uncertainties in the study of plasmon-catalyzed methanol oxidation. Therefore， this paper uses thermal lithography and ultraviolet lithography to prepare a hole array on photoresist coated glass electrode substrate with a period of 450 nm. Gold nanopillars were uniformly grown in the electrode holes with a constant current electrodeposition technique in gold sodium sulfite solution until the holes were completely filled， and a gold nanopillar array structure with a height of about 180 nm and a diameter of about 200 nm was obtained. Combined with gas phase deposition technology， a nano-Au/Pt electrode with ordered structure， uniform hot spots and large-scale production was obtained. With finite element method（FEM） analysis， the visible light absorption peaks of Au/Pt electrodes with different thicknesses and their correspon-ding electric field modes were simulated， which， combined with experimental results， proved that the electrodes have three plasmon excitation modes， including SPR at the bottom of the column and the gold film， the surface plasmon polariton（SPP） coupling on the gold film which blue-shifted when the thickness of Pt increa- ses， and the SPR coupling on the top of the nanopillar. Finally， the electrocatalytic performance of this electrode on methanol oxidation reaction under illuminations was studied， and proved that 2 nm Au/Pt has the best oxidation effect. In the 30 mA constant current oxidation of methanol experiment， light can prolong the lifetime of the electrode about 6 times， and the SPR effects help electrode surface to have a self-cleaning effect.

    Preparation and Electrochromic Properties of TiO2-PTPAT Nano Core/Shell Composite Films
    OUYANG Mi, CHEN Lu, HU Xuming, LI Yuwen, DAI Dacheng, TU Yuanbo, BAI Ru, LÜ Xiaojing, ZHANG Cheng
    2020, 41(12):  2796-2803.  doi:10.7503/cjcu20200455
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    The vertically grown TiO2 nanorod array was prepared on fluorine-doped tin oxide（FTO） con- ductive glass substrates via hydrothermal method， and then TiO2-poly（tris［4-（thiophen-2-yl）phenyl］amine） （PTPAT） core/shell structure composite films were prepared by in?situ electrochemical polymerization using TiO2 nanorod arrays as templates. Compared with the pure PTPAT film， the composite film showed well electrochromic（EC） properties. The optical contrast of PTPAT film is 28% at 600 nm， 60% at 1100 nm， and the discoloring time is 3.86 s and the coloring time is 5.52 s at 1100 nm； the optical contrast of TiO2-PTPAT compo- site film is 43% at 600 nm， 79% at 1100 nm， and the discoloring time is 3.35 s and the coloring time is 4.43 s at 1100 nm. The results show that the core/shell composite structure film has better optical contrast and swit- ching time performance. The PTPAT film and the TiO2-PTPAT composite film are used as the EC layer to assemble EC solid devices. The composite film-based devices show better cycle stability and higher withstand voltage. This is because the composite film maintains the original electrochromic properties of the PTPAT film. Due to the introduction of orderly grown nano-array structure， the specific surface area of the film is increased， and more ordered channels are provided for the doping and dedoping of ions in the electrochromic process， thereby accelerating the ion diffusion speed. At the same time， the introduction of TiO2 array improves the interface bonding between the polymer film and the transparent conductive electrode， thus improves the stability of the device.

    Preparation of InN-In2O3 Nanocomposite with Bottle-shaped Structure and Its Enhanced Formaldehyde Gas Sensitivity
    NING Qiuyang, FENG Wei, WU Guoguang
    2020, 41(12):  2804-2812.  doi:10.7503/cjcu20200336
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    The In2O3 nano-powder was prepared by sol-gel method， and by reacting with NH3， the interme- diate product InN base material was obtained， then the InN-In2O3 nanocomposite was obtained through the in?situ oxidation process， and characterized by means of XRD（X-ray differaction）， SEM（scanning electron microscopy）， TEM（transmission electron microscopy） and XPS（X-ray photoelectron spectroscopy）. The bottle-shaped nanocomposite was then equipped with a micro-chip sensor chip working platform. The results show that at a lower operating temperature（75 ℃）， the detection limit for formaldehyde gas can be as low as ppb（0.13 mg/m3 or 100 ppb）， with higher sensitivity（12）， shorter response time（2 s）， selectivity and stability. In the test of the influence of humidity on the sensitivity of the sensor， due to the water-soluble characteristics of formaldehyde， the sensitivity of the sensor changes with the change of humidity. This change is great when the concentration of formaldehyde is low， but small when the concentration of formaldehyde is high.

    Two-stage Varying-temperature Synthesis of MFI Zeolite Membrane and Their Separation Performance for Xylene Isomers
    XIA Dunyan, PENG Li, WU Zhengqi, WANG Linzhi, JIA Yimin, ZHANG Chun, GU Xuehong
    2020, 41(12):  2813-2821.  doi:10.7503/cjcu20200327
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    MFI zeolite membranes were prepared in situ on alumina supports by constant temperature and two-stage varying-temperature synthesis methods， respectively. The MFI zeolite membranes synthesized by the constant temperature method were composed of large crystals and had no separation performance for PX/OX due to the large defects caused by template removal at high temperature. The membranes synthesized by two-stage varying-temperature synthesis method were composed of the zeolite crystals with smaller sizes in a and b directions， and the formation of defects can be avoided during template removal at high temperature. A good separation performance for PX/OX at 300 ℃ with a separation factor of 42 and the PX permeance of 9.57×10-9 mol·m-2·s-1·Pa-1 can be obtained. Detemplation at low temperature in ozone atmosphere can effectively avoid the formation of large defects to improve the membranes， performance by reducing the stress caused by the thermal shrinkage of zeolite crystals. The membranes synthesized by both the two methods showed separation abilities for the xylene isomer after detemplating at low temperature in ozone atmosphere. The MFI zeolite membranes synthesized by variable synthesis temperature showed a PX/OX separation factor up to 76 and PX permeance of 1.02×10-8 mol·m-2·s-1·Pa-1.

    Polymer Chemistry
    Preparation and Drug Delivery Properties of Thermo/pH Dual Responsive Copolymer Composite Micelles of MPEG-b-PCL/PNVCL-b-PCL
    ZHANG Meng, WANG Shaosen, XIN Yuhao, LIU Xue, WU Qiuhua, ZHANG Guolin
    2020, 41(12):  2822-2831.  doi:10.7503/cjcu20200378
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    Thermo/pH dual responsive copolymer composite micelles（CMs） based on the block copolymers with imine bonds show higher sensitivity and stability due to their imine linkage and core-shell-crown three la-yer structure. Using polyethylene glycol monomethyl ether（MPEG）， N-vinyl caprolactam（NVCL） and ε-caprolactone（ε-CL） as raw materials， the aldehyde-terminated poly（ethylene glycol） monomethyl ether（MPEG-CHO）， aldehyde-terminated poly（N-vinylcaprolactam）（PNVCL-CHO） and amino-terminated polycaprolactone（H2N-PCL） were prepared respectively. Block copolymers， poly（ethylene glycol） monomethyl ether-b-poly（ε-caprolactone）（MPEG-b-PCL） and poly（N-vinylcaprolactam）-b-poly（ε-caprolactone） （PNVCL-b-PCL） based on imine bond， were synthesized by reaction of H2N-PCL with MPEG-CHO and PNVCL-CHO. At room temperature， MPEG-b-PCL and PNVCL-b-PCL self-assembled to form CMs with PCL as the core and MPEG/PNVCL as the mixed shell in water. At the physiological temperature， thermo-responsive PNVCL collapsed on the PCL core， while MPEG still stretched to form core-shell-corona micelles， which might protect the drug encapsulated in the core. Studies on the in vitro drug release showed that a much faster release rate was observed at slightly acidic media， due to the disruption of imine bonds. 3-（4，5）-Dimethylthiahiazo（-z-y1）-3，5-di-phenytetrazoliumromide（MTT） assay demonstrated the low cytotoxicity of the composite micelles.

    Analysis of Characteristic Phosphorus in High Polymerization Ammonium Polyphosphate by 31P NMR
    LIU Yina, YANG Rongjie, HU Weiguo, LI Dinghua
    2020, 41(12):  2832-2837.  doi:10.7503/cjcu20200365
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    In this paper， phosphorus nuclear magnetic resonance（31P NMR）， J-resolved and 31P-DOSY are used to study the characteristic phosphorus and coupling constants of APP. Studies have shown that the end-group phosphors of polyphosphate and diphosphate have double-peak and single-peak characteristics respectively， and the coupling constant of spin-coupled peak is 19.4 Hz； Ammonium phosphate（Ⅱ-APP） contains ammonium di-polyphosphate and ammonium orthophosphate. When 31P NMR is used to quantitatively characterize the degree of APP polymerization， the terminal phosphorus of ammonium di-polyphosphate should be excluded； when APP is prepared by dissolving APP in water at 100 ℃， the appearance of the phosphorus resonance peak of small molecule middle phosphorus proves that APP has partially broken chain.

    Infectious Effect of Organic Small Molecules on Photo-oxidative Aging of Polypropylene
    LIU Xuan, LIU Haoyu, LI Yifeng, ZHAO Jiaohong, YANG Rui
    2020, 41(12):  2838-2844.  doi:10.7503/cjcu20200350
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    Aging of a polymer is generally affected by adjacent polymers， known as infectious behavior of aging. Organic small molecules generated during aging are considered to be infection agents. However， the way they influence aging process and the difference among various infection agents are still unknown. In this paper， the influence of 18 representative organic small molecules on photo-oxidative aging of polypropylene（PP） was studied. The small molecules included acids， esters， aldehydes， ketones and alcohols， correspon-ding to typical photo-oxidative degradation products of polymers. When they were placed near PP during aging， the carbonyl index（CI） of PP was higher compared to the case when PP was aged individually. It was demonstrated that photo-oxidative aging of PP was accelerated by all the small molecules. The acceleration effects of acids， aldehydes and ketones were outstanding. Especially for propanoic acid， isobutyric acid， me- thacrylic acid， formaldehyde， acetaldehyde and butanone， CI was increased by more than 700% when PP was aged with them. Further， infection mechanism of acetone and acetic acid was investigated， since they had been identified as typical infection agents. CI and concentrations of gaseous degradation products of PP with and without acetone or acetic acid were measured with aging time. When PP was aged with acetone， CI was increased from as early as 24 h at an extremely high rate. With acetic acid， CI was increased after an obvious induction period and the increasing rate was lower than that with acetone. Similar phenomenon was observed in gaseous degradation products. The results showed that acetone acted as an initiator， photolyzed to generate CH3· that could initiate the oxidation of PP； while acetic acid acted as a catalyzer， facilitating the decomposition of hydroperoxides and the accumulation of oxidation products.

    Preparation of High-temperature Proton Exchange Membranes Based on Semi-interpenetrating Polymer Networks
    LIANG Minhui, WANG Peng, LI Hongbin, LI Tianyang, CAO Kaiyue, PENG Jinwu, LIU Zhenchao, LIU Baijun
    2020, 41(12):  2845-2850.  doi:10.7503/cjcu20200348
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    To realize the tradeoff between high proton conductivity and high mechanical strength， a semi- interpenetrating polymer network（PIN） based on a sulfonated poly（aryl ether ketone） bearing unsaturated double bonds（Allyl-SPAEK） and an arylether-type polybenzimidazole（PBI） has been fabricated for high- temperature proton exchange membranes in fuel cells. Based on the molecular design and syntheses of Allyl-SPAEK and PBI， a new IPN system composed of covalent bond formed by allyl groups and strong acid-base interactions formed by imidazole-sulfonic acid groups was obtained through a process of solution casting and UV irradiation. The results showed that the PBI/Allyl-SPAEK membranes could have simultaneously improved proton conductivity and mechanical strength， which were much better than the pristine PBI membrane under the same phosphoric acid adsorption level and test conditions. With a phosphoric acid adsorption level of ca.13.0， the maximum tensile strength of one PBI/Allyl-SPAEK membrane was 12.1 MPa， and its young’s modulus reached 131.5 MPa， which was twice of the pristine PBI membrane. At 200 ℃， the proton conductivities of two membranes reached above 200 mS/cm， which was 38% higher than that of the pristine PBI membrane.

    Structures and Properties of Isotactic Polypropylene/Polybutene-1 In-reactor Alloys
    MA Yaping, ZHANG Ning, ZHENG Weiping, XIAO Weijia, LIU Chenguang, HE Aihua, SHAO Huafeng
    2020, 41(12):  2851-2860.  doi:10.7503/cjcu20200277
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    The performance of materials is closely related to the composition， component distribution and molecular chain structure. Therefore， it is vital to analyze the relationship between chain structure and performance of alloys with multiple components. Two novel isotactic polypropylene/polybutene-1 in-reactor alloys（iPP/iPB） synthesized by sequential two-stage polymerization were fractionated by the temperature rising elution fractionation at a temperature ranging from -30 ℃ to 140 ℃. The chain microstructure and sequences distribution， crystallization behavior， molecular weight（Mw） and molecular weight distribution（Mw/Mn） of fractions were characterized by 13C NMR， FTIR， DSC， GPC. The results showed that iPP/iPB alloys were mainly composed of five components， including the high isotactic polybutene-1（iPB） as the main component， a small amount of poly（（butene-1）-block-propylene） block copolymer（PB-b-PP）， isotactic polypropylene（iPP）， etc. With the increase of elution temperatures， the length of PP blocks in the PB-b-PP components gradually increased， while that of PB blocks gradually decreased. At the same elution temperature， Alloy B possessed longer PP block in copolymer fractions and exhibited more perfect PP crystal. Alloy B containing higher iPB and PB-b-PP components showed higher tensile strength， flexural strength， excellent impact resistance， higher Vicat softening temperature and faster crystal transformation rate.

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