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When quantum dots meet blue phase liquid crystal elastomers:visualized full-color and mechanically-switchable circularly polarized luminescence

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light(Science & Applications) 2024年第6期13卷 1210-1220页

作者： Shan li Yuqi Tang Qingyan Fan Ziyuan li Xinfang Zhang Jingxia Wang Jinbao Guo Quan li Key Laboratory of Carbon Fibers and Functional Polymers Ministry of Educationand College of Materials Science and EngineeringBeijing University of Chemical Technology100029BeijingChina Institute of Advanced Materials and school of chemistry and chemical engineering Southeast UniversityNanjing211189China Materials Science Graduate Program Kent State UniversityKentOH44242USA CAS Key Laboratory of Bio-Inspired Materials and Interfacial Sciences Technical Institute of Physics and ChemistryChinese Academy of Sciences100190BeijingChina

Polymer-based circularly polarized luminescence(CPL)materials with the advantage of diversified structure,easy fabrication,high thermal stability,and tunable properties have garnered considerable ***,adequate and precise tuning over CPL in polymer-based materials remains challenging due to the difficulty in regulating chiral ***,visualized full-color CPL is achieved by doping red,green,and blue quantum dots(QDs)into reconfigurable blue phase liquid crystal elastomers(BPLCEs).In contrast to the CPL signal observed in cholesteric liquid crystal elastomers(CLCEs),the chiral 3D cubic superstructure of BPLCEs induces an opposite CPL ***,this effect is entirely independent of photonic bandgaps(PBGs)and results in a high glum value,even without matching between PBGs and the emission bands of ***,the lattice structure of the BPLCEs can be reversibly switched via mechanical stretching force,inducing on-off switching of the CPL signals,and these variations can be further fixed using dynamic disulfide bonds in the ***,the smart polymer-based CPL systems using the BPLCEs for anti-counterfeiting and information encryption have been demonstrated,suggesting the great potential of the BPLCEs-based CPL active materials.

关键词： circular quantum crystal

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Beyond 1,4-addition of in-situ generated(aza-)quinone methides and indole imine methides

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Chinese chemical Letters 2024年第7期35卷 35-53页

作者： Yan-li li Zhi-Ming li Kai-Kai Wang Xiao-Long He Medical College Xinxiang UniversityXinxiang 453000China school of Pharmacy Xinxiang UniversityXinxiang 453000China school of Food and Bioengineering Xihua UniversityChengdu 610039China

The conjugate addition of in-situ generated(aza-)quinone methides(QMs)and indole imine methides(IIMs)emerged as a powerful protocol to access densely functionalized benzenes and *** alcohols,aminobenzhydryl alcohols,and varied indolylmethanols served as most effective precursors for the in-situ generation of such reactive species under acid *** relevant propargylic alcohol has proven to be an elegant precursor to generate the propargylic-QMs and-IIMs via the acid promoted dehydration process,thus enabling diverse challenging remote activation to proceed conjugate1,6-and 1,***,the heteroarene has proven to be workable to transfer the LUMO of the p-QMs and 2-IIMs,thus inducing the remote nucleophilic dearomative *** conjugate additions of(aza-)p-QMs and varied IIMs has made significant contribution in the field of remote activation chemistry in past *** review summarizes the latest advances of the remote conjugate additions of the in-situ generated QMs and IIMs.

关键词： Conjugate addition QMs IIMs LUMO Remote activation Dearomative addition

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Highly selective and efficient photocatalytic NO removal:Charge carrier kinetics and interface molecular process

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Nano Research 2024年第3期17卷 1003-1026页

作者： Huan Shang Hongbao Jia Pengpeng li Hao li Wenbin Zhang Shuangjun li Qing Wang Shuning Xiao Ding Wang Guisheng li Dieqing Zhang school of Materials and chemistry University of Shanghai for Science and TechnologyShanghai 200093China The Education Ministry Key Lab of Resource chemistry Joint International Research Laboratory of Resource Chemistry of Ministry of EducationShanghai Key Laboratory of Rare Earth Functional Materialsand Shanghai Frontiers Science Center of Biomimetic CatalysisShanghai Normal UniversityShanghai 200234China school of Environmental Science and engineering Shanghai Jiao Tong UniversityShanghai 200240China

The widespread nitrogen oxides(NOx,mainly in NO)in the atmosphere have threatened human health and ecological *** dilute NO(ppb)is difficult to efficiently remove via the traditional process due to its characteristics of low concentration,wide range,large total amount,*** can utilize solar energy to purify NO pollutants under mild conditions,but its application is limited due to the low selectivity of nitrate and poor activity of NO *** underlying reason is that the interface mechanism of NO oxidation is not clearly understood,which leads to the inability to accurately regulate the NO oxidation ***,the recent advances in the photocatalytic oxidation of NO are ***,the common strategies to effectively regulate carrier dynamics such as morphology control,facet engineering,defect engineering,plasma coupling,heterojunction and single-atom catalysts are ***,the progress of enhancing the adsorption and activation of reactants such as NO and O_(2) during NO oxidation is described in detail,and the corresponding NO oxidation mechanisms are ***,the challenges and prospects of photocatalytic NO oxidation are presented in term of nanotechnology for air pollution *** review can shed light on the interface mechanism of NO oxidation and provide illuminating information on designing novel catalysts for efficient NOx control.

关键词： nitrogen oxide(NO)oxidation photocatalysis NO/O_(2)activation charge carrier kinetics interfacial mechanism

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Effect and mechanism of reductive polyaniline on the stability of nitrocellulose

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Defence Technology（防务技术） 2024年第8期38卷 217-225页

作者： Wenjiang li Binbin Wang Huimin Chen Aoao Lu Chenguang li Qiang li Fengqiang Nan Ping Du school of chemistry and chemical engineering Nanjing University of Science and TechnologyNanjing 210094China Key Laboratory of Special Energy Materials Ministry of EducationNanjing 210094China

The search for new green and efficient stabilizers is of great importance for the stabilization of nitrocellulose(NC). This is due to the shortcomings of traditional stabilizers, such as high toxicity. In this study, reduced polyaniline(r-PANI), which has a similar functional structure to diphenylamine(DPA) but is non-toxic, was prepared from PANI based on the action with N_(2)H_(4) and NH_(3)-H_(2)O, and used for the first time as a potential stabilizer for NC. XPS, FTIR, Raman, and SEM were used to characterize the reduced chemical structure and surface morphology of r-PANI. In addition, the effect of r-PANI on the stabilization of NC was characterized using DSC, VST, isothermal TG, and MMC. Thermal weight loss was reduced by 83% and 68% and gas pressure release by 75% and 49% compared to pure NC and NC&3%DPA, *** and XPS were used to characterize the structural changes of r-PANI before and after reaction with NO_(2). The 1535 cm^(-1) and 1341 cm^(-1) of the FTIR and the 404.98 eV and 406.05 eV of the XPS showed that the -NO_(2) was generated by the absorption of NO_(2). Furthermore, the quantum chemical calculation showed that NO_(2) was directly immobilized on r-PANI by forming -NO_(2) in the neighboring position of the benzene ring.

关键词： Nitrocellulose Green stabilizer Polyaniline Mechanism of stability

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Zeolite-encaged gold catalysts for the oxidative condensation of furfural

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Frontiers of chemical Science and engineering 2024年第8期18卷 67-77页

作者： Weijie li Mingyang Gao Bin Qin Xin Deng Landong li school of Materials Science and engineering Nankai UniversityTianjin 300350China College of chemistry Nankai UniversityTianjin 300071China Haihe Laboratory of Sustainable chemical Transformations Tianjin 300192China

The oxidative condensation between renewable furfural and fatty alcohols is a crucial avenue for producing high-quality liquid fuels and valuable furan *** selectivity control in this reaction process remains a significant ***,we report the strategy of confining well dispersed gold species within ZSM-5 structure to construct highly active Au@ZSM-5 zeolite catalysts for the oxidative condensation of *** results and spectroscopy analyses demonstrate the efficient encapsulation of isolated and cationic Au clusters in zeolite ***@ZSM-5(K)catalyst shows remarkable performance with 69.7%furfural conversion and 90.2%furan-2-acrolein selectivity as well as good recycle *** is revealed that the microstructure of ZSM-5 zeolite can significantly promote oxidative condensation activity through confinement *** work presents an explicit example of constructing zeolite encaged noble metal catalysts toward targeted chemical transformations.

关键词： zeolite encapsulation gold oxidative condensation furfural

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Understanding of the structural evolution of catalysts and identification of active species during CO_(2) conversion

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Chinese chemical Letters 2024年第4期35卷 17-30页

作者： li li Fanpeng Chen Bohang Zhao Yifu Yu Department of chemistry School of ScienceInstitute of Molecular PlusTianjin UniversityTianjin 300072China

Converting CO_(2) into value-added chemicals and fuels through various catalytic methods to lower the atmospheric CO_(2) concentration has been developed to be a crucial means to alleviate the energy shortage and ameliorate the ever-fragile environment status. However, the complexity of the CO_(2) conversion reaction and the strong reduction conditions lead to the inevitable structural evolution, making it difficult for the prior design of suitable catalytic materials. Herein, to guide the rational design of efficient catalysts,we will be centered on the thermal, electro, and photo-induced structural evolution and active species identification during the CO_(2) conversion, including the in situ/operando characterization techniques monitoring the activation, steady, and deactivation stage of the catalysts as well as the inherent restructuring mechanism towards active species. Besides, the future challenges and opportunities on the merits of combining the structural evolution with the adsorbed intermediates recognized by ultra-fast spectroscopic techniques, simultaneously, the combination of theoretical simulation and the results of in situ experiments will also be addressed. This review can not only guide the identification of real active species, but also provide an approach to design the specific active species towards CO_(2) conversion, rather than only focusing on activity, for the purpose of practical industrial application.

关键词： CO_(2) Structural evolution Active species In situ Operando

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Distribution threshold values of CaCl_2 onto the 10X-zeolite and macro-pore silica gel

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Science china chemistry 2009年第2期52卷 231-235页

作者： TANG YouCheng1,2,li Bin1,YANG JingChang1,CHU Wei1 & LUO ShiZhong1 1 school of chemical-engineering,Sichuan university,Chengdu 610065,china 2 Sichuan Xinguang Silicon Technology Corporation limited,Leshan 614000,china school of chemical-engineering Sichuan University Chengdu China Sichuan Xinguang Silicon Technology Corporation limited Leshan China

The calcium chloride used for adsorption separation of ammonia is promising for its large adsorptive capacity and lower desorption temperature,but difficult to develop because of the liable expansion,lump and chip in the adsorption/desorption *** adsorbents made by monolayer dis-persion of calcium chloride onto carriers with high surface areas exhibit better adsorptive capacity and *** models were developed to confirm the maximum monolayer dispersion capacity of calcium chloride onto the carriers(the distribution threshold value),and the closely packed monolayer dispersion model was considered the most suitable for this *** distribution threshold values given by this model were 0.60 g CaCl2/(g 10X-zeolite) and 0.38 g CaCl2/(g SiO2).When the divalent salt was dispersed onto the carriers,however,anions were separated into two types,causing that the en-tropy of the system tended to increase and the system was not *** minimize the entropy,a new model was put forward as the modified closely packed monolayer dispersion *** on this model,the distribution threshold values are 0.52 g CaCl2/(g 10X-zeolite) and 0.33 g CaCl2/(g SiO2),*** distribution threshold values were also gained experimentally by XRD quantitative phase analysis:0.61 g CaCl2/(g 10X-zeolite) and 0.31 g CaCl2/(g SiO2).Comparison between experi-mental values of distribution threshold with theoretical ones based on two different model showed that the closely packed monolayer dispersion model fits the monolayer dispersion of calcium chloride onto micro-pore carrier - 10X-zeolite,and the modified closely packed monolayer dispersion model is more suitable for the bigger aperture carrier - macro-pore silica gel.

关键词： threshold value monolayer dispersion model 10X-zeolite macro-pore silica gel

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H3PW12O40/SiO2催化合成季戊四醇四庚酸酯的研究

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山西大学学报(自然科学版) 2005年第2期28卷 163-165页

作者：方莉山西大学化学化工学院山西太原030006

以正硅酸乙酯为硅源,采用溶胶-凝胶法制备硅载磷钨酸催化合成了季戊四醇四庚酸酯.考察了催化剂用量、醇酸摩尔比、反应温度、反应时间以及催化剂重复使用对酯含量的影响.实验表明,在催化剂用量(质量分数)为总体系的2%、醇酸摩尔比1∶6... 详细信息

以正硅酸乙酯为硅源,采用溶胶-凝胶法制备硅载磷钨酸催化合成了季戊四醇四庚酸酯.考察了催化剂用量、醇酸摩尔比、反应温度、反应时间以及催化剂重复使用对酯含量的影响.实验表明,在催化剂用量(质量分数)为总体系的2%、醇酸摩尔比1∶6、反应温度120℃～200℃、反应时间4h的条件下,酯化率可达96%以上,且催化剂重复使用效果好.

关键词：溶胶-凝胶法磷钨酸酯化季戊四醇四庚酸酯

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Circularly polarized luminescence switch based on a photochromic europium(Ⅲ) helicate derived coordination polymer

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Chinese chemical Letters 2024年第2期35卷 272-277页

作者： Mei li Yanyan Zhou Jingya li Wenru Huang Zhiwei Yao Yuying li Ting Gao Pengfei Yan Hongfeng li Key Laboratory of Functional Inorganic Material chemistry Ministry of EducationSchool of Chemistry and Materials ScienceHeilongjiang UniversityHarbin 150080China State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization Institution Baotou 014030China

Chiroptical switches based on circularly polarized luminescence(CPL)have shown the promising applications in advanced information ***,a pair of lanthanide coordination polymer enantiomers[Eu_(2)(L^(R))_(3)(BTFPO)_(2)]_(n) and[Eu_(2)(L^(S))_(3)(BTFPO)_(2)]_(n) with light-regulated CPL property are designed,which are assembled by a chiral binuclear triple-stranded Eu^(3+) helicates[Eu_(2)(L^(R/S))_(3)]coordinated with two photochromic triphenylphosphine oxides(BTFPO).Upon the alternative UV and 526 nm light irradiation,the complexes show the reversible photochromism,PL and CPL ***,the luminescence dissymmetry factor,g lum of ^(5)D_(0)→^(7)F_(1)(591 nm)transition shows an obvious increase from 0.19 to 0.29 before and after 275 nm light ***,the emission from Eu^(3+) center is not completely quenched in closed-ring state due to the low photocyclization(Ф_(o-c))quantum yield of the *** partial maintenance of emissive intensity is of essential importance for the monitor of CPL *** importantly,the CPL photo-switching property of the complexes in solid hybrid film is maintained,and still displays the enhanced CPL emission in photostationary ***,the potential applications of the doping film in logic gate and anti-counterfeiting were investigated.

关键词： Chiroptical switches Coordination polymer CPL Anti-counterfeiting Logic gate

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Temperature-controlled ionic liquid dispersive liquid phase microextraction combined with ultra-high-pressure liquid chromatography for the rapid determination of triclosan,triclocarban and methyl-triclosan in aqueous samples

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Science china chemistry 2010年第12期53卷 2600-2607页

作者： GUO JieHong 1,2,li XingHong 2,CAO Xueli 1,QU Lei 2,3,HOU DeKun 2 & XU XiaoBai 2 1 school of chemical and Environmental engineering,Beijing Technology and Business university,Beijing 100048,china 2 State Key Laboratory of Environmental chemistry and Eco-toxicology Research Center of Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,china 3 Zhengzhou university,Zhengzhou 450001,china school of chemical and Environmental engineering Beijing Technology and Business University Beijing China State Key Laboratory of Environmental chemistry and Eco-toxicology Research Center of Eco-Environmental Sciences Chinese Academy of Sciences Beijing China Zhengzhou university Zhengzhou China

As extraction solvents,ionic liquids have green *** this study,an environmentally benign analytical method termed temperature-controlled ionic liquid dispersive liquid phase microextraction (TIL-DLME) combined with ultra-highpressure liquid chromatography (UHPLC)-tunable ultraviolet detection (TUV) was developed for the pre-concentration and determination of triclosan (TCS),triclocarban (TCC) and methyl-triclosan (M-TCS) in water *** parameters that may affect extraction efficiencies were examined and optimized,including the types and amount of ionic liquids,volume of the diluent,heating temperature,cooling time,salt effect and pH *** the optimum conditions,linearity of the method was observed in the ranges of 0.0100-100 μgL-1 for TCS and M-TCS,and 0.00500-50.0 μgL-1 for TCC with correlation coefficients (r2) > *** limits of detection (LODs) ranged from 1.15 to 5.33 *** in domestic water and TCC in reclaimed water were detected at the concentrations of 1.01 and 0.126 μgL-1,*** spiked recoveries of the three target compounds in reclaimed water,irrigating water,waste water and domestic water samples were obtained in the ranges of 68.4%-71.9%,61.6%-87.8%,58.9%-74.9% and 64.9%-92.4%,*** with the previous dispersive liquid-liquid microextraction method (DLLME) about the determination of TCS,TCC and M-TCS,this method is not only more environmentally friendly but also more sensitive.

关键词： ionic liquid temperature-controlled ionic liquid dispersive liquid phase microextraction UHPLC aqueous samples

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