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Probing the pH-dependent chain dynamics of poly(acrylate acid) in concentrated solution by using a cationic AIE fluorophore

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Science China Chemistry 2013年第9期56卷 1253-1257页

作者： ZHANG shuang YAN JiMing QIN AnJun sun JingZhi TANG ben Zhong MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang University Department of Chemistry The Hong Kong University of Science & Technology

We report a novel strategy to study the chain dynamics of poly(acrylic acid) (PAA) in a relative concentrated solution (1.0 g/L). The strategy is based on the fluorescent probe (DCTPE) with unique aggregation-induced emission (AIE) characteristics. Free DCTPE molecules are non-emissive in aqueous solution, but they become highly emissive when trapped in polymer coils. The fluorescence intensity is proportional to the efficiency of trapping DCTPE molecules in polymer coils. By correlation the change of fluorescence intensity with the variation of pH value (from 1.78 to 12.06), the PAA chain's dynamics in the relatively concentrated solution have been elucidated into three processes. In the pH range from 12.06 to 6.0, PAA chains take an extended and non-folding conformation. Changing pH from 6.0 to 3.86, PAA chains are partially protonated and loosely packed polymer coils are formed. Further lowering the pH value of the solution (from 3.86 to 1.78), protonated segments dominate the PAA chains, and at the same time, the intermolecular hydrogen bonding takes effect, thus the polymer chains posses in the conformation of more compact coils.

关键词： polyelectrolyte polymer dynamics coils concentrated solution aggregation-induced emission

The specific detection of Cu(Ⅱ) using an AIE-active alanine ester

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Chinese Chemical Letters 2013年第8期24卷 668-672页

作者： shuang Zhang Ji-Ming Yan An-Jun Qin Jing-Zhi sun ben-Zhong Tang MoE Key Laboratory of Macromolecule Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang University Department of Chemistry Institute of Molecular Functional Materialsthe Institute for Advanced Study(IAS)The Hong Kong University of Science & Technology

Cu（Ⅱ） detection is important because it plays crucial role in several biological processes and ecological *** techniques have attracted more and more attention in Cu（Ⅱ） *** this report,we contribute a novel strategy to use fluorescence spectroscopy for Cu（Ⅱ） specific *** specificity relies on the fact that,of the many metal cations,only Cu（Ⅱ） can catalyze the hydrolyzation of a-amino acid *** novelty originates from the unique aggregation-induced emission（AIE） property of the fluorescent *** designed a model a-amino acid ester（TPE-Ala） constructed with alanine and tetraphenylethene-functionalized methanol（TPE-methanol）.In comparison with the precursor TPE-Ala, TPE-methanol has lower solubility and is easy to form aggregates in water,thereby displaying a higher fluorescent ***,the Cu（Ⅱ） catalyzed hydrolyzation can be monitored by recording the fluorescence enhancement and fluorescent detection Cu（Ⅱ） is rationally achieved.

关键词： Aggregation-induced emission Fluorescence enhancement Cu(Ⅱ) catalyzed

Facile synthesis of poly(aroxycarbonyltriazole)s with aggregation-induced emission characteristics by metal-free click polymerization

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Science China Chemistry 2011年第4期54卷 611-616页

作者： LI HongKun MEI Ju WANG Jian ZHANG shuang ZHAO QiuLi WEI Qiang QIN AnJun sun JingZhi TANG ben Zhong MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang UniversityHangzhou 310027China Department of Chemistry The Hong Kong University of Science & TechnologyClear Water BayKowloonHong KongChina

Regioseletive 1,3-dipolar polycycloadditions of 4,4'-isopropylidenediphenyl dipropiolate (1) and tetraphenylethene (TPE)-containing diazides (2) are carried out in polar solvents such as DMF/toluene at a moderate temperature of 100℃ for 6 h,producing poly(aroxycarbonyltriazole)s (PACTs) P3 with high molecular weights (Mw up to 23900) and regioregularities (F1,4 up to ～90%) in high yields (up to ～99%).These metal-free click polymerizations can propagate smoothly in an open atmosphere without protection from oxygen and *** obtained polymers are soluble in common organic solvents and thermally stable at temperatures up to 375℃.Thanks to their contained TPE moieties,the PACTs show aggregation-induced emission and can serve as fluorescent chemosensors for superamplified detection of explosives.

关键词： aggregation-induced emission metal-free click polymerization propiolate chemosensor

Innovative dual-mode device integrating capacitive desalination and solar vapor generation for high-efficiency seawater desalination

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Journal of Energy Chemistry 2025年第1期 171-179页

作者： Jiacheng Wang Zhaoyu Chen Ruduan Yuan Jiaxin Luo ben Zhang Keju Ji Meng Li Juanxiu Xiao Kuan sun National Innovation Center for Industry-Education Integration of Energy Storage Technology MOE Key Laboratory of Low-grade Energy Utilization Technologies and SystemsCollege of Energy & Power Engineering Chongqing University Xuefeng Mountain Energy Equipment Safety National Observation and Research Station CQU-NUS Renewable Energy Materials & Devices Joint Laboratory Chongqing University Southwest Technology and Engineering Research Institute Jiangsu Provincial Key Laboratory of Bionic Functional Materials College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics State Key Laboratory of Marine Resources Utilization in South China Sea Collaborative Innovation Center of Marine Science and Technology School of Marine Science and Engineering Hainan University

Solar-driven interface evaporation with high solar-to-steam conversion efficiency has shown great potential in seawater ***,due to the influence of latent heat and condensation efficiency,the water yield from solar-driven interface evaporation remains insufficient,posing a significant challenge that requires *** this work,we designed a dual-mode high-flux seawater desalination device that combines solar-driven interface evaporation and capacitive *** utilizing coupled desalination materials exhibiting both photothermal conversion and capacitance activity,the device demonstrated photothermal evaporation rates of 1.41 and 0.97 kg m-2h-1for condensate water yield under one-sun ***,the device exhibited a salt adsorption capacity of up to48 mg g-1and a salt adsorption rate of 2.1 mg *** addition,the salt adsorption capacity increased by approximately 32% under one-sun ***,photo-enhanced capacitive desalination performance was explored through numerical simulations and theoretical *** calculations and characterizations confirmed that the defect energy levels formed by the introduction of sulfur vacancies can effectively widen the light absorption range,improve photothermal conversion performance,and stimulate more photoelectrons to participate in capacitive ***,the electron distribution state of molybdenum disulfide with sulfur vacancies and surface defect sites contributes to ion/electron transport at the solid-liquid *** work provides a novel pathway for integrating solar vapor generation with other low-energy desalination technologies.

关键词：

Dislocation-mediated migration of interphase boundaries

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Journal of Materials Science & Technology 2019年第11期35卷 2714-2726页

作者： Zhipeng sun Fuzhi Dai ben Xu Wenzheng Zhang School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Science and Technology of Advanced Functional Composite Laboratory Aerospace Research Institute of Materials and Processing TechnologyBeijing 100076China Key Laboratory of Advanced Materials(MOE) State Key Laboratory of New Ceramics and Fine ProcessingChina

Faceted interphase boundaries(IPBs)are commonly observed in lath-shaped precipitates in alloys consisting of simple face-centred cubic(fcc),body centred-cubic(bcc)or hexagonal closed packed(hcp)phases,which normally contain one or two sets of parallel *** influence of these dislocations on interface migration and possible accompanying long-range strain field remain *** elucidate this,we carried out atomistic simulations to investigate the dislocation-mediated migration processes of IPBs in a pure-iron *** results show that the migration of these IPBs is accompanied with the slip of interfacial dislocations,even in high-index slip planes,with two migration modes were observed:the first mode is the uniform migration mode that occurs only when all of the dislocations slip in a common slip plane.A shear-coupled interface migration was observed for this *** other interfaces propagate in the stick-slip migration mode that occurs when the dislocations glide on different slip planes,involving dislocation reaction or tangling.A quantitative relationship was established to link the atomic displacements with the dislocation structure,slip plane,and interface *** macroscopic shear deformation due to the effect of overall atomic displacement shows a good agreement with the results obtained based on the phenomenological theory of martensite *** findings have general implications for the understanding of phase transformations and the surface relief effect at the atomic scale.

关键词： Interphase boundary migration O-line interface Shear-coupled interface migration Dislocation gliding Atomic displacement

Detection of the critical micelle concentration of cationic and anionic surfactants based on aggregation-induced emission property of hexaphenylsilole derivatives

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Science China Chemistry 2009年第6期52卷 755-759页

作者： TANG Li JIN JiaKe ZHANG shuang MAO Yu sun JingZhi YUAN WangZhang ZHAO Hui XU HaiPeng QIN AnJun TANG ben Zhong Department of Polymer Science and Engineering Institute of Biomedical MacromoleculesZhejiang UniversityHangzhou 310027China Department of Chemistry The Hong Kong University of Science&TechnologyHong KongChina

We report a fluorescence "turn-on" method to detect the critical micelle concentration (CMC) of surfactants. This method works well for both cationic and anionic surfactants. It employs an unprecedented mechanism (aggregation-induced emission, or AIE) to determine the CMC values, and the results are consistent with the data obtained by the classical techniques. In addition, this method renders the convenient detection of the CMC values. Any large and professional instruments are unnecessary, instead, a portable UV lamp and an ultrasonic generator are enough to carry out the detection in an ordinary laboratory. Considering that micelles are interesting entities and have found applications in many important fields such as emulsion polymerization, template of nanosized materials synthesis, controllable drug delivery and macromolecular self-assembling. Our experimental results may offer a facile, sensitive and promising method to detect the formation of micelles constructed by the new amphiphilic molecules and macromolecules.

关键词： aggregation-induced emission critical micelle concentration fluorescence probe

A universal strategy for fast,scalable,and aqueous synthesis of multicomponent palladium alloy ultrathin nanowires

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Science China Chemistry 2021年第2期64卷 245-252页

作者： Hao Lv Xuwen Guo Lizhi sun Dongdong Xu ben Liu College of Chemistry Sichuan UniversityChengdu 610064China Jiangsu Key Laboratory of New Power Batteries Jiangsu Collaborative Innovation Center of Biomedical Functional MaterialsSchool of Chemistry and Materials ScienceNanjing Normal UniversityNanjing 210023China

Noble metal alloy nanowires(NWs)with ultrathin diameters(2–3 nm)and precisely controllable elemental compositions have attracted dramatically growing attention for(electro)*** numerous achievements in past two decades,noble metal alloy NWs are mostly synthesized with the traditional oil-phase methods that suffer from some undesirable ***,we report a general strategy for fast,scalable,and aqueous synthesis of multicomponent Pd-based alloy ultrathin NWs with an average diameter of 2.6 nm,ranging from bimetallic PdM(PdFe,PdCo,PdNi,PdCu,PdZn,PdRu,PdRh,PdAg,PdCd,PdIr,PdPt,PdAu)and binary PdS/PdP NWs,to trimetallic PdM1M2 NWs(PdAuCu,PdCoNi,PdCuZn,PdCuNi,PdAgCu,PdAuCu,PdRuAg,PdAuRu,and PdPtAu),and to tetrametallic PdM1M2M3 NWs(PdAuAgCu,PdCoCuNi,PdAuCuNi,PdPtAuCu,and PdIrPtAu).The key to the success of this aqueous synthesis is the utilization of N2H4 as the extremely strong reducing agent that directs the synchronous reduction and anisotropic nucleation growth of multicomponent Pd alloy NWs along nanoconfined columnar phase assembled with amphiphilic dioctadecyldimethylammonium ***-resultant Pd-based alloy ultrathin NWs exhibit multiple structural and compositional synergies,which remarkably optimize the removal of poisoning ethoxy intermediates and thus improve electrocatalytic performance towards ethanol oxidation reaction(EOR).Among them,tetrametallic PdAuCuNi alloy ultrathin NWs hold a high EOR activity of 5.14 A mg-1 Pd and a low activation energy of 13.1 kJ mol^-1,both of which are much better than its counterpart catalysts alloyed with less *** work represents an important advance in precise aqueous synthesis of multicomponent noble metal alloy ultrathin NWs as the high-performance electrocatalysts for various targeted applications.

关键词： ultrathin nanowires multicomponent alloys palladium synthetic chemistry ethanol oxidation reaction

Observational constraints on dark matter decaying via gravity portals

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Chinese Physics C 2020年第12期44卷 215-225页

作者： Xu-Dong sun ben-Zhong Dai School of Physics and Astronomy Yunnan UniversityKunming 650091China Key Laboratory of Astroparticle Physics Yunnan ProvinceKunming 650091China

Global symmetry can guarantee the stability of dark matter particles(DMps).However,the nonminimal coupling between dark matter(DM)and gravity can break the global symmetry of DMps,which in turn leads to their *** the framework of nonminimal coupling between scalar singlet dark matter(ssDM)and gravity,it is worth exploring the extent to which the symmetry of ssDM is *** is suggested that the total number of decay products of ssDM cannot exceed current observational *** these lines,the data obtained with satellites such as Fermi-LAT and AMS-02 suggest that the scale of ssDM global symmetry breaking can be *** the mass of many promising DM candidates is likely to be in the GeV-TeV range,we determine reasonable parameters for the ssDM lifetime within this *** find that when the mass of ssDM is around the electroweak scale(246 GeV),the corresponding 3σlower limit of the lifetime of ssDM is 5.3×1026 *** analysis of ssDM around the electroweak scale encompasses the most abundant decay channels of all mass ranges so that the analysis of the behavior of ssDM under the influence of gravity is more comprehensive.

关键词： cosmology of theories beyond the SM dark matter beyond standard model

Aphid populations showing differential levels of virulence on Capsicum accessions

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Insect Science 2020年第2期27卷 336-348页

作者： Mengjing sun Roeland E.Voorrips ben Vosman Plant Breeding Wageningen University&ResearchWageningenThe Netherlands

The green peach aphid,Myzus persicae,is one of the most threatening pests in pepper cultivation and growers would benefit from resistant ***,we identified two Capsicum acessions as susceptible and three as resistant to *** using an aphid population originating from the Netherlands(NL).Later on we identified an aphid population originating from a diferent gcographical region(Switserland,SW)that was virulent on all tested Capsicum *** objeetive of the current work is to describe in detail diferent aspects of the interaction between two aphid populations and two sclected Capsicum acessions(one that was susceptible[PB2013046]and one that was resistant[PB2013071]to population NL),including biochemical processes *** penetration graph(EPG)recordings showed similar feeding activities for both aphid populations on *** acession PB2013071 the aphid population sw was able to devote significantly more time to phloem ingestion than population *** also studied plant defense response and found that plants of acession PB2013046 could not induce an accumulation of reactive oxygen species and callose formation after infestation with either aphid ***,plants of PB2013071 induced a stronger defense response after infestation by population NL than after infestation by population *** on these results,population SW of *** seems to have overcome the resistance of PB2013071 that prevented feeding of aphids from NL *** potential mechanism by which SW population overcomes the resistance is discussed.

关键词： callose deposition EPG plant aphid interaction plant immunity ROS accumulation virulence