检索结果-南通市图书馆

Designing Tough,Printable,and Adaptable Eutectogels with Multinetworks via Synergy of Rapid Orthogonal Photopolymerizations and solvent effect in Seconds

在线全文

学校读者我要写书评

暂无评论

CCS Chemistry 2024年第2期6卷 390-402页

作者： Jupen Liu Lijun Zhou Ping Zhang Yanxia Zhao Hongqiu Wei You Yu Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education College of Chemistry and Materials ScienceNorthwest UniversityXi’an 710069

Achieving a straightforward design of tough,printable,and adaptable polymeric eutectogels is still challenging in related fields due to the uncontrollable polymerization and solvent-exchanging processes,and inherent contrasting multiple networks.Here,we report a one-step synergistic strategy based on ruthenium chemistry-catalyzed photopolymerization and solvent effect for preparing high-performance eutectogels.This orthogonal ruthenium photochemistry helps multinetworks formation via phenol-coupling of gelatin and copolymerization of acrylamide(AAm)and[2-(methacryloyloxy)ethyl]trimethylammonium tetrafluoroborate(META)monomers in seconds.The obvious difference in the supramolecular interactions of free AAm monomers and polymerized units in P(AAm-co-META)with deep eutectic solvents(DESs)significantly promotes the microphase-separation behavior in eutectogels.Consequently,the in situ polymerization and microphase-separation behavior enable the as-prepared eutectogel materials to have excellent mechanical properties(stress of∼1.2 MPa),toughness(∼4.0 MJ m^(−3)),elasticity,adaptivity,and conductivity(∼0.5 S m^(−1)at room temperature).Also,the critical strength of the resultant eutectogels can be modulated by varying the DES constituents.This rapid and well-controlled synergistic approach is compatible with extrusion printing techniques to make flexible sensors with high sensitivities and response times to detect pressure in a range of 0–500 kPa.Such a general and simple strategy has application potential in biological,engineering,and material sciences.

关键词： orthogonal chemistry visible-light photopolymerization solvent effect microphase separation adaptable polymers printable eutectogels

solvent effects on Diels-Alder reaction in ionic liquids:A reaction density functional study

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第2期66卷 180-188页

作者： Zijiang Dou Weiqiang Tang Peng Xie Shuangliang Zhao Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology and School of Chemistry and Chemical Engineering Guangxi UniversityNanning 530004China State Key Laboratory of Chemical Engineering and School of Chemical Engineering East China University of Science and TechnologyShanghai 200237China

Extensive experimental studies have been performed on the Diels-Alder(DA)reactions in ionic liquids(ILs),which demonstrate that the IL environment can significantly influence the reaction rates and selectivity.However,the underlying microscopic mechanism remains ambiguous.In this work,the multiscale reaction density functional theory is applied to explore the effect of 1-butyl-3-methylimidazolium hexafluorophosphate([BMIM][PF_(6)])solvent on the reaction of cyclopentadiene(CP)with acrolein,methyl acrylate,or acrylonitrile.By analyzing the free energy landscape during the reaction,it is found that the polarization effect has a relatively small influence,while the solvation effect makes both the activation free energy and reaction free energy decrease.In addition,the rearrangement of local solvent structure shows that the cation spatial distribution responds more evidently to the reaction than the anion,and this indicates that the cation plays a dominant role in the solvation effect and so as to affect the reaction rates and selectivity of the DA reactions.

关键词： solvent effect Ionic liquids Diels-Alder reaction Reaction density functional theory

维普期刊数据库博看期刊

A reaction density functional theory study of solvent effect in the nucleophilic addition reactions in aqueous solution

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2022年第4期7卷 782-791页

作者： Cheng Cai Weiqiang Tang Chongzhi Qiao Bo Bao Peng Xie Shuangliang Zhao Honglai Liu State Key Laboratory of Chemical Engineering and School of Chemical Engineering East China University of Science and TechnologyShanghai200237China School of Chemistry and Molecular Engineering East China University of Science and TechnologyShanghai200237China Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology School of Chemistry and Chemical EngineeringGuangxi UniversityNanning530004China

Whereas the proper choice of reaction solvent constitutes the cornerstone of the green solvent concept,solvent effects on chemical reactions are not mechanistically well understood due to the lack of feasible molecular models.Herein,by taking the case study of nucleophilic addition reaction in aqueous solution,we extend the proposed multiscale reaction density functional theory(RxDFT)method to investigate the intrinsic free energy profile and total free energy profile,and study the solvent effect on the activation and reaction free energy for the nucleophilic addition reactions of hydroxide anion with methanal and carbon dioxide in aqueous solution.The predictions of the free energy profile in aqueous solution for these two nucleophilic addition reactions from RxDFT have a satisfactory agreement with the results from the RISM and MD-FEP simulation.Meanwhile,the solvent effect is successfully addressed by examining the difference of the free energy profile between the gas phase and aqueous phase.In addition,we investigate the solvent effect on the reactions occurred near solid-liquid interfaces.It is shown that the activation free energy is significantly depressed when reaction takes place in the region within 10A distance to the substrate surface owing to the decrease of hydration free energy at the solid-liquid interface.

关键词： Reaction density functional theory Nucleophilic addition solvent effect Charge models

N,N-dimethylformamide tailors solvent effect to boost Zn anode reversibility in aqueous electrolyte

在线全文

学校读者我要写书评

暂无评论

National Science Review 2022年第10期9卷 147-157页

作者： Yilin Ma Qiu Zhang Luojia Liu Yixin Li Haixia Li Zhenhua Yan Jun Chen Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) Renewable Energy Conversion and Storage Center (RECAST) College of Chemistry Nankai University

Rechargeable aqueous Zn batteries are considered as promising energy-storage devices because of their high capacity,environmental friendliness and low cost.However,the hydrogen evolution reaction and growth of dendritic Zn in common aqueous electrolytes severely restrict the application of Zn batteries.Here,we develop a simple strategy to suppress side reactions and boost the reversibility of the Zn electrode.By introducing 30%(volume fractions) N,N-dimethylformamide(DMF) to the 2 M Zn(CF3SO3)2-H2O electrolyte(ZHD30),the preferential hydrogen-bonding effect between DMF and H2O effectively reduces the water activity and hinders deprotonation of the electrolyte.The ZHD30 electrolyte improves the Zn plating/stripping coulombic efficiency from～95.3% to～99.4% and enhances the cycles from 65 to 300.The Zn-polyaniline full battery employing the ZHD30 ele ctrolyte can operate over a wide temperature range from-40℃ to+25℃ and deliver capacities of 161.6,127.4 and 65.8 mAh g-1at 25,-20 and-40℃,respectively.This work provides insights into the role of tuning solvent effects in designing low-cost and effective aqueous electrolytes.

关键词： aqueous electrolyte Zn reversibility hydrogen bond solvent effect rechargeable Zn battery

solvent effect on Characteristic Vibration of IR Spectrum of 4,4＇-Dibromodiphenyl Ether

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2014年第6期30卷 997-1004页

作者： LI Yu Resources and Environmental Research Academy Key Laboratory of Regional Energy Systems Optimization Ministry of Education North China Electric Power University Beijing 102206 P. R. China

The optimal geometry, IR spectrum and vibration assignment of 4,4＇-dibromodiphenyl ether（BDE-15） in gas phase were calculated via the density functional theory（DFT） at the level of B3LYP/6-3 l＋G（d）. Based on the vi- bration assignment, the calculation of vibration frequencies and intensities of 5 main vibration types of BDE-15 in 25 kinds of solvents was carried out by means of a self-consistent reaction field（SCRF） theoretical model at the level of B3LYP/6-31＋G（d） to analyze the solvent effect on the vibration of IR spectrum of BDE-15. To study the solvent ef- fect further, C--O asymmetric stretching vibration fluctuating, which is relatively acute in both vibration frequency and intensity, was selected as the characteristic vibration to establish different linear solvation energy relation（LSER） models for solvent categoring. solvent parameters（a, /3, ~r＊）, acceptable number（AN） and quantitative structure- activity relationship（QSAR） models were established via chemical quantum parameters of solvent moleculer, which were first been introduced to investigate different solvent-solute interaction mechanisms in alcoholic and non-alcoholic solvents on molecular level. At last, a single solvent molecule was embedded in the framework of po- larizable continuum model（PCM） to validate the effect of hydrogen bonding on solvent-solute interaction in alcohol solvents. The obtained results show that 5 main vibration types of BDE-15 in different solvents have small variation range in frequency and intensity and all the vibration frequencies in solvents are lower than those in gas phase, de- creasing along with the increasing of the dielectric Constant（e） of solvents exponentially. In contrast, all the vibration intensities in solvents are greater than those in gas phase and present positive exponential trend. Twenty-five solvents were divided into two categories（non-alcoholic solvents and alcoholic solvents） by LSER. The CmO asymmetric stretching vibration was mainly regulated by non-specific interaction（dipole-dipole and dip

关键词： solvent effect IR spectrum Vibration assignment Quantitative structure-activity relationship Hydrogenbonding

Responsive mechanism of three novel hypochlorous acid fluorescent probes and solvent effect on their sensing performance

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2017年第8期26卷 123-129页

作者：周勇王云坤王晓菲张玉瑾王传奎 Shandong Provincial Key Laboratory of Medical Physics and Image Processing Technology School of Physics and Electronics Shandong Normal University School of Science Qilu University of Technology

Optical properties and responsive mechanisms of three newly synthesized fluorescent probes for hypochlorous acid （HOC1） are investigated by employing time-dependent density functional theory. The computational results show that the absorption and emission properties of these probes change obviously when they react with hypochlorous acid. It is found that the probe FHZ has the best performance according to the probing behavior. Moreover, the responsive mechanisms of the probes are studied by analyzing the distributions of molecular orbitals and charge transfer, which are shown as the photon- induced electron transfer （PET） for FHZ and the intramolecular charge transfer OCT） for the other two probes. Specially, solvent effect on optical properties of the probe FHZ before and after reaction is studied within the polarizable continuum model （PCM）. It is shown that performance of the probe depends crucially on the solvent polarity. Our computational results agree well with the experimental measurement, and provide information for design of efficient two-photon fluorescent probes.

关键词： responsive mechanism hypochlorous acid fluorescentprobe solvent effect two-photon absorption

Morphology and strain control of hierarchical cobalt oxide nanowire electrocatalysts via solvent effect

在线全文

学校读者我要写书评

暂无评论

Nano Research 2020年第11期13卷 3130-3136页

作者： Xiuming Bu Xiongyi Liang Kingsley O.Egbo Zebiao Li You Meng Quan Quan Yang Yang Li Kin Man Yu Chi-Man Lawrence Wu Johnny C.Ho Department of Materials Science and Engineering City University of Hong KongKowloonHong Kong SARChina Department of Physics City University of Hong KongKowloonHong KongKowloonHong Kong SARChina State Key Laboratory of Terahertz and Millimeter Waves City University of Hong KongKowloonHong Kong SARChina

Designing highly efficient and low-cost electrocatalysts for oxygen evolution reaction is important for many renewable energy applications.In particular,strain engineering has been demonstrated as a powerful strategy to enhance the electrochemical performance of catalysts;however,the required complex catalyst preparation process restricts the implementation of strain engineering.Herein,we report a simple self-template method to prepare hierarchical porous Co_(3)O_(4)nanowires(PNWs)with tunable compressive strain via thermal-oxidation-transformation of easily prepared oxalic acid-cobalt nitrate(Co(NO_(3))_(2))composite nanowires.Based on the complementary theoretical and experimental studies,the selection of proper solvents in the catalyst preparation is not only vital for the hierarchical structural evolution of Co_(3)O_(4) but also for regulating their compressive surface strain.Because of the rich surface active sites and optimized electronic Co d band centers,the PNWs exhibit the excellent activity and stability for oxygen evolution reaction,delivering a low overpotential of 319 mV at 10 mA·cm^(−2)in 1 M KOH with a mass loading 0.553 mg·cm^(−2),which is even better than the noble metal catalyst of RuO_(2).This work provides a cost-effective example of porous Co_(3)O_(4)nanowire preparation as well as a promising method for modification of surface strain for the enhanced electrochemical performance.

关键词： hierarchical structure morphology control compressive strain solvent effect oxygen evolution reaction

A Novel Non-phosgene Process for the Synthesis of Methyl N-Phenyl Carbamate from Methanol and Phenylurea: effect of solvent and Catalyst

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2004年第8期22卷 782-786页

作者：王心葵闫世润曹勇范康年贺鹤勇亢茂青彭少逸 Institute of Coal Chemistry Chinese Academy of Sciences Taiyuan Shanxi 030001 China Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Department of Chemistry Fudan University Shanghai 200433 China

A novel environmentally benign process for the synthesis of methyl N-phenyl carbamate (MPC) from methanol and phenylurea was studied. effect of solvent and catalyst on the reaction behavior was investigated. The IR spectra of methanol and phenylurea dissolved in different solvents were also recorded. Compared with use of methanol as both a reactant and a solvent, phenylurea conversion and selectivity to MPC increased by using toluene, benzene or anisole as a solvent, while phenylurea conversion decreased slightly by using n-octane as a solvent. The phenylurea conversion declined nearly 50% when dimethyl sulfoxide (DMSO) was used as a reaction media, and MPC selec- tivity decreased as well. The catalytic reaction tests showed that a basic catalyst enhanced the selectivity to MPC while an acidic catalyst promoted the formation of methyl carbamate and aniline. Moderate degree of basicity showed the best catalytic performance in the cases studied.

关键词： methyl N-phenyl carbamate synthesis phenylurea phosgene-free solvent effect acid-base catalyst

effect of solvent on the free energy of activation of S_N2 reaction between phenacyl bromide and amines

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2000年第4期18卷 608-613页

作者： NASEHZADEH Asadollah CHAHARDOLI Abbas Department of Chemistry Shahid Bahonar University of Kerman P. O. Box 76175-133 Kerman IranDepartment of Chemistry Shahid Bahonar University of Kerman P. O. Box 76175-133 Kerman Iran

The kinetics of SN2 reaction between phenacyl bromide and various amines in 12 different solvents were studied. solvent effects on the rate of this reaction and free energy of activation, ΔG#, were interpreted by applying the Abraham-Kamlet-Taft (AKT) equation. The solvent polarity (π1*), solvent hydrogen-bond basicity (β1) and Hildebrand cohesive density energy (δ2H) are those parameters which increase the rate constant and decrease ΔG#, while solvent hydrogen-bond acidity (α1) will have the compensatory effect. A comparison among obtained values of second rate constants, k2 for different amines in a given solvent indicates that the amine reactivities are highly dependent on their structures. The consequent decrease of the rate constant for different amines in any given solvent was found to be: primary > secondary > tertiary. This order results from steric effects of amines.

关键词： solvent effect phenacyl bromide n-butylamine diethylamine triethylamine