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Comparative toxicity of silver nanoparticles and silver ions to Escherichia coli

Journal of Environmental sciences 2018年第4期30卷 50-60页

作者： Yoojin Choi Hyun-A Kim Kyoung-Woong Kim Byung-Tae Lee Department of Chemical and Biomolecular Engineering (BK21 Plus Program) Korea Advanced Institute of Science and Technology (KAIST) School of Earth Sciences and Environmental Engineering Gwangju Institute of Science and Technology (GIST)

With the increase in silver（Ag）-based products in our lives, it is essential to test the potential toxicity of silver nanoparticles（Ag NPs） and silver ions（Ag ions） on living organisms under various conditions. Here, we investigated the toxicity of Ag NPs with Ag ions to Escherichia coli K-12 strain under various conditions. We observed that both Ag NPs and Ag ions display antibacterial activities, and that Ag ions had higher toxicity to E. coli K-12 strain than Ag NPs under the same concentrations. To understand the toxicity of Ag NPs at a cellular level, reactive oxygen species（ROS） enzymes were detected for use as antioxidant enzymatic biomarkers. We have also studied the toxicity of Ag NPs and Ag ions under various coexistence conditions including： fixed total concentration, with a varied the ratio of Ag NPs to Ag ions; fixed the Ag NPs concentration and then increased the Ag ions concentration; fixed Ag ions concentration and then increasing the Ag NPs *** to Ag NPs and Ag ions clearly had synergistic toxicity; however, decreased toxicity（for a fixed Ag NPs concentration of 5 mg/L, after increasing the Ag ions concentration） to E. coli K-12 strain. Ag NPs and Ag ions in the presence of L-cysteine accelerated the bacterial cell growth rate, thereby reducing the bioavailability of Ag ions released from Ag NPs under the single and coexistence conditions. Further works are needed to consider this potential for Ag NPs and Ag ions toxicity across a range of environmental *** Significance Statement： As silver nanoparticles（Ag NPs）-based products are being broadly used in commercial industries, an ecotoxicological understanding of the Ag NPs being released into the environment should be further considered. Here, we investigate the comparative toxicity of Ag NPs and silver ions（Ag ions） to Escherichia coli K-12 strain, a representative ecotoxicological bioreporter. This study showed that toxicities of Ag NPs and Ag ions to E. coli

关键词： Nanotoxicity Silver nanoparticles Silver ions Coexist condition Escherichia coli

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Real-Time Quantum Dynamics of Long-Range Electronic Excitation Transfer in Plasmonic Nanoantennas (vol 13, pg 3442, 2017)

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JOURNAL OF chemical THEORY AND COMPUTATION 2017年第12期13卷 6433-6433页

作者： Ilawe, Niranjan V. Oviedo, M. Belen Wong, Bryan M. Department of Chemical & Environmental Engineering and Materials Science & Engineering Program University of California Riverside Riverside California 92521 United States

Using large-scale, real-time, quantum dynamics calculations, we present a detailed analysis of electronic excitation transfer (EET) mechanisms in a multiparticle plasmonic nanoantenna system. Specifically, we utilize real-time, time-dependent, density functional tight binding (RT-TDDFTB) to provide a quantum-mechanical description (at an electronic/atomistic level of detail) for characterizing and analyzing these systems, without recourse to classical approximations. We also demonstrate highly long-range electronic couplings in these complex systems and find that the range of these couplings is more than twice the conventional cutoff limit considered by Förster resonance energy transfer (FRET)-based approaches. Furthermore, we attribute these unusually long-ranged electronic couplings to the coherent oscillations of conduction electrons in plasmonic nanoparticles. This long-range nature of plasmonic interactions has important ramifications for EET; in particular, we show that the commonly used “nearest-neighbor” FRET model is inadequate for accurately characterizing EET even in simple plasmonic antenna systems. These findings provide a real-time, quantum-mechanical perspective for understanding EET mechanisms and provide guidance in enhancing plasmonic properties in artificial light-harvesting systems.

关键词： Nanodevices Plasmonics Coupling reactions Polarity Fluorescence resonance energy transfer

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CHARACTERIZATION OF POLYMER CONFORMATION AND MORPHOLOGY THROUGH SMALL-ANGLE NEUTRON-SCATTERING - A LITERATURE-REVIEW

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POLYMER engineering AND science 1984年第1期24卷 1-21页

作者： SPERLING, LH Materials Research Center #32 Polymer Science and Engineering Program Department of Chemical Engineering Lehigh University Bethlehem PA 18015

Small‐angle neutron scattering, SANS, stands forth as one of the most important of the new tools for evaluating polymer chain conformation and morphology. This paper reviews the SANS literature through 1982, with a few early 1983 references added. The theory of SANS is outlined and compared to light scattering. SANS values of polymer molecular weights and radii of gyration obtained in the bulk state were found to be in agreement with values obtained from dilute solutions by light scattering. In each case, deuterated fractions of polymer were inserted into the hydrogeneous matrix, or vice versa, to provide contrast. Several new research areas are then discussed, including unidirectional stretching of elastomers, stress‐relaxation, polymer‐polymer miscibility, crystallization from the melt compared with crystallization from dilute solutions, nonclassical aggregation during bulk polymerization of thermoset systems, morphology of polymer blends, block copolymers and ionomers, the core‐shell structure of latexes and polymer blocks, and grafts as surfactants in emulsions and latexes. Much new and sometimes unexpected information is being provided by the SANS research now in progress.

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Cu^+-incorporated TiO_2 overlayer on Cu_2O nanowire photocathodes for enhanced photoelectrochemical conversion of CO_2 to methanol

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Journal of Energy Chemistry 2018年第1期27卷 264-270页

作者： Kangha Lee Seokwon Lee Hyunjin Cho Sunil Jeong Whi Dong Kim Sooho Lee Doh C.Lee Department of Chemical and Biomolecular Engineering(BK21+program) KAIST Institute for the NanocenturyKorea Advanced Institute of Science and Technology(KAIST)

In this paper, we report photoelectrochemical（PEC） conversion of carbon dioxide（CO_2） using photocathodes based on Cu_2O nanowires（NWs） overcoated with Cu~＋-incorporated crystalline TiO_2（TiO_2–Cu~＋）shell. Cu_2O NW photocathodes show remanent photocurrent of 5.3% after 30 min of PEC reduction of CO_*** coating Cu_2O with TiO_2–Cu~＋ overlayer, the remanent photocurrent is 27.6%, which is an increase by5.2 fold. The charge transfer resistance of Cu_2O/TiO_2–Cu~＋ is 0.423 k/cm2, whereas Cu_2O photocathode shows resistivity of 0.781 k/cm2 under irradiation. Mott–Schottky analysis reveals that Cu~＋ species embedded in TiO_2 layer is responsible for enhanced adsorption of CO_2 on TiO_2 surface, as evidenced by the decrease of capacitance in the Helmholtz layer. On account of these electrochemical and electronic effects by the Cu~＋ species, the Faradaic efficiency（FE） of photocathodes reaches as high as 56.5% when TiO_2–Cu~＋ is added to Cu_2O, showing drastic increase from 23.6% by bare Cu_2O photocathodes.

关键词： Photoelectrochemical CO2 reductionMethanol generation Copper oxide Titanium dioxide Cu＋ catalyst

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Janus Polymerization:A One-Shot Approach towards Amphiphilic Multiblock Poly(ester-acetal)s Directly from 1,3-Dioxolane withε-Caprolactone

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Chinese Journal of Chemistry 2022年第6期40卷 705-712页

作者： Huan Qiu Ting Shen Zhening Yang Feng Wu Xiaohong Li Yingfeng Tu Jun Ling MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhouZhejiang 310027China College of Chemistry Chemical Engineering and Materials ScienceSoochow UniversitySuzhouJiangsu 215123China

Janus polymerization consists of anionic and cationic ring opening polymerizations(AROP and CROP)at the two ends of a single propagating polymer chain,followed by a self-triggered chain extension generating multiblock copolymers(MBCPs)in one *** the contribution,Janus polymerization by Tm(OTf)_(3) or Er(OTf)_(3) catalyst with an epoxy initiator is applied to synthesize MBCPs of semi-crystalline poly(ε-caprolactone)(PCL)blocks from coordinated AROP and poly(1,3-dioxolane-co-ε-caprolactone)(P(DO-co-CL))blocks from CROP of DO with ***,amorphous random copolymers[P(DO-r-CL)]are synthesized as control by employing other rare earth triflates[RE(OTf)_(3),RE=Y,Nd,Gd and Lu]as catalysts or in the absence of an initiator via *** account of the distinguishable chemical structures and thermal properties between Janus MBCPs and cationic random copolymers,Janus features are confirmed including the CROP and AROP at a single propagating *** resultant amphiphilic copolymers self-assemble to nanoparticles in aqueous solution with designable diameters with the corresponding ratios of hydrophilic and hydrophobic *** exhibit good shape memory properties with appropriate deformation temperature close to human body's,providing a prospect on the applications in biomedical devices.

关键词： Janus polymerization Ring-opening polymerization Multiblock copolymers Homogeneous catalysis(?)Lanthanides

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Optimizing solar-powered multi-generation systems for sustainable energy management in university buildings using Neural Networks and Genetic Algorithms

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Journal of Building engineering 2025年 108卷

作者： Assareh, Ehsanolah Izadyar, Nima Jamei, Elmira Monzavian, Mohammad amin Agarwal, Saurabh Agarwal, Neha Strategic Research Institute (SRI) Asia Pacific University of Technology and Innovation (APU) Technology Park Malaysia Kuala Lumpur Built Environment and Engineering Program College of Sport Health and Engineering (CoSHE) Victoria University Melbourne Australia Department of Renewable Energy Technology Materials and Energy Research Center Dezful Branch Islamic Azad University Dezful Iran Institute for Sustainable Industries and Liveable Cities Victoria University Melbourne 3011 VIC Australia School of Computer Science and Engineering Yeungnam University Gyeongsan 38541 South Korea School of Chemical Engineering Yeungnam University Gyeongsan 38541 South Korea

University campuses operate like small cities, with complex energy demands driven by diverse activities, making energy management particularly challenging in extreme climates. Traditional energy systems often rely on fossil fuels, leading to inefficiencies, high costs, and increased carbon footprints. This study optimizes a solar-powered multi-generation system for a university building in the severe hot climate of Dezful, Iran, using a two-step approach. First, the Building Energy Optimization Tool (BEopt) was used to select optimal building materials, leading to a reduction in total energy demand. Then, Artificial Intelligence algorithms (Neural Networks and Genetic Algorithms) were applied to enhance system performance and cost-effectiveness. The engineering Equation Solver (EES) validated the thermodynamic performance of the optimized system. This optimized system generates 49.55 GW-hours (GWh) of electricity annually, along with 19.47 GWh of heating and 13.93 GWh of cooling, producing a surplus of 34.28 GWh (69 % of total generation). Compared to the base case, electricity generation increased by over 224 %, cooling by 120 %, and heating by more than 3500 %, while CO₂ emissions decreased from 37.18 to 35.34 metric tons/year. The optimized system operates with an exergy efficiency of 23.44 % and a cost rate of 14.93 $/h. What sets this study novel is the integration of demand-side improvements with AI-enhanced multi-generation systems and thermodynamic validation, creating a practical model for achieving net-zero energy on university campuses. This methodology is scalable to more complex energy networks, including district energy systems, with future work focusing on real-time weather integration and advanced forecasting to improve adaptability and resilience. © 2025 The Authors

关键词： Artificial intelligence optimization Energy efficiency Renewable energy integration Solar-powered multi-generation systems Sustainable university campuses

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Emergent dimer-model topological order and quasi-particle excitations in liquid crystals: combinatorial vortex lattices

arXiv

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arXiv 2025年

作者： Meng, Cuiling Wu, Jin-Sheng Kos, Žiga Dunkel, Jörn Nisoli, Cristiano Smalyukh, Ivan I. Department of Physics and Chemical Physics Program University of Colorado BoulderCO80309 United States Hiroshima University Hiroshima Higashihiroshima Japan Department of Mathematics Massachusetts Institute of Technology CambridgeMA02139 United States Faculty of Mathematics and Physics University of Ljubljana Ljubljana Slovenia Department of Condensed Matter Physics Jožef Stefan Institute Ljubljana Slovenia Theoretical Division Physics of Condensed Matter and Complex Systems Center For Nonlinear Studies Los Alamos National Laboratory Los AlamosNM87545 United States Department of Electrical Computer and Energy Engineering Materials Science and Engineering Program University of Colorado BoulderCO80309 United States Renewable and Sustainable Energy Institute National Renewable Energy Laboratory University of Colorado BoulderCO80309 United States

Liquid crystals have proven to provide a versatile experimental and theoretical platform for studying topological objects such as vortices, skyrmions, and hopfions. In parallel, in hard condensed matter physics, the concept of topological phases and topological order has been introduced in the context of spin liquids to investigate emergent phenomena like quantum Hall effects and high-temperature superconductivity. Here, we bridge these two seemingly disparate perspectives on topology in physics. Combining experiments and simulations, we show how topological defects in liquid crystals can be used as versatile building blocks to create complex, highly degenerate topological phases, which we refer to as ‘Combinatorial Vortex Lattices’ (CVLs). CVLs exhibit extensive residual entropy and support locally stable quasi-particle excitations in the form of charge-conserving topological monopoles, which can act as mobile information carriers and be linked via Dirac strings. CLVs can be rewritten and reconfigured on demand, endowed with various symmetries, and modified through laser-induced topological surgery — an essential capability for information storage and retrieval. We demonstrate experimentally the realization, stability, and precise optical manipulation of CVLs, thus opening new avenues for understanding and technologically exploiting higher-hierarchy topology in liquid crystals and other ordered media. Copyright © 2025, The Authors. All rights reserved.

关键词： Laser surgery

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Integrated analytical workflow for quantifying and modeling the hydrocracking of vacuum gas oil and plastic pyrolysis oil

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Fuel 2025年 400卷

作者： Naydu Zambrano Suní Rodríguez Gontzal Lezcano David Trueba Idoia Hita Roberto Palos Alazne Gutiérrez Pedro Castaño Multiscale Reaction Engineering KAUST Catalysis Center (KCC) King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia Department of Chemical Engineering University of the Basque Country UPV/EHU PO Box 644 48080 Bilbao Spain Chemical Engineering Program Physical Science and Engineering (PSE) Division King Abdullah University of Science and Technology Saudi Arabia

The pressing need for more sustainably produced fuels has highlighted the co-feeding of plastics with conventional feedstocks as a promising alternative. However, challenges such as effective feeding, in-depth product characterization, or process optimization require thorough analysis to establish the feasibility of the overall process. This study demonstrates the validity of a workflow for the quantitative and kinetic analysis of the hydrocracking reaction of vacuum gas oil and plastic pyrolysis oil blends using a NiW on HY-zeolite catalyst in a semi-batch reactor. The reaction products are characterized using a combination of gas chromatography with various detectors, Fourier transform ion cyclotron resonance mass spectrometry, and simulated distillation. The workflow refines and integrates data from these techniques into comprehensive quantitative datasets applied to continuous lumping kinetic modeling. Hydrocracking of the blend converts 83 % of heavy cycle oil at 440 °C, yielding substantial amounts of naphtha and middle distillates. The continuous lumping kinetic model accurately predicts product distribution while providing key insights into the reactivity of heavy fractions and S and N removal.

关键词： Gas chromatography

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Validation and Mechanistic Studies of the Headspace Effect in MOF Synthesis

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Angewandte Chemie 2025年第12期137卷

作者： Julia C. Donovan Keenan R. Wright Adam J. Matzger Department of Chemistry Institution University of Michigan Address 930 North University Avenue Ann Arbor Michigan 48109-1055 United States Charles G. Overberger Collegiate Professor of Chemistry and Macromolecular Science & Engineering Department of Chemistry and Macromolecular Science and Engineering Program Institution University of Michigan Address 930 North University Avenue Ann Arbor Michigan 48109-1055 United States

The influence of headspace volume and composition on metal–organic framework (MOF) synthesis has been largely overlooked with no mechanisms currently invoking these factors. Herein, we reveal that an increased volume of oxygen in the headspace during the synthesis of zinc carboxylate-based MOFs (MOF-5, MOF-177, and IRMOF-8) as well as UiO-66 and ZJU-28 accelerates crystal formation. Investigation into the underlying mechanism of this phenomenon elucidates the critical roles played by all reagents, and some of their byproducts, in MOF synthesis. These insights are the key to developing more efficient and sustainable synthetic strategies for MOF production.

关键词： crystal growth formamide nitrosamine nucleation Raman spectroscopy

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Tuning the Excited State of Tetradentate Pd(ll) and Pt(ll) Complexes through Benzannulated N-Heteroaromatic Ring and Central Metal

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Chinese Journal of Chemistry 2022年第2期40卷 223-234页

作者： Guijie Hua Guo Xiaoli Fang Yun-Fang Yang Yulu Sun Weiwei Lou Qisheng Zhang Yuanbin She College of Chemical Engineering Zhejiang University of TechnologyHangzhouZhejiang 310014China MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhouZhejiang 310027China

A series of tetra de ntate Pd(ll)and Pt(ll)complexes containing fused 5/6/6 metallocycles with phe nyl/V-heteroaromatic ben-zo[d]imidazole(pbiz),benzo[d]oxazole(pboz)or benzo[d]thiazole(pbthz)-containing ligands was *** studies by experiments and theoret:ical calculations reveal that both the central metal and the benzannulated A/-heteroaromatic ring have sig-n ificant in flue nee on the electrochemical,photophysical and excited-state properties of the Pd(ll)and Pt(ll)*** identical condition,compared to pb/z-based Pd(ll)and Pt(ll)complexes,the corresponding metal complexes with pboz and pbthz-containing ligand show significant red-shift emission spectra.

关键词： Semiconductors Luminescence Platinum and Palladium Energy conversion OLED

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