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Synthesis and characterization of controlled sizes: Polystyrene latexes

PARTICULATE science AND TECHNOLOGY 1996年第4期14卷 315-326页

作者： Kumar, D Butler, GB [a] Center for Macromolecular Science and Engineering Department of Chemistry University of Florida Gainesville Florida USA

Several parameters and their limitations to prepare monodisperse polystyrene particles were discussed. Polystyrene latexes B, C and D of diameter 129.8, 142.8 and 264.5 nm, respectively, were synthesized by emulsion polymerization method. The latex D is almost monodisperse with very low polydispersity of 0.005 while B and C are having polydispersity of 0.1837 and 0.1601. The particle size and particle size distribution of the latexes were determined by a TEM and Brookhaven particle size analyzer. It was observed that the particle size of the latexes decreased with increasing initiator (ammonium persulfate) or surfactant (SDS) concentrations. The surface area of the latexes were calculated by using BET equation on the basis of the amount of nitrogen gas adsorbed at the surface of the particles to form a monolayer. It was observed that the surface area of latex D is less than B and C because of the bigger size of the particles. The average molecular weights, zeta potentials and densities of the latexes were also presented.

关键词： Latexes

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Analysis of the operation of thin nanowire photoelectrodes for solar energy conversion (vol 5, pg 5203, 2012)

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ENERGY & ENVIRONMENTAL science 2012年第12期5卷 9946-9946页

作者： Foley, Justin M. Price, Michelle J. Feldblyum, Jeremy I. Maldonado, Stephen Program in Applied Physics Macromolecular Engineering Department of Chemistry 930 N University Ann Arbor Michigan

The solar energy conversion properties of thin Si and GaP nanowire photoelectrodes in photoelectrochemical cells have been examined through sets of finite-element simulations. A discussion describing the motivation behind nanostructured, high aspect ratio semiconductor photoelectrode designs and a brief survey of current experimental results reported for nanostructured semiconductor photoelectrodes in photoelectrochemical cells are presented first. An analysis is then shown that outlines the primary recombination pathways governing the steady-state current-potential behaviors of thin, cylindrical nanowire photoelectrodes, with explicit expressions detailing the differences between planar and cylindrical photoelectrodes arising from the solution of carrier fluxes in planar and cylindrical geometries. Results from finite-element simulations used to model the key features of thin nanowire photoelectrodes under low-level injection conditions are shown that illustrate which recombination pathway(s) is operative under various experimental conditions. Specifically, the respective effects of non-uniform doping, tapering along the length, variation in charge carrier mobilities and lifetimes, changes in nanowire radius, and changes in the density of surface defects on the observable photocurrent-potential responses are reported. These cumulative results serve as guides for future experimental work aimed at improving the attainable solar energy conversion efficiencies of doped semiconductor nanowire photoelectrodes. Lastly, separate simulations that model lightly doped nanowire photoelectrodes under high-level injection conditions are discussed. These results suggest discrete, ohmic-selective contacts may afford a way to circumvent the stringent doping requirements discussed herein for thin nanowire photoelectrodes.

关键词： Nanowires

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Anion-Deficient Transition Metal Oxynitrides as Anode Materials for Solid Oxide Fuel Cells

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chemistry - A European Journal 2025年第26期31卷 e202500503页

作者： Zhang, Shi-Rui Wang, Xiao-Ming Li, Wen Fang, Lei-Ming Liu, Tian-Hui Yang, Zu-Pei Kuang, Xiao-Jun Jiao, Huan Department of Key Laboratory of Macromolecular Science of Shaanxi Province Shaanxi Key Laboratory for Advanced Energy Devices Shaanxi Engineering Laboratory for Advanced Energy Technology School of Chemistry & Chemical Engineering Shaanxi Normal University Shaanxi Province Xi'an710062 China Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics Sichuan Mianyang621900 China Advanced Materials Research Group Faculty of Engineering The University of Nottingham University Park NottinghamNG7 2RD United Kingdom Industrial Training Centre Shenzhen Polytechnic University Guangdong Province Shenzhen518055 China School of Materials Science and Engineering Shaanxi Normal University Shaanxi Xi'an710062 China Guangxi Key Laboratory of Electrochemical and Magnetochemical Functional Materials College of Chemistry and Bioengineering Guilin University of Technology Guilin541004 China

Transition metal oxynitrides, with their unique electronic structures and excellent conductivity, hold significant promise as anode materials in fuel cells. In this study, we synthesized and characterized two novel anion-deficient transition metal oxynitrides: Ca4La8V4O8N12 and Sr3La9V4O7N13. Their crystal structures were determined via Rietveld refinement of X-ray and neutron diffraction data, revealing a higher concentration of anion vacancies in Sr3La9V4O7N13. As a result, Sr3La9V4O7N13 exhibits significantly enhanced electrical conductivity compared to Ca4La8V4O8N12. Density functional theory (DFT) calculations indicate that Sr3La9V4O7N13 possesses higher defect formation energies, influencing its band structure and facilitating electron transitions, thereby enhancing conductivity. This study underscores the role of anion deficiencies in modulating the electronic properties of transition metal oxynitrides and offers new insights for designing high-performance anode materials for solid oxide fuel cells (SOFCs). © 2025 Wiley-VCH GmbH.

关键词： Rietveld refinement

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Pyrene-Based Blue Aggregation-Induced Emission Luminogens: The Synergistic Effect of Through-Space Conjugation for High Exciton Utilization Efficiency and Narrow-Band and Blue OLEDs

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Advanced Optical Materials 2025年第14期13卷

作者： Liu, Wei Zhang, Siwei Jiang, Tao Li, Shaoling Xie, Zhixin Zhao, Yu Zhang, Jianyu Redshaw, Carl Feng, Xing Lam, Jacky W. Y. Tang, Ben Zhong Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter Guangdong Provincial Key Laboratory of Information Photonics Technology School of Material and Energy Guangdong University of Technology Guangzhou510006 China Department of Chemistry Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction The Hong Kong University of Science and Technology Clear Water Bay Kowloon999077 Hong Kong MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University Hangzhou310058 China Chemistry School of Natural Sciences University of Hull Yorkshire HullHU6 7RX United Kingdom School of Science and Engineering Shenzhen Institute of Aggregate Science and Technology The Chinese University of Hong Kong Shenzhen Guangdong518172 China

Achieving outstanding narrow-band emission and improving the triplet exciton utilization efficiency is crucial for high organic light-emitting diodes (OLEDs) electroluminescence (EL) efficiency. Herein, novel 1,3-asymmetrical substituted pyrene-based blue "hot exciton" materials with aggregation-induced emission (AIE) characteristics are synthesized, utilizing the pyrene ring's staggered energy levels for high-performance OLEDs. The triphenylamine-decorated pyrene-based blue emitters exhibited narrow full width at half maxima (FWHM) 35.6%) in nondoped OLED devices. Meanwhile, both triphenylamine-decorated and tetraphenylethylene-decorated pyrenes are further utilized as an emitter layer in thermally activated delayed fluorescence (TADF)-sensitized blue OLEDs with great EL performance. Moreover, the TPE-decorated pyrene-based TPE-m2Ph demonstrated a maximum brightness, maximum current efficiency, maximum power efficiency, and maximum external quantum efficiency of 35230 cd m−2, 42 cd A−1, 48 lm W−1, and 14.9%, respectively. © 2025 Wiley-VCH GmbH.

关键词： Organic light emitting diodes (OLED)

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Synergistic Polydopamine/Graphene Oxide Hybrids: Elevating Electrochemical Performance

ACS Electrochemistry

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ACS Electrochemistry 2025年第4期1卷 453-464页

作者： Busra Ozlu Saimon Moraes Silva Simon E. Moulton Bong Sup Shim Program in Biomedical Science & Engineering Inha University 100 Inha-ro Michuhol-gu Incheon 22212 Republic of Korea Department of Biochemistry and Chemistry La Trobe Institute for Molecular Science The Biomedical and Environmental Sensor Technology (BEST) Research Centre La Trobe University Melbourne Victoria 3086 Australia ARC Centre of Excellence for Electromaterials Science Faculty of Science Engineering and Technology Swinburne University of Technology Hawthorn Victoria 3122 Australia；Aikenhead Centre for Medical Discovery St Vincent’s Hospital Melbourne Melbourne Victoria 3065 Australia；Iverson Health Innovation Research Institute Swinburne University of Technology Melbourne Victoria 3122 Australia Program in Biomedical Science & Engineering Inha University 100 Inha-ro Michuhol-gu Incheon 22212 Republic of Korea；Department of Chemical Engineering Inha University 100 Inha-ro Michuhol-gu Incheon 22212 Republic of Korea

Melanin, a natural biopolymer with a conjugated backbone, stands out as a promising candidate for bioelectronics owing to its redox activity, metal ion chelation, hydration-dependent electrical response, wet adhesion, potential electronic transport, anti-inflammatory properties, and excellent thermal stability. In this study, we explore the impact of hybridizing liquid crystalline graphene oxide (LCGO) into the conductive melanin-like polymer polydopamine (PDA) on the morphology, stability, and synergistic electrochemical performance. Our findings reveal that the gold electrode coated with PDA:LCGO composites exhibit more than two orders of magnitude lower impedance and more than 100 times higher charge storage capacity compared to both bare gold electrodes and those coated with pure PDA. Furthermore, we demonstrate that the morphology and the electrode performance could be tuned by adjusting the synthesis parameters in the PDA:LCGO electrochemical deposition. This PDA:LCGO composite, with its superior electrochemical performance, holds promise for diverse bioelectronics applications ranging from biosensors to implantable bionic interfaces.

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Assessing the Potential of Biodegradable Plastics in a Circular Economy: A Methodological Outlook

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Circular Economy and Sustainability 2025年第2期5卷 1291-1305页

作者： Scheers, Quinten Nimmegeers, Philippe Galant, Or Spatari, Sabrina Van den Brande, Niko Brancart, Joost Billen, Pieter Faculty of Applied Engineering Intelligence in Processes Advanced Catalysts and Solvents (iPRACS) University of Antwerp Groenenborgerlaan 171 Antwerp 2020 Belgium Faculty of Business and Economics Department of Engineering Management Environmental Economics (EnvEcon) University of Antwerp Prinsstraat 13 Antwerp 2000 Belgium Flanders Make@UAntwerp Antwerp 2000 Belgium Faculty of Civil and Environmental Engineering Technion– Israel Institute of Technology Haifa 3200003 Israel Grand Technion Energy Program Technion– Israel Institute of Technology Haifa 3200003 Israel Physical Chemistry and Polymer Science (FYSC) Vrije Universiteit Brussel Pleinlaan 2 Brussels 1050 Belgium IVL Swedish Environmental Research Institute Valhallavägen 81 Stockholm 11428 Sweden

Increased biodegradability, in other words reduced environmental recalcitrance, has the potential to be an important asset in the battle against plastics pollution. It can partially mitigate global plastic leakages into the environment, which is next to their impact on climate change the biggest concern regarding plastics use. Biodegradation should be regarded as an optimal safety net in many applications and should often not be the targeted waste management option for biodegradable plastics. Biodegradability should not preclude reuse or proper recyclability, which are impactful means to reduce the carbon intensity of plastics lifecycles. Despite the added advantages, the market penetration of biodegradable plastics is only very slowly growing. Moreover, policy recommends its use only in limited applications, driven by sometimes-higher cost and limited recyclability. In this article, we posit that arguments against widespread application of biodegradable plastics are largely driven by misperceptions arising from intrinsic limitations of contemporary sustainability assessments and offer an alternative viewpoint that could compensate for this. In general, sustainability assessments fail to properly assess learning curves, often do not take littering potential into account, and are rather conservative with respect to background systems. Hence, recyclability– or better: circularity– judgements often do not resolve the paradoxical situation in which increased market shares lead to easier and more profitable recycling schemes and vice versa. Judging disruptive innovations by incorporating thermodynamics-inspired, less data-intensive, state-based methods, based on, e.g., statistical entropy analysis, into the decision support framework could allow to forecast packaging markets with performant materials that are intrinsically circular, having reduced environmental recalcitrance. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.

关键词： Biodegradable Plastics Decision Making Statistical Entropy Sustainability Assessments

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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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Electrochemically stimulated adenosine 5'-triphosphate (ATP) release through redox switching of conducting polypyrrole films and bilayers

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chemistry OF MATERIALS 1996年第1期8卷 128-133页

作者： Pyo, M Reynolds, JR Department of Chemistry Center for Macromolecular Science Engineering University of Florida Gainesville Florida 32611-7200

Electrochemically stimulated adenosine 5'-triphosphate (ATP) release from poly(pyrrole adenosine 5'-triphosphate) (PP-ATP) was investigated using cyclic voltammetry. Two separate redox processes at E(1/2) = -0.4 and 0.0 V were clearly elucidated by switching the film in polyelectrolyte solutions and found to correlate with cation and anion dominant transport, respectively. This voltammetric method allows the dominant mobile ionic species to be determined as redox processes associated with the movement of the polyelectrolyte counterion through the film are observed, while redox processes associated with transport of ions having the same charge as the polyelectrolyte are repressed. As such, the more anodic redox process results in ATP release. Spontaneous ATP exchange in a supporting electrolyte was examined at open circuit, revealing that less than 10% of the electrochemically releasable ATP is spontaneously released after 10 days. The ATP release concept was extended to bilayers consisting of PP-ATP as inner layers and poly(N-methylpyrrole) (PNMP) with various dopant anions as outer layers. PP-ATP:poly(N-methylpyrrole chloride) (PP-ATP:PNMP-Cl) bilayers with varied thicknesses of inner and outer films were constructed to examine electrochemically stimulated ATP release during reduction of PP-ATP. PP-ATP:PNMP/ heparin (PP-ATP:PNMP/HPN) bilayers with varied outer film thicknesses, which are were also prepared and their ATP release properties were compared. It was found that the rate of electrochemical ATP release can be controlled by adjusting each film thickness with minimal change of ionic strength of the switching medium.

关键词： Thickness Redox reactions Vesicles Anions Absorption

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Pyrene-based aggregation-induced emission: A bridge model to regulate aggregation

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Innovation 2025年

作者： Lin, Yuting Zhang, Jianyu Wang, Wen-Jin Tang, Zhenguo Fang, Xianying Xu, Xu Kühn, Fritz E. Zhao, Zheng Yong, Qiang Tang, Ben Zhong Cai, Xu-Min Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources Nanjing Forestry University Nanjing210037 China MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University Hangzhou310058 China School of Science and Engineering Shenzhen Institute of Aggregate Science and Technology The Chinese University of Hong Kong Shenzhen518172 China Molecular Catalysis Department of Chemistry & Catalysis Research Center School of Natural Sciences Technische Universität München MünchenD-85747 Germany Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates Guangzhou510640 China

The aggregation process plays a significant role in regulating the aggregate structures from molecules toward macroscopic photophysical properties. Pyrene (Py), as the simplest dimer candidate, serves as a suitable model for studying the aggregation. Herein, a series of Py-based aggregation-induced emission (AIE) materials have been investigated by clarifying the comprehensive roles of oxygen, substituents, molecular motion, and packing during aggregation, initially realizing the aim of controlling aggregate structures. With a largely planar and conjugated conformation, Py shows anomalous AIE characteristics due to the oxygen quenching at the molecular level but turn-on fluorescence in the aggregate state because of the oxygen isolation. Although introducing substituents induces molecular motion and similarly weakened luminescence in the molecular state, the impact of substituents on the aggregate-state photophysical properties enormously differs, exhibiting from weak blue, strong cyan, and strong green to weak yellow emissions, due to variable aggregate structures. Interestingly, the natural alicycle-substituted Py-dehydroabietylamine (Py-DAA) exhibits both mechanochromism and acidichromism, which can be synergistically applied in dynamic encryption-decryption. This work not only elucidates the unique AIE property of Py for the first time but also clarifies the bridging role of aggregation between single-molecular and aggregate states, achieving preliminary control over the aggregate structures. © 2025 The Author(s)

关键词： Fluorescence

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Thermally Activated Delayed Fluorescence-Guided Photodynamic Therapy Through Skeleton-Homologous Nanoparticles: a Rational Material Design for High-Efficient and High-Contrast Theranostics

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Advanced Materials 2025年 e2500236页

作者： Li, Xuping Huang, Liwen Baryshnikov, Gleb Ali, Amjad Dai, Peiling Yang, Zhongxue Sun, Yuyu Dai, Chunling Guo, Zhixiu Zhao, Qiang Zhang, Fan Zhu, Liangliang College of Energy Materials and Chemistry Inner Mongolia University Hohhot010070 China Department of Chemistry State Key Laboratory of Molecular Engineering of Polymers Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials and iChem Fudan University Shanghai200033 China State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular Science Fudan University Shanghai200033 China Laboratory of Organic Electronics Department of Science and Technology Linköping University NorrköpingSE-601 74 Sweden Nanjing University of Posts & Telecommunications Nanjing210023 China

Although photoluminescence imaging-guided photodynamic therapy (PDT) is promising for theranostics, it easily suffers from tissue autofluorescence and PDT photoproducts. To develop time-resolved imaging (TRI)-guided PDT with long-lived emission pathways, like thermally activated delayed fluorescence (TADF), is urgent but challenging, because of the triplet competition between radiative transition and reactive oxygen species (ROS) production. Herein, skeleton-homologous nanoparticles are designed and constructed to address this dilemma, thereby achieving in vivo TRI-guided PDT for the first time. This system is formed with a lipophilic TADF core (as a TRI probe) encapsulated by an amphiphilic photosensitizer shell (as the corona exposed to oxygen for PDT), both of which are derived from the same donor–acceptor skeleton to minimize phase separation in the single entity, and enable the same long-wavelength photoexcitation for TRI and PDT. The chloropropylamine group is helpful for endoplasmic reticulum targeting to enhance PDT upon minimizing the ROS transmission path. Synchronously, the TADF core exhibits a delayed fluorescence of 40 µs for a clear TRI. The NPs are eventually applied in vivo with a high signal-to-background ratio (45.25) and outstanding PDT effects in a mouse model of deep-seated kidney cancer. Such a material design is beneficial for developing high-efficient and high-contrast theranostic approaches. © 2025 Wiley-VCH GmbH.

关键词： Musculoskeletal system

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