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Probing the effects of external species on poly(acrylate acid) chain dynamics by using cationic AIE-active fluorophore

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science China Chemistry 2016年第2期59卷 218-224页

作者： Junfeng Niu Yuan Gao Yuru You Yinbang Zhu Jingzhi Sun Ben Zhong Tang School of Biological and Chemical Engineering Zhejiang University of Science & Technology Hangzhou 310023 China Key Laboratory of Macromolecular Synthesis and Functionalization Ministry of Education Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 China Department of Chemistry Institute for Advanced Study Division of Biomedical Engineering Division of Life Science State Key Laboratory of Molecular Neuroscience and Institute of Molecular Functional Materials the Hong Kong University of Science and Technology Kowloon Hong Kong China

We report here our results on the investigation of the chain dynamics of poly(acrylic acid) in aqueous solution. The concentration of poly(acrylic acid) was approximately 3.8×10^(-4) mol/L, two orders of magnitude higher than that reported in the literature. The p H value of the solution was 3.9, and the hydrogen bonds between the intrinsic and ionized carboxylic acid groups formed dynamic networks, which captured aggregation-induced emission-active molecules(a tetra-quaternary ammonium modified tetraphenylethene derivative) inside the polymer coils and induced fluorescence emission. The hydrogen bonds can be classified as intra- or intermolecular; both can be probed based on the emission change of the tetra-quaternary ammonium modified tetraphenylethene probes. The effects of different external stimuli on the polymer chain dynamics were investigated using different metal cations(including Na^+, Li^+, Zn^(2+), Ni^(2+), Ca^(2+), and Co^(2+)), different cation concentrations(1×10^(-6) to 4×10^(-4) mol/L), different poly(acrylic acid) molecular weights(5, 240, and 450 k Da), and different copolymers. The experimental results indicate that the long poly(acrylic acid) chains(high molecular weight) tend to form dense globular coils and exclude the probe molecules outside, which are robust and unsusceptible to water-soluble metal cations. However, the shorter poly(acrylic acid) chains tend to form intermolecular hydrogen bonds, which are helpful in capturing more probe molecules inside the networks, thus inducing stronger emission. Because of the dual functions of forming hydrogen bonds with carboxylic groups and acting as an acceptor of protons from the carboxylic acid group to form cationic species, copolymerization with acrylate amide [poly(acrylic acid)-co-poly(acrylamide)] can greatly affect the chain dynamics of poly(acrylic acid) segments, which is reflected by the drastically decreased emission intensity from the fluorescent probes.

关键词： polymer dynamics concentrate solution aggregation-induced emission metal cation hydrogen bonding.

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Carbon-supported layered double hydroxide nanodots for efficient oxygen evolution: Active site identification and activity enhancement

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Nano Research 2021年第9期14卷 3329-3336页

作者： Shenlong Zhao Detao Zhang Shuai Jiang Yanglansen Cui Haijing Li Juncai Dong Zhirun Xie Da-Wei Wang Rose Amal Zhenhai Xia Liming Dai Australian Carbon Materials Centre(A-CMC) School of Chemical EngineeringThe University of New South WalesSydneyNSW 2052Australia Center of Advanced Science and Engineering for Carbon(Case4Carbon) Department of Macromolecular Science and EngineeringCase Western Reserve University(CWRU)10900 Euclid AvenueClevelandOH 44106USA School of Chemical and Biomolecular Engineering The University of SydneySydneyNSW 2006Australia Department of Materials Science and Engineering University of North TexasDentonTX 76203USA Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Chemical Engineering The University of New South WalesSydneyNSW 2052Australia

In this study,we developed a novel confinement-synthesis approach to layered double hydroxide nanodots(LDH-NDs)anchored on carbon nanoparticles,which formed a three-dimensional(3D)interconnected network within a porous carbon support derived from pyrolysis of metal-organic frameworks(C-MOF).The resultant LDH-NDs@C-MOF nonprecious metal catalysts were demonstrated to exhibit super-high catalytic performance for oxygen evolution reaction(OER)with excellent operation stability and low overpotential(-230 mV)at an exchange current density of 10 mA·cm^(-2).The observed overpotential for the LDH-NDs@C-MOF is much lower than that of large-sized LDH nanosheets(321 mV),pure carbonized MOF(411 mV),and even commercial RuO_(2)(281 mV).X-ray absorption measurements and density functional theory(DFT)calculations revealed partial charge transfer from Fe^(3+)through an O bridge to Ni^(2+)at the edge of LDH-NDs supported by C-MOF to produce the optimal binding energies for OER ***,coupled with a large number of exposed active sides and efficient charge and electrolyte/reactant/product transports associated with the porous 3D C-MOF support,significantly boosted the OER performance of the LDH-ND catalyst with respect to its nanosheet *** from the fact that this is the first active side identification for LDH-ND OER catalysts,this work provides a general strategy to enhance activities of nanosheet catalysts by converting them into edge-rich nanodots to be supported by 3D porous carbon architectures.

关键词： carbon nanomaterials layered double hydroxide(LDH)nanodots metal-organic framework(MOF)derivatives oxygen evolution reaction

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Development of hydroxyapatite-mediated synthesis of collagen-based copolymers for application as bio scaffolds in bone regeneration

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Journal of Fluid Mechanics 2014年第1期1621卷 53-58页

作者： Bhuiyan, Didarul Middleton, John Tannenbaum, Rina Department of Biomedical Engineering University of Alabama at Birmingham BirminghamAL35924 United States Department of Materials Science and Engineering Program in Chemical and Molecular Engineering Stony Brook University Stony BrookNY11794 United States

Hydroxyapatite (HAP) is a biocompatible bio-ceramic whose structure and composition is similar to bone. However, its lack of strength and toughness have seriously hampered its applications as a bone graft substitute material. Attempts have been made to overcome these mechanical properties deficiencies by combining HAP bioceramic material with absorbable polymers in order to improve its mechanical properties. However, poor interfacial bonding between the HAP and the polymers has limited the benefits of such biocomposite structures. At the other end of the biomaterials spectrum is collagen, which constitutes the most abundant proteins in the body and exhibits properties such as biodegradability, bioadsorbability with low antigenicity, high affinity to water, and the ability to interact with cells through integrin recognition. These favorable properties renders collagen as a natural candidate for the modification and compatibilization of the polymer-HAP biocomposite. In this study, we developed a novel approach to the synthesis of a potential bone graft material, where the HAP moiety acts not only as a bioceramic filler, but also constitutes the initiator surface that promotes the in-situ polymerization of the adsorbable polymer of choice. The synthesis of poly(D,L-lactide-co-glycolide) (PLGA) polymer was catalyzed by nano-hydroxyapatite (nHAP) particles and upon reaction completion, the biocomposite material was tethered with collagen. The synthesis was monitored by 1H NMR and FTIR spectroscopies and the products after each step were characterized by thermal analysis to probe both thermal stability, morphological integrity and mechanical properties. Copyright © Materials Research Society 2014.

关键词： Hydroxyapatite

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Recent progress in carbon-based electrochemical catalysts:From structure design to potential applications

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Nano Research Energy 2023年第2期2卷 3-25页

作者： Jixin Yan Fenghui Ye Quanbin Dai Xinyue Ma Zhihai Fang Liming Dai Chuangang Hu State Key Laboratory of Organic-Inorganic Composites College of Chemical EngineeringBeijing University of Chemical TechnologyBeijing 100029China Australian Carbon Materials Centre(A-CMC) School of Chemical EngineeringUniversity of New South WalesSydneyNSW 2052Australia Department of Macromolecular Science and Engineering Case School of EngineeringCase Western Reserve UniversityClevelandOhio 44106USA

Advances in research and development of carbon-based metal-free electrocatalysts(C-MFECs)have provided potential alternatives to precious metal catalysts for various reactions important to renewable energy and environmental *** timely but critical review provides an overview of recent breakthroughs(within the past 5 years or so)on C-MFECs in all aspects,including the design and regulation of intrinsic catalytic active sites,design and synthesis of carbon composite and hybrid carbon catalysts,mechanism understanding,and potential applications in clean energy storage and energy/chemical *** challenges and future opportunities in the field of metal-free carbon electrocatalysis are also discussed to provide forward-looking opportunities for their potential applications in various catalytic processes of practical significance.

关键词： carbon-based metal-free electrocatalysts intrinsic regulation structural design optimized composition newly developed application

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Amination of biochar surface from watermelon peel for toxic chromium removal enhancement

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Chinese Journal of chemical engineering 2021年第8期34卷 199-222页

作者： Mohamed A.El-Nemr Ibrahim M.A.Ismail Nabil M.Abdelmonem Ahmed El Nemr Safaa Ragab Department of Chemical Engineering Faculty of EngineeringCairo UniversityGizaEgypt Renewable Energy Program Zewail City of Science and TechnologyEgypt Environmental Division National Institute of Oceanography and FisheriesKayet BeyEl-AnfoushyAlexandriaEgypt

Watermelon peel residues were used to produce a new biochar by dehydration *** new biochar has undergone two methods of chemical modification and the effect of this chemical modification on its ability to adsorb Cr(VI)ions from aqueous solution has been *** biochars,Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA,were made from watermelon peel via dehydration with 50%sulfuric acid to give Melon-B followed by oxidation with ozone and amination using ammonium hydroxide to give Melon-BO-NH_(2) or Triethylenetetramine(TETA)to give *** prepared biochars were characterized by BET,BJH,SEM,FT-IR,TGA,DSC and EDAX *** highest removal percentage of Cr(VI)ions was 69%for Melon-B,98%for Melon-BO-NH_(2) and 99%for Melon-BO-TETA biochars of 100 mg·L^(−1) Cr(VI)ions initial concentration and 1.0 g·L^(−1) adsorbents *** unmodified biochar(Melon-B)and modified biochars(Melon-BO-NH_(2) and Melon-BO-TETA)had maximum adsorption capacities(Q_(m))of 72.46,123.46,and 333.33 mg·g^(−1),*** amination of biochar reduced the pore size of modified biochar,whereas the surface area was *** obtained data of isotherm models were tested using different error function *** Freundlich,Tempkin and Langmuir isotherm models were best fitted to the experimental data of Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA,*** adsorption rate was primarily controlled by pseudo-second–order rate ***,the functional groups interactions are important for adsorption mechanisms and expected to control the adsorption *** adsorption for the Melon-B,Melon-BO-NH_(2) and Melon-BO-TETA could be explained for acid–base interaction and hydrogen bonding interaction.

关键词： Waste treatment Powder technology Citrullus lanatus Hexavalent chromium Biochar amination Adsorption

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Anticorrosion and discharge performance of calcium and neodymium co-doped AZ61 alloy anodes for Mg-air batteries

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Journal of Materials science & Technology 2024年第26期193卷 132-145页

作者： Baosheng Liu Ang Gao Zhechao Zhang Muhun He Ben Bin Xu Xuetao Shi Pengpeng Wu Sijie Guo Mohammed A.Amin Eman Ramadan Elsharkawy Zhanhu Guo School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Department of Mechanical and Civil Engineering Faculty of Engineering and EnvironmentNorthumbria UniversityNewcastle Upon Tyne NE18STUK Department of Chemistry College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Department of Chemistry Faculty of ScienceNorthern Border UniversityArarSaudi Arabia

Calcium(Ca)and neodymium(Nd)were introduced in the AZ61 alloy as alloying *** microstructure,corrosion behavior,and discharge properties of AZ61-1Nd-xCa(x=0,0.5 wt.%,1 wt.%,2 wt.%)alloys as anodes for Mg-air batteries were systematically *** results indicated that the AZ61-1Nd-1Ca alloy exhibits the best corrosion resistance during electrochemical experiments and hydrogen evolution *** performance tests showed that the AZ61-1Nd-1Ca alloy exhibits the best specific capacity(1193.6 mAh g^(-1)),energy density(1893.7 mWh g^(-1)),anode efficiency(60.3%),and cell voltage(1.246 V)at higher current *** is mainly attributed to the addition of Ca element,which refines the grain size of the alloy and increases the grain boundary *** addition,Al_(2)Nd and Al_(2)Ca phases have similar corrosion mechanisms in the cross-section of the extruded *** precipitated granular Al_(2)Ca phase is uniformly dispersed on the substrate and acts as a physical *** not only enhances the corrosion resistance of the alloy but also improves the anode efficiency of the alloy during discharge.

关键词： Mg alloy Ca addition Mg-air battery Corrosion behavior Discharge performance

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High-resolution dynamic imaging of chromatin DNA communication using Oligo-LiveFISH

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Cell 2025年

作者： Zhu, Yanyu Balaji, Ashwin Han, Mengting Andronov, Leonid Roy, Anish R. Wei, Zheng Chen, Crystal Miles, Leanne Cai, Sa Gu, Zhengxi Tse, Ariana Yu, Betty Chentzu Uenaka, Takeshi Lin, Xueqiu Spakowitz, Andrew J. Moerner, W.E. Qi, Lei S. Department of Bioengineering Stanford University Stanford 94305 CA United States Department of Chemistry Stanford University Stanford 94305 CA United States Biophysics PhD Program Stanford University Stanford 94305 CA United States Computational Biology Program Public Health Sciences Division and Translational Data Science IRC Fred Hutchinson Cancer Center Seattle 98109 WA United States Department of Chemical Engineering Stanford University Stanford 94305 CA United States Department of Materials Science and Engineering Stanford University Stanford 94305 CA United States Institute for Stem Cell Biology & Regenerative Medicine and Department of Pathology Stanford University School of Medicine Stanford 94305 CA United States Sarafan ChEM-H Stanford University Stanford 94305 CA United States Chan Zuckerberg Biohub San Francisco 94080 CA United States

Three-dimensional (3D) genome dynamics are crucial for cellular functions and disease. However, real-time, live-cell DNA visualization remains challenging, as existing methods are often confined to repetitive regions, suffer from low resolution, or require complex genome engineering. Here, we present Oligo-LiveFISH, a high-resolution, reagent-based platform for dynamically tracking non-repetitive genomic loci in diverse cell types, including primary cells. Oligo-LiveFISH utilizes fluorescent guide RNA (gRNA) oligo pools generated by computational design, in vitro transcription, and chemical labeling, delivered as ribonucleoproteins. Utilizing machine learning, we characterized the impact of gRNA design and chromatin features on imaging efficiency. Multi-color Oligo-LiveFISH achieved 20-nm spatial resolution and 50-ms temporal resolution in 3D, capturing real-time enhancer and promoter dynamics. Our measurements and dynamic modeling revealed two distinct modes of chromatin communication, and active transcription slows enhancer-promoter dynamics at endogenous genes like FOS. Oligo-LiveFISH offers a versatile platform for studying 3D genome dynamics and their links to cellular processes and disease. © 2025 Elsevier Inc.

关键词： CRISPR imaging DNA communication dynamic tracking enhancer-promoter interaction high-resolution imaging live DNA imaging non-repetitive genome imaging Oligo-LiveFISH polymer modeling primary cell

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Sulfur-substitution-enhanced crystallization and crystal structure of poly(trimethylene monothiocarbonate)

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Chinese chemical Letters 2022年第2期33卷 1021-1024页

作者： Xiaohan Cao Hongliang Wang Jialiang Yang Ruiyang Wang Xin Hong Xinghong Zhang Junting Xu Hai Wang MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China Center of Chemistry for Frontier Technologies Zhejiang UniversityHangzhou 310027China Department of Chemistry Zhejiang UniversityHangzhou 310027China Department of Polymer Science and Engineering College of Chemical EngineeringDalian University of TechnologyDalian 116024China

In this paper,the crystallization behavior of a novel poly(monothiocarbonate),poly(trimethylene monothiocarbonate)(PTMMTC),was investigated and compared with its polycarbonate analogue,poly(trimethylene carbonate)(PTMC).It is found that PTMMTC exhibits strong crystallizability,while un-stretched PTMC is *** and DMA results reveal that PTMMTC possesses higher glass transition temperature(T_(g))andβ-transition temperature(T_(β))than *** based on density functional theory(DFT)shows that,the bond angle of C-S-C is evidently smaller than that of C-O-C,and thus a larger dipole *** leads to the stronger intermolecular interaction and more rigid chain confor-mation in PTMMTC,which is the origin of sulfur-substitution enhanced *** crystal struc-ture of PTMMTC was preliminarily determined for the first *** has an orthorhombic crystal structure with a planar zig-zag chain *** parameters of unit cell are a=10.74 A,b=4.79 A,and c(fiber axis)=7.74 A.

关键词： Poly(monothiocarbonate) Polycarbonate Crystallization behavior Crystal structure Sulfur substitution enhanced crystallization

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InP/ZnS core/shell quantum dots: Synthesis, characterization and their application in fullerene derivative based flexible solar cells

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Results in Physics 2025年 69卷

作者： Zhichu, Chen Tahir, Muhammad Muhammad, Fida Aziz, Fakhra Ayub, Ambreen Badshah, Fazal Refat, Moamen S. Cakmak, Sadiye M. Rehan, Shanza Adam, Abdel Majid A. Alsuhaibani, Amnah Mohammed Ayob, Afida Sarker, Mahidur R Khan, Adam School of Electrical and Information Engineering Hubei University of Automotive Technology Shiyan 442002 China Semiconductor Physics & Devices Laboratory Department of Physics Faculty of Physical and Numerical Sciences Abdul Wali Khan University Mardan 23200 Pakistan Department of Electronics University of Peshawar KP Pakistan Department of Physics Women University Mardan KP 23200 Pakistan Department of Chemistry College of Science Taif University P.O. Box 11099 Taif 21944 Saudi Arabia Program of Medical Monitoring Techniques Osmangazi University Eskisehir Eskisehir 26040 Turkey Faculty of Materials and Chemical Engineering GIK Institute of Engineering Sciences and Technology Topi 23640 Pakistan Department of Physical Sport Sciences College of Sport Sciences & Physical Activity Princess Nourah bint Abdulrahman University P.O. Box 84428 Riyadh 11671 Saudi Arabia Centre for Integrated Systems Engineering and Advanced Technologies (INTEGRA) Department of Electrical Electronic and Systems Engineering Universiti Kebangsaan Malaysia Bangi 43600 Malaysia Institute of Visual Informatics Universiti Kebangsaan Selangor Malaysia Bangi 43600 Malaysia Universidad de Diseno Innovacion y Tecnología UDIT Av. Alfonso XIII 97 Madrid 28016 Spain Department of Electronics Engineering University of Engineering & Technology Peshawar (Abbottabad Campus) Abbottabad Pakistan

Herein, we report on the synthesis and characterization of p-type semiconductor indium phosphide/zinc sulphide (InP/ZnS) core/shell quantum dots (QDs) prepared via a simple solvothermal method and their potential application in bulk heterojunction (BHJ) flexible solar cell (SC). The BHJ SC composed of donor–acceptor (D-A) configuration at nanoscale provides larger interfacial junction area throughout the bulk volume of the photo-absorber D-A blend that facilitates excitons to efficiently dissociate within the bulk layer at D-A interface. Hence, InP/ZnS core–shell QDs and a fullerene derivative – phenyl C61 butyric acid methyl ester (PCBM) – are used as hybrid inorganic–organic D-A materials, respectively, to fabricate Ag/LiF/InP/ZnS-PCBM/P3HT/ITO/PET BHJ flexible SC. Indium tin oxide (ITO) coated on polyethylene terephthalate (PET), poly(3-hexylthiophene) (P3HT), lithium fluoride (LiF) and silver (Ag) are employed as a flexible substrate, hole transport layer (HTL), electron transport layer (ETL) and counter electrode, respectively. Photovoltaic (PV) properties of the fabricated BHJ flexible SC are studied under standard testing conditions (STC) i.e., 25 ⁰C, 1.5 AM global and 100 mW/cm² irradiation, which exhibit fill factor (FF) of 59 ± 0.02 % and power conversion efficiency (PCE) of 4.22 ± 0.05 %. Also, the heterojunction characteristics are investigated in dark condition (0 lx) to find series resistance (R_s), ideality factor (n), and reverse saturation current (I₀). X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and ultraviolet–visible (UV–vis) spectroscopy are performed to further investigate the properties of InP/ZnS-PCBM thin films. Transmission electron microscopy (TEM) image of InP/ZnS core/shell QDs confirmed the successful synthesis of QDs having an average size of 5 ± 1 nm. The InP/ZnS-PCBM D-A photo-absorber layer reveals its potential as one of good candidates for hi

关键词： Flexible solar cell Hybrid bulk heterojunction (BHJ) InP/ZnS core/shell QDs Power conversion efficiency (PCE) Quantum dots (QDs) synthesis

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Reprocessing the NEAT Dataset: Preliminary Results

arXiv

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arXiv 2025年

作者： Nugent, C.R. Bauer, J.M. Benitez, O. Blain, M. D’Souza, N. Garimella, S. Goldwater, M. Kim, Y. Larsen, H.C.G. Linder, T. Mackowiak, K. McGinnis, Z. Pan, E. Pedersen, C.C. Sadhwani, P. Spoto, F. Tan, N.J. Vereš, P. Xue, C. Olin College of Engineering 1000 Olin Way NeedhamMA02492 United States Department of Astronomy University of Maryland College ParkMD20742 United States Department of Earth and Space Sciences College of the Canyons Santa ClaritaCA91355 United States MIT-WHOI Joint Program in Applied Ocean Science & Engineering Cambridge and Woods Hole MA United States Department of Applied Ocean Physics & Engineering Woods Hole Oceanographic Institution 266 Woods Hole Road MS #55 Woods HoleMA02543-1050 United States Aalborg University Fibigerstræde 16 Aalborg9220 Denmark Planetary Science Institute TucsonAZ85719 United States Minor Planet Center Smithsonian Astrophysical Observatory 60 Garden Street CambridgeMA02138 United States School of Physical and Chemical Sciences Te Kura Matū University of Canterbury Private Bag 4800 Christchurch8140 New Zealand

We have created a new image analysis pipeline to reprocess images taken by the Near Earth Asteroid Tracking survey and have applied it to ten nights of observations. This work is the first large-scale reprocessing of images from an asteroid discovery survey in which thousands of archived images are re-calibrated, searched for minor planets, and resulting observations are reported to the Minor Planet Center. We describe the software used to extract, calibrate, and clean sources from the images, including specific techniques that accommodate the unique features of these archival images. This pipeline is able to find fainter asteroids than the original pipeline. © 2025, CC BY.

关键词： Asteroids

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