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A functional PES membrane for hemodialysis-Preparation,characterization and biocompatibility

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Chinese Journal of Chemical Engineering 2015年第7期23卷 1236-1244页

作者： Noel Jacob Kaleekkal A.Thanigaivelan m.Tarun D.mohan membrane laboratory Department of Chemical Engineering Anna University

In this work, we evaluate the properties of solution casted polysulfone （PSf）/sulfonated polyethersulfone （SPES） blend membranes prepared by non-solvent induced phase inversion technique. The morphologies of these blend membranes, observed using scanning electron microscopy （SEm） and atomic force microscopy （AFm） imaging, indicated a smoother skin layer and an increased number of highly interconnected pores in the sub layer. The efficacy of the prepared membranes was evaluated in terms of porosity, ultrafiltration rate （UFR）, molecular weight cut-off （mwCO） and mean pore size. The hydrophilicity of these membranes was in consonance with contact angle values. It was observed that the selectivity and the UFR of the blend membranes were higher when compared to pristine membranes. Furthermore, these blend membranes demonstrated an increase in biocompatibility - prolonged blood clotting time, suppressed platelet adhesion, reduced protein adsorption and lower complement activation. These membranes were also investigated for uremic solute removal. Diffusive permeability of middle molecular weight cytochrome-c revealed an increase from 8 × 10 ^-4 cm·s ^-1 to 18 × 10^-4 cm· s^- and illustrates the possibility that these sulfonated PES/PSf blend membranes can be used to prepare membrane modules for hemodialysis applications.

关键词： Sulfonated polyethersulfone Hydrophilicity Diffusive permeability Biocompatibility molecular weight cut-off

Adhesion between nanobubbles and fine cassiterite particles

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International Journal of mining Science and Technology 2023年第4期33卷 503-509页

作者： Liuyi Ren Zheyi Zhang weineng Zeng Yimin Zhang School of Resources and Environmental Engineering Wuhan University of TechnologyWuhan 430070China Hubei Key laboratory of mineral Resources Processing and Environment Wuhan 430070China State Environmental Protection Key laboratory of mineral metallurgical Resources Utilization and Pollution Control Wuhan University of Science and TechnologyWuhan 430081China Hubei Collaborative Innovation Center for High Efficient Utilization of Vanadium Resources Wuhan 430081China

Adhesion is an important process of particle-bubble interaction in fine particle(-10μm)*** paper studied the adhesion process and mechanism between nanobubbles and fine cassiterite particles by using a high-speed camera,atomic force microscope(AFm),adsorption capacity tests,and induction time *** being pretreated with nanobubbles(NBs)water,fine cassiterite particles flotation tests were carried out using caprylhydroxamic acid(CHA)as a *** results showed that NBs can improve the recovery and flotation rate of fine cassiterite while decreasing the collector *** adsorption capacity test indicated that the cassiterite treated with NBs had lower demand for collector *** AFm imaging results further demonstrate that NBs could reduce the adsorption of CHA on the surface of *** NBs played a part of the role of collector,it can improve the flotation effect while reducing the amount of *** induction time test and the high-speed camera observation test showed that NBs promoted the attachment between bubbles and cassiterite *** the other hand,NBs agglomerate cassiterite particles,increasing the probability of particles colliding with bubbles.

关键词： Nanobubbles Cassiterite Flotation Caprylhydroxamic acid

(Catecholate)Cu^(I)_(2)-Displayed Porous Organic Polymers as Efficient Heterogeneous Catalysts for the mild and Selective Aerobic Oxidation of Alcohols

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CCS Chemistry 2023年第2期5卷 445-454页

作者： Youlong Zhu Debabrata mukherjee Theodore R.Helgert SonBinh T.Nguyen Key laboratory for Polymeric Composite and Functional materials of ministry of Education School of ChemistrySun Yat-sen UniversityGuangzhou 510006 Chemical Sciences and Engineering Division Argonne National LaboratoryArgonneIL 60439 Department of Chemistry International Institute for NanotechnologyNorthwestern UniversityEvanstonIL 60208

Porous organic polymers(POPs)containing catalytically active sites are of paramount importance for heterogeneous ***,the catalytically active sites of reported POPs are mostly limited to mononuclear metal ***,we report the reaction between catechol-containing POPs(Cat-POPs)and[CuImes]n to afford the corresponding Cu^(I)_(2)-CatPOPs with a putative vicinal binuclear(catecholate)Cu^(I)_(2)*** resulting Cu^(I)_(2)-CatPOPs exhibit high Brunauer–Emmett–Teller surface areas,good stability,and excellent catalytic activity toward the aerobic oxidation of a broad range of primary and secondary alcohols under mild conditions,with either 2,2,6,6-tetramethylpiperidinyl-N-oxyl or 9-azabicyclo[3.3.0]nonane-N-oxyl as the *** green aerobic oxidation catalysts,the Cu^(I)_(2)-CatPOPs are much more active than the correspondingmononuclear CuIICatPOPs,where each catecholate moiety only supports one CuII center;CuI-ConPOPs,where the binding sites for CuI is a nonvicinal 1,4-dihydroxybenzene moiety;and the homogeneous analogue(3,6-di-tert-butyl catecholate)Cu^(I)_(2).These results are consistent with a proposed vicinal binuclear Cu^(I)_(2)structure that can efficiently activate molecular oxygen for the aerobic oxidation of alcohols,mechanistically similar to that observed in dicopper-containing *** results demonstrate the facile preparation of POPs with binuclear catalytically active sites that function as green heterogeneous catalysts for efficient oxidation of alcohols.

关键词： porous organic polymers binuclear copper(I) heterogeneous catalysis aerobic oxidation green chemistry

Controllable growth of type-II Dirac semimetal PtTe2 atomic layer on Au substrate for sensitive room temperature terahertz photodetection

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Infomat 2021年第6期3卷 705-715页

作者： Yang Yang Kaixuan Zhang Libo Zhang Guo Hong Chao Chen Hongmei Jing Jiangbo Lu Peng wang Xiaoshuang Chen Lin wang Hua Xu Key laboratory of Applied Surface and Colloid Chemistry ministry of Education Shaanxi Key Laboratory for Advanced Energy DevicesSchool of Materials Science and EngineeringShaanxi Normal UniversityXi'anChina State Key laboratory for Infrared Physics Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghaiChina Department of Optoelectronic Science and Engineering Donghua UniversityShanghaiChina Department of Physics and Chemistry Faculty of Science and TechnologyInstitute of Applied Physics and Materials EngineeringUniversity of MacaoMacaoChina School of Physics and Information Technology Shaanxi Normal UniversityXi'anChina

Platinum telluride(PtTe_(2)),a member of metallic transition metal dichalcogenides,provides a new platform for investigating various properties such as type-II Dirac fermions,topological superconductivity,and wide-band ***,the study of PtTe_(2)is largely limited to exfoliated flakes,and its direct synthesis remains ***,we report the controllable synthesis of highly crystalline 2D PtTe_(2)crystals with tunable morphology and thickness via chemical vapor deposition(CVD)growth on Au *** adjusting Te amount and substrate temperature,anisotropic and isotropic growth modes of PtTe_(2)were realized on the solid and molten Au substrates,*** domain size of PtTe_(2)crystal was achieved up to 30μm,and its thickness can be tuned from 5.6 to 50 nm via controlling the growth ***,a metal–PtTe_(2)–metal structural device was fabricated to validate the wide-band terahertz(THz)photodetection from 0.04 to 0.3 THz at room *** to the high crystallinity of PtTe_(2)crystal,the photodetector acquires high responsivity(30–250 mA w-1 from 0.12 to 0.3 THz),fast response rate(rise time:7μs,decay time:8μs),and high-quality imaging *** work demonstrates the feasibility for realistic exploitation of high-performing photodetection system at THz band based on the CVDgrown 2D Dirac semimetal materials.

关键词： 2D materials chemical vapor deposition Dirac semimetal platinum telluride terahertz photodetection

Self-assembly of anisotropic tobacco mosaic virus nanoparticles on gold substrate

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Science China Chemistry 2011年第1期54卷 137-143页

作者： PENG Bo LIU NingNing LIN Yuan wANG Liming ZHANG wenKe NIU Zhongwei wANG Qian SU ZhaoHui State Key laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China State Key laboratory of Supramolecular Structure and materials College of Chemistry Jilin University Changchun 130012 China Department of Chemistry and Biochemistry and Nanocenter University of South Carolina Columbia SC 29208 USA

A facile approach to assembled virus film with tunable structure is ***-like tobacco mosaic virus (TmV) was selected as the prototype in this study for its anisotropic structural *** can either "lie down" or "stand up" on gold substrate by tuning the solution pH.A quartz crystal microbalance with dissipation monitoring was used to monitor the pH-dependent self-assembly behavior of TmV nanoparticles,and atomic force microscopy and single molecule force spectroscopy further confirmed the different assembly structures.

关键词： tobacco mosaic virus self-assembly quartz crystal microbalance with dissipation single molecule force spectroscopy

Convergent and divergent beam electron holography and reconstruction of adsorbates on free-standing two-dimensional crystals

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Frontiers of physics 2019年第1期14卷 43-57页

作者： T. Latychevskaia C. R. woods Yi Bo wang m. Holwill E. Prestat S. J. Haigh K. S. Novoselov Institute of Physics Laboratory for Ultrafast Microscopy and Electron Scattering (LUMES)école Polytechnique Fédérale de Lausanne (EPFL) CH-1015 Lausanne Switzerland National Graphene Institute University of Manchester Oxford Road Manchester M13 9PL UK School of Physics and Astronomy University of Manchester Oxford Road Manchester M13 9PL UK School of materials University of Manchester Oxford Road Manchester M13 9PL UK

Van der waals heterostructures have been lately intensively studied because they offer a large variety of properties that can be controlled by selecting 2D materials and their sequence in the stack. The exact arrangement of the layers as well as the exact arrangement of the atoms within the layers, both are important for the properties of the resulting device. However, it is very difficult to control and characterize the exact position of the atoms and the layers in such heterostructures, in particular, along the vertical (z) dimension. Recently it has been demonstrated that convergent beam electron diffraction (CBED) allows quantitative three-dimensional mapping of atomic positions in three-dimensional materials from a single CBED pattern. In this study we investigate CBED in more detail by simulating and performing various CBED regimes, with convergent and divergent wavefronts, on a somewhat simplified system: a two-dimensional (2D) monolayer crystal. In CBED, each CBED spot is in fact an in-line hologram of the sample, where in-line holography is known to exhibit high intensity contrast in detection of weak phase objects that are not detectable in conventional in-focus imaging mode. Adsorbates exhibit strong intensity contrast in the zero and higher order CBED spots, whereas lattice deformation such as strain or rippling cause noticeable intensity contrast only in the first and higher order CBED spots. The individual CBED spots can thus be reconstructed as typical in-line holograms, and a resolution of 2.13 A can in principle be achieved in the reconstructions. we provide simulated and experimental examples of CBED of a 2D monolayer crystal. The simulations show that individual CBED spots can be treated as in-line holograms and sample distributions such as adsorbates, can be reconstructed. Individual atoms can be reconstructed from a single CBED pattern provided the later exhibits high-order CBED spots. The experimental results were obtained in a transmission ele

关键词： graphene two-dimensional materials van der waals structures electron holography convergent beam electron diffraction

Characterization of a velocity-tunable ^(87)Rb cold atomic source with a high-speed imaging technology

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Chinese Physics B 2009年第8期18卷 3373-3378页

作者：冯焱颖朱常兴王晓佳薛洪波叶雄英周兆英 State Key laboratory of Precision measurement Technology and Instruments Department of Precision Instruments and MechanologyTsinghua University School of Electronic and Computer Science and Technology North University of China Information Engineering School China University of Geosciences

This paper has developed and characterized a method to produce a velocity-tunable ^87Rb cold atomic source for atomic interferometry application. Using a high speed fluorescence imaging technology, it reports that the dynamic process of the atomic source formation is observed and the source performances including the flux and the initial velocity are characterized. A tunable atomic source with the initial velocity of 1.4-2.6 m/s and the atomic source flux of 2× 10^8 - 6 × 10^9 atoms/s has been obtained with the built experimental setup.

关键词： cold atomic source velocity-tunable hizh sueed fluorescence imaging

Stacking transition in rhombohedral graphite

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Frontiers of physics 2019年第1期14卷 67-73页

作者： Tataiana Latychevskaia Seok-Kyun Son Yaping Yang Dale Chancellor michael Brown Servet Ozdemir Ivan madan Gabriele Berruto Fabrizio Carbone Artem mishchenko Kostya S. Novoselov Institute of Physics Laboratory for Ultrafast Microscopy and Electron Scattering (LUMES)école Polytechnique Fédérale de Lausanne (EPFL) CH-1015 Lausanne Switzerland National Graphene Institute University of Manchester Oxford Road Manchester M13 9PL UK School of Physics and Astronomy University of Manchester Oxford Road Manchester M13 9PL UK

Few-layer graphene (FLG) has recently been intensively investigated for its variable electronic properties, which are defined by a local atomic arrangement. while the most natural arrangement of layers in FLG is ABA (Bernal) stacking, a metastable ABC (rhombohedral) stacking, characterized by a relatively high-energy barrier, can also occur. when both types of stacking occur in one FLG device, the arrangement results in an in-plane heterostructure with a domain wall (Dw). In this paper, we present two approaches to demonstrate that the ABC stacking in FLG can be controllably and locally turned into the ABA stacking. In the first approach, we introduced Joule heating, and the transition was characterized by 2D peak Raman spectra at a submicron spatial resolution. The transition was initiated in a small region, and then the Dw was controllably shifted until the entire device became ABA stacked. In the second approach, the transition was achieved by illuminating the ABC region with a train of 790-nm-wavelength laser pulses, and the transition was visualized by transmission electron microscopy in both diffraction and dark-field imaging modes. Further, using this approach, the Dw was visualized at a nanoscale spatial resolution in the dark-field imaging mode.

关键词： graphene graphite van der waals heterostructures domain wall Raman spectroscopy transmission electron microscopy electron diffraction structural transition

3D RNA nanocage for encapsulation and shielding of hydrophobic biomolecules to improve the in vivo biodistribution

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Nano Research 2020年第12期13卷 3241-3247页

作者： Congcong Xu Kaiming Zhang Hongran Yin Zhefeng Li Alexey Krasnoslobodtsev Zhen Zheng Zhouxiang Ji Sijin Guo Shanshan Li wah Chiu Peixuan Guo Center for RNA Nanobiotechnology and Nanomedicine College of PharmacyDivision of Pharmaceutics and Pharmaceutical ChemistryCollege of MedicineDorothy M.Davis Heart and Lung Research InstituteJames Comprehensive Cancer CenterThe Ohio State UniversityColumbusOH43210USA Department of Bioengineering James H.Clark CenterStanford UniversityStanfordCA94305USA Department of Physics University of Nebraska at OmahaOmahaNE68182USA Nanoimaging Core Facility Office of Vice-Chancellor for ResearchUniversity of Nebraska Medical CenterOmahaNE68198USA SLAC National Accelerator laboratory Stanford UniversityMenlo ParkCA94025USA

Ribonucleic acid(RNA)nanotechnology platforms have the potential of harboring therapeutics for in vivo delivery in disease ***,the nonspecific interaction between the harbored hydrophobic drugs and cells or other components before reaching the diseased site has been an obstacle in drug *** we report an encapsulation strategy to prevent such nonspecific hydrophobic interactions in vitro and in vivo based on a self-assembled three-dimensional(3D)RNA *** placing an RNA three-way junction(3wJ)in the cavity of the nanocage,the conjugated hydrophobic molecules were specifically positioned within the nanocage,preventing their exposure to the biological *** assembly of the nanocages was characterized by native polyacrylamide gel electrophoresis(PAGE),atomic force microscopy(AFm),and cryogenic electron microscopy(cryo-Em)*** stealth effect of the nanocage for hydrophobic molecules in vitro was evaluated by gel electrophoresis,flow cytometry,and confocal *** in vivo sheathing effect of the nanocage for hydrophobic molecules was assessed by biodistribution profiling in *** RNA nanocages with hydrophobic biomolecules underwent faster clearance in liver and spleen in comparison to their ***,this encapsulation strategy holds promise for in vivo delivery of hydrophobic drugs for disease treatment.

关键词： ribonucleic acid(RNA)nanocage three-way junction(3wJ) encapsulation hydrophobic biomolecule RNA nanotechnology