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Nano Research 2024年第11期17卷 10069-10082页

作者： Michael Zharnikov Angewandte physikalische chemie Universität Heidelberg Im Neuenheimer Feld 253 D-69120 Heidelberg Germany

The use of bioinert materials is crucially important for medicine and *** most popular systems in this context are oligo-and poly(ethylene glycols)(OEGs and PEGs),applied generally in different forms as bulk materials,thin films,and functional molecular ***,i review the fabrication,properties,and applications of porous hydrogel PEG films(PHFs)and nanosheets(PHNs)formed by thermally activated crosslinking of amino-and epoxy-terminated,star-branched PEG oligomers with variable molecular *** systems possess various useful characteristics,including tunable thickness and porosity,hydrogel properties,bioinertness,robustness,and extreme *** can serve as the basis for composite materials,advanced nanofabrication,and lithography,bioinert supports for high-resolution transmission electron microscopy,susceptible elements in micro-electromechanical systems,and basic building blocks of temperature,humidity,chemical,and biological *** examples of the respective applications are *** though these examples span a broad field-from nanoengineering to biosensing,the applications of the PHFs and PHNs are certainly not limited to these cases but can be specifically adapted and extended to other fields,such as tissue engineering and drug delivery,relying on versatility and tunability of these systems.

关键词： poly(ethylene glycol) hydrogel films bioinertness nanosheets sensors composite materials

Effects of temperature and sodium carboxylate additives on mineralization of calcium oxalate in silica gel systems

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Science China Chemistry 2004年第4期47卷 311-319页

作者： Bernd Tieke institut fur physikalische chemie Universitt zu Kln Luxemburgerstr. 116 D-50939 Kln Germany

The effects of temperature and multifunctional sodium carboxylate additives on the phase composition and morphology of calcium oxalate (CaOxa) crystals grown in silica gel system were systematically investigated using scanning electron microscopy (SEM), powder X-ray diffraction (XRD), and Fourier-transform infrared spectra (FT-iR). The sodium carboxylates investigated include: monocarboxylate sodium acetate (NaAc), disodium tartrate (Na2tart), trisodium citrate (Na3cit), and the disodium salt of ethylenediaminetetraacetic acid (Na2edta). The temperature range was from 7°C to 67°C. The crystallization temperature affects the phase compositions, the growth rate, and the morphology of CaOxa. First, the logarithm of the percentage of calcium oxalate dihydrate (COD) formed at a certain temperature (T) is proportional to the reciprocal of temperature (1/T). Second, the weight of CaOxa crystals decreases as decreasing the temperature. At a given temperature, the ability of the sodium carboxylates to induce COD follows the order: Na2edta Na3cit Na2tart NaAc. Third, the multicarboxylates can decrease the surface area of calcium oxalate monohydrate (COM). it makes the edges and tips of COM crystals blunt and oval. All the three changes, an increase of the content of COD, a decrease of the weight of CaOxa crystals, and a decrease of the surface area of COM crystals, can inhibit the formation of CaOxa stones. These results support the clinical use of citrates and may be helpful in elucidating the mechanisms of the formation of CaOxa calculus. Keywords calcium oxalate - sodium carboxylate - gel - urinary calculi - crystallization - biomineralization

关键词： calcium oxalate sodium carboxylate gel urinary calculi crystallization biomineralization

Compact High-Velocity Atmospheric Pressure Dielectric Barrier Plasma Jet in Ambient Air

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Plasma Science and Technology 2015年第1期17卷 14-19页

作者： Annette MEiNERS Michael LECK Bernd ABEL University of Applied Science and Arts Department of Science and Technology Leibniz-institut für Oberflachenmodifizierung(iOM) Wilhelm-Ostwald-institut für physikalische und Theoretische chemie Universitat Leipzig

in this paper,a non-thermal atmospheric pressure plasma jet at high streaming velocity operating with ambient air is *** the present technological approach,the employment of air poses a significant *** high oxygen concentration in air results in a reduced concentration of reactive species in combination with a short species *** plasma jet assembly presented here contains a special dielectric barrier with a high secondary emission *** this way,the electron density and in turn the density of reactive species is *** addition,the plasma jet assembly is equipped with a short *** leads to a higher voltage across the discharge gap and in turn to an increased density of reactive plasma *** plasma jet is formed within and emitted by a small conical nozzle.A high-speed gas flow with gas velocity of 340 m/s was achieved at the end of the *** the jet the concentration of toxic and unwanted neutral plasma species like O3 or NOx is significantly reduced because of the shorter residence time within the *** range of short-lived active plasma species is in turn considerably *** jet efficiency and action range measured through the oxidation of a test surface were determined by measuring the increase of surface tension of a polypropylene substrate via contact angle measurements after plasma *** modeling of the plasma plume indicates that oxygen atoms are in fact the main active species in the plasma plume.

关键词： plasma jet atmospheric plasma dielectric barrier radicals plasma modeling

Selective Suspension in Aqueous Sodium Dodecyl Sulfate According to Electronic Structure Type Allows Simple Separation of Metallic from Semiconducting Single-Walled Carbon Nanotubes

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Nano Research 2009年第8期2卷 599-606页

作者： Kai Moshammer Frank Hennrich Manfred M.Kappes Forschungszentrum Karlsruhe Institut für NanotechnologieD-76021 KarlsruheGermany institut für physikalische chemie Universität KarlsruheD-76128 KarlsruheGermany

Both density gradient centrifugation and gel electrophoresis have been reported to allow high throughput separation of metallic from semiconducting single-walled carbon nanotubes(SWNTs)when using aqueous sodium dodecyl sulphate(SDS)*** show here that both methods rely on an initial dispersion-by-sonication step,which is already selective with respect to electronic structure *** corresponding aqueous SDS“starting”suspensions obtained after sonication and purifi cation by simple centrifugation(70,000 g,1 h)contain semiconducting SWNTs primarily in the form of small bundles whereas metallic SWNTs are predominantly suspended as individual *** gradient centrifugation then separates the bundles from the individual tubes on the basis of differences in their overall buoyant *** electrophoresis separates the longer bundles from the shorter individual tubes on the basis of their different *** also demonstrate that such starting suspensions can be fractionated according to electronic structure type by even simpler techniques such as size exclusion chromatography or gel fi ltration,thus opening the way for simple scale-up.

关键词： Single-walled carbon nanotubes metallic–semiconducting separation electrophoresis density gradient centrifugation size exclusion chromatography

High-dimensional neural network potentials for magnetic systems using spin-dependent atom-centered symmetry functions

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npj Computational Materials 2021年第1期7卷 1541-1551页

作者： Marco Eckhoff Jörg Behler Universität Göttingen Institut für Physikalische ChemieTheoretische ChemieTammannstrasse 637077 GöttingenGermany Universität Göttingen International Center for Advanced Studies of Energy Conversion(ICASEC)Tammannstrasse 637077 GöttingenGermany

Machine learning potentials have emerged as a powerful tool to extend the time and length scales of first-principles quality ***,most machine learning potentials cannot distinguish different electronic spin arrangements and thus are not applicable to materials in different magnetic *** we propose spin-dependent atom-centered symmetry functions as a type of descriptor taking the atomic spin degrees of freedom into *** used as an input for a high-dimensional neural network potential(HDNNP),accurate potential energy surfaces of multicomponent systems can be constructed,describing multiple collinear magnetic *** demonstrate the performance of these magnetic HDNNPs for the case of manganese oxide,*** method predicts the magnetically distorted rhombohedral structure in excellent agreement with density functional theory and *** efficiency allows to determine the Néel temperature considering structural fluctuations,entropic effects,and *** method is general and is expected to be useful also for other types of systems such as oligonuclear transition metal complexes.

关键词： magnetic symmetry neural

Molecular structure of diatomic lanthanide compounds

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Science China Chemistry 2002年第1期45卷 91-96页

作者：曹晓燕刘文剑 MichaelDolg 1. institut für physikalische & Theoretische chemie 53115 Bonn Germany 2. Biochemistry Department Zhongshan University 510275 Guangzhou China 3. Lehrstuhl für Theoretische chemie Ruhr-Universit?t 44780 Bochum Germany

The molecular constants of selected diatomic lanthanide compounds (LaH, LaO, LaF, EuH, EuO, EuF, EuS, GdO, GdF, GdH, YbH, YbO, YbF, YbS, LuH, LuO and LuF) have been calculated by using relativistic small-core pseudopotentials and optimized (14s13p10d8f6g)/ [6s6p5d4f3g] valence basis sets. The results are in good agreement with available experimental data, with exception of YbO and LuF. The reasons for the discrepancies in case of YbO are due to a complicated mixing of configurations in the ground state, whereas in case of LuF the binding energy estimated by experimentalists appears to be too low.

关键词： molecular structure lanthanide element pseudopotential valence basis set.

The 3,4-dimethoxybenzyl group as solubilizing protective group for the in situ deprotection/deposition of extended aromatic thiolate monolayers

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Nano Research 2023年第1期16卷 1695-1702页

作者： Adrian Wiesner Sonja Katzbach Dariusz Bebej Martina Dettenhöfer Michael Zharnikov Andreas Terfort institut für Anorganische und Analytische chemie Johann Wolfgang Goethe Universität FrankfurtMax-von-Laue-Straße 7Frankfurt am Main D-60438Germany Angewandte physikalische chemie Universität HeidelbergIm Neuenheimer Feld 253Heidelberg D-69120Germany

While self-assembled monolayers(SAMs)of aromatic thiolates are frequently used in a wide range of applications,their formation is often hampered by the low solubilities of their *** we introduce the 3,4-dimethoxybenzyl group as a protective group for the thiol moiety,which increases the solubility and stability of the precursor,but becomes cleaved off during monolayer formation,especially at elevated temperature(60°C)and in presence of protons(trifluoroacetic acid).For a series of substituted terphenylthiols as model systems,it could be demonstrated by using ellipsometry,infrared-reflection absorption spectroscopy,and scanning-tunneling microscopy that the resulting SAMs have the same structure and quality as the ones obtained from the respective unprotected *** protective group has the additional advantage to be stable under Pdcatalyzed C–C bond formation reaction conditions,facilitating the syntheses of the respective precursors.

关键词： self-assembled monolayers protective group solubility scanning-tunneling microscopy infrared-reflection absorption spectroscopy

Aromatic self-assembled monolayers with pentafluoro-λ^(6)-sulfanyl(−SF_(5))termination:Molecular organization and charge transport properties

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Nano Research 2023年第5期16卷 7991-8002页

作者： Yangbiao Liu Marc Zeplichal Sonja Katzbach Adrian Wiesner Saunak Das reas Terfort Michael Zharnikov Angewandte physikalische chemie Universität HeidelbergIm Neuenheimer Feld 253D-69120 HeidelbergGermany institut für Anorganische und Analytische chemie Johann Wolfgang Goethe Universität FrankfurtMax-von-Laue-Straße 7D-60438 Frankfurt am MainGermany

A series of molecules with oligophenylene backbone,thiolate anchoring group,pentafluoro-λ^(6)-sulfanyl(−SF_(5))tail group was synthesized and used as precursors to form self-assembled monolayers(SAMs)on Au(111)*** resulting SAMs feature dense molecular packing,upright molecular orientation,chemically homogeneous SAM-ambient interface,comprised entirely of the−SF_(5)*** SAMs exhibit exceptional wetting and electrostatic properties,showing advancing water contact angles up to 103°and work function values up to 5.96 eV—probably the highest values reported for any aromatic monolayers on *** also feature a comparably low value of the tunnelling decay coefficient(0.38±0.07Å^(−1)),typical of oligophenylene backbone,which is not affected by the introduction of the−SF_(5)*** latter also hardly affects the current densities at a specific bias compared to analogous monolayers with other electronegative tail *** superior electrostatic and good charge transport properties of the designed,SF_(5)-terminated SAMs make them potentially useful for interface engineering in organic electronics and photovoltaics.

关键词： backbone charge electrostatic

introduction of a Reliable Method for Determination of intrinsic Viscosity for Any Polymer with High Precision

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Chinese Journal of Polymer Science 2014年第2期32卷 209-217页

作者：熊晓鹏 Qi-rong Ke Shi-qin Zhu Department of Materials Science and Engineering College of Materials Xiamen University Fujian Provincial Key Laboratory of Polymer Materials Fujian Normal University institut für physikalische chemie der Johannes Gutenberg-Universit t Mainz

intrinsic viscosities for a given polyelectrolyte in salt free and low-salt solvents reported in literatures are normally not comparable, because of inadequate valuation procedures. This article describes a theoretically justified reliable method, which is free of any model assumptions： The so called Wolf plot （logarithm of the relative viscosity as a function of polymer concentration） enables the unequivocal determination of intrinsic viscosities for all kinds of macromolecules, irrespective of whether they are chain molecules of different architecture or globular polymers, whether they are charged or uncharged. The validation of the method was examined by evaluation of the viscosities of a polyelectrolyte, some uncharged polymers of different architectures, uncharged polymer blends, and some literature data.

关键词： intrinsic viscosity Polyelectrolyte New method Wolf plot introduction.

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磁性非对称双链长表面活性剂囊泡凝胶

物理化学学报 2017年第8期33卷 1655-1664页

作者：赵文荣郝京诚 Heinz Hoffmann 山东大学胶体与界面化学教育部重点实验室济南250100 physikalische chemie i Bayreuth University

合成了一系列含磁性反离子的非对称双疏水链长的阳离子表面活性剂,其中三氯一溴铁合十六烷基戊基二甲基铵(C_(16)C_5DMA^+[FeCl_3Br]-~)与偶氮羧酸钠盐(AzoNa_4)在酸性条件水溶液中形成磁性囊泡凝胶。运用cryo-透射电镜(TEM)、冷冻蚀刻T... 详细信息

合成了一系列含磁性反离子的非对称双疏水链长的阳离子表面活性剂,其中三氯一溴铁合十六烷基戊基二甲基铵(C_(16)C_5DMA^+[FeCl_3Br]-~)与偶氮羧酸钠盐(AzoNa_4)在酸性条件水溶液中形成磁性囊泡凝胶。运用cryo-透射电镜(TEM)、冷冻蚀刻TEM(FF-TEM)、流变仪、傅里叶变换红外光谱(FT-iR)和超导量子干涉(SQUiD)等表征技术对囊泡凝胶进行了结构和性质研究,结果发现:凝胶含有曲率多变的融合性的双层囊泡,这些双分子层结构模构了自然界中各种物象的结构轮廓,展现了不可预测的多变曲率和良好柔性。聚集体双分子层膜内由长短不对称烷基链采取交错相扣的双分子层排列模式,这种构建模式结构稳定,短烷基链可游离出囊泡双分子层并伸向外部水相介质。两个相邻囊泡间的短链在疏水相互作用下形成非共价的囊泡"补丁",疏水的囊泡"补丁"克服相邻囊泡之间的斥力而融合。磁性反离子[FeCl_3Br]^-不仅赋予囊泡磁性,且在囊泡的形成过程中调控烷基链的组装。这种多形态融合性囊泡为揭示膜曲率的调节机制和构建人工细胞提供实验数据和理论参考。

关键词：非对称双链长表面活性剂粘连囊泡磁性凝胶双分子层多曲率