Lander on Cu(2 1 1) – selective adsorption and surface restructuring by a molecular wire

2003 ◽  
Vol 371 (5-6) ◽  
pp. 750-756 ◽  
Author(s):  
Leo Gross ◽  
Francesca Moresco ◽  
Micol Alemani ◽  
Hao Tang ◽  
André Gourdon ◽  
...  
Keyword(s):  
Selective Adsorption ◽  
Molecular Wire ◽  
Surface Restructuring

Atom-probe analysis of the solid-liquid interface

1995 ◽  
Vol 53 ◽  
pp. 676-677
Author(s):  
J.A. Panitz
Keyword(s):  
Molecular Level ◽  
Selective Adsorption ◽  
Electronic Devices ◽  
Atom Probe ◽  
Chemical Agent ◽  
Hostile Environment ◽  
Solid Interface ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Chemically Selective

The first few atomic layers of a solid can form a barrier between its interior and an often hostile environment. Although adsorption at the vacuum-solid interface has been studied in great detail, little is known about adsorption at the liquid-solid interface. Adsorption at a liquid-solid interface is of intrinsic interest, and is of technological importance because it provides a way to coat a surface with monolayer or multilayer structures. A pinhole free monolayer (with a reasonable dielectric constant) could lead to the development of nanoscale capacitors with unique characteristics and lithographic resists that surpass the resolution of their conventional counterparts. Chemically selective adsorption is of particular interest because it can be used to passivate a surface from external modification or change the wear and the lubrication properties of a surface to reflect new and useful properties. Immunochemical adsorption could be used to fabricate novel molecular electronic devices or to construct small, “smart”, unobtrusive sensors with the potential to detect a wide variety of preselected species at the molecular level. These might include a particular carcinogen in the environment, a specific type of explosive, a chemical agent, a virus, or even a tumor in the human body.

Evolution of Metastable Structures in Bimetallic Catalysts from Microscopy and Machine-Learning Molecular Dynamics

2020 ◽  
Author(s):  
Jin Soo Lim ◽  
Jonathan Vandermause ◽  
Matthijs A. van Spronsen ◽  
Albert Musaelian ◽  
Christopher R. O’Connor ◽  
...  
Keyword(s):  
Machine Learning ◽  
Molecular Dynamics ◽  
Large Scale ◽  
Materials Science ◽  
Complete Characterization ◽  
Layer By Layer ◽  
Surface Restructuring ◽  
Metastable Structures ◽  
Mechanistic Investigation ◽  
Underlying Mechanisms

Restructuring of interface plays a crucial role in materials science and heterogeneous catalysis. Bimetallic systems, in particular, often adopt very different composition and morphology at surfaces compared to the bulk. For the first time, we reveal a detailed atomistic picture of the long-timescale restructuring of Pd deposited on Ag, using microscopy, spectroscopy, and novel simulation methods. Encapsulation of Pd by Ag always precedes layer-by-layer dissolution of Pd, resulting in significant Ag migration out of the surface and extensive vacancy pits. These metastable structures are of vital catalytic importance, as Ag-encapsulated Pd remains much more accessible to reactants than bulk-dissolved Pd. The underlying mechanisms are uncovered by performing fast and large-scale machine-learning molecular dynamics, followed by our newly developed method for complete characterization of atomic surface restructuring events. Our approach is broadly applicable to other multimetallic systems of interest and enables the previously impractical mechanistic investigation of restructuring dynamics.

New Molecular Scaffolds for Fluorescent Voltage Indicators

2018 ◽  
Author(s):  
Steven Boggess ◽  
Shivaani Gandhi ◽  
Brian Siemons ◽  
Nathaniel Huebsch ◽  
Kevin Healy ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Action Potentials ◽  
Induced Pluripotent Stem Cell ◽  
Molecular Wire ◽  
Voltage Sensing ◽  
Design Synthesis ◽  
Cardiac Action ◽  
Action Potential Waveform ◽  
Induced Pluripotent ◽  
Voltage Sensing Domain

<div> <p>The ability to non-invasively monitor membrane potential dynamics in excitable cells like neurons and cardiomyocytes promises to revolutionize our understanding of the physiology and pathology of the brain and heart. Here, we report the design, synthesis, and application of a new class of fluorescent voltage indicator that makes use of a fluorene-based molecular wire as a voltage sensing domain to provide fast and sensitive measurements of membrane potential in both mammalian neurons and human-derived cardiomyocytes. We show that the best of the new probes, fluorene VoltageFluor 2 (fVF 2) readily reports on action potentials in mammalian neurons, detects perturbations to cardiac action potential waveform in human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes, shows a substantial decrease in phototoxicity compared to existing molecular wire-based indicators, and can monitor cardiac action potentials for extended periods of time. Together, our results demonstrate the generalizability of a molecular wire approach to voltage sensing and highlights the utility of fVF 2 for interrogating membrane potential dynamics.</p> </div>

The Structure of a Biological Insulated Transmembrane Molecular Wire

2019 ◽  
Author(s):  
Marcus Edwards ◽  
Gaye White ◽  
Julea Butt ◽  
David J. Richardson ◽  
Thomas A. Clarke
Keyword(s):  
Molecular Wire

Application of iron-coated sand on the treatment of toxic metals

2004 ◽  
Vol 4 (5-6) ◽  
pp. 335-341 ◽  
Author(s):  
Jae-Kyu Yang ◽  
Yoon-Young Chang ◽  
Sung-Il Lee ◽  
Hyung-Jin Choi ◽  
Seung-Mok Lee
Keyword(s):  
Heavy Metals ◽  
Selective Adsorption ◽  
Complete Removal ◽  
Batch Adsorption ◽  
Column Experiments ◽  
Adsorption Behaviour ◽  
Optimum Amount ◽  
Initial Ph ◽  
New Treatment ◽  
Coated Sand

Iron-coated sand (ICS) prepared by using FeCl3 and Joomoonjin sand widely used in Korea was used in this study. In batch adsorption kinetics, As(V) adsorption onto ICS was completed within 20 minutes, while adsorption of Pb(II), Cd(II), and Cu(II) onto ICS was slower than that of As(V) and strongly depended on initial pH. At pH 3.5, ICS showed a selective adsorption of Pb(II) compared to Cd( II) and Cu(II) . However, above pH 4.5, near complete removal of Pb(II), Cd(II), and Cu(II) was observed through adsorption or precipitation depending on pH. As(V) adsorption onto ICS occurred through an anionic-type and followed a Langmuir-type adsorption behaviour. In column experiments, pH was identified as an important parameter in the breakthrough of As(V). As(V) breakthrough at pH 4.5 was much slower than at pH 9 due to a strong chemical bonding between As(V) and ICS as similar with batch adsorption behaviour. With variation of ICS amounts, the optimum amount of ICS at pH 4.5 was identified as 5.0 grams in this research. At this condition, ICS could be used to treat 200 mg of As(V) with 1 kg of ICS until 50 ppb of As(V) appeared in the effluent. In this research, as a new treatment system, ICS can be potentially used to treat As(V) and cationic heavy metals.

Core-Shell Molecularly Imprinted Polymer Nanocomposites for Biomedical and Environmental Applications

2019 ◽  
Vol 25 (34) ◽  
pp. 3633-3644
Author(s):  
Nasrullah Shah ◽  
Saba Gul ◽  
Mazhar Ul-Islam
Keyword(s):  
Food Processing ◽  
Selective Adsorption ◽  
Environmental Applications ◽  
Core Shell ◽  
Template Molecule ◽  
Hollow Core ◽  
Imprinted Polymer ◽  
Adsorption Selectivity ◽  
Molecularly Imprinting Polymers ◽  
Relative Adsorption

: Core-shell polymers represent a class of composite particles comprising of minimum two dissimilar constituents, one at the center known as a core which is occupied by the other called shell. Core-shell molecularly imprinting polymers (CSMIPs) are composites prepared via printing a template molecule (analyte) in the coreshell assembly followed by their elimination to provide the everlasting cavities specific to the template molecules. Various other types of CSMIPs with a partial shell, hollow-core and empty-shell are also prepared. Numerous methods have been reported for synthesizing the CSMIPs. CSMIPs composites could develop the ability to identify template molecules, increase the relative adsorption selectivity and offer higher adsorption capacity. Keen features are measured that permits these polymers to be utilized in numerous applications. It has been developed as a modern technique with the probability for an extensive range of uses in selective adsorption, biomedical fields, food processing, environmental applications, in utilizing the plant's extracts for further applications, and sensors. This review covers the approaches of developing the CSMIPs synthetic schemes, and their application with special emphasis on uses in the biomedical field, food care subjects, plant extracts analysis and in environmental studies.

scholarly journals The formation and constitution of crystals of lead salts containing water-soluble colloid

1935 ◽  
Vol 235 (749) ◽  
pp. 125-164 ◽  
Keyword(s):  
Selective Adsorption ◽  
Water Soluble ◽  
Lead Salts ◽  
The Subject ◽  
As If ◽  
Saturated Solutions

The influence of small amounts of dissolved foreign substances on the growth of crystals from saturated solutions has been the subject of much investigation. Usually the added substances have been electrolytes. Dyestuffs have not been neglected, but with some few exceptions comparatively little attention has been given to the effect of non-ionized water-soluble electrolytes such as gelatine or dextrine. As a rule, the presence of the foreign substances is found to cause the crystals to assume a different habit. Whenever this occurs the absorption must have occurred on certain crystal-faces in preference to others, but, although the added material is active by virtue of its close attachment to such faces, it is rarely found to be incorporated into the solid to any great extent. The growing crystals appear to reject the impurity—thrusting it outwards as the growth advances. The action of water-soluble colloids on the halides and certain other salts of lead is exceptional in several ways. Although when such colloids are present in small concentrations one can generally observe a modification of habit, at higher concentrations there may be little selective adsorption, and the result may be a rounded crystal on which no plane faces at all can be distinguished, as if the forces by which atoms are attracted to the structure had been equalized in every direction.

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