Read by QxMD icon Read

Molecular adsorbant

Alberto Roldan, Nora H de Leeuw
The interaction of water with catalyst surfaces is a common process which requires investigation. Here, we have employed density functional theory calculations to investigate the adsorption of up to ten water molecules on the {001} surface of greigite (Fe3S4), which owing to its redox properties, is of increasing interest as a catalyst, e.g. in electro-catalysis. We have systematically analyzed and characterized the modes of water adsorption on the surface, where we have considered both molecular and dissociative adsorption processes...
April 26, 2017: Physical Chemistry Chemical Physics: PCCP
Zachary A Morseth, Toan V Pho, Matthew V Sheridan, Thomas J Meyer, Kirk S Schanze, John R Reynolds, John M Papanikolas
Photoinduced electron injection, intra-assembly electron transfer, and back-electron transfer are investigated in a single-site molecular assembly formed by covalently linking a phosphonated terthiophene (T3) chromophore to a Ru(terpyridine)(bipyridine)(L)2+ (L = MeCN or H2O) water oxidation catalyst adsorbed onto a mesoporous metal oxide (MOx) film. Density functional theory calculations of the T3-trpy-Ru-L assembly indicate that the molecular components are strongly coupled, with enhanced low-energy absorptions owing to the presence of an intra-ligand charge transfer (ILCT) transition between the T3 and trpy moieties...
April 26, 2017: ACS Applied Materials & Interfaces
Constantinos D Zeinalipour-Yazdi, Justin S J Hargreaves, Said Laassiri, C Richard A Catlow
The reactants for ammonia synthesis have been studied, employing density functional theory (DFT), with respect to their adsorption on tantalum nitride surfaces. The adsorption of nitrogen was found to be mostly molecular and non-activated with side-on, end-on and tilt configurations. At bridging nitrogen sites (Ta-N-Ta) it results in an azide functional group formation with a formation energy of 205 kJ mol(-1). H2 was found also to chemisorb molecularly with an adsorption energy in the range -81 to -91 kJ mol(-1)...
April 25, 2017: Physical Chemistry Chemical Physics: PCCP
N V Brilliantov, Yu A Budkov, C Seidel
We analyze, theoretically and by means of molecular dynamics (MD) simulations, the generation of mechanical force by a polyelectrolyte (PE) chain grafted to a plane and exposed to an external electric field; the free end of the chain is linked to a deformable target body. Varying the field, one can alter the length of the non-adsorbed (bulk) part of the chain and hence the deformation of the target body and the arising force. We focus on the impact of added salt on the magnitude of the generated force, which is especially important for applications...
April 25, 2017: Faraday Discussions
Zhengping Zhang, Xinjin Gao, Meiling Dou, Jing Ji, Feng Wang
Exploring sustainable and high-performance electrocatalysts for the oxygen reduction reaction (ORR) is the crucial issue for the large-scale application of fuel cell technology. A new strategy is demonstrated to utilize the biomass resource for the synthesis of N-doped hierarchically porous carbon supported single-atomic Fe (SA-Fe/NHPC) electrocatalyst toward the ORR. Based on the confinement effect of porous carbon and high-coordination natural iron source, SA-Fe/NHPC, derived from the hemin-adsorbed bio-porphyra-carbon by rapid heat-treatment up to 800 °C, presents the atomic dispersion of Fe atoms in the N-doped porous carbon...
April 25, 2017: Small
Tomonori Waku, Yuko Imanishi, Yuta Yoshino, Shigeru Kunugi, Takeshi Serizawa, Naoki Tanaka
Orientation-controlled protein immobilization on a solid substrate surface is important for the development of biomedical materials such as scaffolds used in tissue engineering. In this study, the authors demonstrated that the introduction of material-binding peptides (MBPs) in Arg-Gly-Asp (RGD)-fused artificial proteins called blocking peptide fragment (BPF), which are fragments (residues 419-607) of the molecular chaperone DnaK, enhances the oriented adsorption of proteins on the polymer surface and improves their cell adhesion capability...
April 24, 2017: Biointerphases
Bogdana Borca, Tomasz Michnowicz, Rémi Pétuya, Marcel Pristl, Verena Schendel, Ivan Pentegov, Ulrike Kraft, Hagen Klauk, Peter Wahl, Rico Gutzler, Andrés Arnau, Uta Schlickum, Klaus Kern
The ability to elucidate the elementary steps of a chemical reaction at the atomic scale is important for the detailed understanding of the processes involved which is key to uncover avenues for improved reaction paths. Here, we track the chemical pathway of an irreversible direct desulfurization reaction of tetracenothiophene adsorbed on the Cu(111) closed-packed surface at the submolecular level. Using the precise control of the tip position in a Scanning Tunneling Microscope and the electric field applied across the tunnel junction, the two carbon-sulfur bonds of a thiophene unit are successively cleaved...
April 24, 2017: ACS Nano
Sandipan Chakraborty, Biman Jana
The mechanism of ice recognition by antifreeze protein (AFP) is a topic of recent interest. Here, using equilibrium simulations and free energy calculations, we provide structural rationale to the observed experimental anomalies on type I AFP (wfAFP isoform HPLC6) and its mutants as well as probe the molecular origin of ice recognition by them. Our results clearly demonstrate that the interplay between the conformational and hydration properties dictates the ice binding ability of type I AFP and its mutants...
April 24, 2017: Physical Chemistry Chemical Physics: PCCP
Huichun Zhang, Shubo Wang
A large number of organic contaminants are commonly found in industrial and municipal wastewaters. For proper unit design to remove contaminant mixtures by adsorption, multi-component adsorption equilibrium models are necessary. The present work examined the applicability of Ideal Adsorbed Solution Theory (IAST), a prevailing thermodynamic model, and its derivatives, i.e., Segregated IAST (SIAST) and Real Adsorbed Solution Theory (RAST), to bi-solute adsorption of organic compounds onto a hyper-crosslinked polystyrene resin, MN200...
April 24, 2017: Environmental Science & Technology
Xiong Li, Hang Li, Gang Yang
Electric fields exist ubiquitously in chemical and biological systems while how to affect the interfacial adsorption processes remain elusive. Here, molecular dynamics simulations are used to understand at a molecular level the adsorption of metal ions at the interface of aqueous solutions and clay materials that are generally endowed with strong electric fields. In absence of electric fields, even Cs(+), one of the strongest adsorbed metal ions, is facile to detach from solvated clay surfaces. Electric fields are critical to construct stable inner-sphere complexes and enhance pronouncedly the adsorption strengths of both inner- and outer-sphere complexes...
April 13, 2017: Journal of Colloid and Interface Science
Zhu Liang, Tao Li, Minkyu Kim, Aravind Asthagiri, Jason F Weaver
Methane undergoes highly facile C-H bond cleavage on the stoichiometric IrO2(110) surface. From temperature-programmed reaction spectroscopy experiments, we found that methane molecularly adsorbed as a strongly bound σ complex on IrO2(110) and that a large fraction of the adsorbed complexes underwent C-H bond cleavage at temperatures as low as 150 kelvin (K). The initial dissociation probability of methane on IrO2(110) decreased from 80 to 20% with increasing surface temperature from 175 to 300 K. We estimate that the activation energy for methane C-H bond cleavage is 9...
April 21, 2017: Science
Medhat A Al-Ghobashy, Aliaa N ElMeshad, Rania M Abdelsalam, Mohammed M Nooh, Muhammad Al-Shorbagy, Götz Laible
Recombinant human myelin basic protein (rhMBP) was previously produced in the milk of transgenic cows. Differences in molecular recognition of either hMBP or rhMBP by surface-immobilized anti-hMBP antibodies were demonstrated. This indicated differences in immunological response between rhMBP and hMBP. Here, the activity of free and controlled release rhMBP poly(ε-caprolactone) nanoparticles (NPs), as a therapeutic vaccine against multiple sclerosis (MS) was demonstrated in experimental autoimmune encephalomyelitis (EAE) animal model...
April 20, 2017: Scientific Reports
Karin Danielsson, Julián A Gallego-Urrea, Martin Hassellov, Stefan Gustafsson, Caroline M Jonsson
Engineered nanoparticles released into the environment may interact with natural organic matter (NOM). Surface complexation affects the surface potential, which in turn may lead to aggregation of the particles. Aggregation of synthetic TiO2 (anatase) nanoparticles in aqueous suspension was investigated at pH 2.8 as a function of time in the presence of various organic molecules and Suwannee River fulvic acid (SRFA), using dynamic light scattering (DLS) and high-resolution transmission electron microscopy (TEM)...
2017: Journal of Nanoparticle Research: An Interdisciplinary Forum for Nanoscale Science and Technology
Markéta Prusková, Veronika Sutrová, Miroslav Šlouf, Blanka Vlčková, Jiří Vohlídal, Ivana Šloufová
The assembly of Ag and Au nanoparticles (NPs) into nanoparticulate arrays mediated by terpyridine (tpy), 4'-(2-thienyl)terpyridine (T-tpy), and short α,ω-bis(tpy)oligothiophene ligands has been accomplished at the interface between the Ag or Au NP hydrosol and a solution of the molecular species in dichloromethane. The relationship between the morphology and the optical responses of the arrays has been investigated by advanced methods of TEM (transmission electron microscopy) image analysis and surface plasmon extinction (SPE) spectra...
April 19, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Hao Li, Jian Shang, Zhiping Yang, Wenjuan Shen, Zhihui Ai, Lizhi Zhang
Understanding the chemistry of hydrogen peroxide (H2O2) decomposition and hydroxyl radicals (•OH) transformation on the surface molecular level is a great challenge for the application of heterogeneous Fenton system in the fields of chemistry, environmental and life science. We report in this study a conceptual oxygen vacancy associated surface Fenton system without any metal ions leaching, exhibiting unprecedented surface chemistry based on the oxygen vacancy of electron-donor nature for heterolytic H2O2 dissociation...
April 18, 2017: Environmental Science & Technology
Aaron W Thornton, Cory M Simon, Jihan Kim, Ohmin Kwon, Kathryn S Deeg, Kristina Konstas, Steven J Pas, Matthew R Hill, David A Winkler, Maciej Haranczyk, Berend Smit
The Materials Genome is in action: the molecular codes for millions of materials have been sequenced, predictive models have been developed, and now the challenge of hydrogen storage is targeted. Renewably generated hydrogen is an attractive transportation fuel with zero carbon emissions, but its storage remains a significant challenge. Nanoporous adsorbents have shown promising physical adsorption of hydrogen approaching targeted capacities, but the scope of studies has remained limited. Here the Nanoporous Materials Genome, containing over 850 000 materials, is analyzed with a variety of computational tools to explore the limits of hydrogen storage...
April 11, 2017: Chemistry of Materials: a Publication of the American Chemical Society
Karin Björklund, Loretta Y Li
Adsorption filters have the potential to retain suspended pollutants physically, as well as attracting and chemically attaching dissolved compounds onto the adsorbent. This study investigated the adsorption of eight hydrophobic organic compounds (HOCs) frequently detected in stormwater - including four polycyclic aromatic hydrocarbons (PAHs), two phthalates and two alkylphenols - onto activated carbon produced from domestic sewage sludge. Adsorption was studied using batch tests. Kinetic studies indicated that bulk adsorption of HOCs occurred within 10 min...
April 13, 2017: Journal of Environmental Management
Lingqing Dong, Kui Cheng, Ying Zhou, Mengfei Yu, Jiaxing Gong, Yihan Lin, Qi Luo, Qi Wang, Wenjian Weng, Huiming Wang
Stem cells in contact with materials are able to sense their surface features, integrate extracellular matrix (ECM) protein cues through a signal transduction pathway, and ultimately direct cell fate decisions. However, discovering the interdisciplinary mechanisms of how stem cells respond to inherent material surface features still remains a challenge due to the complex, multicomponent signaling milieu present in the ECM environment. Here, we demonstrate that the fate of human mesenchymal stem cells (hMSCs) can be regulated by the inherent physical cue of the material surface down to atomic-scale features...
April 27, 2017: ACS Applied Materials & Interfaces
Yan Zhang, Guohe Huang, Chunjiang An, Xiaying Xin, Xia Liu, Maya Raman, Yao Yao, Wenxia Wang, Mukesh Doble
From the view of economic efficiency and technology sustainability, biomass adsorbent has a high potential for pollution control. In the present study, the performance of gemini 12-2-12 surfactant-modified wheat bran (MWB) for the removal of anionic azo dyes from aqueous solution was investigated. A new insight was gained into the modification mechanism through synchrotron-assisted infrared analysis and molecular interaction simulation. The equilibrium and kinetic studies for the adsorption of Acid Red 18 (AR-18), Acid Orange 7 (AO-7) and Acid Black 1 (AB-1) on MWB were conducted...
April 10, 2017: Science of the Total Environment
Haoxue Han, Samy Mérabia, Florian Müller-Plathe
The integration of three-dimensional microelectronics is hampered by overheating issues inherent to state-of-the-art integrated circuits. Fundamental understanding of heat transfer across soft-solid interfaces is important for developing efficient heat dissipation capabilities. At the microscopic scale, the formation of a dense liquid layer at the solid-liquid interface decreases the interfacial heat resistance. We show through molecular dynamics simulations of n-perfluorohexane on a generic wettable surface that enhancement of the liquid structure beyond a single adsorbed layer drastically enhances interfacial heat conductance...
April 17, 2017: Journal of Physical Chemistry Letters
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"