Protein Adsorption on Topographically Structured Surfaces: A Mesoscopic Computer Simulation for the Prediction of Prefered Adsorption Sites

2010 ◽  
Vol 638-642 ◽  
pp. 542-547 ◽  
Author(s):  
Patrick Elter ◽  
Regina Lange ◽  
R. Thull ◽  
Ulrich Beck
Keyword(s):  
Computer Simulation ◽  
Brownian Dynamics ◽  
Field Calculation ◽  
Dispersion Interactions ◽  
Structured Surfaces ◽  
Adsorption Sites ◽  
Egg White Lysozyme ◽  
Initial Adsorption ◽  
Solid Liquid Interface ◽  
Solid Liquid

In this study the influence of edges and spikes of a topographical nanostructure on the adsorption behavior of proteins at a solid-liquid interface is examined by a computer simulation. An algorithm has been developed, which combines a Finite Differences field calculation with Brownian Dynamics. A (16 nm)3 nano-cube with sharp edges as well as flat faces was chosen as model system and the adsorption of Hen Egg White Lysozyme was investigated. An increased adsorption rate along the edges of a the model cube is reached in the initial adsorption phase under consideration of electrostatic and dispersion interactions. At later times also the surfaces of the cube are covered, if the salt concentration is sufficient to screen the repelling protein-protein electrostatic interaction.

Direct Observation of the Atomic Structure in a Solid–Liquid Interface

2000 ◽  
Vol 6 (4) ◽  
pp. 358-361 ◽  
Author(s):  
Shigeo Arai ◽  
Susumu Tsukimoto ◽  
Shunsuke Muto ◽  
Hiroyasu Saka
Keyword(s):  
Computer Simulation ◽  
High Resolution ◽  
Direct Observation ◽  
Atomic Structure ◽  
Transition Layer ◽  
Liquid Interface ◽  
Resolution Image ◽  
High Resolution Image ◽  
Solid Liquid Interface ◽  
Solid Liquid

AbstractAn experimental high-resolution image of a solid–liquid interface of solid Si and liquid Al–Si alloy has been compared with theoretical images obtained by computer simulation. It has been concluded that the solid–liquid interface has a transition layer, the structure of which is compatible with the 1 × 1 Si-{111} surface.

scholarly journals Novel lignocellulosic wastes for comparative adsorption of Cr(VI): equilibrium kinetics and thermodynamic studies

2017 ◽  
Vol 19 (2) ◽  
pp. 6-15 ◽  
Author(s):  
Hajira Haroon ◽  
Syed Mubashar Hussain Gardazi ◽  
Tayyab Ashfaq Butt ◽  
Arshid Pervez ◽  
Qaisar Mahmood ◽  
...  
Keyword(s):  
Active Sites ◽  
Low Cost ◽  
Liquid Interface ◽  
Order Kinetic ◽  
Batch Mode ◽  
Adsorption Sites ◽  
Equilibrium Data ◽  
Controlled Adsorption ◽  
Solid Liquid Interface ◽  
Solid Liquid

Abstract Cr(VI) adsorption was studied for abundantly available low-cost lignocellulosic adsorbents in Pakistan namely, tobacco stalks (TS), white cedar stem (WCS) and eucalyptus bark (EB). Several process variables like contact time, adsorbent dose, pH, metal concentration, particle size and temperature were optimized in batch mode. EB showed high Cr(VI) adsorption of 63.66% followed by WCS 62% and TS 57% at pH 2, which is higher than most of the reported literature. Langmuir isotherm (R2 = 0.999) was well fitted into the equilibrium Cr(VI) data of EB, suggesting homogeneous active sites and monolayer coverage of Cr(VI) onto the EB surface. Freundlich (R2 = 0.9982) isotherm was better fitted to the equilibrium data of TS and WCS, revealing the adsorption sites with heterogeneous energy distribution and multilayer Cr(VI) adsorption. Moreover, the Cr(VI) adsorption of studied adsorbents followed the pseudo-second order kinetic model. Thermodynamic properties were investigated in two temperature ranges, i.e., T1 (303–313 K) and T2 (313–323 K). TS and EB showed the exothermic at T1 and endothermic reactions at T2 with entropy controlled adsorption at the solid-liquid interface, and WCS exhibited an opposite thermal trend with decreasing disorderness at solid-liquid interface as temperature rises. Gibbs free energy (ΔG>0) confirmed the non-spontaneous adsorption process for all studied adsorbents.

Competitive transport of cadmium and lead through a natural porous medium: influence of the solid/liquid interface processes

2003 ◽  
Vol 48 (3) ◽  
pp. 9-16 ◽  
Author(s):  
A. Bianchi ◽  
M. Petrangeli Papini ◽  
A. Corsi ◽  
P. Behra ◽  
M. Beccari
Keyword(s):  
Liquid Interface ◽  
Equilibrium Adsorption ◽  
Adsorption Model ◽  
Adsorption Sites ◽  
Advection Dispersion ◽  
Transport Behaviour ◽  
Cadmium And Lead ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Medium Influence

Contaminated groundwater typically contains different metal contaminants which may compete with each other for the same adsorption sites. Understanding the fate of these micro-pollutants is of primary importance for the assessment of the risk associated with their dispersion in the environment and for the evaluation of the most appropriate remediation technology. In this regard, column techniques can be considered as useful tools both to perform transport experiments and to obtain equilibrium adsorption data without any perturbation of the actual solid/liquid interface. Cd and Pb monocomponent step column experiments were used to obtain adsorption isotherms on a natural aquifer material. A General Composite approach was used to define the equilibrium adsorption model characterized by two types of sites (ion-exchange and surface complexation sites). Coupling the adsorption model with the Advection-Dispersion equation (by IMPACT code) allowed us to well represent the monocomponent step experiments. The model was successfully used to predict the competitive Cd and Pb transport behaviour. Cd peaks of concentration due to Pb competition were experimentally observed and simulated by the model. This behaviour can be described only by an accurate modelling of the interaction and cannot be predicted by simple isotherms (such as Langmuir or Freundlich type).

Direct Observation of the Atomic Structure in a Solid–Liquid Interface

2000 ◽  
Vol 6 (4) ◽  
pp. 358-361 ◽  
Author(s):  
Shigeo Arai ◽  
Susumu Tsukimoto ◽  
Shunsuke Muto ◽  
Hiroyasu Saka
Keyword(s):  
Computer Simulation ◽  
High Resolution ◽  
Direct Observation ◽  
Atomic Structure ◽  
Transition Layer ◽  
Liquid Interface ◽  
Resolution Image ◽  
High Resolution Image ◽  
Solid Liquid Interface ◽  
Solid Liquid

Abstract An experimental high-resolution image of a solid–liquid interface of solid Si and liquid Al–Si alloy has been compared with theoretical images obtained by computer simulation. It has been concluded that the solid–liquid interface has a transition layer, the structure of which is compatible with the 1 × 1 Si-{111} surface.

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.

The role of (bio)surfactant sorption in promoting the bioavailability of nutrients localized at the solid-water interface

1999 ◽  
Vol 39 (7) ◽  
pp. 91-98 ◽  
Author(s):  
Ryan N. Jordan ◽  
Eric P. Nichols ◽  
Alfred B. Cunningham
Keyword(s):  
Mass Transfer ◽  
Cell Membrane ◽  
Substrate Concentration ◽  
Water Interface ◽  
Industrial Systems ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Surfactant Sorption

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.

Observation of Femtosecond Acoustic Anomaly in a Solid Liquid Interface

2020 ◽  
Vol 124 (5) ◽  
pp. 2987-2993
Author(s):  
Chi-Kuang Sun ◽  
Yi-Ting Yao ◽  
Chih-Chiang Shen ◽  
Mu-Han Ho ◽  
Tien-Chang Lu ◽  
...  
Keyword(s):  
Liquid Interface ◽  
Acoustic Anomaly ◽  
Solid Liquid Interface ◽  
Solid Liquid
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