Effect of intraparticle diffusion resistance on apparent stability of immobilized enzymes

1981 ◽  
Vol 23 (9) ◽  
pp. 1991-2000 ◽  
Author(s):  
Hiroshi Ooshima ◽  
Yoshio Harano
Keyword(s):  
Immobilized Enzymes ◽  
Intraparticle Diffusion ◽  
Diffusion Resistance ◽  
Apparent Stability

Modeling Trienzyme Biosensor at Internal Diffusion Limitation

2004 ◽  
Vol 9 (2) ◽  
pp. 139-144 ◽  
Author(s):  
J. Kulys
Keyword(s):  
Immobilized Enzymes ◽  
Internal Diffusion ◽  
Significant Response ◽  
Diffusion Limitation ◽  
Enzyme Reactions ◽  
Substrate Conversion ◽  
Apparent Stability ◽  
Biosensor Response

A model of biosensor containing three immobilized enzymes utilizing consecutive substrate conversion in the chain was developed. The modeling was performed at an internal diffusion limitation and a steadystate condition. The calculations showed that significant response of biosensors was produced if diffusion modules were larger than 1 for all enzyme reactions. Due to diffusion limitation the apparent stability of biosensor response increased many times in comparison to stability of the most labile enzyme of the chain.

Effects of intraparticle diffusion resistance on catalytic reactions over decaying catalysts

1988 ◽  
Vol 43 (5) ◽  
pp. 1195-1198 ◽  
Author(s):  
K. Kumbilieva ◽  
M.M. Kostjukovsky ◽  
L. Petrov ◽  
S.L. Kiperman
Keyword(s):  
Intraparticle Diffusion ◽  
Catalytic Reactions ◽  
Diffusion Resistance

Adsorption of Food Dye onto Gelatin Microspheres: pH Effect in Kinetics and Mechanism

2012 ◽  
Vol 476-478 ◽  
pp. 2296-2299
Author(s):  
Hai Yan Xue ◽  
Fang Han ◽  
Bao Yuan He
Keyword(s):  
Ph Effect ◽  
Intraparticle Diffusion ◽  
Kinetics And Mechanism ◽  
Diffusion Resistance ◽  
Gelatin Microspheres ◽  
Food Dye ◽  
Pseudo Second Order ◽  
Ph Increase ◽  
Dyes Adsorption ◽  
Influence Of Ph

Gelatin microspheres (GMSs) prepared by the inverse suspension cross-linking reaction, was characterised by scanning electron microscopy. The influence of pH on kinetics and mechanism was verified. The kinetic models such as pseudo-first-order, pseudo-second-order and intraparticle diffusion models were selected to understand the reaction pathways and mechanism of adsorption process. Adsorption of food red 7 (FR7) and food yellow 2 (FY2) onto GMSs occurred by chemisorption. For both dyes, adsorption occurred by film and intraparticle diffusion, and the pH increase caused an increase in film diffusion resistance. The biomass GMSs had a substantial potential for removing food dye from wastewater owing to great adsorption capacity and adsorption rate to dye.

EIS study of the corrosion behavior of an organic coating applied on Algerian oil tanker

2020 ◽  
Vol 117 (6) ◽  
pp. 610
Author(s):  
Nadia Hammouda ◽  
Kamel Belmokre
Keyword(s):  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Paint Film ◽  
Organic Coating ◽  
Diffusion Resistance ◽  
Double Layer Capacitance ◽  
Carbon Steel Surface ◽  
Chloride Environment ◽  
Oil Tanker ◽  
Epoxy Paint

Organic coatings are widely employed in the corrosion protection of most metal surfaces, particularly steel. They provide a barrier against corrosive species present in the environment, due to their high resistance to oxygen, water and ions transport. This study focuses on the evaluation of corrosion protection performance of epoxy paint on the carbon steel surface in chloride environment (3% NaCl) by Electrochemical Impedance Spectroscopy (EIS). The electrochemical behavior of painted surface was estimated by EIS parameters that contained paint film resistance, paint film capacitance and double layer capacitance. On the basis of calculation using EIS spectrums it was observed that pore resistance (Rpore) decreased with the appearance of doubled layer capacitance (Cdl) due to the electrolyte penetration through the film. This was further confirmed by the decrease of diffusion resistance (Rd) which was also the indicator of the deterioration of paint film protectiveness. Microscopic analyses have shown that oxidation dominates the corroded surfaces.

Untersuchungen zum Diffusionswiderstand von Holzwerkstoffen | Diffusion resistance of timber materials

2005 ◽  
Vol 156 (3-4) ◽  
pp. 100-103
Author(s):  
Rudolf Popper ◽  
Peter Niemz ◽  
Gerhild Eberle
Keyword(s):  
Relative Humidity ◽  
Water Vapour ◽  
Middle Lamella ◽  
Solid Wood ◽  
Diffusion Resistance ◽  
Water Vapour Diffusion ◽  
Wood Panels ◽  
Vapour Diffusion ◽  
Wet Climate ◽  
Panel Thickness

The water vapour diffusion resistance of timber materials were tested in a wet climate (relative humidity ranging from 100%to 65% at 20 °C) and in a dry climate (relative humidity ranging from 0% to 65% and from 0% to 35% at 20 °c) with variation by relative humidity and vapour pressure gradient. The diffusion resistance of multilayer solid wood panels lies under or within the range of the solid wood (spruce), tending even to a lower range. This can be attributed to the loosely inserted middle lamella of the used solid wood panels, which were not correctly glued by the manufacturer. The diffusion resistance of the solid wood panels increases with decreasing moisture content and decreasing panel thickness, as well as with increasing water vapour gradient from 818 to 1520 Pa. There were clear differences between the tested timber materials. The diffusion resistance of particle composites is strongly dependent on the specific gravity. Due to laminar particles OSBs(Oriented Strand Boards) have a larger diffusion resistance than chipboards. The water vapour diffusion resistance of OSBs lies within the range of plywood.

Enzyme Immobilization on Nanomaterials for Biosensor and Biocatalyst in Food and Biomedical Industry

2019 ◽  
Vol 25 (24) ◽  
pp. 2661-2676 ◽  
Author(s):  
Sundaresan Bhavaniramya ◽  
Ramar Vanajothi ◽  
Selvaraju Vishnupriya ◽  
Kumpati Premkumar ◽  
Mohammad S. Al-Aboody ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Enzyme Immobilization ◽  
Food Industry ◽  
Environmental Changes ◽  
Immobilized Enzymes ◽  
Food Industries ◽  
Physiological Processes ◽  
Different Types ◽  
Simple Processing ◽  
Biomedical Industry

Enzymes exhibit a great catalytic activity for several physiological processes. Utilization of immobilized enzymes has a great potential in several food industries due to their excellent functional properties, simple processing and cost effectiveness during the past decades. Though they have several applications, they still exhibit some challenges. To overcome the challenges, nanoparticles with their unique physicochemical properties act as very attractive carriers for enzyme immobilization. The enzyme immobilization method is not only widely used in the food industry but is also a component methodology in the pharmaceutical industry. Compared to the free enzymes, immobilized forms are more robust and resistant to environmental changes. In this method, the mobility of enzymes is artificially restricted to changing their structure and properties. Due to their sensitive nature, the classical immobilization methods are still limited as a result of the reduction of enzyme activity. In order to improve the enzyme activity and their properties, nanomaterials are used as a carrier for enzyme immobilization. Recently, much attention has been directed towards the research on the potentiality of the immobilized enzymes in the food industry. Hence, the present review emphasizes the different types of immobilization methods that is presently used in the food industry and other applications. Various types of nanomaterials such as nanofibers, nanoflowers and magnetic nanoparticles are significantly used as a support material in the immobilization methods. However, several numbers of immobilized enzymes are used in the food industries to improve the processing methods which not only reduce the production cost but also the effluents from the industry.

scholarly journals Functionalized Materials as a Versatile Platform for Enzyme Immobilization in Wastewater Treatment

2021 ◽  
Author(s):  
Agnieszka Kołodziejczak-Radzimska ◽  
Long D. Nghiem ◽  
Teofil Jesionowski
Keyword(s):  
Wastewater Treatment ◽  
Enzyme Immobilization ◽  
Organic Dyes ◽  
Scientific Progress ◽  
Immobilized Enzymes ◽  
Chemical Oxidation ◽  
Biologically Active ◽  
Water Pollutants ◽  
Untreated Wastewater ◽  
Functionalized Materials

Abstract Purpose of Review Untreated wastewater discharge can significantly and negatively impact the state of the environment. Rapid industrialization and economic development have directly contributed to land and water pollution resulting from the application of many chemicals such as organic dyes, pharmaceuticals, and industrial reagents. The removal of these chemicals before effluent discharge is crucial for environmental protection. This review aims to explore the importance of functionalized materials in the preparation of biocatalytic systems and consider their application in eliminating water pollutants. Recent Findings Wastewater treatment methods can be classified into three groups: (i) chemical (e.g., chemical oxidation and ozonation), (ii) physical (e.g., membrane separation and ion exchange), and (iii) biological processes. Biological treatment is the most widely used method due to its cost-effectiveness and eco-friendliness. In particular, the use of immobilized enzymes has recently become more attractive as a result of scientific progress in advanced material synthesis. The selection of an appropriate support plays an important role in the preparation of such biologically active systems. Recent studies have demonstrated the use of various materials for enzyme immobilization in the purification of water. Summary This review identifies and discusses different biocatalytic systems used in the enzymatic degradation of various water pollutants. Materials functionalized by specific groups can serve as good support matrices for enzyme immobilization, providing chemical and thermal stability to support catalytic reactions. Enzymatic biocatalysis converts the pollutants into simpler products, which are usually less toxic than their parents. Due to immobilization, the enzyme can be used over multiple cycles to reduce the cost of wastewater treatment. Future studies in this field should focus on developing new platforms for enzyme immobilization in order to improve degradation efficiency.

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