The ion-exchange kinetics of a tracer ion (Cs and Ba) in presence of a bulk ion (Na/H) has been measured in Nafion-117 membrane for a range of concentrations of NaCl/HNO using the nonstationary radiotracer method. A systematic increase in the ion-exchange rate and decrease in the partition coefficients of the tracer ions between membrane and solution have been observed with the increase in bulk ion concentration. The sigmoidal nature of experimental profiles indicates film-diffusion-controlled kinetics even for well-stirred solutions. In the absence of an existing analytical or numerical solution, a simple empirical approach has been proposed to find the variable membrane surface concentration and has been used to solve the membrane diffusion equation by the finite difference method. The fitting of the experimental curves with a single diffusion coefficient for Cs/Ba has been achieved. The exchange rate has been found to be independent of the stirring speed beyond a limiting speed.
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http://dx.doi.org/10.1021/acs.jpcb.7b07615 | DOI Listing |
Biotechnol Prog
January 2025
Automation, Digital and Learning Solutions, Cytiva, Karlsruhe, Germany.
Mechanistic modeling of chromatographic steps is an effective tool in biopharma process development that enhances process understanding and accelerates optimization efforts and subsequent risk assessment. A relatively new model for ion exchange chromatography is the colloidal particle adsorption (CPA) formalism, which promises improved separation of material and molecule-specific parameters. This case study demonstrates a straightforward CPA modeling workflow to describe an ion exchange chromatography polishing step of a knobs-into-holes construct bispecific antibody molecule.
View Article and Find Full Text PDFAdv Mater
January 2025
Department of Materials Science and Engineering, Institute of Innovative Materials (I2, M), Shenzhen Key Laboratory of Full Spectral Solar Electricity Generation (FSSEG), Southern University of Science and Technology (SUSTech), No. 1088, Xueyuan Rd., Shenzhen, Guangdong, 518055, China.
Mutual acquisition of phase-stability and controllable phase-transition becomes a predominant criterion of phase-change materials for the practical long-term energy storage but seems contradictory always. Here a strategy combining coordination and hydrogen bonds hierarchically to create a supercooled liquid in a core-shell coordination structure is reported, addressing that demand successfully. This new material is composed of a Mn-methylurea complex (MM) core and the hierarchically bonded erythritols shell.
View Article and Find Full Text PDFFood Chem
January 2025
Laboratory for Functional Foods and Human Health, Center for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University, NC Research Campus, 500 Laureate Way, Kannapolis, North Carolina 28081, United States. Electronic address:
Barley (Hordeum vulgare L.; Poaceae), the second most important grain after wheat, contains phenolamides, specifically hordatines and their agmatinated precursors. Hordatines are the unique compounds found in barley, consumption of which is associated with beneficial effects for human health.
View Article and Find Full Text PDFBMC Microbiol
January 2025
Liver and Gastrointestinal Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
Background: Microbial cholesterol oxidase (ChoX) has wide clinical and industrial applications; therefore, many efforts are being made to identify promising sources. This study aimed to isolate a novel ChoX-producing bacterial strain from whey samples.
Results: The most efficient strain was selected based on extracellular ChoX-producing ability and characterized as Escherichia fergusonii (E.
RSC Adv
January 2025
Electronic Material Research Center, Northwest Institute for Nonferrous Metal Research Xi'an 710016 China.
Potassium is a harmful impurity in the rhenium sinter, which adversely affects its mechanical properties by significantly reducing the density of sintered rhenium. Cationic resin is a promising material for potassium removal. In this study, the strong acid cationic exchange resin C160H was pretreated with an HNO solution to enhance its performance in potassium removal.
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