A5056127853- Chemical Synthesis and Characterization
- Electrochemical Analysis and Applications
- Membrane-based Ion Separation Techniques
- Adsorption and biosorption for pollutant removal
- Enhanced Oil Recovery Techniques
- Analytical chemistry methods development
- Analytical Chemistry and Chromatography
- Chemical and Physical Properties in Aqueous Solutions
- Crystallization and Solubility Studies
- Analytical Chemistry and Sensors
- Radioactive element chemistry and processing
- Various Chemistry Research Topics
- Electrochemical sensors and biosensors
- Petroleum Processing and Analysis
- History and advancements in chemistry
- Surfactants and Colloidal Systems
- Reservoir Engineering and Simulation Methods
- Electrostatics and Colloid Interactions
- Extraction and Separation Processes
- Hydraulic Fracturing and Reservoir Analysis
- Mass Spectrometry Techniques and Applications
- Surface Chemistry and Catalysis
- Microfluidic and Capillary Electrophoresis Applications
- Molecular Sensors and Ion Detection
- Spectroscopy and Quantum Chemical Studies
Delft University of Technology
2024
California Institute of Technology
1958-2006
Pennsylvania State University
1984-2001
The University of Texas at Austin
1982
Shell (Netherlands)
1961-1978
Shell (United States)
1962-1978
Emery Oleochemicals (Malaysia)
1962
Berkeley College
1962
Max Planck Institute for Biophysical Chemistry
1957
Massachusetts Institute of Technology
1955
Ideal limiting laws are calculated for the kinetics of particle diffusion controlled ion exchange processes involving ions different mobilities between spherical exchanger beads uniform size and a well-stirred solution. The calculations based on nonlinear Nernst-Planck equations ionic motion, which take into account effect electric forces (diffusion potential) within system. Numerical results counter equal valence six mobility ratios presented. They were obtained by use digital computer....
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIon-Exchange Kinetics. V. Ion Exchange Accompanied by ReactionsF. HelfferichCite this: J. Phys. Chem. 1965, 69, 4, 1178–1187Publication Date (Print):April 1, 1965Publication History Published online1 May 2002Published inissue 1 April 1965https://pubs.acs.org/doi/10.1021/j100888a015https://doi.org/10.1021/j100888a015research-articleACS PublicationsRequest reuse permissionsArticle Views1246Altmetric-Citations214LEARN ABOUT THESE METRICSArticle Views...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTION-EXCHANGE KINETICS.1 III. EXPERIMENTAL TEST OF THE THEORY PARTICLE-DIFFUSION CONTROLLED ION EXCHANGEF. HelfferichCite this: J. Phys. Chem. 1962, 66, 1, 39–44Publication Date (Print):January 1962Publication History Published online1 May 2002Published inissue 1 January 1962https://pubs.acs.org/doi/10.1021/j100807a008https://doi.org/10.1021/j100807a008research-articleACS PublicationsRequest reuse permissionsArticle...
The differential equation derived previously which describes the particle diffusion controlled ion exchange between spherical beads of uniform size and a well-stirred solution is solved numerically for monovalent ions bivalent ions, ions. approach based on Nernst-Planck equations ionic motion. Numerical results six different mobility ratios are presented discussed. They were obtained by use digital computer. An explicit approximating numerical data given.
Abstract The interfacial activity and mobility control of a chemical flooding process are affected by the concentrations cationic anionic species that travel with surfactant polymer. In this paper we use equations from literature to describe environmental composition changes resulting cation exchange occurs as flood traverses reservoir. This presents examples two or three exchanging cations (calcium, sodium, magnesium) without mobilized oil present up four fluids in typical sequence (connate...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLigand Exchange. I. EquilibriaF. HelfferichCite this: J. Am. Chem. Soc. 1962, 84, 17, 3237–3242Publication Date (Print):September 1, 1962Publication History Published online1 May 2002Published inissue 1 September 1962https://pubs.acs.org/doi/10.1021/ja00876a003https://doi.org/10.1021/ja00876a003research-articleACS PublicationsRequest reuse permissionsArticle Views469Altmetric-Citations66LEARN ABOUT THESE METRICSArticle Views are the...
Partition coefficients can be determined with accuracy by a "tracerpulse" method in which the retention volume of tracer respective species is measured. The applicable to multicomponent equilibria and used at elevated temperature pressure. A less accurate "differential" not requiring also described.
The effect of the electric potential produced by diffusion in ion exchange kinetics is examined for film-controlled monovalent ions. It shown that, rather than resulting a minor correction, field as rule makes an essential contribution to process.
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMulticomponent Ion Exchange in Fixed Beds. Generalized Equilibrium Theory for Systems with Constant Separation FactorsF. G. HelfferichCite this: Ind. Eng. Chem. Fundamen. 1967, 6, 3, 362–364Publication Date (Print):August 1, 1967Publication History Published online1 May 2002Published inissue 1 August 1967https://pubs.acs.org/doi/10.1021/i160023a006https://doi.org/10.1021/i160023a006research-articleACS PublicationsRequest reuse permissionsArticle...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTToward a Generalized Theory of Gas Chromatography at High Solute ConcentrationsD. L. Peterson and F. HelfferichCite this: J. Phys. Chem. 1965, 69, 4, 1283–1293Publication Date (Print):April 1, 1965Publication History Published online1 May 2002Published inissue 1 April 1965https://pubs.acs.org/doi/10.1021/j100888a032https://doi.org/10.1021/j100888a032research-articleACS PublicationsRequest reuse permissionsArticle Views86Altmetric-Citations52LEARN...
Abstract In this paper, we extend some of the results Part 1 by discussing aspects effects dispersion, two-cation exchange, and adsorption on a chemical flood:we show that when slug sizes are small dispersion is moderate, inclusion in calculation can modify calculated methods which assume no dispersion;we describe new phenomenon itself initiate cation exchange; andfinally, an asymptotic concentration profile toward dispersive, self-sharpening fronts tend. Introduction One most important...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLigand Exchange. II.1Separation of Ligands Having Different Coördinative ValencesF. HelfferichCite this: J. Am. Chem. Soc. 1962, 84, 17, 3242–3245Publication Date (Print):September 1, 1962Publication History Published online1 May 2002Published inissue 1 September 1962https://doi.org/10.1021/ja00876a004RIGHTS & PERMISSIONSArticle Views107Altmetric-Citations30LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum full text article...
G. Scatchard and F. Helfferich, Discuss. Faraday Soc., 1956, 21, 70 DOI: 10.1039/DF9562100070
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTION-EXCHANGE KINETICS. IV. DEMONSTRATION OF THE DEPENDENCE INTERDIFFUSION COEFFICIENT ON IONIC COMPOSITIONF. HelfferichCite this: J. Phys. Chem. 1963, 67, 5, 1157–1159Publication Date (Print):May 1, 1963Publication History Published online1 May 2002Published inissue 1 1963https://pubs.acs.org/doi/10.1021/j100799a506https://doi.org/10.1021/j100799a506research-articleACS PublicationsRequest reuse permissionsArticle Views132Altmetric-Citations18LEARN...
Abstract Many theories of ion‐exchange column performance, differing widely in their simplifying assumptions and results, have been advanced. For successful application it is vital to choose, each particular case, the most appropriate theory. this requires a thorough general understanding phenomena precise knowledge consequences assumptions. The important qualitative characteristics columns are outlined, especially formtion self‐sharpening non‐sharpening boundaries constant proportionate...
Abstract Geschwindigkeitsbestimmender Schritt beim Ionenaustausch ist die Diffusion der lonen entweder im Inneren des Austauschers oder durch einen anhaftenden Flüssigkeitsfilm. Die Anwendung ersten Fickschen Gesetzes führt zu einer geschlossenen Theorie Isotopenaustauschs, als experimentell bestätigt angesehen werden darf, während für den Austausch von verschiedener Beweglichkeit Wertigkeit Berücksichtigung entstehenden Diffusionspotentials noch mathematische Schwierigkeiten bereitet und...
Abstract Bifunctional cation exchangers with carboxylic and sulfonic acid groups can be oxidized aqueous hydrogen peroxide which converts the to percarboxylic groups. The resins used hydroxylate compounds olefinic double bonds form α‐glycols. thus transfer active oxygen from a an unsaturated substrate. Oxidation reduction of is reversible.
Abstract Solutions are presented for equations which describe the chromatographic transport of binary surfactant mixtures. The formation micelles in bulk fluid is taken into account. effects micellization on behavior pulses illustrated by solutions specific cases. Schemes offsetting tendency to undergo separation because preferential adsorption surfactants solid substrate. These schemes take advantage micelle formation. Generalizations n‐component systems outlined.
Revised numerical solutions of the differential equation for exchange ions equal valence and different mobilities are presented finite slabs spherical particles under simple initial boundary conditions. The also apply to sorption desorption with a particular concentration dependence diffusion coefficient. relations given by others semi-infinite media discussed.