Salt effects on the diffusion of caffeine in aqueous solutions

Ribeiro, Ana C.F.; Santos, Cecília I.A.V.; Barros, Marisa C.F.; Gomes, Joselaine C.S.; Veríssimo, Luís M.P.; Miguel, Maria G.; Esteso, Miguel A.; Nostro, Pierandrea Lo; Lobo, Victor M.M.; Leaist, Derek G.

doi:10.1016/j.fluid.2012.11.017

Cited by 4 publications

(4 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hofmeister or specific ion effectso ccur everywhere.T hey emerge in bulk solutions and at interfaces, from the inorganic to the living realms, andr efer to the different and specific effect that ap articular ion exerts on the properties of ag iven system. [1][2][3][4][5] Usually,b ut not always, they appear in moderately concentrated electrolyte solutions, for example, above 10 mm, but sometimesa tm uch lower ionic strengths. [6] Hofmeister was the first to recognize the occurrenceo fs pecific ion effects in the precipitation of egg albumin at room temperature upon the addition of salt solutions.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Specific Anion Effects on the Kinetics of Iodination of Acetone

et al. 2016

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Specific Anion Effects on the Kinetics of Iodination of Acetone

et al. 2016

View full text Add to dashboard Cite

show abstract

“…The parameter "B" (Eq. 14b) is the diffusion parameter, which represents the diffusion of caffeine in this system, and it seems to be larger than the corresponding value for passive diffusion in water by an order of magnitude [48]. This can be considered as a velocity (v x (HETP(min)) = 0.19 m/s) multiplied by a distance (L S = v x (HETP(min))⋅C = 0.2 µm), which also indicates that it should not be equal to the diffusion coefficient for passive diffusion that may be applied at slow LFRs.…”

Section: Van Deemter Equationmentioning

confidence: 67%

Evaluation of the van Deemter equation in terms of open‐ended flow to chromatography

Andersen

Mukami

Maina

2020

J of Separation Science

View full text Add to dashboard Cite

Plate theory and adsorption theory are the main tools available for understanding chromatographic experiments. Both theories predict a Gaussian distribution of solute molecules within the tubular system. However, Gaussian concentration distributions are observed predominantly at slow linear flow rates, while asymmetric concentration distributions are observed at the linear flow rates most used in chromatography. Allegedly, this asymmetry originates from an inhomogeneous distribution of grain sizes in the column and column overload. However, it is an experimental fact that the distribution of chemicals within an injected volume of solute changes as a function of time, while the response is measured simultaneously. Accordingly, the obtained signal cannot be compared to the theory before some type of time‐based deconvolution of the data has been performed. Adjustments to high‐performance liquid chromatography data were thus proposed through empirical equations that describe the relevant time values, peak height, peak area, and parameters of the van Deemter equation. It was proposed that the transfer of solute from the front to the rear part of the pulse during laminar open‐ended flow occurs at rate that depends on the linear flow rate, and to a lesser extent, on properties of the response function.

show abstract

“…Hofmeister or specific ion effects describe the specific influence of different ions on some physicochemical properties of a system or on a reactive process. Ranging from the biological to the inorganic world, the presence of specific ion effects has been extensively shown to affect aqueous and nonaqueous , systems, emerging both in the solution bulk or at interfaces. − Typically, they influence moderately concentrated electrolyte solutions (above 10 mM), but sometimes, they can occur at a much lower ionic strength. , Biological systems offer the richest variety of examples where the presence of specific ions can critically affect living functionalities, and this is why understanding ion specific phenomena is of transversal relevance to many fields, including Origin of Life and biomedicine …”

Section: Introductionmentioning

confidence: 99%

Hofmeister Effect in Self-Organized Chemical Systems

et al. 2020

View full text Add to dashboard Cite

We studied the effect of spectator ions in the prototype of far-from-equilibrium selforganized chemical systems, the Belousov−Zhabotinsky (BZ) reaction. In particular, we investigated the specific ion effect of alkali metal cations, connoted for their kosmotropic and chaotropic properties. By means of combined experimental and numerical approaches, we could show a neat and robust evidence for the Hofmeister effect in this system. Spectator cations induce a marked increment of the induction period that preludes regular oscillations and decrease the oscillation amplitude following the sequence Li + < Na + ≪ K + ∼ Cs + . These ions affect the system kinetics by interfering in the interaction between the oxidized form of the catalyst and the organic substrate, responsible for resetting the BZ system to preautocatalytic (reduced) conditions. The specific ion effect on these key reactive steps is systematically characterized and correlated with different parameters which describe the interaction of the cations with the solvent.

show abstract

Salt effects on the diffusion of caffeine in aqueous solutions

Cited by 4 publications

References 25 publications

Specific Anion Effects on the Kinetics of Iodination of Acetone

Specific Anion Effects on the Kinetics of Iodination of Acetone

Evaluation of the van Deemter equation in terms of open‐ended flow to chromatography

Hofmeister Effect in Self-Organized Chemical Systems

Contact Info

Product

Resources

About