scholarly journals A Surfactant Concentration Model for the Systematic Determination of the Critical Micellar Concentration and the Transition Width

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5339
Author(s):  
Wajih Al-Soufi ◽  
Mercedes Novo
Keyword(s):  
Surfactant Concentration ◽  
Fundamental Property ◽  
Critical Micellar Concentration ◽  
Transition Width ◽  
Amyloid Peptides ◽  
Self Diffusion ◽  
Modular Concept ◽  
Yield Values ◽  
Systematic Determination

The critical micellar concentration (cmc) is a fundamental property of surfactant solutions. Many proposed methods for the definition and determination of the cmc from property-concentration plots yield values, which depend on the studied property, on the specific technique used for its analysis and in many cases on the subjective choice of the chosen type of plot and concentration interval. In this focus review, we revise the application of a surfactant concentration model we proposed earlier that defines the cmc directly based on the surfactant concentration. Known equations for the concentration-dependence of different surfactant properties can then be combined with this concentration model and fitted to experimental data. This modular concept makes it possible to determine the cmc and the transition width in a systematic and unambiguous way. We revise its use in the literature in different contexts: the determination of the cmc of surfactants and their mixtures from different properties (electrical conductivity, NMR chemical shift, self-diffusion, surface tension, UV-Vis absorption, fluorescence intensity and fluorescence correlation). We also revise the dependence of the width of the transition region on composition, detailed studies of the properties of fluorescent probes and the aggregation of non-surfactant systems, namely amyloid peptides.

scholarly journals A Study of Local Anaesthetics. Part 202. Determination of the Critical Micellar Concentration of Carbisocainium Chloride in Water Using Spectral Methods and the Probe Pyrene

2013 ◽  
Vol 60 (1) ◽  
pp. 1-6 ◽  
Author(s):  
J. Gališinová ◽  
F. Andriamainty ◽  
I. Malík ◽  
J. Čižmárik ◽  
J. Karlovská ◽  
...  
Keyword(s):  
Spectral Methods ◽  
Emission Spectroscopy ◽  
Surfactant Concentration ◽  
Fluorescence Emission ◽  
Local Anaesthetics ◽  
Critical Micellar Concentration ◽  
Ratio Data ◽  
Micellization Process ◽  
Second Procedure

The micellization process of the local anaesthetic carbisocainium chloride in water was investigated by two spectral methods using the probe pyrene. First, the absorption spectroscopy in UV/VIS region was based on studying changes in characteristic absorption spectrum of pyrene in presence of surfactant. The resultant plot of the sum of absorbances for all the major pyrene peaks as a function of the total surfactant concentration shows, around the critical micellar concentration, a typical sigmoidal increase. The fluorescence emission spectroscopy in UV/VIS region of spectrum by the probe pyrene, second procedure, was applied for determination of the cmc from the measurements of the pyrene I1 /I3 ratio as a function of the surfactant concentration. The pyrene ratio data were fitted by the Boltzmann-type sigmoid of decreasing character.

Self-diffusion study of bile salt-monoolein micelles determination of the intermicellar bile salt concentration

1983 ◽  
Vol 80 ◽  
pp. 315-323 ◽  
Author(s):  
Marc Lindheimer ◽  
Jean-Claude Montet ◽  
Roselyne Bontemps ◽  
Jacques Rouviere ◽  
Bernard Brun
Keyword(s):  
Bile Salt ◽  
Salt Concentration ◽  
Diffusion Study ◽  
Bile Salt Concentration ◽  
Self Diffusion

Tire Treadwear — A Comprehensive Evaluation of the Factors: Generic Type, Aspect Ratio, Tread Pattern, and Tread Composition Part I: Introduction and Details on the Organization of the Program

1986 ◽  
Vol 14 (4) ◽  
pp. 201-218 ◽  
Author(s):  
A. G. Veith
Keyword(s):  
Aspect Ratio ◽  
Comprehensive Evaluation ◽  
Test Method ◽  
Interactive Effects ◽  
Data Analyses ◽  
Main Effect ◽  
Systematic Determination ◽  
Relationship Of ◽  
The Relationship

Abstract This four-part series of papers addresses the problem of systematic determination of the influence of several tire factors on tire treadwear. Both the main effect of each factor and some of their interactive effects are included. The program was also structured to evaluate the influence of some external-to-tire conditions on the relationship of tire factors to treadwear. Part I describes the experimental design used to evaluate the effects on treadwear of generic tire type, aspect ratio, tread pattern (groove or void level), type of pattern (straight rib or block), and tread compound. Construction procedures and precautions used to obtain a valid and functional test method are included. Two guiding principles to be used in the data analyses of Parts II and III are discussed. These are the fractional groove and void concept, to characterize tread pattern geometry, and a demonstration of the equivalence of wear rate for identical compounds on whole tread or multi-section tread tires.

Direct determination of the self-diffusion mechanism in bccβ-titanium

1989 ◽  
Vol 39 (8) ◽  
pp. 5025-5034 ◽  
Author(s):  
G. Vogl ◽  
W. Petry ◽  
Th. Flottmann ◽  
A. Heiming
Keyword(s):  
Diffusion Mechanism ◽  
Direct Determination ◽  
The Self ◽  
Self Diffusion

scholarly journals Systematic Determination of Pesticide Residues in Citrus Fruits

1996 ◽  
Vol 37 (4) ◽  
pp. 215-221_1 ◽  
Author(s):  
Yoshiyuki CHATANI ◽  
Takeji CHIKAMOTO ◽  
Misako MUNEHISA ◽  
Tohru ADACHI ◽  
Masamoto KOMATSU
Keyword(s):  
Pesticide Residues ◽  
Citrus Fruits ◽  
Systematic Determination

scholarly journals Interferometric studies of rapid rotators

2010 ◽  
Vol 6 (S272) ◽  
pp. 44-55 ◽  
Author(s):  
Ming Zhao ◽  
John D. Monnier ◽  
Xiao Che
Keyword(s):  
Fundamental Property ◽  
Optical Interferometry ◽  
Rotating Stars ◽  
Stellar Rotation ◽  
Rapid Rotation ◽  
Long Baseline ◽  
Imaging Results ◽  
Basic Physics ◽  
Stellar Photosphere

AbstractStellar rotation, like stellar mass and metallicity, is a fundamental property of stars. Rapid rotation distorts the stellar photosphere and affects a star's luminosity, abundances and evolution. It is also linked to stellar wind and mass loss. The distortion of the stellar photosphere due to rapid rotation causes the stellar surface brightness and effective temperature to vary with latitude, leading to a bright pole and a dark equator - a phenomenon known as ‘Gravity Darkening’. Thanks to the development of long baseline optical interferometry in recent years, optical interferometers have resolved the elongation of rapidly rotating stars, and have even imaged a few systems for the first time, directly confirming the gravity darkening effect. In this paper, we review the recent interferometric studies of rapid rotators, particularly the imaging results from CHARA-MIRC. These sub-milliarcsecond resolution observations permit the determination of the inclination, the polar and equatorial radius and temperature, as well as the fractional rotation speed of several rapid rotators with unprecedented precision. The modeling also allows the determination of the true effective temperatures and luminosities of these stars, permitting the investigation of their true locations on the HR diagram. Discrepancies from standard models were also found in some measurements, suggesting the requirement of more sophisticated mechanisms such as non-uniform rotation in the model. These observations have demonstrated that optical interferometry is now sufficiently mature to provide valuable constraints and even model-independent images to shed light on the basic physics of stars.

Systematic Determination of the Packaging Limit of Lentiviral Vectors

2001 ◽  
Vol 12 (15) ◽  
pp. 1893-1905 ◽  
Author(s):  
Mukesh Kumar ◽  
Brian Keller ◽  
Ndeye Makalou ◽  
Richard E. Sutton
Keyword(s):  
Lentiviral Vectors ◽  
Systematic Determination

scholarly journals Precise determination of water exchanges on a mineral surface

2016 ◽  
Vol 18 (41) ◽  
pp. 28819-28828 ◽  
Author(s):  
Andrew G. Stack ◽  
Jose M. Borreguero ◽  
Timothy R. Prisk ◽  
Eugene Mamontov ◽  
Hsiu-Wen Wang ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Fundamental Property ◽  
Precise Determination ◽  
Solid Surfaces ◽  
Mineral Surface ◽  
Dissolved Ions

Solvent exchanges on solid surfaces and dissolved ions are a fundamental property important for understanding chemical reactions, but the rates of fast exchanges are poorly constrained.

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