Effect of Added Counterions on the Micellization of Cetylpyridinium Chloride in the Presence of Acetonitrile–Water Mixture

Abstract

Solvent allows the assessment of surfactant aggregates at different compositions, which can provide useful information on surfactant molecules for their fundamental and practical significance. The critical micelle concentration (cmc) is one of the basic parameters that assists in understanding the aggregation behavior of amphiphiles. In our present studies, the cmc values of CPC are determined using the surface tension method (STM). The adsorption isotherm of CPC in the presence of acetonitrile−water mixture measured by STM is found to be quite unusual compared to that of CPC in an aqueous medium as a result of the change in solvophobicity of the medium. It can be quantified in terms of the Gordon parameter (GP), and the calculated GP value of acetonitrile lies ∼2.74 J m–3 ≥ GP > 1.68 ± 0.01. The present studies envisage that the CPC monomer has two different premicellar and micellar regions of aggregates, which is further confirmed by the addition of different sets of electrolytes. The role of selective counterion pairs (Cl counterion from CPC and X counterions from added electrolyte) in the micellization parameter of CPC has also been studied in detail using Corrin–Harkins and the modified Corrin–Harkins equation. The present studies of the micellization and adsorption behavior of CPC can assist in inducing their different modes of application in the practical world.

Counterion Association of Ionic Drugs with Sodium Tetradecyl Sulfate in the Aqueous Medium

“…Numerous drug–surfactant assemblies have been researched recently because of the vital significance of the pharmacological and therapeutic interactions between the drugs and the surfactant. − Combining a drug and a surfactant shows interaction and provides greater features than the drug or surfactant functioning independently. − Ionic medications have grown in importance recently as organic counterions or additions to enhance the interfacial and micellization properties of a charged surfactant and also to boost the concentration of pharmaceuticals that are only partially dissolved in the aqueous medium. , Whenever there are extra ingredients such as electrolytes, the critical micelle concentration (CMC) of the surfactants decreases. , Since they decrease their efficacy surface area per headgroup by limiting undesirable contact between each headgroup, additives, remarkably, make it simpler to induce an appearance change in surfactant micelles. The total amount of counterions that are physically associated with a micelle is compared to the amount of surfactant molecules (aggregate number) that reside in an ionic micelle to determine the counterion binding constant. − The most often used acceptable methods for estimating the counterion binding constant are the Corrin–Harkins (CH), modified CH approach, and the slope–ratio of conductance method …”

Micellar Solution Behavior of Cetylpyridinium Surfactants in 2-Propanol–Water Mixed Media at Different Temperatures

“…Several research groups have investigated the effect of various organic solvent–water mixed media ,− including alcohol–water mixed media − on the aggregation behavior of different surfactants and have shown the ability to tune the physicochemical properties of surfactant solutions. Cosolvents such as ethanol, propanol, butanediol, 1-propanol, ethylene glycol, glycerol, and so forth have shown dual features (owing to the presence of different numbers of carbon atoms, positions and/or the number of hydroxyl groups, etc.)…”

Micellization Behavior of Antidepressant Imipramine Hydrochloride Drug and Hydrotrope (Sodium Tosylate) Mixtures at Different Compositions and Temperatures in Different Media

“…The characteristics of solutions of amphiphiles possibly will be conveniently altered via additives, for instance, inorganic compounds, polar and nonpolar solvents, organic compounds, and so on, under akin circumstances to outfit the desired purposes. 11,12 Akin to other amphiphiles such as surfactants, bile salts, some hydrotropes, etc., a variety of amphiphilic drugs such as antidepressants, phenothiazines, etc., also form micelles but at a higher concentration, and these drugs have a diverse medical use. 2,13−15 These drugs are categorized based on diverse functional groups present on their head.…”

“…The interior or core of micelles which is hydrophobic in nature can be used as a tool for the inclusion of hydrophobic drugs, water unsolvable compounds, along with a variety of other materials, whereas the exterior corona acts like a stabilizing boundary amid the hydrophobic interior and the peripheral solvent. The characteristics of solutions of amphiphiles possibly will be conveniently altered via additives, for instance, inorganic compounds, polar and nonpolar solvents, organic compounds, and so on, under akin circumstances to outfit the desired purposes. , …”