Surface activity of cationic surfactants, influence of molecular structure

Para, G.; Hamerska-Dudra, Agnieszka; Wilk, Kazimiera A.; Warszyński, Piotr

doi:10.1016/j.colsurfa.2010.02.004

Cited by 44 publications

(27 citation statements)

References 24 publications

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“…In Figure 2(b), the scattering intensity distribution helps to reveal that large aggregates are still present in concentration of 10 −2 mol dm −3 , but in much lower volume fraction since they do not appear in the volume distribution. after that an exponential-like decay happens, a typical behavior of a surfactant above its critical micelle concentration (CMC) [16]. At 5 × 10 −2 mol dm −3 , the decay trend has already changed; so, the CMC lies somewhere between 2 to 5 × 10 −2 mol dm −3 .…”

Section: Polymer Structuration In Aqueous Solutionsmentioning

confidence: 99%

Physical and Chemical Characterization of Poly(hexamethylene biguanide) Hydrochloride

2011

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Abstract:We present the characterization of commercially available Poly(hexamethylene biguanide) hydrochloride (PHMB), a polymer with biocidal activity and several interesting properties that make this material suitable as a building block for supramolecular chemistry and -smart‖ materials. We studied polymer structure in water solution by dynamic light scattering, surface tension and capacitance spectroscopy. It shows typical surfactant behavior due to amphiphilic structure and low molecular weight. Spectroscopic (UV/Vis, FT-NIR) and thermal characterization (differential scanning calorimetry, DSC, and thermogravimetric analysis, TGA) were performed to give additional insight into the material structure in solution and solid state. These results can be the foundation for more detailed investigations on usefulness of PHMB in new complex materials and devices.

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Section: Polymer Structuration In Aqueous Solutionsmentioning

confidence: 99%

Physical and Chemical Characterization of Poly(hexamethylene biguanide) Hydrochloride

2011

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“…The appropriate surfactant activity is determined from the value of the ¡ S parameter. The lower the value of ¡ S , the higher the surface activity of the compound, which means that the investigated gemini ester quats are slightly more surface active than the previously studied classical gemini bromide d(DDA)EBr, 14 also containing an ethylene spacer. Such differences in the surface activities of the studied compounds are also seen with respect to the cmc values.…”

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confidence: 87%

“…14 The best theoretical description of the experimental isotherms of TMEAL-nBr was obtained for K = 0.04 m 3 mol ¹1 . Adsorption of the studied geminis strongly depends on their structure, making them more surface active in comparison to single-head/single-tail structures.…”

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confidence: 99%

Cleavable Gemini Cationic Surfactants: Experimental and Theoretical Description of Adsorption

et al. 2012

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The aim of the present study was to examine, both experimentally and theoretically, the interfacial behavior of cleavable gemini ester quat-type cationic surfactants in comparison to a standard gemini representative. For the theoretical description of the air/water surface tension isotherms of the corresponding geminis, a modified model of multiply charged ionic surfactant adsorption (surface quasi-two-dimensional electrolyte, STDE), taking into account counter ion specificity and formation of surfactant ioncounter-ion associates, was used. As a result, good agreement between theory and experiment was obtained.Following the example of Nature, the researchers have designed a variety of novel ecologically safe amphiphiles, which are functionalized with structural motifs, borrowed from biological systems, and thus often possess new interesting physicochemical and biological functionalities. 13 The search for environmentally friendly surfactants and a basic understanding of their self-assembling phenomena are of immense current interest because of the emerging necessity for specific applications in several areas, such as new cosmetic formulations and drug delivery systems, and in nanotechnology. Furthermore, the grafting of a labile moiety onto the hydrophobic backbone of the surfactant structure makes it possible to obtain high-quality environmentally friendly products with multifunctional capabilities, improved performances, and lower toxicities. The introduction of weak (so-called "labile") bonds into the hydrophobic backbone of the surfactant structure makes it possible to improve the rate of biodegradation and to obtain the most suitable environmentally friendly products. Labile groups such as ester, amide, and acetal groups deliberately inserted into surfactant structure are commonly called cleavable. In the literature, the terms chemodegradable, destructible, triggerable, temporary, hydrolyzable, and acid-(alkali-)sensitive surfactants can also be found. 47 The most well-known, and probably the most commercially viable, example of cleavable surfactants comprises the family of ester quats, i.e., cationic surfactants with an ester bond inserted between the hydrocarbon tail(s) and the quaternary ammonium head group(s).In the present work, we attempted to describe quantitatively and qualitatively the nonequivalent adsorption (considered both experimentally and theoretically) of cleavable newly synthesized cationic gemini ethylenebis[N,N-dimethyl-N-(n-alkyl)oxycarbonyl(methyl)methylammonium] dibromides (TMEAL-nBr; n = 10, 12) in relation to standard N,N,N¤,N¤-tetramethyl-N,N¤-di(dodecyl)ethylenediammonium bromide [d(DDA)EBr] in terms of the surface quasi-two-dimensional-electrolyte (STDE) model modified for multicharged structures. 810The studied ester quat-type gemini compounds were synthesized according to the method shown in Scheme 1. The obtained surfactants were purified by repeated crystallization until no impurities could be detected by 1 H NMR spectroscopy.The chemical structures of the compounds were det...

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“…Sulakhe and coworkers [38] have reported the value of Γ max value as 3.20 mol nm −2 for CTAB by using the Wilhelmy plate method on tensiometer. The equilibrium surface tension measurements were performed using the pendant drop shape analysis method by Para and coworkers [39], and Γ max value for CTAB was found as similar. Changes in the surrounding medium due to increased hydrophobicity with the presence of a conventional surfactant and the interaction between surfactants molecules-water can be responsible for these variations.…”

Section: Adsorption Parameters Of Pure and Binary Surfactants Solutionsmentioning

confidence: 99%

A novel cationic Gemini surfactant with amide group: synthesis and micellization behavior in aqueous solutions

et al. 2016

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Novel cationic Gemini surfactant with amide group, N 1 ,N 10 -bis(3-dodecanamidopropyl)-N 1 ,N 1 ,N 10 ,N 10 -tetramethyldecan-1,10-diammonium bromide (abbreviated as 2C 12 enAm) has been synthesized by two-step reactions, purified and characterized in our laboratory. The critical micelle concentration (CMC) values of this Gemini surfactant were determined using electrical conductivity and surface tension measurements in the range of temperatures from 298.15 to 328.15 K. It was observed that the CMC value of Gemini surfactant has a much lower value compared with monomeric ones and shows a slight increase with an increase in the temperature. The interactions between Gemini and conventional monomeric surfactant hexadecyltrimethylammonium bromide (CTAB) have been studied using the conductivity at a certain micellar concentration and temperature range. Rubingh's theory is used to evaluate the micellar interaction parameters (β) for the mixed systems. It has been observed that mixed micelle formation in all the binary mixtures exhibited negative synergism (antagonism) or ideal behavior due to positive β values. Thermodynamics parameters were also obtained from the temperature dependence of the CMC values.From the surface tension measurements, CMC, maximum surface excess concentration at the solution/air interface (Γ max ), minimum area per surfactant molecule (A min ), the surface pressure at CMC (Π CMC ), the surfactant concentration required to reduce the surface tension of solvent by 20 mN m −1 (pC 20 ), and thermodynamic parameters have been evaluated at same temperatures.

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Surface activity of cationic surfactants, influence of molecular structure

Cited by 44 publications

References 24 publications

Physical and Chemical Characterization of Poly(hexamethylene biguanide) Hydrochloride

Physical and Chemical Characterization of Poly(hexamethylene biguanide) Hydrochloride

Cleavable Gemini Cationic Surfactants: Experimental and Theoretical Description of Adsorption

A novel cationic Gemini surfactant with amide group: synthesis and micellization behavior in aqueous solutions

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