Micellization and mixed micellization of cationic gemini (dimeric) surfactants and cationic conventional (monomeric) surfactants: Conductometric, dye solubilization, and surface tension studies

2016 ◽  
Vol 38 (2) ◽  
pp. 280-287 ◽  
Author(s):  
Md. Sayem Alam ◽  
A. Mohammed Siddiq ◽  
R. Ragupathy ◽  
Asit Baran Mandal
Keyword(s):  
Surface Tension ◽  
Mixed Micellization ◽  
Monomeric Surfactants ◽  
Dye Solubilization ◽  
Dimeric Surfactants

Preparation of a Gemini Surfactant from Mixed Fatty Acid and its Use in Cosmetics

2021 ◽  
Vol 58 (1) ◽  
pp. 67-73
Author(s):  
Kirti Datir ◽  
Harshada Shinde ◽  
Amit P. Pratap
Keyword(s):  
Surface Tension ◽  
Gemini Surfactant ◽  
Uv Spectroscopy ◽  
Micelle Formation ◽  
Mixed Fatty Acid ◽  
Lower Surface ◽  
H Nmr ◽  
Emulsification Index ◽  
Monomeric Surfactants ◽  
Dimeric Surfactants

Abstract Among the surfactants, dimeric surfactants represent a niche group with multifunctional properties. In this work a modified gemini surfactant was synthesized using symmetrical fatty acids. Due to the spacers used to combine the two symmetrical monomers, the synthesized gemini surfactant is cationic. The structure of the compound was confirmed with 1H-NMR. The most advantageous property of the gemini surfactant is that it has a lower surface tension, i. e. less than 35 mNm–1 at 25°C, compared to monomeric surfactants. The surface tension was determined with a Kyowa tensiometer. The CMC (critical micelle formation concentration) was calculated according to the pyrene method and detected by UV spectroscopy at 25°C. The very low CMC is another market advantage of the gemini surfactant. Hydrophobicity and hydrophilicity of the synthesized compound were checked by the emulsification method. The ability of the synthesized gemini surfactant to wet and foam and the emulsification index at different pH values were tested. Based on the results, the gemini surfactant was used in formulations for hair and skin care. Conditioners and creams were prepared with the synthesized compound and the properties were analyzed at different concentrations of the gemini surfactant in the respective formulation.

Mixed micellization of dimeric surfactant–amphiphilic drug systems: effect of surfactant structure

RSC Advances ◽  
2016 ◽  
Vol 6 (24) ◽  
pp. 20324-20336 ◽  
Author(s):  
Andleeb Z. Naqvi ◽  
Sahar Noori ◽  
Kabir-ud-Din Kabir-ud-Din
Keyword(s):  
Drug Delivery ◽  
Aqueous Solutions ◽  
Mixed Micellization ◽  
Drug Delivery Vehicles ◽  
Amphiphilic Drug ◽  
Imipramine Hydrochloride ◽  
Delivery Vehicles ◽  
Dimeric Surfactant ◽  
Dimeric Surfactants

For their applications as drug delivery vehicles, the mixed interfacial/micellar behaviour of zwitterionic, cocogem and anionic dimeric surfactants with an amphiphilic drug imipramine hydrochloride in aqueous solutions has been investigated.

scholarly journals SYNTESIS of DIMERIC SURFACTANTS based on SYNTHANOL DS-10 AND ADIPINIC ACID

2018 ◽  
Vol 61 (2) ◽  
pp. 91
Author(s):  
Elena A. Lominoga ◽  
Konstantin S. Burmistrov ◽  
Victor S. Gevod
Keyword(s):  
Surface Tension ◽  
Sodium Hydroxide ◽  
Surface Activity ◽  
Alkaline Medium ◽  
Chemical Properties ◽  
Acylating Agent ◽  
Colloidal Properties ◽  
Cloud Points ◽  
Dimeric Surfactants ◽  
New Compounds

Mono- and di- esters of adipinic acid with long chain ethoxylated aliphatic alcohols (mixture of C10 – C12 and C16 – C18 alkohols) were obtained by the reaction of Synthanol DS-10 and adipinic acid and its dichloroanhydride. If adipinic acid with p-toluenesulfonic acid as catalyst were used as acylating agent and the mole ratio of Synthanol DS-10 to adipinic acid is 1:1 the yield of monoacylated product was 76 %. (temperature 120-125 °C, 3 h). If the mole ratio of Synthanol DS-10 to adipinic acid is 2:1 the yield of diacylated product was 80 % (temperature 120-125 °C, 6 h). Using dichloroanhydride of adipinic acid as acylating agent gives the 90 % (temperature 90-100 °C, 7.5 h) yield of diacylated product. The structure of all compounds was established by IR and NMR spectroscopy. Surface tension dependence on concentration in aqueous and alkaline medium was investigated for the obtained compounds. It was determined that the colloidal properties of the synthesized products differ significantly from the original Synthanol DS-10. The minimal surface tension of synthesized compounds is 25-33 mN/m. The surface activity of monoester in 5 % sodium hydroxide is 5.74 N·m2·mol-1 (for Synthanol DS-10 3.06 N·m2·mol-1). But in water their surface activity is 4.00 and 4.17, respectively. Opacity temperature in different mediums was established for the new compounds. Cloud point at the concentration of 0.25 g/dm3 of diester of adipinic acid in water (>100 °C) is significantly higher than for Synthanol DS-10 (81 °C) and for monoester (46 °C). In 5 % solution of sodium hydroxide the cloud points of all these compounds are the same (difference is 2-3 °C). The new products are stable in water and alkaline medium, but not stable in 0.1N solution of hydrochloric acid. The new synthesized surfactants from Synthanol DS-10 and adipinic acid (by the complex of colloidal and physical-chemical properties) are interesting as the ingredients of technical and household compositions. Forcitation:Lominoga E.A., Burmistrov K.S., Gevod V.S. Syntesis of dimeric surfactants based on synthanol DS-10 and adipinic acid. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N2. P. 91-96

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

1970 ◽  
Vol 28 ◽  
pp. 278-279
Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Surface Tension ◽  
Critical Point ◽  
Freeze Drying ◽  
Attractive Alternative ◽  
Crystal Formation ◽  
Critical Point Drying ◽  
Time Required ◽  
Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

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