Micropolarity and water penetration in micellar aggregates of linear and branched hydrocarbon surfactants

• Published in: Langmuir Vol. 6; no. 8; pp. 1376 - 1378
• Main Authors: Varadaraj, Ramesh, Bock, Jan, Valint, Paul, Brons, Neil
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.08.1990
• Subjects: 02 PETROLEUM; 020400 - Petroleum- Processing; ALKALI METAL COMPOUNDS; AQUEOUS SOLUTIONS; Chemistry; Colloidal state and disperse state; DATA; DISPERSIONS; ELECTRICAL PROPERTIES; Exact sciences and technology; EXPERIMENTAL DATA; General and physical chemistry; INFORMATION; MICELLAR SYSTEMS; Micelles. Thin films; MIXTURES; NUMERICAL DATA; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; POLARIZABILITY; SODIUM COMPOUNDS; SODIUM SULFATES; SOLUTIONS; SULFATES; SULFUR COMPOUNDS; SURFACTANTS; TEMPERATURE EFFECTS; Aggregation; Sodium Compounds; Anionic surfactant; Temperature; Micelle; Solvatochromism; Polarity; Experimental study; Microstructure
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la00098a010

The micropolarity of aqueous micellar solutions of ethoxylates, sodium ethoxy sulfates, and sulfates derived from linear and branched hydrocarbon alcohols was investigated by using a solvatochromic pyridinio-N-phenoxide betaine, ET-30, polarity probe. Branching of the hydrophobe resulted in a more porous micellar aggregate. Thermosolvatochromism of ET-30 allowed an investigation of the effect of temperature on micropolarity. Increase in temperature was observed to expel water from the hydrophobic regions of the aggregate and decrease the effective micropolarity in linear and branched surfactants.