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Titolo:
VISCOELASTIC BEHAVIOR OF AQUEOUS-SOLUTIONS OF A POLYOXYETHYLENE-NONIONIC-AMPHIPHILE SURFACTANT
Autore:
DARRIGO G; BRIGANTI G;
Indirizzi:
UNIV ROMA LA SAPIENZA,DIPARTIMENTO ENERGET,INFM,VIA SCARPA 16 I-00161ROME ITALY UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,INFM I-00161 ROME ITALY
Titolo Testata:
Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics
fascicolo: 1, volume: 58, anno: 1998,
pagine: 713 - 723
SICI:
1063-651X(1998)58:1<713:VBOAOA>2.0.ZU;2-G
Fonte:
ISI
Lingua:
ENG
Soggetto:
ULTRASONIC-ABSORPTION; DENSE MICROEMULSIONS; MICELLAR SOLUTIONS; LIGHT-SCATTERING; SOUND-PROPAGATION; PHASE-BEHAVIOR; WATER; PERCOLATION; VISCOSITY; MIXTURES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
50
Recensione:
Indirizzi per estratti:
Citazione:
G. Darrigo e G. Briganti, "VISCOELASTIC BEHAVIOR OF AQUEOUS-SOLUTIONS OF A POLYOXYETHYLENE-NONIONIC-AMPHIPHILE SURFACTANT", Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 58(1), 1998, pp. 713-723

Abstract

We present extensive measurements of shear viscosity, sound velocity,and ultrasonic absorption in aqueous solutions of the polyoxyethylenenonionic amphiphile C12H25(OCH)(2)(CH2)(6)OH (i.e., C12E6) in a wide temperature range (5-55 degrees C) and in a concentration range extending from the critical one up to the hexagonal mesomorphic phase. The static shear viscosity rapidly increases with concentration, and presents maxima as a function of temperature. The sound velocity exhibits anapparently complex behavior that can be interpreted as being due to aregular elastic contribution from the micellar moiety. Data on sound absorption in most concentrated solutions show unambiguous evidence ofa viscoelastic behavior. Despite the qualitative similarity of our results with those observed in microemulsions of reversed micelles, the underlying interpretation is different. In particular, our analysis leads us to conclude that percolation phenomena due to increased connectivity cannot explain the sound velocity behavior. Rather, the sound velocity behavior can be related to the formation of long micellar structures which, on increasing temperature, become softer, likely resembling entangled polymeric solutions in a good solvent.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/09/20 alle ore 08:54:36