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Influence of Sonication on the Molecular Characteristics of Carbopol® and Its Rheological Behavior in Microgels.
Pérez-González, José; Muñoz-Castro, Yusef; Rodríguez-González, Francisco; Marín-Santibáñez, Benjamín M; Medina-Bañuelos, Esteban F.
Afiliação
  • Pérez-González J; Laboratorio de Reología y Física de la Materia Blanda, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, U. P. Adolfo López Mateos, Ciudad de México C.P. 07738, Mexico.
  • Muñoz-Castro Y; Laboratorio de Reología y Física de la Materia Blanda, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, U. P. Adolfo López Mateos, Ciudad de México C.P. 07738, Mexico.
  • Rodríguez-González F; Departamento de Biotecnología, Centro de Desarrollo de Productos Bióticos, Instituto Politécnico Nacional, Carretera Yautepec-Jojutla Km. 6, Calle CEPROBI No. 8, Col. San Isidro, Yautepec, Morelos C.P. 62731, Mexico.
  • Marín-Santibáñez BM; Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, U. P. Adolfo López Mateos, Ciudad de México C.P. 07738, Mexico.
  • Medina-Bañuelos EF; Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, U. P. Adolfo López Mateos, Ciudad de México C.P. 07738, Mexico.
Gels ; 10(7)2024 Jun 26.
Article em En | MEDLINE | ID: mdl-39057445
ABSTRACT
In this work, the effect of sonication on the molecular characteristics of polyacrylic acid (Carbopol® Ultrez 10), as well as on its rheological behavior in aqueous dispersions and microgels, was analyzed for the first time by rheometry, weight-average molecular weight (Mw) measurements via static light scattering (SLS), Fourier transform infrared (FTIR) spectroscopy and confocal microscopy. For this, the precursor dispersion and the microgels containing 0.25 wt.% of Ultrez 10 were sonicated in a commercial ultrasound bath at constant power and at different times. The main rheological properties of the microgel, namely, shear modulus, yield stress and viscosity, all decreased with increasing sonication time, while the microgel's Herschel-Bulkley (H-B) behavior, without thixotropy, was preserved. Also, Mw of Ultrez 10 decreased up to almost one-third (109,212 g/mol) of its original value (300,860 g/mol) after 180 min of sonication. These results evidence a softening of the gel microstructure, which results from the reduction in the Mw of polyacrylic acid with sonication time. Separately, FTIR measurements show that sonication produces scission in the C-C links of the Carbopol® backbone, which results in chains with the same chemistry but lower molecular weight. Finally, confocal microscopy observations revealed a diminution of the size of the microsponge domains and more free solvent with sonication time, which is reflected in a less compact and softer microstructure. The present results indicate that both the microstructure and the rheological behavior of Carbopol® microgels, in particular, and complex fluids, in general, may be manipulated or tailored by systematic high-power ultrasonication.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Idioma: En Revista: Gels Ano de publicação: 2024 Tipo de documento: Article País de afiliação: México País de publicação: Suíça
Texto completo
Adicionar na Minha BVS
Imprimir
XML
PubMed Links
Buscar no Google

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Idioma: En Revista: Gels Ano de publicação: 2024 Tipo de documento: Article País de afiliação: México País de publicação: Suíça