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Wormlike micelles of CTAB with phenols and with the corresponding phenolate derivatives - When hydrophobicity and charge drive the coacervation.
Creatto, Eduardo José; Okasaki, Fernando Bonin; Cardoso, Mateus Borba; Sabadini, Edvaldo.
Afiliação
  • Creatto EJ; Department of Physical-Chemistry, Institute of Chemistry, University of Campinas, P.O. BOX 6154, 13084-862 Campinas, SP, Brazil.
  • Okasaki FB; Department of Physical-Chemistry, Institute of Chemistry, University of Campinas, P.O. BOX 6154, 13084-862 Campinas, SP, Brazil.
  • Cardoso MB; Brazilian Synchrotron Light Laboratory (LNLS), National Center for Research in Energy and Materials (CNPEM), P.O. BOX 6154, CEP 13083-970, Campinas, São Paulo, Brazil.
  • Sabadini E; Department of Physical-Chemistry, Institute of Chemistry, University of Campinas, P.O. BOX 6154, 13084-862 Campinas, SP, Brazil. Electronic address: sabadini@unicamp.br.
J Colloid Interface Sci ; 627: 355-366, 2022 Dec.
Article em En | MEDLINE | ID: mdl-35863194
HYPOTHESIS: Hydrophobicity and the presence or absence of charge in phenol derivatives are relevant on the rheology and phase behavior when they are assembled with a cationic surfactant, forming wormlike micelles. The incorporation of phenols with a greater number of rings into the micellar palisade is entropically favored, but a solubilization limit or coacervation are two paths followed by the solutions, depending on the electrical nature of the aromatic co-solutes. EXPERIMENTS: The investigations were carried out with systems formed by a fixed concentration of hexadecyltrimethylammonium bromide (CTAB) and increasing concentrations of neutral phenols (1-naphthol, 2-naphthol, 2,3-dihydroxynaphthalene and R and S-binol) and with their corresponding phenolate derivatives. The monophasic limits of the systems were established, as well as their linear and non-linear rheology. The structural investigation of the coacervates formed with the phenolates were done using SAXS and Cryo-TEM. FINDINGS: The zero-shear viscosity of the solutions reaches maxima values close to the solubility limit of the aromatics, which depends on the numbers of rings and hydroxyl groups (position and number). However, when the correspondent ionized phenols were investigated, beyond the maxima values for the zero-shear viscosity, liquid-liquid biphasic systems are formed, in which the upper phase contains a coacervate, associated with branched wormlike micelles. However, when the ratio between phenolate and CTAB is around 3:1 the coacervate evolves to a lamellar structure.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Fenóis / Micelas Idioma: En Revista: J Colloid Interface Sci Ano de publicação: 2022 Tipo de documento: Article País de afiliação: Brasil País de publicação: Estados Unidos
Texto completo
Adicionar na Minha BVS
Imprimir
XML
PubMed Links
Buscar no Google

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Fenóis / Micelas Idioma: En Revista: J Colloid Interface Sci Ano de publicação: 2022 Tipo de documento: Article País de afiliação: Brasil País de publicação: Estados Unidos