Polyacids self-dissociation model

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dc.contributor.authorNeto, Augusto Agostinho [UNESP]
dc.contributor.authorDrigo Filho, Elso [UNESP]
dc.contributor.authorFossey, Marcelo Andrés [UNESP]
dc.contributor.authorNeto, João Ruggiero [UNESP]
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.date.accessioned2014-05-27T11:18:17Z
dc.date.available2014-05-27T11:18:17Z
dc.date.issued1997-11-20
dc.description.abstractThis work deals with a model to interpret pH measurements of solutions of weak rodlike polyacids, in the absence of added salts or titrating base. The polyacid is modeled as a series of point charges discretely distributod in a straight line with a distance of closest approach for the protons and an average distance between dissociable monomers, projected in the polymer chain axis. Aside from these two geometrical parameters, the dissociation constant for the isolated monomer that describes the proton dissociated monomer interaction forms the basis of the model. The assumption of cylindrical symmetry and the adoption of the cell model lead to a form written in terms of elementary functions for the mean electrostatic potential. Values of pH (related to the proton concentration in a region beyond the influence of the polyacid) as a function of polymer concentration are displayed graphically for some values of the geometrical parameters and of the dissociation, constant. Theoretical predictions of pH values as a function of polymeric concentration are compared with measured values for poly-L-glutamic and polygalacturonic acids, and a good agreement is found. Theoretical values for the dissociation degree in terms of polymeric concentration are shown for the two experimentally investigated systems. These values are in a range appreciably smaller than what is usually studied as a result of titration.en
dc.description.affiliationDepartamento de Física Instituto de Biociências Letras e Ciências Exatas UNESP, R. C. Colombo, 2265, Jd. Nazareth, 15054-000, Sao Jose do Rio Preto, SP
dc.description.affiliationUnespDepartamento de Física Instituto de Biociências Letras e Ciências Exatas UNESP, R. C. Colombo, 2265, Jd. Nazareth, 15054-000, Sao Jose do Rio Preto, SP
dc.format.extent9833-9837
dc.identifierhttp://dx.doi.org/10.1021/jp971784e
dc.identifier.citationJournal of Physical Chemistry B, v. 101, n. 47, p. 9833-9837, 1997.
dc.identifier.doi10.1021/jp971784e
dc.identifier.issn1089-5647
dc.identifier.lattes3277957413291567
dc.identifier.lattes4101562077663619
dc.identifier.scopus2-s2.0-0031275061
dc.identifier.urihttp://hdl.handle.net/11449/65230
dc.identifier.wosWOS:A1997YH53100022
dc.language.isoeng
dc.relation.ispartofJournal of Physical Chemistry B
dc.rights.accessRightsAcesso restrito
dc.sourceScopus
dc.subjectComposition effects
dc.subjectDissociation
dc.subjectElectrostatics
dc.subjectMathematical models
dc.subjectMonomers
dc.subjectpH effects
dc.subjectPolymers
dc.subjectProtons
dc.subjectDissociation constant
dc.subjectPolyacids
dc.subjectAcids
dc.titlePolyacids self-dissociation modelen
dc.typeArtigo
dcterms.licensehttp://pubs.acs.org/paragonplus/copyright/jpa_form_a.pdf
unesp.author.lattes3277957413291567
unesp.author.lattes4101562077663619
unesp.author.orcid0000-0002-2012-388X[3]
unesp.campusUniversidade Estadual Paulista (Unesp), Instituto de Biociências Letras e Ciências Exatas, São José do Rio Pretopt

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