Molecular theory of glyphosate adsorption to pH‑responsive polymer layers

By means of a molecular-level theory we investigate glyphosate adsorption from aqueous solutions to surface-grafted poly(allylamine) layers. Our molecular model of glyphosate and the polymeric material includes description of size, shape, conformational freedom, and state of protonation of both comp...

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Autores principales: Pérez Chávez, Néstor Ariel, Albesa, Alberto Gustavo, Longo, Gabriel Sebastián
Formato: Articulo
Lenguaje:Inglés
Publicado: 2019
Materias:
Química
Glyphosate
Adsorption
Molecular theory
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/120282
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-120282
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Química
Glyphosate
Adsorption
Molecular theory
spellingShingle Química
Glyphosate
Adsorption
Molecular theory
Pérez Chávez, Néstor Ariel
Albesa, Alberto Gustavo
Longo, Gabriel Sebastián
Molecular theory of glyphosate adsorption to pH‑responsive polymer layers
topic_facet Química
Glyphosate
Adsorption
Molecular theory
description By means of a molecular-level theory we investigate glyphosate adsorption from aqueous solutions to surface-grafted poly(allylamine) layers. Our molecular model of glyphosate and the polymeric material includes description of size, shape, conformational freedom, and state of protonation of both components. The composition of the bulk solution (pH, salt concentration and glyphosate concentration) plays a critical role to determine adsorption. Adsorption is a non-monotonic function of the solution pH, which can be explained in terms of the pH-dependent protonation behavior of both adsorbate and adsorbent material. Lowering the solution salinity is an efficient way to enhance glyphosate adsorption. This is because glyphosate and salt anions compete for adsorption to the polymer layer. In this competition, glyphosate deprotonation, to increase its negative charge upon entering the polymer layer, plays an critical role to favor its adsorption under a variety of solution conditions. This deprotonation is the result of the higher pH that establishes inside the polymer. Our results show that such pH increase can be controlled, while achieving significant glyphosate adsorption, through varying the grafting density of the material. This result is important since glyphosate degradation by microbial activity is pH-dependent. These polymeric systems are excellent candidates for the development functional materials that combine glyphosate sequestration and in situ biodegradation.
format Articulo
Articulo
author Pérez Chávez, Néstor Ariel
Albesa, Alberto Gustavo
Longo, Gabriel Sebastián
author_facet Pérez Chávez, Néstor Ariel
Albesa, Alberto Gustavo
Longo, Gabriel Sebastián
author_sort Pérez Chávez, Néstor Ariel
title Molecular theory of glyphosate adsorption to pH‑responsive polymer layers
title_short Molecular theory of glyphosate adsorption to pH‑responsive polymer layers
title_full Molecular theory of glyphosate adsorption to pH‑responsive polymer layers
title_fullStr Molecular theory of glyphosate adsorption to pH‑responsive polymer layers
title_full_unstemmed Molecular theory of glyphosate adsorption to pH‑responsive polymer layers
title_sort molecular theory of glyphosate adsorption to ph‑responsive polymer layers
publishDate 2019
url http://sedici.unlp.edu.ar/handle/10915/120282
work_keys_str_mv AT perezchaveznestorariel moleculartheoryofglyphosateadsorptiontophresponsivepolymerlayers
AT albesaalbertogustavo moleculartheoryofglyphosateadsorptiontophresponsivepolymerlayers
AT longogabrielsebastian moleculartheoryofglyphosateadsorptiontophresponsivepolymerlayers
bdutipo_str Repositorios
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