title: Binding of bis-(2-ethylhexyl) phthalate at the surface of hydrozincite nanocrystals: An example of organic molecules absorption onto nanocrystalline minerals.
abstract: As a contribution to understand the interactions between mineral surfaces and organic molecules, this study reports an accurate characterization of the bis-(2-ethylhexyl) phthalate (DEHP)-Hydrozincite (DEHP-HY), that has been conduced combining the following techniques: FTIR, NMR, XAS spectroscopies and XRD. XRD patterns indicate that the HY is made of nanocrystals whose size is not influenced by the presence of DEHP. The (1)H NMR analysis of DEHP-HY samples points out the presence of interactions of DEHP with HY. CPMAS NMR analysis suggests that the interaction is operated by ester carbonyl groups while the aliphatic chain, as expected, is not involved. MAS and CPMAS NMR measurements, performed on (13)C ester carbonyl enriched DEHP, allow to demonstrate that there are two ester carbonyl linkage sites interacting at the HY surface: an acid site with a strong link and a second one with weak chemical interactions. Zn K-edge XAS spectroscopy demonstrates that the local atomic structure around Zn in DEHP-HY sample remains essentially unchanged with respect to that of HY. Such a weak structural effect suggests that HY interaction with DEHP is limited to the nanoparticle surface.
authors.affiliation: Porto Conte Ricerche, Porto Conte, Tramariglio, Alghero, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Sanna
authors.affiliation: Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario, S.S. 554, I-09042 Monserrato, Cagliari, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Medas
authors.affiliation: Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario, S.S. 554, I-09042 Monserrato, Cagliari, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Podda
authors.affiliation: Dipartimento di Scienze, Università Roma Tre, Via della Vasca Navale 84, st. 42, I-00146 Roma, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Meneghini
authors.affiliation: Dipartimento di Fisica, Università di Cagliari, Complesso Universitario, S.S. 554, I-09042 Monserrato, Cagliari, Italy. Electronic address: mcasu@unica.it.
authors.forename: Mariano
authors.initials: M
authors.lastname: Casu
authors.affiliation: Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario, S.S. 554, I-09042 Monserrato, Cagliari, Italy.
authors.forename: Pierfranco
authors.initials: P
authors.lastname: Lattanzi
authors.affiliation: Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario, S.S. 554, I-09042 Monserrato, Cagliari, Italy.
authors.forename: Mariano Andrea
authors.initials: MA
authors.lastname: Scorciapino
authors.affiliation: Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario, S.S. 554, I-09042 Monserrato, Cagliari, Italy.
authors.forename: Costantino
authors.initials: C
authors.lastname: Floris
authors.affiliation: Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario, S.S. 554, I-09042 Monserrato, Cagliari, Italy; INSTM, Cagliari Unit, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Cannas
authors.affiliation: Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario, S.S. 554, I-09042 Monserrato, Cagliari, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: De Giudici
mesh_terms: D065966:Absorption, Physicochemical; D001665:Binding Sites; D004051:Diethylhexyl Phthalate / Q000737:chemistry*; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry*; D013499:Surface Properties; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D017967:Zinc Compounds; C417308:hydrozincite; D004051:Diethylhexyl Phthalate
keywords: Adsorption; Ester carbonyl group; Hydrozincite; Mineral surface; NMR; Nanocrystal; XAS