title: The effect of dichlorophen binding to silica nanoparticles on its photosensitized degradation in water.
abstract: The production of dichlorophen (2,2'-methylenebis(4-chlorophenol), DCP) and its use as an anthelmintic and in pesticide products result in its direct release to the environment. To the purpose of modelling the possible photodegradation routes of DCP sorbed on sediments or suspended particles, the synthesis and characterization of silica nanoparticles modified with DCP (NP-DCP) is reported. The reactivity of NP-DCP with the excited states of riboflavin, a sensitizer usually present in natural waters, and with singlet oxygen were investigated. Comparison of the kinetic results obtained here to those previously reported for irradiated aqueous solutions of DCP allowed the discussion of the effect of adsorption of the pesticide on its photodegradation. We show with the aid of computer simulations that in natural waters the relevance of the different photodegradation routes dichlorophen is very much affected by attachment to sediments.
authors.affiliation: Unidad Académica Río Gallegos de la Universidad Nacional de la Patagonia Austral, Argentina.
authors.forename: Juan P
authors.initials: JP
authors.lastname: Escalada
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, La Plata, Argentina.
authors.forename: Valeria B
authors.initials: VB
authors.lastname: Arce
authors.affiliation: Departamento de Química, Universidad Nacional de Río Cuarto, Campus Universitario, Río Cuarto, Argentina.
authors.forename: Gabriela V
authors.initials: GV
authors.lastname: Porcal
authors.affiliation: Departamento de Química, Universidad Nacional de Río Cuarto, Campus Universitario, Río Cuarto, Argentina.
authors.forename: M Alicia
authors.initials: MA
authors.lastname: Biasutti
authors.affiliation: Departamento de Química, Universidad Nacional de Río Cuarto, Campus Universitario, Río Cuarto, Argentina.
authors.forename: Susana
authors.initials: S
authors.lastname: Criado
authors.affiliation: Departamento de Química, Universidad Nacional de Río Cuarto, Campus Universitario, Río Cuarto, Argentina.
authors.forename: Norman A
authors.initials: NA
authors.lastname: García
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, La Plata, Argentina. Electronic address: dmartire@inifta.unlp.edu.ar.
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Mártire
mesh_terms: D003198:Computer Simulation; D017666:Deuterium Oxide / Q000737:chemistry; D004003:Dichlorophen / Q000737:chemistry*; D007700:Kinetics; D008027:Light; D053758:Nanoparticles / Q000737:chemistry*; D010100:Oxygen / Q000032:analysis; D010782:Photolysis / Q000528:radiation effects; D011789:Quantum Theory; D017382:Reactive Oxygen Species / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013057:Spectrum Analysis; D014867:Water / Q000737:chemistry*
chemical_list: D017382:Reactive Oxygen Species; D014867:Water; D012822:Silicon Dioxide; D017666:Deuterium Oxide; D010100:Oxygen; D004003:Dichlorophen
keywords: Dichlorophen; Natural waters; Photodegradation; Silica nanoparticles