Exploring electrochemical reactivity toward ametryn of hybrid silicate films with phosphomolybdic acid

Author(s)

Olivio, Pedro H. P. ^[1] ; Correia, Leonardo A. ^[1] ; Paula, Julia H. ^[1] ; Oliveira, Jr., Osvaldo N. ^[2] ; Souza, Adriano L. ^[1]

Affiliation

^[1] Fed Univ Sao Carlos UFSCar, Dept Nat Sci Math & Educ DCNME, Campus Araras, Rodovia Anhanguera Km 174, POB 153, BR-13604900 Araras, SP - Brazil

^[2] Univ Sao Paulo, Sao Carlos Inst Phys, Ave Trabalhador Sao Carlene 400, POB 369, BR-13566590 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS; v. 229, p. 13-19, MAR 2018.
• Web of Science Citations: 2

Abstract

This paper describes the synthesis of organically-modified silicates (ormosils) with phosphomolybic acid (HPMo), and their use to detect ametryn. Gold electrodes coated with an ormosil film made of 3-cyanopro-pyltriethoxysilane (CPTS) and HPMo were used to detect ametryn between 3.5 and 24 mu mol L-1 in an acidic medium. There was no evidence of electroreduction of ametryn when ormosils with HPMo and (3-glycidyloxypropyl)trimethoxysilane (GLPTS) or 3-aminopropyltriethoxysilane (APTS) were used. This difference in behavior is ascribed to aggregation in CPTS ormosil, while GLPTS and APTS ormosils displayed homogeneous surfaces, according to scanning electron microscopy. HPMo had its structure preserved in CPTS ormosil as indicated by P-31 solid-state nuclear magnetic resonance spectra. Using polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS), we inferred that the functional group dipole moments in all ormosils are oriented parallel to the interface. Control of morphology thus seems essential for applications of ormosil films, being particularly promising to monitor environmentally-relevant herbicides. (AU)

• FAPESP's process: 13/14262-7 - Nanostructured films from biologically-relevant materials
• Grantee: Osvaldo Novais de Oliveira Junior
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 15/24136-4 - Reactivity of hybrid films containing polyoxometalates toward pesticides
• Grantee: Adriano Lopes de Souza
• Support Opportunities: Regular Research Grants