Investigation of the crystalline structure and photoluminescence, photocatalytic and antibacterial properties of the nanocrystals (Ag2-2xZnX)WO4 with (x = 0, 0.25, 0.50, 0.75 and 1) incorporated in chitosan

• Grant number: 14/14171-4
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): August 01, 2015
• Effective date (End): November 28, 2019
• Field of knowledge: Physical Sciences and Mathematics - Chemistry
• Cooperation agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Elson Longo da Silva
• Grantee: Paula Fabiana dos Santos Pereira Lima
• Home Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 13/07296-2 - CDMF - Center for the Development of Functional Materials, AP.CEPID
• Associated scholarship(s): 17/13008-0 - Metallic nanoparticles-modified by in situ real-time TEM and femtosecond pulsed laser and incorporated into chitosan, BE.EP.PD

Abstract

The goal of this proposed postdoctoral project is to investigate the preparation and modification of nanosized compounds Ag2-2xZnxWO4 with (x = 0, 0.25, 0.50, 0.75 and 1) and their inclusion in the polymer matrix chitosan (CS) for the formation of nanocomposites (CS/Ag2-2xZnxWO4) by co-precipitation method. These modifications can enhance or even induce new chemical, physical, optical, photocatalytic and anti-microbial properties that are superior to polymer matrices and pure nanocrystals. In order to create the nanocomposites, first the (Ag2-2xZnX)WO4 nanocrystals will be synthesized from salts diluted in aqueous solutions per the various concentration of ions Zn2+ and Ag+. Then the (Ag2-2xZnX)WO4 nanocrystals will be dispersed in the CS matrix at various mass ratios of the nanocrystal relative to the CS. The obtained materials will be characterized structurally by X-ray diffraction (XRD), Raman and Infrared spectroscopies. To study the thermal stability of the material will be accomplished by thermal gravimetric analysis (TG). For better structural characterization of the nanocrystals and nanocomposites, X-ray scattering at low angle (SAXS) will also be performed. The morphological characteristics of the nanocrystals and nanocomposites will be verified by field emission gun scanning electron microscopy (FEG-SEM) and transmission electron microscopy (TEM). The optical properties of these materials will be investigated by ultraviolet visible (UV-vis) spectroscopy and photoluminescence measurements. The photocatalytic properties of the nanocrystals and nanocomposites will be characterized for the degradation of organic dyes (Rhodamine B and methyl orange) dispersed in aqueous solution exposed to UV illumination and by analyzing total organic carbon (TOC), which will be assessed the actual mineralization of dyes.. The photodegradation of these dyes will be quantified by monitoring the intensity of the absorption band. Moreover, the potential of these nanocrystals and nanocomposite materials to combat common bacteria in contaminated water (Salmonella typhi and Escherichia coli) will also be assessed. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DOS SANTOS, CLAYANE CARVALHO; DE ASSIS, MARCELO; MACHADO, THOLES RAFAEL; DOS SANTOS PEREIRA, PAULA FABIANA; MINGUEZ-VEGA, GLADYS; CORDONCILLO, ELOISA; BELTRAN-MIR, HECTOR; DONATE-BUENDIA, CARLOS; ANDRES, JUAN; LONGO, ELSON. Proof-of-Concept Studies Directed toward the Formation of Metallic Ag Nanostructures from Ag3PO4 Induced by Electron Beam and Femtosecond Laser. PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, v. 36, n. 6 JUN 2019. Web of Science Citations: 0.

PEREIRA, P. F. S.; GOUVEIA, A. F.; ASSIS, M.; DE OLIVEIRA, R. C.; PINATTI, I. M.; PENHA, M.; GONCALVES, R. F.; GRACIA, L.; ANDRES, J.; LONGO, E. ZnWO4 nanocrystals: synthesis, morphology, photoluminescence and photocatalytic properties. Physical Chemistry Chemical Physics, v. 20, n. 3, p. 1923-1937, JAN 21 2018. Web of Science Citations: 20.

PEREIRA, PAULA F. S.; SANTOS, CLAYANE C.; GOUVEIA, AMANDA F.; FERRER, MATEUS M.; PINATTI, IVO M.; BOTELHO, GLEICE; SAMBRANO, JULIO R.; ROSA, IEDA L. V.; ANDRES, JUAN; LONGO, ELSON. alpha-Ag2-2xZnxWO4 (0 <= x <= 0.25) Solid Solutions: Structure, Morphology, and Optical Properties. Inorganic Chemistry, v. 56, n. 13, p. 7360-7372, JUL 3 2017. Web of Science Citations: 9.