EVALUATION OF SILICA NANOPARTICLE COLLOIDAL STABILITY WITH A FIBER OPTIC QUASI-ELASTIC LIGHT SCATTERING SENSOR

Author(s)

Marco César Prado Soares ^[1] ; Matheus Kauê Gomes ^[2] ; Egont Alexandre Schenkel ^[3] ; Matheus dos Santos Rodrigues ^[4] ; Carlos Kenichi Suzuki ^[5] ; Lucimara Gaziola de la Torre ^[6] ; Eric Fujiwara ^[7]

Affiliation

^[1] Universidade Estadual de Campinas. Faculdade de Engenharia Mecânica. Laboratório de Materiais e Dispositivos Fotônicos - Brasil

^[2] Universidade Estadual de Campinas. Faculdade de Engenharia Mecânica. Laboratório de Materiais e Dispositivos Fotônicos - Brasil

^[3] Universidade Estadual de Campinas. Faculdade de Engenharia Mecânica. Laboratório de Materiais e Dispositivos Fotônicos - Brasil

^[4] Universidade Estadual de Campinas. Faculdade de Engenharia Mecânica. Laboratório de Materiais e Dispositivos Fotônicos - Brasil

^[5] Universidade Estadual de Campinas. Faculdade de Engenharia Mecânica. Laboratório de Materiais e Dispositivos Fotônicos - Brasil

^[6] Universidade Estadual de Campinas. Faculdade de Engenharia Química. Laboratório de Desenvolvimento Avançado de Nano e Biotecnologia - Brasil

^[7] Universidade Estadual de Campinas. Faculdade de Engenharia Mecânica. Laboratório de Materiais e Dispositivos Fotônicos - Brasil

• Document type: Journal article
• Source: Brazilian Journal of Chemical Engineering; v. 36, n. 4, p. 1519-1534, 2020-01-13.

Abstract

Abstract Colloidal silica is an important biocompatible, inert and non-toxic material for imaging, therapy, and drug delivery biomedical applications. In this context, the evaluation of colloidal suspensions and their stabilities by a Fiber Optic Quasi-Elastic Light Scattering sensor is proposed. Two different silica nanoparticles were prepared and characterized by scanning electron microscopy and X-ray diffraction, being completely amorphous, with mean diameters of 125 and 159 nm and average specific weight of 1.94 g.cm-3. The nanoparticles were dispersed in deionized water in different concentrations ranging from 0 to 2% (m/m), resulting in suspensions with mean kinematic viscosity of 0.009157 cm².s-1. The sensor showed different sensitivities regarding concentrations and diameters, with an increase in the light intensity dispersion caused by the scattering. A decreasing tendency of the decay rate of the autocorrelation function of the light intensity signal was verified with the variation of pH, and this decay rate also showed an abrupt decrease with the enhancement of the ionic strength, detecting the limits of the colloidal stability. This work presents a simple and reliable methodology for the colloidal assessment in a low-cost and minimally invasive way, easily extendable for different chemical and biological systems. (AU)

• FAPESP's process: 17/06190-7 - Characterization of silicon dioxide nanofluids using the fiber optic sensor
• Grantee: Matheus Kaue Gomes
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 17/20445-8 - Development of fiber optic sensor for reflectance and light scattering monitoring for microfluidics applied to biotechnology
• Grantee: Marco César Prado Soares
• Support Opportunities: Scholarships in Brazil - Master