Study of Polyelectrolytes Adsorption onto Highly Charged Surfaces

• Grant number: 24/06841-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2024
• End date: February 28, 2025
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Sidney Jurado de Carvalho
• Grantee: Felipe Arantes Africo
• Host Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil

Abstract

The interaction between polyelectrolytes and oppositely charged surfaces is a central topic of the Statistical Physics of Macromolecules, and it is involved in several applications. It has been observed that varying the solution pH and ionic strength can lead to abrupt variations in measurable quantities sensitive to adsorption, such as turbidity, demonstrating a similar behavior to a phase transition. The critical adsorption conditions onto flat, cylindrical, and spherical surfaces were obtained by solving the Edwards equation using the WKB method in a low surface charge density regime, where the Debye-Hückel approximation is suitable for modeling the interaction between the surface and the polymer segments. Studies using Monte Carlo simulations using approximate solutions of the non-linear Poisson-Boltzmann equation indicated the appearance of a limiting value of ionic strength, beyond which adsorption does not occur, regardless of the charge density of the surface. This limit arises from the non-linear dependence of the potential on the surface on the surface charge density. An alternative way of observing these effects is to replace the charge density in the known solutions using the Debye-Hückel theory with a renormalized form. In this proposal, the WKB method and the charge renormalization will be used to study the effects of this non-linearity on the critical adsorption conditions and the spatial distribution of the polyelectrolyte segments in comparison with the Debye-Huckel approach.

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)

AFRICO, FELIPE ARANTES; CHERSTVY, ANDREY G.; DE CARVALHO, SIDNEY JURADO. Critical adsorption of polyelectrolytes onto highly oppositely charged surfaces: Effects of charge renormalization. Journal of Chemical Physics, v. 161, n. 19, p. 11-pg., 2024-11-21. (24/06841-1)