Solvent-mediated interactions in electrolyte solutions

• Grant number: 15/03549-9
• Support type: Scholarships abroad - Research Internship - Doctorate
• Effective date (Start): August 10, 2015
• Effective date (End): August 09, 2016
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal researcher: Sidney Jurado de Carvalho
• Grantee: Daniel Lucas Zago Caetano
• Supervisor abroad: Sylvio May
• Home 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
• Research place: North Dakota State University (NDSU), United States
• Associated to the scholarship: 13/13151-7 - Study by computational simulation of the interaction between polyelectrolytes and macromolecules with helical charge distribution, BP.DR

Abstract

The proposal "Solvent mediated interactions in electrolyte solutions" describes a research project to be carried out by Daniel Caetano during a 12 month stay from July 2015-July 2016 as Visiting Scholar in the group of Prof. Sylvio May, Department of Physics at North Dakota State University. The project is part of an effort in the May group to account for ion specificity in the Poisson-Boltzmann model of electrolyte solutions near charged surfaces. Ion specificity is manifested in the Hofmeister series and arises from the tendency of mobile ions to modify local solvent structure. This gives rise to non-electrostatic ion-ion and ion-surface interactions that are to be incorporated consistently into mean-field electrostatics. Recent atomistic Molecular Dynamics simulations suggest that these interactions can, generally, be described by damped oscillating Yukawa potentials. Daniel Caetano's specific task is to develop and perform systematic Monte Carlo simulations of ionic systems. These simulations will not contain explicit solvent. Instead, the solvent will implicitly be accounted for by adding non-electrostatic ion-ion interactions (namely oscillating Yukawa potentials) to the Coulomb potential. The simulation results will be compared with the predictions of an ion-specific Poisson-Boltzmann model that is in the process of being developed by the May group. Carrying out Monte Carlo simulations is crucial for the success of the entire project because they allow the investigators to assess the level of accuracy of the ion-specific Poisson-Boltzmann model, especially with regard to the neglect of ion-ion correlations. Within its range of applicability, the ion-specific Poisson-Boltzmann model will offer a simple method to extend the scope of the classical Poisson-Boltzmann model to different ion types. Daniel Caetano's current expertise includes Monte Carlo simulations of ionic systems with Coulomb and hard core interactions. He has already demonstrated his ability to add non-electrostatic interactions to the simulation scheme, which makes him the best available candidate to successfully complete this project. In addition, Daniel Caetano and Prof. May have discussed the feasibility of the project during a visit of Prof. May to Daniel Caetano's home institution, IBILCE, in Summer 2014. The Department of Physics at North Dakota State University has a strong research focus in computational and experimental soft condensed matter: 8 out of 13 faculty and the majority of its graduate students work in these and related fields. Hence, Daniel Caetano will benefit during his one-year stay in the Department of Physics from a strong exposure to soft condensed matter physics and numerous opportunities to engage in research discussions with faculty and students. He will give several research talks and poster presentations and contribute to the writing of at least one publication. (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)

CAETANO, DANIEL L. Z.; DE CARVALHO, SIDNEY J.. Conformational properties of block-polyampholytes adsorbed on charged cylindrical surfaces. EUROPEAN PHYSICAL JOURNAL E, v. 40, n. 3, MAR 27 2017. (15/03549-9, 13/13151-7)

CAETANO, DANIEL L. Z.; BOSSA, GUILHERME V.; DE OLIVEIRA, VINICIUS M.; BROWN, MATTHEW A.; DE CARVALHO, SIDNEY J.; MAY, SYLVIO. Role of ion hydration for the differential capacitance of an electric double layer. Physical Chemistry Chemical Physics, v. 18, n. 40, p. 27796-27807, OCT 28 2016. (15/03549-9)