In this paper, we investigate the interaction between two identical soft-particles with charged cores. We derived the analytic formula for the interaction energy in a compact form. We showed that the interaction energy involves a screened Coulomb-like interaction term with a distance-independent coefficient. The numerical calculations showed that the interaction energy has very small amplitude and exponentially decays on the distance between the soft particles. The results indicate that it is possible to measure this kind of interaction energy when the system is put into a salt solution with the concentration low enough. | Communications in Physics, Vol. 27, No. 2 (2017), pp. 165-172 DOI: INTERACTION BETWEEN TWO CHARGED-HARDCORE SOFT PARTICLES QUYEN THI LE BUI1 , THIEN DUC NGO2 , THUY THI PHUONG NGUYEN2 AND HOAI THI LAM NGUYEN2,† 1 Thai Binh University of Medicine and Pharmacy, Ly Bon, Thai Binh city 2 Institute of Physics, Vietnam Academy of Science and Technology, 10 Dao Tan, Ba Dinh, Hanoi, Vietnam † E-mail: nlhoai@ Received 12 April 2017 Accepted for publication 27 July 2017 Published 30 July 2017 Abstract. During the two last decades, theories of soft-particles have been introduced and developed in order to describe the behavior of bacteria and viruses which can be considered as the bio-colloid particles. Soft particles are assumed to consist of a rigid core inside an ion-permeable shell. The outer layer is always negatively charged while the core can be neutral or charged. In this paper, we investigate the interaction between two identical soft-particles with charged cores. We derived the analytic formula for the interaction energy in a compact form. We showed that the interaction energy involves a screened Coulomb-like interaction term with a distance-independent coefficient. The numerical calculations showed that the interaction energy has very small amplitude and exponentially decays on the distance between the soft particles. The results indicate that it is possible to measure this kind of interaction energy when the system is put into a salt solution with the concentration low enough. Keywords: soft particle, Poisson-Boltzmann equations, electrophoresis mobility, interaction energy. Classification numbers: , . c 2017 Vietnam Academy of Science and Technology 166 QUYEN T. L. BUI et. al. I. INTRODUCTION Removal of the bacterial and viral pathogens has been always the biggest obstacle in the way of finding out novel water treatment and reuse methods which are low-cost and effective. Many experiments have been
