Chapter 10 Attraction of Like-Charged Surfaces Mediated by Spheroidal Nanoparticles with Spatially Distributed Electric Charge. Theory and Simulation

The interaction between equal, uniformly charged flat surfaces, separated by a solution of spheroidal nanoparticles was studied theoretically. The nanoparticles were assumed to have spatially distributed electric charge. The nonlocal Poisson-Boltzmann (PB) theory for the spheroidal nanoparticles, which play the role of counterions, was developed. In the model the center of the spheroidal nanoparticle could not approach the charged surfaces closer than the radius of the nanoparticle. It was shown that for large enough diameters of nanoparticles and large enough surface charge densities of membrane surfaces, the two equally charged surfaces could experience an attractive force due to the spatially distributed charges within the nanoparticles. The results presented in this chapter may add to a better understanding of the coalescence of negatively charged membrane surfaces induced by positively charged nanoparticles (e.g., proteins) which are proposed to play an important role in the complex vital processes such as blood clot formation. © 2009 Elsevier Inc. All rights reserved.