Agasanapura B, Baltus RE, Tanneru CT, Chellam S. Effect of electrostatic interactions on rejection of capsular and spherical particles from porous membranes: theory and experiment.
J Colloid Interface Sci 2015;
448:492-500. [PMID:
25771291 DOI:
10.1016/j.jcis.2015.02.016]
[Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 02/06/2015] [Accepted: 02/06/2015] [Indexed: 11/17/2022]
Abstract
HYPOTHESES
Particle rejection from porous membranes will increase when particle and membrane carry like charges. The influence of charge on particle rejection can be modeled by first solving the Poisson-Boltzmann equation for the electrostatic particle-pore wall interaction energy, enabling one to predict the cross sectional particle concentration in a pore. Rejection coefficients can then be predicted by combining the Boltzmann factor with a hydrodynamic lag coefficient.
EXPERIMENTS
Rejection experiments were conducted with three different spherical colloidal silica particles, a spherical virus (PRD1) and gold nanorods of two different aspect ratios (ratio of length to diameter). Track-etched polycarbonate microfiltration and ultrafiltration membranes having nearly parallel pores of cylindrical cross-section were used. Experiments were conducted under conditions where both particle and membrane carried a negative charge as well as under conditions where surface charges had minimal impact. Experiments were designed to cover a broad range of dimensionless particle sizes under conditions when convection dominated particle transport.
FINDINGS
Model predictions and experimental measurements demonstrate that particle rejection can be enhanced significantly when particle and pore carry like charges.
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