Microfluidic osmotic compression of a charge-stabilized colloidal dispersion: Equation of state and collective diffusion coefficient

Abstract

We show, using a model coupling mass transport and liquid theory calculations for a charge-stabilized colloidal dispersion, that diffusion significantly limits measurement times of its Equation Of State (EOS), osmotic pressure vs composition, using the osmotic compression technique. Following this result, we present a microfluidic chip allowing one to measure the entire EOS of a charged dispersion at the nanoliter scale in a few hours. We also show that time-resolved analyses of relaxation to equilibrium in this microfluidic experiment lead to direct estimates of the collective diffusion coefficient of the dispersion in Donnan equilibrium with a salt reservoir.

7 pages, 4 figures

References in corpus (5)

• Effective charges and virial pressure of concentrated macroion solutions
• Humidity-insensitive water evaporation from molecular complex fluids
• On the macroion virial contribution to the osmotic pressure in charge-stabilized colloidal suspensions
• Poisson -- Boltzmann Brownian Dynamics of Charged Colloids in Suspension
• Collective diffusion coefficient of a charged colloidal dispersion: interferometric measurements in a drying drop

Cited by in corpus (1)

• Microfluidic free interface diffusion: measurement of diffusion coefficients and evidence of interfacial-driven transport phenomena