This newly revised edition provides updated discussions throughout and features critical new material on microfluidic power sources, sensors, cell separation, organ-on-chip and drug delivery systems, 3D culture devices, droplet-based chemical synthesis, paper-based microfluidics for point-of-care, ion concentration polarization
, micro-optofluidics and micro-magnetofluidics.
Axiomatically, instable bubbles caused by aeration is advantageous to sweep away concentration polarization
on membrane surface.
The total filtration resistance can be expressed by three variables: a) [R.sub.m] (hydraulic resistance of the clean membrane); b) [R.sub.ir] (irreversible fouling or deposition onto the membrane, such as adsorption); c) [R.sub.r] (the hydraulic resistance due to reversible phenomena, such as concentration polarization
and/or reversible deposition).
Similarity of the gradients (around -0,45) showed that mass transfer would not be a strong function of the feed flowrate and concentration polarization
at the upstream membrane/solution interface should be reduced .
Eijkel, "Concentration polarization
in translocation of dna through nanopores and nanochannels," Physical Review Letters, vol.
 applied the solution-diffusion model modified with the concentration polarization
theory for analyzing the operation and performance of RO systems.
The results indicated that both the activation and concentration polarization
increased because of the low electrical conductivity and poor hydration effect.
The concentration polarization
occurs around membrane surface leading to increase in ion resistance, and this is minimized with the help of suitable spacer design, temperature, pH, and flow rates applied [5-11].
(19) developed a mathematical model according to heat and mass transfer correlations that was able to describe the behavior of PV processes with strong control of concentration polarization
under common non-isothermal and non-stationary conditions using plates-and frames membrane modules.
However, membrane treatments have operating problems such as concentration polarization
and membrane fouling .
On the one hand, the curved flow channel structure hindered the concentration polarization
development and the fouling of a membrane, which was helpful to improve membrane flux.