Membrane Roughness and Dispersive

Klosgen, Beate, Membrane Roughness and Dispersive Phase as Effects of Higher-order Bending in Fluid Membranes, 6, 243 see also Thimmel, Johannes, 6, 253. 

Membrane Roughness and Dispersive Phase as Effects of Higher-order Bending in Fluid Membranes... 

Ottewill and co-workers106,200 have used a compression method to measure the double-layer repulsion between the plate-like particles of sodium montmorillonite. This is a particularly suitable system for such studies, since the particles are sufficiently thin (c. 1 nm) for van der Waals forces to be unimportant and surface roughness is not a problem. The dispersion was confined between a semipermeable filter and an impermeable elastic membrane and an external pressure was applied via a hydraulic fluid so that the volume concentration of particles and, hence, the distance of separation between the particles could be measured as a function of applied pressure. 

A defect in a porous layer on a porous support is a microstructural or textural feature which hampers application of a defect-free functional membrane layer. Defects are cracks or micro-cracks in the substrate layer, irregularities in surface roughness, pinholes or voids percolating the layer or large percolating pores as a result of the particle packing process. These last defects are not really defects because they are an unavoidable result of the particle size distribution in the dispersion and random packing. 

The permittivity curve reveals one dispersion. Table 1 summarizes the measured permittivity step compared with theoretical values of the yS-dispersion calculated by using the formula (1) and (2). The cell diameter of neutrophils is between 12 to 15 trm. An average radius R= 6.75 am can be assumed for a rough estimation. The maximum volume fraction p of the neutrophils by expecting a face-centred cubic order reaches a value of 0.74. Actually, values from (0.6...0.7) for pellets and cell suspension were reported [7-9]. A typical value known from literature for the membrane capacitance C is 0.01 F/m and for the intracellular conductivity o = 0.05 S/m [10]. The extracellular conductivity can be estimated with a higher conductivity of physiological sodium chloride solution ([0.02]S/m). The comparison... 

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