Effect of moisture on and kinetic features of the ultrafiltration rate of dialysis membrane.
The kinetic features of ultrafiltration of cellulose dialysis membrane stored under various humidity and temperature conditions were studied to obtain basic information of shelf-life characteristics of dialyzers. The ultrafiltration rate (UFR) decreased with time and the UFR-time curve suggested that the UFR would approach a certain equilibrium value. This phenomenon could be simulated well by the following equation: UFR = a.b.t/(1 + a.t) + c, where a, b, and c are constants and t is time. The effect of moisture adsorption onto the membrane on the UFR is discussed. A hypothesis is that in the amorphous region of cellulose, adsorbed water molecules would serve as molecular crosslinks through hydrogen bonding, and as this would reduce size of fine pores in the amorphous region, the UFR decreases.
Diffusive and hydraulic permeabilities of commercially available cellulosic hemodialysis films and hollow fibers
Abstract The diffusive and hydraulic permeabilities of cellulosic hemodialysis films, tubes, and hollow fibers prepared via the cuprammonium process by Enka-Glanzstoff have been measured. Mass transport properties were measured for several manufacturing lots and for various film thicknesses and hollow fiber types. Hollow fibers were found to be more permeable than flat sheets having the same wet thickness. The diffusive permeability of small molecules is not correlated with the hydraulic permeability, but there is correspondence between hydraulic permeability and diffusive permeability of larger solutes. Radiation sterilization was found to have a deleterious effect on transport properties, as did extended dry heating at 80°C. Washing procedures and/or ethylene oxide sterilization did not affect permeation properties significantly
Laminar heat or mass transfer in rectangular channels and in cylindrical tubes for fully developed flow: comparison of solutions obtained for various boundary conditions
Abstract A comparison is made of results obtained with various boundary conditions at the wall of the channels. By comparing blood Sherwood numbers for finite wall resistance with those for constant concentration boundary condition only a small variation is found for various points along the blood channel.