Showing papers in "Journal of Membrane Science in 1980"

TL;DR: In this article, a refined integral method has been successfully applied to moving boundary problems encountered in the diffusional release of a solute from a polymeric matrix, and the release kinetics has been analyzed for both erodible and non-erodible matrices with perfect sink and constant, finite external volume conditions.

TL;DR: Ions were used as mobile, membrane-bound carriers for selected gas species, these being introduced as the counter ions in ion-exchange membranes as mentioned in this paper, which could be useful in practical gas separations, giving longer operating life under certain adverse conditions.

TL;DR: A drug diffusion model for the case of diffusion of an initially uniformly distributed drug through a polymeric matrix is presented and solved in this paper, where drug concentration profiles within the polymer and drug release rates can be determined.

TL;DR: In this article, progesterone-dispersed monolithic devices were prepared from either polyhydroxyethyl methacrylate (HEMA) or a copolymer of HEMA and MEEMA.

TL;DR: In this article, a mathematical model for the mass transport of binary mixtures within the membrane is presented, based on the transport equations of Shelden and co-workers, and tested experimentally with benzene-cyclohexane mixtures.

TL;DR: In this article, a free volume approach has been used to describe the effect of apparent solute molecular size on solute membrane diffusion coefficient in poly(2-hydroxyethyl methacrylate) (pHEMA) and pHEMA crosslinked with 1 mole % ethyleneglycol dimethacrylation (EGDMA).

TL;DR: In this article, the authors derived expressions for the effective (apparent) permeability and diffusion coefficients, as well as for the diffusion timelag, and the implications of these results to the separation of gas and vapor mixtures by permeation through glassy polymer membranes are discussed.

TL;DR: In this paper, the authors presented a model which adequately describes the kinetics of copper removal by liquid surfactant membranes and determined the kLa of this model and found to range from 1 X 10−4 to 1 x 10−3 sec−1.

TL;DR: In this article, the authors describe the coupled transport of uranium ions through liquid membranes, which consist of a microporous polymeric support with an organic solution of a tertiary amine complexing agent held within the pores by capillary forces.

TL;DR: In this study, rods composed of a blend of drug and copolymer were found to be useful for the long-term release of drugs having low aqueous solubility, such as progesterone and levonorgestrel, while capsules were better suited for shorter durations of release.

TL;DR: The functionality of a new class of monolithic systems for the controlled release of drugs is discussed in this article, which consist of uniformly dispersed particles of osmotically active therapeutic agents (drugs) in biocompatible polymeric matrices.

TL;DR: A new approach for externally controlling release rates of drugs using magnetism has been developed by incorporating magnetic particles and drugs into polymeric matrices and can then be increased by an appropriate application of an external magnetic field.

TL;DR: An investigation has been made of the extent to which useful similarity relations for solute-membrane transport coefficients can be obtained by dimensional analysis, as based on some physical knowledge about membrane transport, but without the need to assume any detailed model of microscopic membrane structure.

TL;DR: In this paper, the authors studied several binary systems: poly(vinylpyrrolidone)-phenol; amylose-iodine; and polymers containing iminodiacetate or hydroxycarboxylic functional groups-cations.

TL;DR: In this paper, a liquid membrane was prepared by entrapping tributyl phosphate (TBP) in a cellulose triacetate (TAC) membrane matrix, which was used to separate two aqueous solutions, one acidic and the other alkaline.

TL;DR: In this article, the effects of swelling on membrane permeability were examined in some detail with cellophane membranes, and the results showed that the effect of pre-treatment is negligible for cellulose 2.5-acetate and nylon-6 membranes.

TL;DR: In this article, the basic features and process characteristics of pertraction through emulsion-type liquid membranes are reviewed and discussed and compared with double liquid-liquid extraction in three industrial interest, namely, the separation of hydrocarbons, the removal of phenol from water, and the recovery of copper from dilute solutions.

TL;DR: In this paper, mass transfer of organic compounds through aqueous and non-aqueous liquid surfactant membranes was studied in a single-drop extraction colum and in a multi-emulsion.

TL;DR: In this article, a mathematical model is given for a hollow fiber dialyzer in which the dialysate side resistance to mass transfer is taken into account, and the mass balance equations are integrated by a numerical procedure for cocurrent and countercurrent flow.

TL;DR: Large semipermeable microcapsules with ultrathin polymer membranes were prepared by interfacial polymerization using a drop method and after being incorporated into the polymer membrane the Na+-K+-ATPase retained 50—100% of its original ouabain-sensitive activity.

TL;DR: The use of liquid membranes can selectively concentrate specific ions and separate short-lived reaction intermediates as discussed by the authors, which can be accelerated by making them thin, with a large surface area per unit volume.

TL;DR: In this paper, the authors investigated the relationship between water content and diffusion coefficient in copolymers of MEMA and MEEMA with poly(2-hydroxyethyl methacrylate) (pHEMA).

TL;DR: In this article, the authors measured the transient and steady-state permeability of carbon dioxide through glassy poly(acrylonitrile) (PAN) microspheres and films at temperatures between 25°C and 65°C, and pressures up to 30 atmospheres.

TL;DR: In this paper, a theoretical treatment to estimate the interdiffusion flux and membrane potential in a bi-ionic system is presented on the basis of the Nernst-Planck equation, assuming a steady counter-ion flux through both a membrane and two unstirred film layers.

TL;DR: In this article, an experimental study was carried out on the ultrafiltration of two linear synthetic polymers: polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP) in a stirred batch system.

TL;DR: In this article, the mass transport induced by temperature gradients through coarsely porous membranes (effect of thermodialysis) in various aqueous solutions demonstrates that a close analogy exists with thermal diffusion in the bulk liquid phase (Soret effect).

TL;DR: Electrochemical typing of blood was performed with sera, using a pair of membranes with immobilized A- and B-type blood group substances, and the blood type was determined by measuring the transmembrane potential across these membranes before and after the agglutination reaction.

TL;DR: In this article, a number of commercially available polymeric films and several modified poly(vinylidene fluoride) films were tested for the removal of CO 2 from a synthetic biogas containing 60% CO 2 and 40% CH 4.

TL;DR: In this paper, the influence of multiple holes on particle transmission in nuclear track filters was investigated using a two-dimensional model, and upper and lower limits for the transmission were given by the "areal transmission function" T s and the ''particle transmission function'' T r, respectively.