An equation for the flux of electrolyte through a water-swollen cation-exchange resin membrane separating two solutions of the same electrolyte at different concentrations is derived on the basis of several assumptions regarding the physical nature of a swollen resinous exchanger. The complete flux equation contains three terms, one determined by the concentration difference across the membrane, another determined by the variation of the activity coefficient of the electrolyte with concentration in the membrane and a third concerned with the rate of osmotic or hydrostatic flow through the membrane. If ions in the resin are transported entirely in an internal aqueous phase, the mobilities required for the flux equation can be related to mobilities in aqueous solution and to the volume fraction of resin in the swollen membrane. The treatment is readily extended to anion exchangers.

The diffusion of electrolytes in a cation-exchange resin membrane I. Theoretical

Transport Processes and Electrical Phenomena in Ionic Membranes

Es wird uber Synthese, Eigenschaften und Reaktionen einiger makromolekularer Stoffe mit reaktiven Gruppen berichtet, und zwar uber Derivate der Polyacrylsaure (Polyacrylsaure-hydrazid, Polyacrylhydroxamsaure, Polyacrylsaureamid), des Polyvinylalkohols, uber Polyacrolein und Polymethacrolein, Polyvinylsulfonsaure und ihre Derivate sowie uber Copolymere aus Styrol und Maleinsaureanhydrid. An den reaktiven Gruppen dieser polymeren Stoffe werden chemische Reaktionen ausgefuhrt. Dabei zeigt sich, das unter Bedingungen, die dem makromolekularen Bau des Reaktionspartners angepast sind, eine Reihe von Reaktionen, die aus der niedermolekularen Chemie gut bekannt sind, auf solche Polymere ubertragen werden konnen. Dadurch werden neue makromolekulare Stoffe zuganglich, die durch Polymerisation oder Polykondensation nicht zu erhalten sind.

Synthetische makromolekulare Stoffe mit reaktiven Gruppen

In attempting to improve the evaluation of Q and e values, some 900 reactivity ratios were recalculated.

Recalculation of Some Reactivity Ratios

Publisher Summary Adsorption may be considered a prototype for all fluid–solid separation operations. When it is conducted under countercurrent conditions, the calculation methods required are entirely analogous to those for countercurrent absorption or extraction. Adsorption is analogous to selective condensation of gas molecules or to selective crystallization or fusion from a liquid. It is based upon intermolecular attractive forces of the van der Waals type between a solute and the solid surface. An efficient adsorbent in contact with a gas phase may hold a volume of adsorbate equal to as much as 1.0% of the particle volume (silica gel has an even larger capacity). This chapter discusses theories and practice of adsorption methods for separation puts stress on column dynamics under linear equilibrium and column dynamics at a constant separation factor. It also describes the chromatographic separation method in which only a small amount of solution containing the components to be separated is admitted to the column. If the column is long enough, the zones will draw apart completely from one another, and may be recovered in the effluent as separate solutions of each individual solute. Finally, the chapter addresses the problems of data interpretation and apparatus design extensively, focusing on fixed-bed operations

C. G. Overberger

Papers

Studies on ion-exchange resins. Capacity of sulfonic acid cation-exchange resins

Copolymerization of Butyl Vinylsulfonate. Comments on Sulfur Shell Expansion1