Regenerated fibers, contaminants

Again, irrespective of the hardware the chemistry is consistent. The partially regenerated fiber from the spinning machine is contaminated with sulfuric acid, 2inc sulfate, sodium sulfate, carbon disulfide, and the numerous incompletely decomposed by-products of the xanthation reactions. The washing and drying systems must yield a pure cellulose fiber, suitably lubricated for the end use, and dried to a moisture level of around 10%. 

Fiber and membrane suppressors represent an improvement over the classical suppressor columns, but they are not entirely problem-fme. Contamination builds up for example, heavy-metal ions stron y adsorb on the cation-exchange membranes used as suppressors in anion chromatography. Therefore, the membranes also need to be regenerated or replaced in intervals that depend on the application. 

Drawbacks of the CMS membranes from hollow-fiber polymeric membranes have also been reported (Jones and Koros, 1994b Jones and Koros, 1995). These membranes were vulnerable to organic vapors as well as moisture. These molecules seemed to adsorb strongly in the pores and reduced the fluxes of the permanent gas molecules. Membrane deterioration was observed with organic contaminations at concentrations as low as 0.1 ppm. However, a promising regeneration process was reported by the use of propylene significant recovery of the... 

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