Fluorination hollow fiber

The high-temperature stability of the PBI attracted the attention of the scientists to develop suitable membrane material for high-temperature industrial applications. Asymmetric hollow fiber membranes were successfully prepared by Kumbharkar et al. using the fluorinated PBI synthesized by a solution polycondensation method using PPA (Figure 5.47). To have defect-free asymmetric PBI membranes for gas... 

Membrane degasification units generally use hydrophobic hollow-fiber polypropylene or polytetrafluoroethylene (PTFE) (Teflon) microporous membrane (Wiesler, 1996). Hollow-fiber modules are made by potting the desired number of fibers into an external shell. The potting compound may be polyurethane, epoxy, polyolefin, or fluorinated polymers. Since the membranes are hydrophobic and have small pores (Fig. 13.15), water will not easily pass through the pores. 

Y. Zhang, R. Wang, Fabrication of novel polyetherimide-fluorinated silica organic-inorganic composite hollow fiber membranes intended for membrane contactor application, J. Memb. Sci. 443 (2013) 170-180. 

To treat hollow dialysis fibers the fluorine gas was passed through the inside ofthe capillaries (Figure 17.3). By flow stream measurements the exact amount of gas that entered the capillaries could be determined. The treatment time and the fluorine concentration was measured to determine possible effects on the main biocompatibility properties.7,8... 

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