Polysulfone membranes curves

Figure 7.39 Sum curve of molecular weight distribution ( , %) in permeate and reactor after 25 hr. Polysulfone membrane type 2, dextran T70 1.19 wt%, pH = 6.0. Blank symbols permeate filled symbols reactor. (0) standardization solution, saccharose ( ) standardization solution, dextran T70 (o) 3 bar, (A) 5 bar.74...

Table 5. Gaussian - Lorentzian peaks used for C Is and O Is curve fitting for polysulfone membranes...

Table 6 lists the AC percentage for both polyamide/polysulfone membranes the N/0 ratio indicates an excess of oxygen atoms for the commercial membrane and a defeet of oxygen for the experimental one with respect to theoretical polyamide value ((N/0) = 1). Sinee the presence of polyamide non-characteristic elements was very low, impurities or rare chemicals must contain the same type of atoms than polyamide, which can be estimated by curve fitting of the core-level speetra. 

Figure 10. Curve fitting of Cls, Ols andNls spectra forC-PA commercial (top) and PAO experimental (bottom) composite polyamide/polysulfone membranes...

Figure 3.5 shows the curve for an experiment carried out with a membrane obtained with 20% polysulfone in dimethyl formamide (DMF) and precipitated in a coagulation bath composed of 50% water and 50% DMF. The test fluid was obtained by mixing six dextrans of different molecular weights (17, 40, 70, 100, 200, 500 kDa) from Leuconostoc (Fluka). The concentration of each one in solution was 1.0 g/L. From the curve obtained, a MWCO of 28kDa could be determined. Transmembrane pressure (driving force) was set to 9 bar. 

Impedance plots for the other studied membranes (composite polyamide/ polysulfone nanofiltration NF45 and RgC regenerated cellulose) are shown in Figures 9.16 and 9.17 respectively, and differences in the IS curves and equivalent circuits associated with both kinds of membranes are related to their different structures ... 

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