Composite polymer membranes

A composite polymer membrane has also been used as an effective amperometric detector for ion exchange chromatography [42] and showed detection limits similar to those obtained with a conductivity detector. An advantage of the amperometric detector based on micro-ITIES over the conductometric detector is that selectively can be tailored by proper choice of the ionophore. For instance, the selectivity of the membrane toward ammonium in the presence of an excess of sodium could be substantially increased by introducing an ammonium-selective ionophore (such as valinomycin) in the gel membrane [42]. 

The above discussion is sufficient to indicate that a promising start has now been made in the understanding of the transport properties of composite polymer membranes when the microscopic component domains are well defined and do not interact appreaciably with one another or with the penetrant. 

The number of publications referred to pervaporation and zeolite membranes is exponentially increasing (see Figure 11.19a). In the bibliographic search about this subject for the period 1995-2005, we found that many efforts, 28% of the publications, pertained to zeolite composite-polymer membranes, and the rest corresponded to different zeolite structures that are summarized in the pie chart shown in... 

Bhattacharyya, A., Mohapatra, P. K., Ghanty, T. K., and Manchanda, V. K. 2008. A pH dependent transport and back transport of americium(III) through the cellulose triacetate composite polymer membrane of Cyanex-301 and TBP Role of H-bonding interactions. Physical Chemistry Chemical Physics 10 6274-6280. 

Yang CC, Lee YJ, Chiu SJ, Lee KT, Chien WC, Lin CT, Huang CA (2008) Preparation of PVA/HAP composite polymer membrane for a direct ethanol fuel cell (DEFC). J Appl... 

Yang CC, Chiu SJ, Lin CT (2008) Electrochemical performance of an air-breathing direct methanol fuel cell using poly(vinyl alcohol)/hydroxiapatite composite polymer membrane. J... 

Yang CC (2007) Synthesis and characterization of the cross-linked PVA/Ti02 composite polymer membrane for alkaline DMFC. J Membr Sci 288 51-60... 

Zeng L, Zhao TS, Li YS (2012) Synthesis and characterization of crosslinked poly(vinyl alcohol)Aayered double hydroxide composite polymer membranes for alkaline direct ethanol fuel cells. Int J Hydrogen Energ 37 18425-18432... 

Yang CC, Chiu SJ, Chien WC, Chiu SS (2010) C)uatemized poly(vinyl alcohol)/alnmina composite polymer membranes for alkaline direct methanol fuel cells. J Power Sources 195 2212-2219... 

Yang CC, Lee YJ, Yang JM (2009) Direct methanol fuel cell (DMFC) based on PVA/MMT composite polymer membranes. J Power Sources 188 30-37... 

Yang CC, Chien WC, Li YJ (2010) Direct methanol fuel cell based on poly(vinyl alcohol)/ titanium oxide nanotubes/poly(styrenesulfonic acid)(PVA/nt-Ti02/PSSA) composite polymer membrane. J Power Sources 195 3407-3415... 

The SEM micrographs for the PVA/PAA (10 5) composite polymer membranes with highly sulfonated PP/PE separator are shown in Fig. 17. It has been found no phase separation. The improvement in hydrophilicity of PP/PE separator produced no visible voids on the surface and the cross-section. The binding between PP/PE and PVA/PAA polymer has been very well. 

Figure 17. SEM micrographs for the PVA/PAA composite polymer membrane reinforced with sulfonated PP/PE separator (a) top surface and (b) cross-section.

I. Nicotera, T. Zhang, A. Bocarsly, S. Greenbaum, NMR characterization of composite polymer membranes for low-humidity PEM fuel cells, J. Electrochem. Soc. 154 (2007) B466-B473. 

Lawson, D. R., Liang, W., and Martin, C. R., Inorganic and biological electron transfer across an electronically conductive composite polymer membrane, Chem. Mater., 5, 400-402 (1993). 

The conductive composite polymer membrane was then immersed in CH2CI2 to dissolve away the Nuclepore (32). Two 60 min. extractions in 100 mL volumes of CH2CI2 were performed. This procedure left an ensemble of conductive pol3nner fibrils. An electron micrograph (32) of such fibrils is shown in Figure 4. 

Lee HJ, Beattie PD, Seddon BJ, Osborne MD, Girault HH (1997) Amperometric ion sensors based on laser-patterned composite polymer membranes. J Electroanal Chem 440 73... 

Composite polymer membranes have been already proved as an effective technique for the strengthening of higher temperature and lower humidity fuel cell applications. The improvements that have been made are related with... 

Lee, H. J., C. Beriet, and H. H. Girault, Amperometric detection of alkali metal ions on micro-fabricated composite polymer membranes, J Electroanal Chem, Vol. 453, (1998) p. 211. 

Ingole PG, Singh K, Bajaj HC. Preparation of enantioselec-tive thin film composite polymer membrane for optical resolution of a-amino acids. J. Trends Chem. 2010 l(l) l-7. 

FIGURE 6.10 Appearance of BEMA/PEGMA composite polymer membrane with 3 wt% MFC. (Data from Chiappone, A. et al., Journal of Power Sources, 196, 10280-10288, 2011.)... 

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