Direct poly -based electrolytes

The PEO salt complexes are generally prepared by direct interaction in solution for soluble systems or by immersion method, soaking the network cross-linked PEO in the appropriate salt solution [52-57]. Besides PEO, poly(propylene)oxide, poly(ethylene)suceinate, poly(epichlorohydrin), and polyethylene imine) have also been explored as base polymers for solid electrolytes [58]. Polyethylene imine) (PEI) is prepared by the ring-opening polymerization of 2-methyloxazoline. Solid solutions of PEI and Nal are obtained by dissolving both in acetonitrile (80 °C) followed by cooling to room temperature and solvent evaporation in vacuo. Polyethyleneimine-NaCF3S03 complexes have also been explored [59],... 

Membrane-based pretreatment, before reverse osmosis (RO), employing poly electrolytes, is used on wastewater, brackish water, and sea water plants [109-114]. It includes ultrafiltration or nanofiltration membrane units with feed pressure from 1-1.5 to 2.5-4 MPa. RO units need much higher feed pressure, 6-8 up to 10 MPa. It makes the RO technology economically expensive. Decreasing the high feed pressure in RO plants is the main direction for designers efforts. 

In the preceding section, the remarkable salt concentration effect on the acid dissociation equilibria of weak polyelectrolytes has been interpreted in a unified manner. In this treatment, the p/( ,pp values determined experimentally are believed to reflect directly the electrostatic and/or hydrophobic nature of polyelectrolyte solutions at a particular condition. It has been proposed that the nonideality term (Ap/Q corresponds to the activity ratio of H+ between the poly electrolyte phase and the bulk solution phase, and that the ion distribution equilibria between the two phases follow Donnan s law. In this section, the Gibbs-Donnan approach is extended to the equilibrium analysis of metal complexation of both weak acidic and weak basic polyelectrolytes, i.e., the ratio of the free metal ion activity or concentration in the vicinity of polyion molecules to that of bulk solution phase is expressed by the ApAT term. In Section III.A, a generalized analytical treatment of the equilibria based on the phase separation model is presented, which gives information on the intrinsic complexation equilibria at a molecular level. In Secs. B and C, which follow, two representative examples of the equilibrium analyses with weak acidic (PAA) and weak basic (PVIm) functionalities have been presented separately, in order to validate the present approach. The effect of polymer conformation on the apparent complexation equilibria has been described in Sec. III.D by exemplifying PMA. 

Higa M, Sugita M, Maesowa S, Endo N (2010) Poly(vinyl alcohol)-based polymer electrolyte membranes for direct methanol fuel cells. Electrochim Acta 55 1445-1449... 

Yang, C.-C., Lue, S.J., and Shi, J.-Y. (2011) A novel organic/inorganic polymer membrane based on poly(vinyl alcohol)/ poly(2-acrylamido-2-methyl-l-propanesulfonic acid/3-glycidyloxypropyl trimethoxysilane polymer electrolyte membrane for direct methanol fuel cells. /. Power Sources, 196, 4458-4467. 

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