Applications performance modeling Polymer

We begin with the discussion of cell thermodynamics and electrochemistry basics (Chapter 1). This chapter may serve as an introduction to the field and we hope it would be useful for the general reader interested in the problem. Chapter 2 is devoted to basic principles of structure and operation of the polymer electrolyte membrane. Chapter 3 discusses micro- and mesoscale phenomena in catalyst layers. Chapter 4 presents recent results in performance modeling of catalyst layers, and in Chapter 5 the reader will find several applications of the modeling approaches developed in the preceding chapters. 

In this book, we discuss low-temperature fuel cells with a polymer electrolyte membrane (PEM). Two main representatives of the family of low-T cells are hydrogen-fed polymer electrolyte fuel cells (PEFCs) and liquid-fed direct methanol fuel cells (DMFCs). Though the major part of this book is devoted to materials and performance modeling of PEFCs, some features of DMFCs will also be discussed due to a great potential of these cells for small-scale mobile applications. 

Hollow silica gels were prepared using PNlPAAm by Liu et al. Rhodamine B was taken as the model drug, it was observed that the LCST of the PNlPAAm was increased to 40.6°C, which indicates a good performance of temperature-dependent phase transition. To further confirm the temperature responsiveness of the system, the release study was carried out at 25°C and 40°C. it was observed that 82.5% of the RHB was released for 12 h at 25°C while 86.5% was released at 40°C in 12 h. Thus, this indicates the prepared microgels achieve thermoresponsive controlled release behavior and were also found to be biocompatible [36]. Some of the applications of thermoresponsive polymers in drug delivery are summarised in Table 20.1. 

Sulfonated poly(arylene ether)s have shown promise for durability in fuel cell systems, while poly-(styrene)- and poly(imide)-based systems serve as model systems for studying structure-relationship properties in PEMs because their questionable oxidative or hydrolytic stability limits their potential application in real fuel cell systems. Sulfonated high performance polymer backbones, such as poly(phe-nylquinoxaline), poly(phthalazinone ether ketone)s, polybenzimidazole, and other aromatic or heteroaromatic systems, have many of the advantages of poly-(imides) and poly(arylene ether sulfone)s and may offer another route to advanced PEMs. These high performance backbones would increase the hydrated Tg of PEMs while not being as hydrolytically sensitive as poly(imides). The synthetic schemes for these more exotic macromolecules are not as well-known, but the interest in novel PEMs will surely spur developments in this area. 

This paper has provided the reader with an introduction to a class of polymers that show great potential as reverse osmosis membrane materials — poly(aryl ethers). Resistance to degradation and hydrolysis as well as resistance to stress Induced creep make membranes of these polymers particularly attractive. It has been demonstrated that through sulfonation the hydrophilic/hydrophobic, flux/separation, and structural stability characteristics of these membranes can be altered to suit the specific application. It has been Illustrated that the nature of the counter-ion of the sulfonation plays a role in determining performance characteristics. In the preliminary studies reported here, one particular poly(aryl ether) has been studied — the sulfonated derivative of Blsphenol A - polysulfone. This polymer was selected to serve as a model for the development of experimental techniques as well as to permit the investigation of variables... 

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