Conducting polymers parameters affecting conduction properties

The parameters involved in the electrospinning processes that affect the nanofiber geometry and structure can be divided into two groups (i) System parameters such as polymer molecular weight, molecular weight distribution, polymer architecture (branched, linear), concentration of the polymer solution and its properties, including viscosity, electrical conductivity, and surface tension and (ii) Process parameters such as applied electric voltage, polymer flow rate, distance between the needle tip and the collector, ambient parameters such as temperature, humidity, and air velocity in the chamber, and motion of the collector (Frenot and Chronakis 2003). 

The properties of polymer electrolyte membranes change with the cation associated with the sulfonic acid sites. The conductivity of the membrane decreases when larger cations replace the protons. Other cations are at least four times less mobile than protons. The mobility of multivalent cations is lower than monovalent cations at similar molecular weight, but this is somewhat offset by the fact that multivalent ions carry more than one charge per molecule. The cationic composition also affects other properties of the polymer electrolyte membrane. Nonproton forms of the membrane do not hold as much water as the protonic form. In addition, the electroosmotic drag of water by other cations is greater than that by protons. Parameters for membranes equilibrated with several cationic species and mixtures of species have been measured and reported in the literature [2-4]. 

The unusual dielectric properties of conducting polymers make them a unique new class of microwave absorbing materials (1). We have previously studied the links between structural (crystal structure, counter-anion size, molar mass, length of the alkyl chain on the substituted monomer) and electrical properties (Cdc and values) (2). The key parameters affecting conduction properties are clearly the interchain distance and the delocalization length as it was proposed by Wang et. al. a few years ago (3). These parameters are closely related to the method by which the polymer is synthesized, and doped. 

This chapter deals with the creation of conducting PPy s, including the parameters that are important in affecting the polymerization process. Chapter 3 discusses how these synthesis parameters influence the polymer properties. 

The following parameters and processing variables affect the electrospinning process (i) system parameters such as molecular weight, molecular weight distribution and architecture (branched, linear, etc.) of the polymer, and polymer solution properties (viscosity, conductivity, dielectric constant, and surface tension, charge carried by the spinning jet) and (ii) process parameters such as electric potential, flow rate and concentration, distance between the capillary and collection screen, ambient parameters... 

The thermophysical properties of multiphase systems are affected by matrix and filler characteristics. In the case of the polymer phase, the microstructure is the most important feature that influences thermal conduction ability. When discussing the filler, one must take into consideration filler physicochanical properties but also several microstructural parameters, such as the diameter, length, shape, distribution, volume fraction, the alignment, and the packing arrangement. Fillers may be in the form of fibers or particles uniformly or randomly placed in the polymer matrix material. Therefore, thermal conduction of particle-filled polymers is isotropic, although... 

Abstract Bi-component melt-spinning has been widely applied to produce functional and novel fibres such as hollow fibres, electrically conductive fibres, etc. This chapter details the extrusion of bi-component fibres and discnsses issnes affecting the structure-property of the fibres during the spinning process, interfacial interaction parameters and compatibility of the polymers to be chosen for sheath-core spinning. 

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