Conductivity of poly

Figure 11. Cyclic votammetry (top) and in situ electronic conductivity from rotating-disk voltammetry [ , Fig. 9(C)] and sandwich electrode voltammetry [ , Fig. 9(B)] for poly(3-methylthiophene) in acetonitrile containing 0.1 M BU4CIO4.60 (Reprinted from J. Ochmanska and P. G. Pickup, In situ conductivity of poly-(3-methylthiophene) and (3-methylthiophene)x,-[Ru(2,2 -bipyridine)2 (3- pyrrol-l-ylmethyl pyridine)2]2+ copolymers, J. Electroanal. Chem. 297, 211-224, 1991, with kind permission from Elsevier Sciences S.A.)...

Gathers and Fuoss have shown that the conductance of poly-(4-vinyl-N-butylpyridinium bromide) increases with the dielectric constant of the medium. The energy of removal of a mobile bromide ion from the electrostatic field of the molecule decreases as the dielectric constant is increased hence the number of free ions and the net charge on the polymeric ion should increase. Both contribute toward increasing the conductance. ... 

Many polymer-salt complexes based on PEO can be obtained as crystalline or amorphous phases depending on the composition, temperature and method of preparation. The crystalline polymer-salt complexes invariably exhibit inferior conductivity to the amorphous complexes above their glass transition temperatures, where segments of the polymer are in rapid motion. This indicates the importance of polymer segmental motion in ion transport. The high conductivity of the amorphous phase is vividly seen in the temperature-dependent conductivity of poly(ethylene oxide) complexes of metal salts. Fig. 5.3, for which a metastable amorphous phase can be prepared and compared with the corresponding crystalline material (Stainer, Hardy, Whitmore and Shriver, 1984). For systems where the amorphous and crystalline polymer-salt coexist, NMR also indicates that ion transport occurs predominantly in the amorphous phase. An early observation by Armand and later confirmed by others was that the... 

A pioneering study of the electrical conductivity of poly(2,5-dibutoxy-p-phenylene ethynylene), a fully soluble PPE derivative, was conducted by the groups of Shinar and Barton (Table 1, entry 3) [38]. The polymer employed displayed a band gap. Eg, of 2.5 eV, which is typical for 2,5-dialkyloxy-PPEs. A conductivity of 10 Scm was reported for the undoped polymer. This value was later confirmed in an independent study by Lo Sterzo et al.,who reported a conductivity of 4-10 Scm for the same polymer [39]. It was reported that upon exposure to I2 vapor at a pressure of 1 Torr, the room-temperature conductivity of poly(2,5-dibutoxy-p-phenylene ethynylene) increased by about three orders of magnitude to 10 Scm [38]. It increased further and imme-... 

The conductivity of poly(acrylic acid) and polyfmethacrylic acid) has been measured as a function of orientation (65). Little effect is seen. It is suggested that orientation effects depend upon the nature of the polymer chain-like molecules show a slight decrease in conductivity on orientation, whereas that of globular molecules increases. 

It is concluded, on the basis of the two linear regions found in the logo vs l/T curve that the conductivity of poly(methyl methacrylate) is ionic in nature (67). Kallweit (68) reaches the same conclusion from an extensive analysis of the transitory phenomena occurring in poly-(methyl methacrylate) and other polymers. His conclusions are based on... 

The conductivity of doped poly(3,4-dimethylpyrrole) is lOScm-1, while conductivities of poly(diphenylpyrrole) and of poly(A-methyl pyrrole) are both about 10 3 S cm-1, very much reduced from pyrrole and dimethylpyrrole. This is attributed by Street to non-planarity of the substituted polymers 393). 

Polymers containing plasticizing salts. It appears that when the Li salts used are of large anions, e.g., LiN(S02CF3)2, the conductivity of poly-... 

Peng, Z.L., Wang, B., Li, S.Q., Wang, S.J. (1994) Free volume and ionic conductivity of poly(ether urethane)-LiC104 polymeric electrolyte studied by positron annihilation . J. Appl. Phys. 76(12), 1. 

The temperature dependence of conductivity of poly(thienylpyrrole) is shown in Figure 6. The non-linear character of the conductivity throughout the whole range of temperatures studied here (room temperature to liquid nitrogen) indicates that the conduction mechanism could be different in different temperature... 

Fast extrusion furnace black with a particle size of 360 A, was used to verify different theoretical concepts of percolation which by definition predicts a rapid change in conductance when volume fraction of conductive particles attains a critical value. Figure 15.38 shows the effect of a carbon black addition to polychloroprene. Up to 30 phr carbon black, the conductivity of poly chloroprene is almost constant and then it increases linearly as concentration of carbon black increases. The following equation applies o = o (P - P Jwhere c is constant, P is concentration of conducting particles, Pc is percolation threshold, and P is exponent which accounts for cluster size."" When data from the Figure 15.38 are replotted as in Figure 15.39 it is evident that the percolation law is valid. 

In 1973, Peter Wright and coworkers first reported [39-41] the ionic conductivity of poly(ethylene oxide), [CH2CH20]n, (PEO), with alkali metal salts. This was followed by the visionary suggestion of M. Armand for the use of PEO as a solid electrolyte system for the transport of ions [42-43]. Since then, the area of polymer electrolytes has attracted considerable interest. In the following account, first a discussion is presented on the general features applicable to polymer electrolytes. This is followed by an account on individual polymer electrolytes, par-... 

Recently, three types of novel poly(disilanylenebutenyne-l,4-diyls) (44) with molecular weights (Mv) of 1.0 X 10" - . 0x10 were synthesized (equation 42) from diethynyldisilanes by use of rhodium(I) catalysts . The scission of Si—Si bonds by UV-light irradiation took place easily for poly(disilanylenebutenye-l,4-diyls) in solution and in a solid film, while poly[(methylphenylsilylene)butenyne-l,4-diyl] was found to be photochemically stable. Conductivities of poly(disilanylbutenyne-l,4-diyls) doped with SbFs were 10 -10 S cm" in air and lO -lO" S cm" in vacuo. 

Figure 16.22. Ageing behaviour with regard to the conductivity of poly(pyrrolephenylsulphonate) films exposed to NaOH solution of different concentrations. Film thickness is 90 micron, ageing temperature is 140°C and time of exposure is 240 min. Adapted from Polymer 27, 899 (1986), with ptermission of Elsevier Science Ltd., Kidlington.

Figure 5. Electrical conductivity of poly(l,6-heptadiyne) films as a function of time after exposure to iodine at 25 °C in a vacuum.

The use of an SECM to probe the surface conductivity of ultrathin films has been proposed [162]. Lateral conductivity of poly(3-hexylthiophene) films containing gold nanoparticles in addition was measured with an SECM in the feedback mode [163]. 

G. Kossmehl and G. Chatzitheodorou, Electrical conductivity of poly(2,5-thiophenediyl)-arsenic pentafluoride-complexes, Makromol. Chem., Rapid Commun., 2, 551-555 (1981). 

Crispin, X., Jakobsson, E, Crispin, A., Grim, P, Andersson, P., Volodin, A., Van Haesendonck, C., Van Der Auweraer, M., Salaneck, W.R., Berggren, M., 2006. The origin of the high conductivity of poly (3, 4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT-PSS) plastic electrodes. Chem. Mater. 18, 4354-4360. 

Lee, M.-H., Kim, H.J., Kim, E., Rhee, S.B., Moon, M.J., 1996. Effect of phase separation on ionic conductivity of poly(methyl methacrylate)-based solid polymer electrolyte. Solid State Ionics 85,91-98. 

---