Polystyrene doping

A.R. Tameev, Z. He, G.H.W. Milburn, A.A. Kozlov, A.V. Vannikov, A. Puchala, D. Rasala, Electron drift mobility in polystyrene doped with bispyrazolopyridine derivatives, Appl. Phys. Lett. 81 (2002) 969-971. 

Figure 43. Comparison of the mobilities of holes in polystyrene doped with equivalent molar concentrations of TTA (above, 30 wt.%) and TAPC (below, 33 wt,%) at various field strengths and temperatures. Because the two triarylamine moieties in TAPC are linked, their arrangement should be somewhat different from that in TTA, yet the mobility behavior is nearly identical. At least in this example, differences in molecular packing do not lead to major differences in the mobility. Zero field values are extrapolations. (Reprinted with permission from Ref. [60b].)...

Figure 44. Velocity (o, not mobility) of holes in polystyrene doped with equivalent, low molar concentrations of TTA (6.8 wt.%), TAPC (7.5 wt."/)), and TETRA (7.3 wt.%), all at 335 K. Unlike the situation at high concentrations (Figure 43), linking the triarylamine groups in clusters of two (TAPC) or four (TETRA) dramatically affects the transport behavior. In TETRA, at high field strengths ), the mobility [v/E) drops so rapidly that even the velocity itself decreases with increasing E. (Reprinted with permission from Ref. [69a].)...

The electrical conductivity of a thiophene/benzene copolymer increases from 9.5 x 10 Scm"Mn the neutral state to 10 Scm" on iodine doping, in contrast to poly-p-phenylene which has no significant evolution of conductivity on doping. The crystalline structure of poly-p-phenylene and of a thiophene/ benzene copolymer is similar, but the copolymer has a lower degree of crystallinity which allows for easier penetration of iodine into the bulk material [281]. A blend of PAT (n = 8,12,22) and polystyrene doped with iodine vapor has an electrical conductivity of up to 10 Scm [282],... 

That simple models suffice in polystyrene polymers is further illustrated by work we have carried out on polystyrene doped with a... 

Figure 12-14. Loguridun ol llie zero-rieUJ mobility vs T lor TAl C-doped polystyrene, TAPC-dopcd polycarbonate, and pure TAPC. (Ref. 165J).

Figure 12-25. The temperature dependencies of die zero-field mobility for TTA and TTA doped wilh DTA, DAT, and TAA. The TTA concentration was 40%, ihe hinder material was polystyrene. The DTA, DAT and TAA to TTA concemialiinis were 1.11x10 5 niol/niol TIA (Ref. 7(> ).

From an analysis of data for polypyrrole, Albery and Mount concluded that the high-frequency semicircle was indeed due to the electron-transfer resistance.203 We have confirmed this using a polystyrene sulfonate-doped polypyrrole with known ion and electron-transport resistances.145 The charge-transfer resistance was found to decrease exponentially with increasing potential, in parallel with the decreasing electronic resistance. The slope of 60 mV/decade indicates a Nemstian response at low doping levels. 

An illustration of the potential for improved resolution in the determination of size distributions with particles in the small size range is indicated in Figures 12 to ik. These results are for a polydisperse polystyrene (labelled 2D2) which has been doped by the addition (29% by mamber) of the Dow 380 X polystyrene standard. 

Wang, Z., Masuo, S., Machida, S. and Itaya, A. (2007) Site-selective doping of dyes into polystyrene-fclock-Poly(4-vinyl pyridine) diblock copolymer films and selective laser... 

Fe(6-Mepy)2(py)tren] (004)2 Doped in PSS. Magnetic susceptibilities measured for a microcrystalline sample of the complex produce a magnetic moment value = 0.36 pg at 10 K and 0.61 pg at 150 K, followed by a gradual increase to Peff = 2.80 pe at 311 K [138]. Thus 26% of the complexes are in the HS state at 300 K if a magnetic moment of 5.1 Pe is assumed for the pure HS compound. On the other hand, the complex doped into a polystyrene sulfonate (PSS) film does not provide any evidence for a thermal population of the HS state up to 340 K as demonstrated by variable-temperature UV-VIS and Mossbauer spectra. In fact, all the complexes doped into the PSS film are in the LS state at temperatures below 340 K. However, if irradiated by a single pulse of a Q-switched Nd/YAG laser (532 mp), the complex is excited from the LS ground state to the HS J2 states via an intermediate MLCT state and the metal states. The subsequent back relaxation from the excited T2 state to the... 

Lanthanide-doped inverse photonic crystals have been reported.282 The lattices were prepared by infilling self-assembled polystyrene sphere templates with a mixture of zirconium alkoxide and europium at 450 °C, the polystyrene spheres were burnt out leaving hollow spheres of air, and the infilled material was converted to Zr02 Eu3+. The PL properties of the resulting photonic lattice were reported.282 The possibility of including phosphors into photonic lattices could lead to many... 

B. Fragneaud, K. Masenelli-Varlot, A. Gonzalez-Montiel, M. Terrones, J.Y. Cavaille, Efficient coating of N-doped carbon nanotubes with polystyrene using atomic transfer radical polymerization., Chemical Physics Letters, vol. 419, pp. 567-573, 2006. 

Fig. 10.12. MALDI-TOF spectra of polystyrene 12500 doped with Ag" ions. Adapted from Ref. [106] by permission. John Wiley Sons, 2001.

Many other polymeric systems are of interest in polymer LEDs. Polythiophenes have been known for some time but it was not until improved synthetic methods were developed that their potential was realised. The process involves the reaction of the substituted monomer with FeClj in chloroform solution. After polymerisation has occurred the product precipitates and is isolated and washed. Further special purification methods are required to obtain satisfactorily pure materials. One product, of commercial interest, developed by Bayer is poly(ethylenedioxy)thiophene, known as PEDOT (3.110). This product when doped with polystyrene sulfonate, sold as Baytron P, has been found to be effective as a conducting, hole-injecting layer on the ITO electrode. ... 

Mohan 8R, Joshi MP, 8ingh MP (2009) Negative electric fleld dependence of mobility in TPD doped polystyrene. Chem Phys Lett 470 279... 

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