Conjugated polymer poly

The requirements outlined above represent a considerable challenge for polymer synthesis. This article describes an appealing development, based on two central substance-classes of conjugated polymers, poly(para-phenylene)s and poly(para-phenylenevinylene)s. 

M. Grell, D.D.C. Bradley, X. Long, T. Chamberlain, M. Inbasekaran, E.P. Woo, and M. Soliman, Chain geometry, solution aggregation and enhanced dichroism in the liquid-crystalline conjugated polymer poly(9,9-dioctylfluorene), Acta Polym., 49 439-444, 1998. 

M. Ariu, D.G. Lidzey, M. Sims, A.J. Cadby, P.A. Lane, and D.D.C. Bradley, The effect of morphology on the temperature-dependent photoluminescence quantum efficiency of the conjugated polymer poly(9,9-dioctylfluorene), J. Phys. Condens. Matter, 14 9975-9986, 2002. 

J. Pei, W.-L. Yu, W. Huang, and A.J. Heeger, The synthesis and characterization of an efficient green electroluminescent conjugated polymer poly[2,7-h s(4-hexylthienyl)-9,9-dihexylfluorene], Chem. Commune. 1631-1632, 2000. 

Among the n-conjugated polymers, poly(p-phenylenevinylene)s (PPVs) have attracted particular attention since the 1990 report of Friend et al. on... 

Poly acetylenes. The first report of the synthesis of a strong, flexible, free-standing film of the simplest conjugated polymer, poly acetylene [26571-64-2], (CH), was made in 1974 (16). The process, known as the Shirakawa technique, involves polymerization of acetylene on a thin-film coating of a heterogeneous Ziegler-Natta initiator system in a glass reactor, as shown in equation 1. 

Long-lived photoluminescence, at 826 nm, is reported (t 15 (is) for thin films of the processable, -conjugated polymer, poly(3-hexylthio-phene) (93JA8447). Excitation of the n—n transition with 518 nm light (So >S ) yields only very weak luminescence of 826-nm light, even at 18 K. The emission is enhanced, to point where it can be observed at room temperature, when the excitation wavelength is 250 nm, but it is completely quenched by oxygen. Prompt fluorescence decays within... 

The spectroscopic signatures of excited states of derivatives of the conjugated polymer poly (p-phenylene vinylene) have been widely investigated both... 

Fig. 21 Reaction scheme for CVD synthesis of azomethine conjugated polymer, poly.

Two types of composite films on the basis of ji-conjugated polymers, poly-(V-epo> propyl)carbazole (PEPC) and poly-(V-vinyl)carbazoIe (PVC), and metal nanoparticles have been fabricated. The sizes of nanoparticles depend on type of the polymer matrix. Complex testing of the obtained materials has shovwi that conductivity and optical effects are more evident in the case of PEPC films. 

Rothe C, Guentner R, Scherf U, Monkman AP (2001) Trap influenced properties of the delayed luminescence in thin solid films of the conjugated polymer poly(9,9-di(ethylhexyl)fluorene). J Chem Phys 115(20) 9557—9562... 

Mollay B, Lemmer U, Kersting R, Mahrt RF, Kurz H, Kauffman HF, Bassler H (1994) Dynamics of Singlet Excitations in Conjugated Polymers - Poly(Phenylenevinylene) and Poly(Phenylphenylenevinylene). Phys Rev B 50(15) 10769—10779... 

Kijima, M. Kinoshita, L Shirakawa, H. Synthesis and characterization of a novel linear conjugated polymer, poly(2,5-didodecyloxy-l,4-phenyleneocta-tetraynylene) Chem. Lett. 1999, (6), 531-532. 

FIGURE 8.9 Linear unsubstituted conjugated polymers poly(p-phenylene), poly(para-phenylene vinylene), polythiophenes, and polyfluorenes. 

Surface gratings have been generated in various azobenzene-modified polymers epoxy polymers, polyacrylates, polyesters, conjugated polymers, poly(4-phenylazophenol), and cellulose [54-56]. 

Murali M, Ramya M, Udayakumar D, Lakshmi N, Philip R. Synthesis and third order optical nonlinearity studies of the donor-acceptor conjugated polymer, poly(2-[3,4-didodecylo-xy-5-(l,3,4-oxadiazol-2-yl)thiophen-2-yl]-5-phenyl-l,3,4-oxadiazole) and a polymer/tio2 nanocomposite. Synth Met 2010 160(23-24) 2520-5. 

That detection limit was recently improved by Wang et al. [20]. The authors replaced the 16 mm vacuum-deposited CuPc-Ceo bilayer devices by 1 mm solution-processed polymer devices based on a 1 1 blend by weight of the conjugated polymer poly(3-hexylthiophene) (P3HT) and 6,6-phenyl-C6i-butyric acid methyl ester (PCBM), a soluble derivative of Ceo- The device has an active area of 1 mm and an external quantum efficiency of more than 50 % between 450 and 550 nm (Fig. 12). The device... 

Several experiments have been carried out to confirm the physical properties of solitons in mns-polyacetylene [27]. Lately, this excitation has also been studied in another degenerate ground state conjugate polymer, poly(l,6-heptadiene) [28]. The onedimensional spin diffusion and associated spin dynamics are verified from electron magnetic resonance spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and electron nuclear double resonance (ENDOR) measurements [13]. The density of neutral solitons has been estimated by Motsovoy and co-workers [29]. For more details on the physical properties of solitons, the reader is referred to a review article by Heeger and co-workers [13]. However, more theoretical and experimental work is... 

Parker, I.D., et al. 1993. Fabrication of a novel electro-optical intensity modulator from the conjugated polymer, poly(2,5-dimethoxy-p-phenylene vinylene). Appl Phys Lett 62 1519. 

Chen, S.-A. and C.-C. Lee. 1995. Processable low band gap ir-conjugated polymer, poly(isothia-naphthene) Its synthesis and reaction mechanism. Pure Appl Chem 67 1983. 

Yan, W., C.-S., Hsu, and Y. Wei. 2002. Synthesis and characterization of small band-gap conjugated polymers—poly(pyrrolyl methines). Chin Chem Lett 13 988. 

As an example of RBS applied to a polymer system, figure 3.22 shows the spectrum obtained from a sample of the conjugated polymer poly(phenylene, vinylene) after exposure to arsenic pentafluoride vapour (Masse et al. 1990). This dopant diffuses into the polymer and reacts with it to form an electrically conducting complex and RBS is well suited to following the kinetics of the doping process by providing concentration-depth profiles of the elemental components of the dopant as a function of time. The peaks in the spectrum... 

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