Optical response poly

D.A. Halliday, P.L. Burn, D.D.C. Bradley, R.H. Friend, O.M. Gelsen, A.B. Holmes, A. Kraft, J.H.F. Martens, and K. Pichler, Large changes in optical response through chemical pre-ordering of poly(/j-phcnylcnc vinylene), Adv. Mater., 5 40-43, 1993. 

Multiple Heck reactions have also been applied in a number of ways to prepare polymers (Scheme 40). One-dimensionally 7r-conjugated polymers are attractive materials because of their optical and electrical properties resulting from 7r-electron delocalization along their main chains. Among these, poly(p-phenylenevinylene) (PPV) shows high electrical conductivity, large non-linear optical responses, and electroluminescent activity. One approach... 

For the nonlinear optical response to be stable during processing and operation of chromophore/poly mer materials, the chromophores need to be chemically stable at all temperatures that the system encounters in electric field poling, and should withstand the fabrication steps needed for device fabrication. Usually, during device processing, the temperature can rise up to 250°C, whereas during operation, the material is subject to temperatures around 100°C for long periods of time. 

Similarly, using the same particles as those used for the synthesis of CdS QDs (see Sect. 6.2, Fig. 36), silver nanoparticles could be deposited onto carboxylated poly(MMA-co-MAA) particles using silver salts as precursors [315, 316]. As for the case of CdS, periodic structures of polymer/silver hybrid colloids were elaborated. The method obviously opens a new avenue for production of optically responsive materials with a controlled periodicity. In another work using commercial llOnm carboxylate-functionalized PS particles as templates, Hao et al. reported the synthesis of silver nanodisks formed through chemical reduction of silver salts in DMF [332]. The composite particles obtained (Fig. 39) exhibited an intense electronic spectrum differing markedly from those of spheres. Still using... 

When nematic liqiud crystal cells are aligned by conductive polymers such as poly(aniline) or doped poly(pyrrole), a fast electro-optical response can be observed [43]. 

Halliday, D.A., et al. 1993. Large changes in optical response through chemical preordering of poly(p-phenylenevinylene). Adv Mater 5 40. 

Optical response of poly(aniline-N-butyl sulfonate) in contact with different polymer/electrolyte systems is reportedly a function of electrolyte composition [278]. 

Semiconductor particles can also be used advantageously in coating applications to provide specific optical response to the material. As an example, Kumacheva et al. recently described the synthesis of monodisperse nanocomposite particles with inorganic CdS nanocrystals sandwiched between a PMMA core and a P(MMA-co-BA) outer copolymer shell layer. The particles are prepared by emulsion polymerization in three steps (Fig. 4.21) [144]. In a first step, polymer latexes are used as host matrices for CdS nanocrystals formation [145,146]. To do so, monodisperse poly(methyl methacrylate-co-methacrylic acid) (PMMA-PMAA) latex particles were ion-exchanged with a Cd(Cl04)2 solution. The Cd + ions thus introduced into the electrical double layer were further reduced into CdS nanoclusters by addition of a Na2S solution. The CdS-loaded nanocomposite particles were subsequently recov-... 

Giani E, Spamacci K, Laus M, Palamone G, Kapeliouchko V, Arcella V (2003) PTFE-poly-styrene core-shell nanospheres and nanocomposites. Macromolecules 36(12) 4360-4367 17. Antonioli D, Deregibus S, Panzarasa G, Spamacci K, Laus M, Berti L, Frezza L, Gambini M, Boarino L, Enrico E, Comoretto D (2012) PTFE-PMMA core-shell colloidal particles as building blocks for self-assembled opals synthesis, properties and optical response. Polym Int61(8) 1294... 

Pace S, Vasani RB, Cunin F, Voelcker NH (2013) Study of the optical properties of a thermore-sponsive polymer grafted onto porous silicon scaffolds. New J Chem 37 228 Pang-Leen O, Levitsky lA (2011) Fluorescent gas sensors based on nanoporous optical resonators (microcavities) infiltrated with sensory emissive polymers. Sens J IEEE 11 2947 Park JS, Meade SO, Segal E, Sailor MJ (2007) Porous silicon-based polymer replicas formed by bead patterning. Physica Stat Solidi a-Appl Mater Sci 204 1383 Perelman LA, Moore T, Singelyn J, Sailor MJ, Segal E (2010) Preparation and characterization of a pH- and thermally responsive poly(V-isopropylacrylamide-co-acrylic acid)/porous Si02 hybrid. Adv Funct Mater 20 826... 

Natarajam, L. V., Meyers, K., Cooper, T. M., Epling, B., and Tokarski, Z., Synthesis, characterization, and nonlinear optical response of poly(/7-nitrobenzyl-L-glutamate), Po-lym. Prepr., 34, 366 (1993). 

Other electroactive materials based on poly(hydroquinone) [344, 345], polyanilines [346-349], and amino-substituted ECPs [350,351] showed a pH-sensitive voltammetric, potentiometric, or optical response. 

Ozer et al. (1998) reported a sol-gel EC-device of the configuration glass/FTO/ WOs/a-PEO/NiO cHy/ FTO/ glass with a lithiated oxymethylene-linked poly(ethylene oxide) (a-PEO) ion conductor. The devices had a fast optical response (50 s) and a transmittance change from 80% to 50% at 550 nm but a short cycling lifetime. 

The existence of highly polarizable tt electrons in poly-conjugated molecules makes them interesting objects with possible large nonlinear optical responses when they are placed in strong electromagnetic fields. 

---