Conjugates multilayer films

EI59 Kubasik, N.P., Mayer, T.K., Sine, H.E. and D Souza, J.P. (1984). The Eastman Kodak Ektachem multilayer film measurement of conjugated bilirubin is a better indicator of obstructive relief than is direct bilirubin. Clin. Chem. 30, 970, Abstr. 156. 

The 9-BCMU multilayer films show more subtle differences in the degree of order and conjugation, when prepared differently. The solution-cast film, when polymerized by u.v. light, shows the least order (X = 635 nm) for a blue form. When a 9-BCMU monomer monolayer film is polymerized at the air-water interface, and then transferred to a substrate, it shows a greater degree of order and conjugation (X = 645 nm). The most ordered polymerized multilayer film is obtained when the monomer is first transferred as a multilayer and then polymerized (X = 655 nm). 

Table 1. d-Spacings and layer thicknesses for multilayer films of conjugated polymers and their precursors... 

Schanze et al. have described the layer-by-layer (LBL) fabrication of multilayer films and photovoltaic cells using poly(phenylene ethynylene)-based anionic conjugated polyelectrolytes as electron donors and water-soluble cationic fuUerene C ) derivatives as acceptors [44]. LBL film deposition was found to be linearly related to the number of bUayers, as monitored by UV/vis absorption. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) of the mtiltilayer... 

Monolayer Polymerization. Polymerization of the highly ori-ented monomer films can simply be achieved by UV irradiation under nitrogen (Figure 8.). The polymerization of the diacetylene monomers (2, 5-9) is a topochemical reaction (32,38) that only takes place, if the monomers are perfectly orderecTT i.e. in the crystalline state or in oriented mono- (32) or multilayers (39) and leads to the formation of conjugated Tlue and red colorecT polymer backbones (Eqn. I.). 

Similarly, Chien et al. used a poly(acrylic acid)/poly(acrylamide) (PAA/PAM) multilayer system in which PAA was replaced by PAA conjugated with photoreactive 4-azidoaniline (AZ) after several bilayers [110]. As a result, the polyelectrolyte multilayer could be covalently crosslinked by UV irradiation through a mask. For an enhanced cell repellence, poly(allylamine) was conjugated with polyethylene glycol methyl ether) and incorporated into the top layers of the film. 

In contrast to the small molecules, polymers can be processed easily from solution and therefore are useful for applications on flexible plastic substrates and in multilayer device configurations. However, solution-processed polymer films are inherently more disordered than in case of molecular FETs. It can be concluded from the above results that conjugated polymer based FETs are much cheaper than Si based device. However, the slow response and limited lifetime of the device restrict them to replace current Si technology. Nevertheless, the possibility of making flexible and flat panel with conjugated polymers open a new area of large-area low-cost plastic electronics [10]. 

M. Ferreira, J.FI. Cheung, M.F. Rubner, Molecular Self-Assembly of Conjugated Polyions - A New Process for Fabricating Multilayer Thin Film Heterostructures , Thin Solid Films, 244, 806 (1994)... 

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