Poly coated films

Currem field characteristics measured wiih conjugated polymers sandwiched between an indium-tin oxide (ITO) anode and an aluminum cathode are usually hole dominated and are, consequently, appropriate for testing injection/lransport models for the case of unipolar current How. Data shown in Figure 12-1 refer to injection-limited currents recorded on typically 100 nm thick spin-coated films of derivatives of poly(y d/"fi-phenylenevinylene) (PPV) and a planarized poly(/ /" -pheny-leue) employing a Keilhley source measure unit. The polymers were ... 

Figure 3 shows the cyclic vo1tammogram of an aceton i tr i 1 e solution containing 9-fluorenone on a bare Pt electrode and on a Polv-1 coated Pt electrode using II as the electrolyte. The only significant difference between the vo1tammograms is the presence of the poly-I reduction and oxidation waves for the coated electrode. We have previously determined by other means that poly-I films should not be permeable to molecules as large as 9-... 

Spin-coating films of other compositionally different dendritic macromolecules such as carbosilane dendrimers and hyperbranched poly(styrene) were studied by Sheiko et al. [20-22] using tapping mode AFM. 

As described in Section 3 of Chapter 4, the stabilization of n-Si electrode by coating with poly(pyrrole) has attracted much attention. The stabilization of a small bandgap n-semiconductor electrode against oxidation is of great value not only to convert visible light into chemical energy, but also to construct liquid-junction solar cells operated under visible irradiation. The poly(pyrrole) film is usually electropolymerized on the semiconductor electrode dipped in the aqueous solution of pyrrole. The remarkable stabilizing effect of poly(pyrrole) film on polycrystalline n-Si is shown in Fig. 22 67). The photocurrent obtained under irradiation in the aqueous solution of... 

Sekkat et al. 93 have investigated the photobehavior under polarized light of spin-coated films obtained from a hairy-rod poly(L-glutamate) with azobenzene in the side chains (Scheme 11, compound XIX). It is known 96,971 that, in the presence of a linearly polarized pump light beam, azo molecules experience a cycle of photoisomerization reactions and align themselves perpendicularly to the pump beam polarization direction. For the above polypeptide it was shown that, in the trans cis photoisomerization cycle, the created cis state is aligned perpendicularly to the polarization of the pump beam. 95 ... 

Poly(vinyl chloride), also known as PVC, is prepared by radical polymerization to produce material composed of an average of 10,000 to 24,000 monomer units. It is atactic and therefore amorphous, but it has a relatively high Tg because of the large size of its molecules and its polar carbon-chlorine bonds. It is a rigid material and is used to make pipe, panels, and molded objects. About 68% of PVC is used in the building and construction industry. A more flexible form of PVC is produced by adding a plasticizer such as dioctyl phthalate. This is used to prepare electric wire coatings, film, and simulated leather or vinyl. ... 

Fig. 2.28. Case diagram for NADH oxidation at a glassy carbon electrode coated with a poly(aniline)/poly(vinylsulfonate) film. The points are the experimental data. The surface and case boundaries have been determined from the inhibited fit parameters given in Table 2.8. The residuals are shown as a function of the concentration of NADH below the plot.

Poly(vinyl ethers) have extensive uses as nonmigrating tackifiers in adhesives and particularly pressure-sensitive tapes and labels, as viscosity-index improvers in lubricants and as plasticizers in coatings, films, and elastomers. They are available and used in dry state, solution or as blends with a wide variety of compatible polymers and copolymers. 

Fig. 18.8. Doping and undoping of a poly(pyrrole) film during oxidation and reduction cycles. When a poly(pyrrole) coated electrode is cycled between the reduction and oxidation potentials, the current observed at the oxidation potential is related to the ability of anions to enter the polymer film and dope the polypyrrole.

Fig. 11.12. Raman spectra of poly-Si films formed on Cr-coated soda lime and quartz glass substrates [28]. A clear c-Si peak located at 520 cm-1 can be observed, whereas no significant signal relating to a-Si can be observed at approximately 480 cm-1, indicating high crystallinity. A FWHM of the c-Si peaks of 7-9 cm-1 indicates the existence of fine grains less than 10 nm in size, consistent with the TEM image...

The permeable membrane (barrier layer) plays a crucial role for the ALILE process. Usually, the barrier layer is formed by exposure of the Al-coated glass substrate to air. The thickness of this barrier layer (A1 oxide), which is on a nanometer scale, can be influenced by the variation of the exposure time. With increasing exposure time, the thickness of the barrier layer increases. The thicker the barrier layer, the lower is the nucleation density and the longer is the process time necessary to form a continuous poly-Si film [19]. By X-ray photoelectron spectroscopy (XPS) measurements it was shown that the barrier layer stays in place during the whole ALILE process. 

Lamellae in Spin-Coated Films of Poly(ethylene oxide) (PEO) by TM-AFM... 

A detailed study of the SHG from both spin-coated and evaporated films of trinitro-(l) [73,74], trhodo-(4) [74] and trioctylsulfonyl-(7) [74] subphthalocyanines has been carried out. In order to induce molecular ordering in hie spin coated film, a corona poling technique was used. Films were prepared by spin-coating from a solution of the corresponding SubPc in poly(methylmethacrylate) (PMMA). For comparison purposes, evaporated films were also prepared by vacuum sublimation onto amorphous silica plates. 

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