Polyaniline spin coating

Figure 4. Differential scanning calorimetry of polyaniline spin coated films as a function of chemical reduction R = 0.00 -emeraldine base, R = 1.11 -leucoemeraldine base.

Figure 6. Thermoelectric power of a polyaniline spin coated film. R = 0.36 is the molar ratio of reducing agent to emeraldine base (based on a four ring repeat unit) of the solution used to prepare film.

Ferraris and colleagues studied laminate films of PEDOTT spin coated on electropolymerized N-methylpolypyrrole, polyaniline spin coated on PEDOT PSS, and polyaniline deposited on electropolymerized N-methylpolypyr-role. The films were analyzed using CIE (x, i/)-chromaticity coordinates. The observed colors in their fully doped and reduced states were found to be linearly dependent on the color coordinates of the two individual polymers of the laminate, which allows for adjusting the observed color by variation of layer thickness of an electrochromic device in a viable and predictable way. Inganas ° studied a laminate structure made from polypyrrole electro-chemically deposited on top of a PEDOTPSS layer formed by spin coating. In contrast to Ferraris et al. he found that the spectra of the laminate electrode matches well with spectra of pure polypyrrole. 

Polyaniline is less tolerant of preparation conditions than polypyrrole, and the list of anion dopants used in the preparation is more limited. However, subsequent replacement of the anion used in preparation by a dodecylben-zene sulfonate makes polyaniline become soluble in solvents such as Af-methyl pyrrolidone (NMP), or zn-cresol, and it can be spin-coated or otherwise solution-processed. In a similar way derivatives of aniline, such as... 

However, ultra-thin films of unsubstituted polyaniline deposited on ITO glass electrode produced by dip coating, spin coating and the LB technique showed the most informative voltammetric characteristics. The single-layer LB films of polymer showed much better and reversible electrochromic activity on repeated scanning within up to 0,9 V in 1,0 M HCl solution than in electrochemically prepared materials [287],... 

The commercially available, stable polyaniline dispersion for the spin coating of HILs—the developmental type Covion PAT 010—has a particle size distribution of the water-based PAT 010 compared to commercially available PEDT samples as shown in Figure 1.47. 

The synthesis of a nanoscaled, water-dispersible polyaniline powder leads to long-term stable, agglomerate-free HI system that can be easily spin-coated onto ITO. The dried PAni layers show significantly lower conductivity than PEDT ( 10 with EIS respectively 5 x 10 S/cm on... 

Polyaniline was used as hole injection material for polymer hght-emitting devices (PLED) spin-coated from a water-based polyaniline/poly-styrenesulfonate (PAni/PSS) dispersion. Data presented here were based on red, yellow, green, and blue LEPs. Depending on the applied bias voltages, the devices were studied by electrical impedance spectroscopy (EIS) in a wide frequency range. Experimental data could... 

The electropolymerization of o-methoxyaniline in the presence of (+)-(lS)- or (-)-(ll )-CSA yields an optically active polyaniline derivative. The polymer shows intense CD bands as a film deposited on an electrode. The polymer is soluble in NMP, CHCI3, DMF, DMSO, and MeOH, and the polymer also showed CD absorption in a solution probably based on a chiral main-chain conformation such as a helix. A film made by spin-coating a mixture of polyaniline with CSA also showed strong CD absorptions, which may be based on a helical conformation of the main chain. The electropolymerization method has been applied to the synthesis of an optically active polypyrrole which may have a helical conformation. ... 

Figure 2a shows the ultraviolet-visible-near infrared spectrum of an —2% solution of as-synthesized emeraldine base in A -methyl-2-pyrrolidone (NMP) [16]. The two absorption peaks at 328 and 635 nm have been assigned as the tt-tt and exciton transitions, respectively. The ratio of the intensity of the exciton transition to that of the TT-TT transition is 0.886. This ratio and the position of the exciton peak are very sensitive to the oxidation state of the polyaniline sample. Thin films of EB spin coated on quartz plates from the NMP solution give similar spectra with the positions of the two absorption peaks at 329 and 623 nm, respectively. The ratio of these two peaks also changes to 0.68, an indication of conformational change during the evaporation of the solvent. 

Figure 8 shows UV-vis-NIR spectra of thin films of HCSA fully doped polyaniline emeraldine salt that were spin coated on quartz plates from solutions in chloroform and m-cresol, respectively. As discussed previously, different polymer conformations are responsible for these two totally different UV-vis-NlR spectra. Figure 8a indicates a random coil conformation for the polymer chains the three distinctive absorption peaks at 360,440, and 780 nm are consistent with an electronic structure... 

Bavane G. Ravindra Kumar, Mahajan M. Ashok, Shirsat D. Mahendra, and Gore B. Ratnakar. Ammonia gas sensing characteristics of spin coated polyaniline films. J. Adv. Phys. 3 no. 3 (2013) 241-248. 

Several techniques, such as casting, spin-casting, and in situ deposition methods, can be used to produce polymer coated thin films, such as polyaniline and... 

For the evaluation of the SIM technique in chemical sensors application, an experimental set-up was developed as shown in Fig. 31. A fiber-optic chemical sensor was prepared, using polyaniline as the modified cladding for a short MM sensing fiber. The spin-casting method was used for coating a thin layer of polyaniline material on the fiber core surface. Then, the modified fiber was tested for the detection of HCl vapor and NH3 gas. The sensor was tested by both the total intensity modulation and the SIM techniques. 

The production and properties of PPy are described in papers from McNeill et al. (1963) and Bolto et al. (1963). Electrically conducting yams can be created using polyaniline (PANI) and PPy by either melt spinning or a coating process (Kim et al., 2004). The use of PANI is described in a recent review paper. PANI has low cost, good processability and good stability (Razak et al., 2014). 

A method used to prevent charging of the sample during scanning electron microscopic inspection is to coat the sample with a conducting metal such as gold, which is a destructive process as the metal cannot be removed from the surface of the substrate. Conducting polymers that can be spin-applied onto the sample and subsequently removed cleanly are ideal. Polyaniline has been demonstrated to provide such a solution. 

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