Langmuir-Blodgett manipulation of poly(3-alkylthiophenes)

Abstract

Langmuir-Blodgett (LB) multilayer thin films were fabricated from mixed monolayers containing stearic acid and various poly(3-alkylthiophenes). It has been found that mixed LB films containing as much as 80 mol % of poly(3-alkylthiophenes) form stable monolayers at the air-water interface that can be deposited onto solid substrates as Y-type films by the vertical lifting method. The LB films exhibit well-defined layered structures as determined by optical, capacitance, and X-ray diffraction measurements. Multilayer thin films containing highly ordered domains of cadmium stearate can be formed with polythiophenes substituted with alkyl chain lengths ranging from 4 to 18 carbon atoms. The molecular organization and the electrical and optical properties of the films depend on the length of the alkyl chain of the polythiophene backbone. All of these LB films can be rendered electrically conductive by doping with strong oxidizing agents. In some cases, conductivities as high as 2 S/cm were obtained via this doping process.

Development of metal sulfide-poly (3-octylthiophene) composite LB multilayers

“…2. In all the three cases, the absorption spectra in the as-deposited state show a broad peak at 500 nm, characteristic of POT, confirming the presence of the polymer in the composite multilayers [22]. In the case of POTCdA multilayer exposed to H 2 S gas ( Fig.…”

“…There has recently been considerable interest toward their application in electroluminescent and photovoltaic devices [20,21]. In the present work, the composite monolayer methodology [22,23], in which a non amphiphilic polymer is mixed with a suitable metal ion containing amphiphilic molecule, has been used to develop composite LB multilayers of poly(3-octylthiophene) (POT) with cadmium arachidate (POT-CdA), zinc arachidate (POT-ZnA) and copper arachidate (POTCuA).The composite multilayers were subjected to post deposition H 2 S exposure to grow CdS, ZnS and Cu 2 S nanoclusters within the polythiophene -arachidic acid (POT-AA) composite multilayers. The formation of semiconducting nanoclusters in the POT-AA matrix was studied by FTIR and UV-VIS spectroscopies and X-ray reflectivity was used to study the layered structure of the multilayers.…”

PEDOT-PSSA as an alternative support for Pt electrodes in PEFCs

“…It exhibits high electrical conductivity in its oxidized state with chemical stability under ambient conditions. As a promising conducting polymer with environmental stability and sensitivity, PEDOT is commonly used in sensors for detecting ammonia, nitrogen dioxide and other toxic organicvapours (Watanabe et al 1990;Hu and Xu 2000). It is reported that during the synthesis of PEDOT, the solubility of 3,4-ethylenedioxythiophene (EDOT) is facilitated by the use of a water-dispersible polymer electrolyte, viz.…”

Molecular packing in CdS containing conducting polymer composite LB multilayers

“…This approach has recently been extended to develop CdS nanocluster containing polyaniline LB films using precursor polyanilinecadmium arachidate (PANI-CdA) composite LB multilayer [14]. The composite monolayer methodology in which a non-amphiphilic polymer is mixed with suitable metal ion containing amphiphilic molecule provides a simple approach to develop these polymer based precursors [15]. The composite precursors can subsequently be subjected to post deposition treatments to generate semiconducting nanoclusters within the layered polymer matrix.…”