Poly(SNS) Quantitative Electrosynthesis and Electrodissolution
- PDF / 340,546 Bytes
- 6 Pages / 414.72 x 648 pts Page_size
- 30 Downloads / 185 Views
ABSTRACT The electrogeneration and electrodissolution of poly(SNS) have been improved by using aqueous acetonitrile solutions having a 1% (v/v) of water constant. Compact, adherent and thick films (until 0.4 mg cm- 2 ) were galvanostatically electrogenerated. The electrodeposited (oxidized) polymer is insoluble in 0.1 M LiCIO4 aqueous acetonitrile solution and solubilizes by cathodic reduction. Both, electrogeneration and electrodissolution, are faradaic processes. Those facts mimic electrodeposition and electroerosion of metals and their concomitant industrial applications. New technological possibilities using polymers in electrophotography, electroreprography, electropolishing, electro-erosion and electromachining are open through polymeric electrodissolution altogether to a new processible way, through the obtained solution, for the conducting polymers. INTRODUCTION Most of the electrogenerated conducting polymers form insoluble and infusible films on the electrode. Those properties are restrictive to apply those materials in different technological fields where a greater processibility is required. Between soluble electrogenerated polymers, poly-2,5-di-(2-thienyl)-pyrrole [poly(SNS)] has been reported as soluble in some organic solvents [1,2]. Previous studies performed in our laboratories [3,5] showed a new property of particular technological interest: the electrogenerated polymer is insoluble in acetonitrile salt solutions under oxidized state and solves quantitatively during electrochemical reduction. That means the opening of new technological possibilities. First of all, a conducting polymer is available in solution. The second and most important aspect is the possibility to mimic metals in applications based on electro-machining or electroerosion. So, a new process is available to form a polymeric mass by electrogeneration (equivalent to the electrodeposition of metals) which can be solved by electrochemical reduction (equivalent to the corrosion controlled by electrochemical processes). In this sense we can talk about a true synthetic organic metal, formed by electrochemical oxidation and solved by electrochemical reduction, in spite that such processes are the inversed ones of inorganic metals (cathodic deposit and anodic solubility). In this work we present the electrogeneration of poly(SNS) from monomer in acetonitrile-containing 1% (v/v) water. The same background solution was used to study its electrodissolution process. The water content is hoped to improve the polymeric conductivity showing the availability to obtain of thicker films than those obtained in pure acetonitrile.
799 Mat. Res. Soc. Symp. Proc. Vol. 328. @1994 Materials Research Society
EXPERIMENTAL 2,5-Di-(-2-thienyl)-pyrrole (SNS) was synthesized as described in (4). Anhydrous lithium perchlorate (Janssen, analytical reagent grade) was stored in an oven at 80°C. Acetonitrile (Lab Scan, HPLC grade) was used in the electrochemical experiments without further purification. Solutions were prepared with bidistilled water. Cyclic volta
Data Loading...
