Synthesis of conducting polymer with green chemistry and its electrochromic properties

İletken polimerler ilginç optik ve elektriksel özellikleri sayesinde teknolojik uygulamalarda kullanım potansiyeli en yüksek malzemelerden biridir. Fakat iletken polimerlerin zayıf çözünürlüğü, kolayca işlenememesi, mekanik dayanımının ve stabilitesinin iyi olmaması gibi nedenler pratik uygulamalarda kullanımını sınırlandırmaktadır. Bu çalışmada iletken polimerler organik çözücüler (diklorometan, asetonitril, kloroform vb.) yerine polistirensülfonikasit yardımıyla hazırlanan sulu dispersiyonunun elektrokimyasal olarak polimerleştirilmesiyle elde edilmiştir. Böylelikle suda çözünmeyen bir monomer, çevre ve insan sağlığına zararlı organik çözücüler yerine sulu ortamda polimerleştirilmiştir. Ayrıca sulu ortamda elde edilen iletken polimerin organik çözücü varlığında elde edilen iletken polimere göre optik ve elektriksel özelliklerinin daha üstün olduğu saptanmıştır. Bu makale ile çevre ve insan sağlığına zararlı organik çözücülerde sentezlenen diğer iletken polimerlerin de sulu ortamda sentezlenebileceği ve elde edilen polimerlerin teknolojik uygulamalarda kullanımı için çok önemli olan optik ve elektriksel özelliklerinin daha üstün olabileceği gösterilmiştir.Thanks to their interesting optical and electrical properties, conductive polymers are one of the materials to have highest potential utility in technological applications. But theirs usage in practical applications are limited due to poor solubility, cannot be easily processed and lack of good mechanical strength and stability. In this work, synthesis of conductive polymer was achieved in environmentally friendly aqueous dispersion of polystyrene sulfonic acid instead of harmful organic solvent (dichloromethane, acetonitrile, chloroform,). Thus, a water-insoluble monomer was polymerized in an aqueous medium instead of organic solvents which are harmful to environment and human health. Also, conductive polymer obtained in aqueous medium has superior optical and electrical properties than the conductive polymer obtained in the presence of organic solvents. This paper has been shown that other conductive polymers synthesized in hazardous organic solvents can be synthesized in aqueous media with superior optic and electrical properties which is important for the technological application

Electrochemistry of secondary amine substituted 2,5-di(2-thienyl)pyrrole derivative and its copolymer

Since the discovery of conductive polymers, one of the most promising innovations in the field of polymer chemistry, these materials have been used in many practical applications. However, new monomers are being designed to overcome some of the disadvantages of conductive polymers, such as their inherent stability, low optical and electrical properties. It is known that minor arrangement on the monomer structure lead to very large changes in the polymer properties. In this study, a thienyl pyrrole monomer, one of the most studied monomers in the field of conductive polymers, has been produced using hydrazine derivatives instead of amines. For this purpose, the model monomer, N-phenyl-2,5-di(thiophen-2-yl)-1H-pyrrol-1-amine, was synthesized and the optical, electrochemical and electrochromic properties of its conductive polymer were investigated. Furthermore, copolymer studies with 3,4-ethylenedioxythiophene (EDOT) have been done to emphasize the importance of copolymerization on electrochromic properties of the conducting polymers. Effects of the feed ratio of the monomers and applied potential for copolymerization on optical and electrochemical properties of the electrochemically synthesized copolymers were investigated in detail

Public Health Rep

Established risk factors for osteoporosis and associated fractures are increasing age, female sex, white race, removal of the ovaries at an early age, prolonged immobility, and prolonged use of corticosteroids. Obesity and use of estrogen replacement therapy are protective. Factors that probably or possibly increase risk in postmenopausal white women include a low calcium intake, cigarette smoking, and, at least for hip fractures, use of long half-life psychotrophic drugs and heavy alcohol consumption. Factors probably or possibly associated with a decreased risk include ingestion of vitamin D and its metabolites, fluoride levels of 2 ppm or more in drinking water, moderate physical activity, pregnancies and breast feeding, use of thiazide diuretics, and progestogens. Some evidence suggests that calcium intake and physical activity at young ages may be important determinants of peak bone mass. Few studies have been undertaken in males and blacks, although at least some risk factors in males may be similar to those in females. Preventive efforts may be aimed at increasing peak bone mass at young ages, preventing bone loss in postmenopausal women, and preventing fractures and their adverse consequences in older people with osteoporosis.2517695PMCnul