Karim Faid

Functionalized regioregular polythiophenes: towards the development of biochromic sensors

Biochromic polythiophenes have been synthesized and the interaction of avidin with the biotinylated water-soluble polymers results in stunning chromic effects, opening the way to the detection of numerous biological components.

Design of new electroactive polybithiophene derivatives

Abstract Various derivatives of polybithiophene were synthesized and characterized. Poly(3,3′-dibutoxy-2,2′-bithiophene) and poly(4,4′-dibutoxy-2,2′-bithiophene) were found to be conducting upon doping but only partially soluble in common organic solvents. The oxidation potential of poly(4,4′-dibutoxy-2,2′-bithiophene) was only +0.05 V vs. SCE, one of the lowest values for a polythiophene derivative. This low oxidation potential allows then the formation of a stable conducting state in the polymer. Moreover, upon oxidation, thin films of poly(dialkoxybithiophenes) became nearly transparent. Asymmetric disubstitution gave poly(3-butoxy-3′-decyl-2,2′-bithiophene) and poly(4-butoxy-4′-decyl-2,2′-bithiophene) which were completely soluble in chloroform. Their properties were intermediate between those of poly(alkylthiophenes) and poly(dialkoxybithiophenes).

Thermochromic properties of polythiophenes : oligomers vs. polymers

The temperature dependence of the UV–VIS absorption maximum of alkyl tetrasubstituted sexithiophene and poly(dialkylterthiophene) have been investigated, and the results are consistent with a rotation of the main conjugated chain induced by an increase of disorder in the side chains upon heating.