J. Lowe et S. Holdcroft, POLY(3-(2-ACETOXYETHYL)THIOPHENE) - A MODEL POLYMER FOR ACID-CATALYZED LITHOGRAPHY, Synthetic metals, 85(1-3), 1997, pp. 1427-1430
Treatment of poly(3-(2-acetoxyethyl)thiophene) (P3AcET) with sulfuric
acid simultaneously cleaves the side chain and dopes the polymer backb
one. Upon neutralization, the resultant polymer, poly(3-(2-hydroxyleth
yl)thiophene) (P3HET), is found to be insoluble. Furthermore, the loss
of the bulky acetyl group causes a significant red-shift in the absor
ption spectra as a result of the decrease in intramolecular steric int
eractions. The hydroxy functionality can be partially reacted to furth
er modify the surface of the film. These phenomena were used to spatia
lly modify the physico-chemical properties of poly(3-alkylthiophene)-b
ased films. Selectively exposure of P3AcET to acid via conventional ph
otolithographic procedures was employed to (i) deposit electronically
conducting polymeric patterns, (ii) spatially modify the optical featu
res of films, (iii) spatially modify the surface functionality of film
s.