A SOLUBLE AND CONCDUCTIVE POLYANILINE COPOLYMER HAVING SYNERGISTIC NIR LIGHT ABSORPTION AND LOWER CRITICAL TEMPERATURE (LCST) Silvestre

SILVESTRE BONGIOVANNI ABEL; MARIA MOLINA; CLAUDIA RIVAROLA; CESAR BARBERO

Congreso; XXVII INTERNATIONAL MATERIALS RESEARCH CONGRESS; 2018

A linear block copolymer (PNIPAM-b-PANI), containing a thermosensitive block(poly(NâÃÂ?ÂÂ?ÃÂ?ÂÂ?isopropylacrylamide, PNIPAM) and a NIR light absorbing block (polyaniline,PANI), is synthesized. A PNIPAM block terminated in an aniline moiety is first made by radicalpolymerization of NIPAM using p-aminethiofenol as chain transfer agent. Then, the PANI block isgrown the PNIPAM block by oxidative polymerization of aniline. The copolymer is soluble in aqueousand non-aqueous solvents, where PNIPAM is soluble, unlike PANI. Thin films of the copolymer areelectrically conductive suggesting that the PANI blocks are electrically connected. Besides, studiesusing H1-NMR and FT-IR spectroscopies confirm the proposed structure. We propose that the PANIblock act as light-heat transductor, thus after absorbtion of NIR light, the produced heat shouldtriggers the colapse of the PNIPAM block. Indeed, it is shown that the soluble polyaniline aggregateupon NIR light irradiation. The photothermal induced aggregattion occurs in solution, as shown byturbidimetry, and in thin films, as shown by atomic force microscopy. Therefore, PNIPAM-b-PANIÂcould be applied in photothermal therapy, sensors/actuators devices, and in responsivesurfaces/coatings.