Remote radiofrequency triggering of topography changes in a surface micropatterned PANI@PNIPAM nanocomposite

MULKO, LUCINDA E.; PINO, GUSTAVO A.; BARBERO, CESAR A.; ROSSA, MAXIMILIANO; CUELLO, EMMA A.; MOLINA, MARÍA*

APPLIED SURFACE SCIENCE

ELSEVIER SCIENCE BV

Año: 2020 vol. 509

0169-4332

The presence of polyaniline (PANI) conducting polymer loaded in thick films of a transparentand thermosensitive poly(N-isopropylacrylamide) (PNIPAM) hydrogel network allowed forabsorption of UV light and modification of dry (PANI@PNIPAM) nanocomposites by direct laserinterference patterning (DLIP) at 355 nm. This resulted in a surface morphology of a nano-foamsuperimposed on a dominant line/groove pattern. The observations are rationalized based oncurrently accepted mechanisms for laser-induced polymer surface modification. Furthermore, thePANI in the nanocomposite films absorbs radiofrequency (RF) radiation remotely inducing thevolume phase transition of PNIPAM. The swelled, low-roughness state for PANI@PNIPAMcollapsed into a non-swelled and patterned film. The procedure provided the optimum RF doserange for preserving the surface topography of the films. The evidence suggests that the DLIPprocessing of PANI@PNIPAM films preserve the thermosensitivity of the original PNIPAMmaterial and shows up the potential for tuning the surface morphology of the composite due tosynergistic effects of both RF actuation on PANI and temperature rise of PNIPAM. In this sense,the surface pore size increase accompanying the development of line/groove pattern by DLIP,creates a structure onto PANI@PNIPAM films with potential for the development of remotelytriggered soft-sensors and drug delivery systems.