Electroactive Meso-structured films by self-assembly of amine-appended polyaniline and alkyl-phosphate

WALDEMAR A. MARMISOLLÉ; LORENZO, AGUSTIN; ELIANA MAZA; MARCELO CEOLÍN; AZZARONI, OMAR

Bolonia

Congreso; 69th Annual meeting of the International Society of Electrochemistry (ISE); 2018

International Society of Electrochemistry (ISE)

Molecular design and preparation of redox active films displaying mesoscopic levels of organization represents one of the most actively pursued research areas in nanochemistry. These mesostructured materials not only are of great interest at the fundamental level because of their unique properties but they can also be employed for a wide range of applications such as electrocatalysts, electronic devices, and electrochemical energy conversion and storage. Herein, we introduce a simple and straightforward strategy to chemically modify electrode surfaces with self-assembled electroactive polyelectrolyte-surfactant complexes. These assemblies are constituted of amino-appended polyaniline (PABA) and monododecyl phosphate (DP). After spin-coating, the films presented a well-defined lamellar structure, directed by the strong interaction between the phosphate groups of DP and the positive charged ammonium groups in the polyelectrolyte. The amounts of surfactant used to precipitate the electroactive polymer allowed obtaining different film thickness between 10 and 45 nm. Also, as proved by GISAXS, the proportion of surfactant works as a driving force to order the lamellas parallel to the substrate. The films obtained displayed intrinsic electroactivity in both acidic and neutral solutions. The self-assembled films were also able to manage the electron transfer to a soluble reversible redox couple. These results suggest that although the increment of the surfactant concentration yields more ordered stratified and hydrophobic coatings, the PANI-like polymer remains electroactive and ionic transport is still possible through the film.The enhanced electroactivity in neutral solution of PABA as compared with PANI also makes these assembled films good platforms for the integration of bioelectroactive proteins, such as glucose oxidase. Furthermore, due to their high hydrophobicity, they could also provide adequate environments for membrane or membrane-associated proteins, which may pave the way to new bio-nanoarchitectonic devices. The present results also open the door to further studies involving the assemblies of PABA and other surfactants in order to enhance their conducting properties for the design of highly connected films as electroactive components in sensing or energy devices.