Investigation of the correlation between chemical structure and morphology in oligoaniline microspheres produced in buffered conditions

Author(s)

dos Santos, Isabela F. S. ^[1] ; Temperini, Marcia L. A. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Chem, Dept Fundamental Chem, Av Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: EUROPEAN POLYMER JOURNAL; v. 122, JAN 5 2020.
• Web of Science Citations: 0

Abstract

Although the mainly intermolecular forces involved in the self-assembly of oligoaniline molecules have been consistently discussed (hydrogen bonds and pi-pi stacking interactions) the correlation between the driving forces and the large variations of morphology that can be obtained is still open in discussion, mostly because a detailed chemical characterization of such products is usually difficult to achieve. In this work, 3-D fluorescence spectroscopy is presented as a powerful technique in the identification and differentiation of phenazinic segments, with Raman spectroscopy being crucial for identification of 1,4-Michael-type segments and the verification of non-hydrolyzed imine groups in oligoaniline microspheres produced under pH 4.5 buffered conditions and employing different reagent concentrations. The results suggested that the self-assembly must occur by hydrogen bonds related to the non-hydrolyzed iminic groups and pi-pi stacking interactions between non-substituted phenazinic segments. Moreover, obtaining specific morphologies (flower-like structures, porous microspheres and hollow microspheres) showed dependence with the increase of the relative reagent concentrations. (AU)

• FAPESP's process: 16/21070-5 - Vibrational spectroscopy with spatial resolution
• Grantee: Mauro Carlos Costa Ribeiro
• Support Opportunities: Research Projects - Thematic Grants