Studies of Interfacial Interaction between Polyaniline and Corn Gluten Meal and their Effect on Electroactive and Free Radical Scavenging Properties

Abstract

Preparation and characterisation of Corn Gluten Meal (CGM)-polyaniline (PANI) blends by direct deposition of PANI onto the CGM surface via in situ oxidative polymerisation of aniline was studied. A series of different CGM-PANI blends were prepared by varying CGM-aniline feed mass ratios 95:5, 90:10, 80:20, 70:30, 60:40 and 50:50. The blend compositions were studied by Elemental analysis. Interfacial interactions between nitrogen containing groups from CGM and PANI were detected by X-ray photoelectron spectroscopy and FTIR spectroscopy. Formation of electrically conductive emeraldine salt form of PANI in these blends was evident from their characteristic dark green colour. The conductivity of the blends was increased with increasing PANI content in the blends in the range between 10⁻² S·cm⁻¹ to 2 S·cm⁻¹. Similarly all these blends showed free radical scavenging activity and the effect was more pronounced at higher PANI content. Therefore inclusion of PANI introduced valuable functional properties in CGM which can be applicable for commercial uses.

Keywords:

• Corn gluten meal
• electrical conductivity, polyaniline
• in situ polymerisation
• free radical scavenging

Acknowledgments

The authors would like to thank the New Zealand Ministry of Business, Innovation & Employment (MBIE) for its support and funding for Biocide Tool Box research programme (UOAX1410) and the Research for Industry Hybrid Polymers program UOAX0812 which supported this publication and also Dr. Michél Nieuwoudt for assistance with FTIR spectroscopy, Dr. Colin Doyle and Dr. Ashveen Nand for assistance with XPS.