Effect of template type on the preparation of the emeraldine salt form of polyaniline (PANI-ES) with horseradish peroxidase isoenzyme C (HRPC) and hydrogen peroxide

Horseradish peroxidase isoenzyme C (HRPC) is often used as catalyst for the preparation of the conductive emeraldine salt form of polyaniline (PANI-ES) from aniline and hydrogen peroxide (H2O2) in the presence of anionic templates in aqueous solution. Here, a direct comparison of three types of soft templates was made, (i) the sodium salt of sulfonated polystyrene (SPS), (ii) micelles from sodium dodecylbenzenesulfonate (SDBS), and (iii) vesicles from either a 1:1 molar mixture of SDBS and decanoic acid or from AOT (sodium bis(2-ethylhexyl)sulfosuccinate). Based on UV/vis/NIR, EPR and Raman spectroscopy measurements all three types of templates are similarly suitable, with advantages of the two vesicle systems in terms of aniline conversion degree and radical content in the final PANI-ES product. First experiments with sulfated cellulose nanocrystals (CNCs) indicate that they are promising rigid templates for the preparation of electroconductive PANI-ES-coated cellulose materials or devices.Financial support for this work was provided by the Swiss National Science Foundation projects 200020_150254 and IZ73Z0_152457 (P. W., S. S.-L., G. C.-M., D. B.-B., and M. M.-R.), the Ministry of Education, Science and Technological Development of Serbia project OI172043 (G. C.-M., D. B.-B. and M. M.-R.) and through the generous fellowships given to K. K (National Institute of Technology, Faculty Research Abroad Program, Japan) and T. F. (TOBITATE! Young ambassador program from The Japan Public-Private Partnership Student Study Abroad Program) for their stay at ETH. E. L. thanks The Spanish Ministry of Education, Culture and Sport for the "Jose Castillejo" mobility grant and Dr Elena Tervoort-Gorokhovat for the assistance provided during the SEM analyses