Spectroscopy, Morphology, and Electrochemistry of Electrospun Polyamic Acid Nanofibers

Siyabulela Hamnca; Jessica Chamier; Sheila Grant; Timothy Glass; Emmanuel Iwuoha; Priscilla Baker

doi:10.3389/fchem.2021.782813

Spectroscopy, Morphology, and Electrochemistry of Electrospun Polyamic Acid Nanofibers

Front Chem. 2022 Feb 16:9:782813. doi: 10.3389/fchem.2021.782813. eCollection 2021.

Authors

Siyabulela Hamnca¹, Jessica Chamier², Sheila Grant³, Timothy Glass³, Emmanuel Iwuoha¹, Priscilla Baker¹

Affiliations

¹ SensorLab, Chemistry Department, University of the Western Cape, Bellville, South Africa.
² HySA Catalysis, Department of Chemical Engineering, University of Cape Town, Rondebosch, Cape Town, South Africa.
³ Chemistry Department, University of Missouri, Columbia, MO, United states.

Abstract

Polyamic acid (PAA) nanofibers produced by using the electrospinning method were fully characterized in terms of morphology and spectroscopy. A PAA nanofiber-modified screen-printed carbon electrode was applied to the detection of selected sulfonamides by following an electroanalytical protocol. The polyamic acid (PAA) nanofibers were characterized using Fourier transform infrared (FTIR) spectroscopy to study the integrity of polyamic acid functional groups as nanofibers by comparing them to chemically synthesized polyamic acid. A scanning electron microscope (SEM) was used to confirm the morphology of the produced nanofibers and 3D arrangement at the electrode interface. The Brunauer-Emmett-Teller (BET) method was used to determine the surface area of the nanofibers. Atomic force microscopy (AFM) was used to study the porosity and surface roughness of the nanofibers. Electrochemical evaluation based on diffusion-controlled kinetics was applied to determine the number of electrons transferred in the system, the surface concentration of the deposited PAA thin film (2.14 × 10^-6 mol/cm²), and the diffusion coefficient (D_e) for the PAA nanofiber-modified screen-printed carbon electrode (9.43 × 10^-7 cm^-2/s). The reported LODs for sulfadiazine and sulfamethazine detection are consistent with requirements for trace-level monitoring by early warning diagnostic systems.

Keywords: electrochemistry; electrospun (ES) nanofibers; nanofibers; polyamic acid; screen-printed carbon electrodes.