TY - JOUR
T1 - Pseudo-doping effect on structural and electrical properties of polyaniline-camphorsulfonic acid
AU - Garrudo, Fábio F.F.
AU - Ferreira, L. F.Vieira
AU - Ferraria, Ana M.
AU - do Rego, Ana M.Botelho
AU - Charas, Ana
AU - André, Vânia
AU - Duarte, M. Teresa
AU - Linhardt, Robert J.
AU - Ferreira, Frederico Castelo
AU - Morgado, Jorge
N1 - Publisher Copyright:
© 2023 The Authors
PY - 2024/1/1
Y1 - 2024/1/1
N2 - Electroconductive polymers (ECP) are critical for the design of soft electronic and bioelectronic devices. Polyaniline:camphorsulfonic acid (PANI:CSA) is an example of a biocompatible and affordable ECP, whose electroconductivity is highly dependent on chain organization/conformation. PANI:CSA aggregation ordering is overlooked in most works, but it can greatly impact the performance of PANI:CSA-based devices and limit their applicability. A simple and cheap method to avoid random coil aggregation of PANI:CSA is to select solvents with pseudo-doping properties. This work presents a novel alternative solvent system, based on trifluoroethanol (TFE) and hexafluoropropanol (HFP) mixtures, capable of being removed without hampering the structural and electrical properties of PANI:CSA. For the first time, we present a systematic study that compares the performance of solvent systems containing different amounts of TFE and HFP, which, unlike m-cresol, the golden-standard of pseudo-doping, are easy to remove without compromising the ECP's electroconductivity and biocompatibility. We also evaluate the influence of the processing method, drop-casting vs spin-coating, on the structural and electrical properties of the obtained samples. Samples obtained by spin-coating show a more consistent improvement in electroconductivity (σ(TFE) = 61 S cm−1, σ(TFE:HFP (50:50 vol)) = 70 S cm−1) and more intense near-infrared (NIR) absorption bands. Atomic force microscopy (AFM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) indicate that samples processed with HFP and m-cresol have higher benzenoid content, lower random coil aggregation and more efficient CSA doping. The solvent system comprised of equal parts of TFE and HFP was found to simultaneously enhance the electrical properties and structural ordering of PANI:CSA. We believe our results are critical for the fabrication of PANI-based next generation bioelectronic devices.
AB - Electroconductive polymers (ECP) are critical for the design of soft electronic and bioelectronic devices. Polyaniline:camphorsulfonic acid (PANI:CSA) is an example of a biocompatible and affordable ECP, whose electroconductivity is highly dependent on chain organization/conformation. PANI:CSA aggregation ordering is overlooked in most works, but it can greatly impact the performance of PANI:CSA-based devices and limit their applicability. A simple and cheap method to avoid random coil aggregation of PANI:CSA is to select solvents with pseudo-doping properties. This work presents a novel alternative solvent system, based on trifluoroethanol (TFE) and hexafluoropropanol (HFP) mixtures, capable of being removed without hampering the structural and electrical properties of PANI:CSA. For the first time, we present a systematic study that compares the performance of solvent systems containing different amounts of TFE and HFP, which, unlike m-cresol, the golden-standard of pseudo-doping, are easy to remove without compromising the ECP's electroconductivity and biocompatibility. We also evaluate the influence of the processing method, drop-casting vs spin-coating, on the structural and electrical properties of the obtained samples. Samples obtained by spin-coating show a more consistent improvement in electroconductivity (σ(TFE) = 61 S cm−1, σ(TFE:HFP (50:50 vol)) = 70 S cm−1) and more intense near-infrared (NIR) absorption bands. Atomic force microscopy (AFM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) indicate that samples processed with HFP and m-cresol have higher benzenoid content, lower random coil aggregation and more efficient CSA doping. The solvent system comprised of equal parts of TFE and HFP was found to simultaneously enhance the electrical properties and structural ordering of PANI:CSA. We believe our results are critical for the fabrication of PANI-based next generation bioelectronic devices.
KW - Electroconductivity
KW - Materials Chemistry and Engineering
KW - Spin-coating
KW - Structural characterization
KW - Tissue engineering
UR - http://www.scopus.com/inward/record.url?scp=85179480491&partnerID=8YFLogxK
U2 - 10.1016/j.synthmet.2023.117523
DO - 10.1016/j.synthmet.2023.117523
M3 - Article
AN - SCOPUS:85179480491
SN - 0379-6779
VL - 301
JO - Synthetic Metals
JF - Synthetic Metals
M1 - 117523
ER -