Intriguing properties of graphite/polysiloxane composite-based
pencil electrodes

J 2024

Intriguing properties of graphite/polysiloxane composite-based pencil electrodes

LI, Xiaochun, Jan ČECHAL, Lubomír ŠPAŇHEL, Siro TOSCANI, Jakub MARTINÍK et. al.

Basic information

Original name

Intriguing properties of graphite/polysiloxane composite-based pencil electrodes

Authors

LI, Xiaochun (156 China, belonging to the institution), Jan ČECHAL (203 Czech Republic), Lubomír ŠPAŇHEL (203 Czech Republic, belonging to the institution), Siro TOSCANI, Jakub MARTINÍK (203 Czech Republic, belonging to the institution), Radka OBOŘILOVÁ (203 Czech Republic, belonging to the institution) and Libuše TRNKOVÁ (203 Czech Republic, belonging to the institution)

Edition

Electrochimica Acta, Oxford, Elsevier, 2024, 0013-4686

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10405 Electrochemistry

Country of publisher

United Kingdom of Great Britain and Northern Ireland

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

URL

Impact factor

Impact factor: 6.600 in 2022

Organization unit

Faculty of Science

DOI

http://dx.doi.org/10.1016/j.electacta.2023.143615

UT WoS

001135407300001

Keywords in English

Polysiloxanes; Composites; Pencil graphite electrode; XPS; DSC; GC-MS/MS; EIS; CV; Elimination voltammetry with linear scan; (EVLS); SEM

Abstract

V originále

Pencil leads can be considered well-defined and cheap graphite electrodes for a wide range of electrochemistry applications. These electrodes display many intriguing properties; however, the origin of these properties is not clear. Using various analytical approaches applied to two different commercially available Tombow (TO) and Staedtler (ST) pencils we reveal a causal relationship between the unique properties of pencils and their graphite/polysiloxane composite. We explore the impact of chloroform etching on chemical composition changes, thermal stability and electrochemical parameters of pencils. Using a combination of X-ray photoelectron spectroscopy (XPS) and gas chromatography-mass spectrometry (GC-MS/MS) various polydimethylsiloxanes in composites are revealed. The polysiloxane species leave into the chloroform solvent during the etching resulting in a significant decrease of their content within the electrodes. Differential scanning calorimetry (DSC) data, corroborated by gravimetric measurements, provide additional proof of the presence of composite structures in ST and TO pencils, showing glass transition temperatures at around 76 degrees C and 81 degrees C. The main difference between the TO and ST electrodes is the content and composition of the polysiloxanes within the graphite matrix. ST composites have significantly higher polymer content (- 30 %) with traces of Na and S impurities compared to TO ones (- 14 %) free of contaminations. Furthermore, mainly cyclic nanostructures appear in chloroform extracts of ST composites whereas rather chain-like clusters are liberated out of the TO counterparts. Complementary electrochemical experiments using cyclic voltammetry (CV), impedance spectroscopy (EIS) and the less known elimination voltammetry with linear scan (EVLS) reflect the performance superiority of TO electrodes with much lower polysiloxane content and free of impurities. High conductivity, low capacitive current along with favoured charge carrier transfer all promise a wide range of technological applications for the TO pencil material.

Links

LM2023069, research and development project

Name: Výzkumná infrastruktura RECETOX

Investor: Ministry of Education, Youth and Sports of the CR, RECETOX research infrastructure

MUNI/A/1421/2022, interní kód MU

Name: Vývoj metod a instrumentace pro analýzu biologicky významných látek 2023

Investor: Masaryk University

90251, large research infrastructures

Name: CzechNanoLab II

Citovat

LI, Xiaochun, Jan ČECHAL, Lubomír ŠPAŇHEL, Siro TOSCANI, Jakub MARTINÍK, Radka OBOŘILOVÁ and Libuše TRNKOVÁ. Intriguing properties of graphite/polysiloxane composite-based pencil electrodes. Electrochimica Acta. Oxford: Elsevier, 2024, vol. 475, January, p. 1-12. ISSN 0013-4686. Available from: https://dx.doi.org/10.1016/j.electacta.2023.143615.

@article{2364722,
   author = {Li, Xiaochun and Čechal, Jan and Špaňhel, Lubomír and Toscani, Siro and Martiník, Jakub and Obořilová, Radka and Trnková, Libuše},
   article_location = {Oxford},
   article_number = {January},
   doi = {http://dx.doi.org/10.1016/j.electacta.2023.143615},
   keywords = {Polysiloxanes; Composites; Pencil graphite electrode; XPS; DSC; GC-MS/MS; EIS; CV; Elimination voltammetry with linear scan; (EVLS); SEM},
   language = {eng},
   issn = {0013-4686},
   journal = {Electrochimica Acta},
   title = {Intriguing properties of graphite/polysiloxane composite-based pencil electrodes},
   url = {https://www.sciencedirect.com/science/article/pii/S0013468623017851},
   volume = {475},
   year = {2024}
}

TY  - JOUR
ID  - 2364722
AU  - Li, Xiaochun - Čechal, Jan - Špaňhel, Lubomír - Toscani, Siro - Martiník, Jakub - Obořilová, Radka - Trnková, Libuše
PY  - 2024
TI  - Intriguing properties of graphite/polysiloxane composite-based pencil electrodes
JF  - Electrochimica Acta
VL  - 475
IS  - January
SP  - 1-12
EP  - 1-12
PB  - Elsevier
SN  - 00134686
KW  - Polysiloxanes
KW  - Composites
KW  - Pencil graphite electrode
KW  - XPS
KW  - DSC
KW  - GC-MS/MS
KW  - EIS
KW  - CV
KW  - Elimination voltammetry with linear scan
KW  - (EVLS)
KW  - SEM
UR  - https://www.sciencedirect.com/science/article/pii/S0013468623017851
N2  - Pencil leads can be considered well-defined and cheap graphite electrodes for a wide range of electrochemistry applications. These electrodes display many intriguing properties; however, the origin of these properties is not clear. Using various analytical approaches applied to two different commercially available Tombow (TO) and Staedtler (ST) pencils we reveal a causal relationship between the unique properties of pencils and their graphite/polysiloxane composite. We explore the impact of chloroform etching on chemical composition changes, thermal stability and electrochemical parameters of pencils. Using a combination of X-ray photoelectron spectroscopy (XPS) and gas chromatography-mass spectrometry (GC-MS/MS) various polydimethylsiloxanes in composites are revealed. The polysiloxane species leave into the chloroform solvent during the etching resulting in a significant decrease of their content within the electrodes. Differential scanning calorimetry (DSC) data, corroborated by gravimetric measurements, provide additional proof of the presence of composite structures in ST and TO pencils, showing glass transition temperatures at around 76 degrees C and 81 degrees C. The main difference between the TO and ST electrodes is the content and composition of the polysiloxanes within the graphite matrix. ST composites have significantly higher polymer content (- 30 %) with traces of Na and S impurities compared to TO ones (- 14 %) free of contaminations. Furthermore, mainly cyclic nanostructures appear in chloroform extracts of ST composites whereas rather chain-like clusters are liberated out of the TO counterparts. Complementary electrochemical experiments using cyclic voltammetry (CV), impedance spectroscopy (EIS) and the less known elimination voltammetry with linear scan (EVLS) reflect the performance superiority of TO electrodes with much lower polysiloxane content and free of impurities. High conductivity, low capacitive current along with favoured charge carrier transfer all promise a wide range of technological applications for the TO pencil material.
ER  -

LI, Xiaochun, Jan ČECHAL, Lubomír ŠPAŇHEL, Siro TOSCANI, Jakub MARTINÍK, Radka OBOŘILOVÁ and Libuše TRNKOVÁ. Intriguing properties of graphite/polysiloxane composite-based pencil electrodes. \textit{Electrochimica Acta}. Oxford: Elsevier, 2024, vol.~475, January, p.~1-12. ISSN~0013-4686. Available from: https://dx.doi.org/10.1016/j.electacta.2023.143615.

Detailed Information on Publication Record