Detailed Information on Publication Record
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:
Impact factor
Impact factor: 6.600 in 2022
Organization unit
Faculty of Science
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
Tags
Tags
International impact, Reviewed
Změněno: 5/11/2024 15:45, Mgr. Pavla Foltynová, Ph.D.
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 |
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| MUNI/A/1421/2022, interní kód MU |
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| MUNI/A/1594/2023, interní kód MU |
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| 90251, large research infrastructures |
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