2024
Intriguing properties of graphite/polysiloxane composite-based pencil electrodes
LI, Xiaochun, Jan ČECHAL, Lubomír ŠPAŇHEL, Siro TOSCANI, Jakub MARTINÍK et. al.Základní údaje
Originální název
Intriguing properties of graphite/polysiloxane composite-based pencil electrodes
Autoři
LI, Xiaochun (156 Čína, domácí), Jan ČECHAL (203 Česká republika), Lubomír ŠPAŇHEL (203 Česká republika, domácí), Siro TOSCANI, Jakub MARTINÍK (203 Česká republika, domácí), Radka OBOŘILOVÁ (203 Česká republika, domácí) a Libuše TRNKOVÁ (203 Česká republika, domácí)
Vydání
Electrochimica Acta, Oxford, Elsevier, 2024, 0013-4686
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10405 Electrochemistry
Stát vydavatele
Velká Británie a Severní Irsko
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Impakt faktor
Impact factor: 6.600 v roce 2022
Organizační jednotka
Přírodovědecká fakulta
UT WoS
001135407300001
Klíčová slova anglicky
Polysiloxanes; Composites; Pencil graphite electrode; XPS; DSC; GC-MS/MS; EIS; CV; Elimination voltammetry with linear scan; (EVLS); SEM
Štítky
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 19. 2. 2024 12:20, Mgr. Pavla Foltynová, Ph.D.
Anotace
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.
Návaznosti
LM2023069, projekt VaV |
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MUNI/A/1421/2022, interní kód MU |
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90251, velká výzkumná infrastruktura |
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