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Programming Viscosity in Silicone Oils: Reversible Tuning of Rheological Properties in 9-Anthracene Ester-Terminated Polydimethylsiloxanes

Gäbert, C.; Rosenstingl, T.; Linsler, D.; Dienwiebel, M.; Reinicke, S.

Abstract (englisch):
Programmable oils feature tunable viscosity and therefore possess potential for technical improvements and innovative solutions in many lubricated applications. Herein, we describe the first assessment of the variability of rheological properties of light-programmable 9-anthracene ester-terminated polydimethylsiloxanes (PDMS-As), including implications that arise with UV-light as an external trigger. We applied a modified rheometer setup that enables the monitoring of dynamic moduli during exposure to UV-light. The reversible dimerization of anthracene esters is used to either link PDMS chains by UV-A radiation (365 nm) or cleave chains by UV-C radiation (254 nm) or at elevated temperatures (>130 °C). Thermal cleavage fully restores the initial material properties, while the photochemical cleavage of dimers occurs only to a limited extent. Prolonged UV radiation causes material damage and in turn reduces the range of programmable rheological properties. The incomplete cleavage contributes to a gradual buildup of viscosity over a course of several switching cycles, which we suggest to result from chain length-dependent reaction kinetics. ... mehr

DOI: 10.1021/acsapm.0c00794
Zitationen: 2
Zitationen: 2
Zugehörige Institution(en) am KIT Institut für Angewandte Materialien - Computational Materials Science (IAM-CMS)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2020
Sprache Englisch
Identifikator ISSN: 2637-6105
KITopen-ID: 1000127697
Erschienen in ACS applied polymer materials
Verlag American Chemical Society (ACS)
Band 2
Heft 12
Seiten 5460-5468
Nachgewiesen in Dimensions
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