• English
  • Deutsch
  • Log In
    Password Login
    or
  • Research Outputs
  • Projects
  • Researchers
  • Institutes
  • Statistics
Repository logo
Fraunhofer-Gesellschaft
  1. Home
  2. Fraunhofer-Gesellschaft
  3. Artikel
  4. Programming Viscosity in Silicone Oils: Reversible Tuning of Rheological Properties in 9-Anthracene Ester-Terminated Polydimethylsiloxanes
 
  • Details
  • Full
Options
2020
Journal Article
Titel

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

Abstract
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 lightprogrammable9-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 cleavagefully 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. Material property gradients induced during radiation due to attenuation of the light beam upon its passing through the oil layer have to be considered, emphasizing the need for proper mixing protocols during the programming step. The material in focus shows integrated photorheology and is suggested to improve the performance of silicone oils in friction systems.
Author(s)
Gäbert, Chris
Fraunhofer-Institut für Angewandte Polymerforschung IAP
Rosenstingl, Tobias
Fraunhofer-Institut für Werkstoffmechanik IWM
Linsler, Dominic
Fraunhofer-Institut für Werkstoffmechanik IWM
Dienwiebel, Martin
Fraunhofer-Institut für Werkstoffmechanik IWM
Reinicke, Stefan
Fraunhofer-Institut für Angewandte Polymerforschung IAP
Zeitschrift
ACS applied polymer materials
Funder
Fraunhofer-Gesellschaft FhG
Thumbnail Image
DOI
10.1021/acsapm.0c00794
Language
English
google-scholar
Fraunhofer-Institut für Angewandte Polymerforschung IAP
Tags
  • polysiloxane

  • lubricant

  • light-programmable vi...

  • anthracene dimerizati...

  • reversible chain exte...

  • Cookie settings
  • Imprint
  • Privacy policy
  • Api
  • Send Feedback
© 2022