Mechanisms of Local Stress Sensing in Multifunctional Polymer Films Using Fluorescent Tetrapod Nanocrystals

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review

11 Scopus Citations
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Author(s)

  • Shilpa N. Raja
  • Danylo Zherebetskyy
  • Siva Wu
  • Peter Ercius
  • Alexander Powers
  • Andrew C. K. Olson
  • Daniel X. Du
  • Liwei Lin
  • Sanjay Govindjee
  • Lin-Wang Wang
  • Ting Xu
  • A. Paul Alivisatos

Detail(s)

Original languageEnglish
Pages (from-to)5060-5067
Journal / PublicationNano Letters
Volume16
Issue number8
Early online date19 Jul 2016
Publication statusPublished - 10 Aug 2016
Externally publishedYes

Abstract

Nanoscale stress-sensing can be used across fields ranging from detection of incipient cracks in structural mechanics to monitoring forces in biological tissues. We demonstrate how tetrapod quantum dots (tQDs) embedded in block copolymers act as sensors of tensile/compressive stress. Remarkably, tQDs can detect their own composite dispersion and mechanical properties with a switch in optomechanical response when tQDs are in direct contact. Using experimental characterizations, atomistic simulations and finite-element analyses, we show that under tensile stress, densely packed tQDs exhibit a photoluminescence peak shifted to higher energies ("blue-shift") due to volumetric compressive stress in their core; loosely packed tQDs exhibit a peak shifted to lower energies ("red-shift") from tensile stress in the core. The stress shifts result from the tQD's unique branched morphology in which the CdS arms act as antennas that amplify the stress in the CdSe core. Our nanocomposites exhibit excellent cyclability and scalability with no degraded properties of the host polymer. Colloidal tQDs allow sensing in many materials to potentially enable autoresponsive, smart structural nanocomposites that self-predict impending fracture.

Research Area(s)

  • fluorescence spectroscopy, mechanical, Nanocomposite, polymer, sensor, tetrapod nanocrystal

Citation Format(s)

Mechanisms of Local Stress Sensing in Multifunctional Polymer Films Using Fluorescent Tetrapod Nanocrystals. / Raja, Shilpa N.; Zherebetskyy, Danylo; Wu, Siva; Ercius, Peter; Powers, Alexander; Olson, Andrew C. K.; Du, Daniel X.; Lin, Liwei; Govindjee, Sanjay; Wang, Lin-Wang; Xu, Ting; Alivisatos, A. Paul; Ritchie, Robert O.

In: Nano Letters, Vol. 16, No. 8, 10.08.2016, p. 5060-5067.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review