Polymer microbubbles as universal platform to accelerate polymer mechanochemistry

Nature Communications, vol. 16, pp. 5380

Abstract

The flow-induced activation of mechanophores embedded in linear polymers by ultrasound (US) suffers from slow mechanochemical conversions at the commonly used frequency of 20 kHz and in many cases remains ineffective with higher MHz frequencies. Here, we present polymeric microbubbles (PMBs) as a platform that accelerates the mechanochemical activation of several mechanophores under both 20 kHz and MHz irradiation. MHz irradiation generated by biocompatible high-intensity focused US (HIFU). Through their pressure-sensitive gas core, PMBs act as acousto-mechanical transducers for the transformation of sound energy into stretching and compression forces as well as fracturing the polymer shell by the volume oscillation of PMB. We investigate three different mechanophores among which one flex-activation derivative was unexpectedly activated by US. Through a combination of experiments and computation, we find that PMBs likely exert compressive force onto the copolymerized mechanophores rather than the typical elongational forces solvated chain fragments experience in flow. We thereby underscore the mechanochemical properties of the PMB platform and its versatility for accelerated mechanochemical transformations with a perspective on biomedical applications.

Authors 7

1. Jilin Fan Aachen DWI - Leibniz Institute for Interactive Materials Institute of Technical and Macromolecular Chemistry

   DWI – Leibniz Institute for Interactive Materials · RWTH Aachen University

   Affiliation as printed

   DWI - Leibniz Institute for Interactive Materials, 52056, Aachen, Germany

   Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, 52074, Aachen, Germany

2. Regina Lennarz

   Heinrich Heine University Düsseldorf

   Affiliation as printed

   Institute for Physical Chemistry, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany

3. Kuan Zhang Aachen DWI - Leibniz Institute for Interactive Materials Institute of Technical and Macromolecular Chemistry

   DWI – Leibniz Institute for Interactive Materials · Wenzhou Institute, University of Chinese Academy of Sciences · RWTH Aachen University

   Affiliation as printed

   DWI - Leibniz Institute for Interactive Materials, 52056, Aachen, Germany

   Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, 52074, Aachen, Germany

   Wenzhou Institute, University of Chinese Academy of Sciences, 325001, Wenzhou, China

4. Ahmed Mourran Aachen DWI - Leibniz Institute for Interactive Materials

   DWI – Leibniz Institute for Interactive Materials

   Affiliation as printed

   DWI - Leibniz Institute for Interactive Materials, 52056, Aachen, Germany

5. Jan Meisner

   Heinrich Heine University Düsseldorf

   Affiliation as printed

   Institute for Physical Chemistry, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany

6. Mingjun Xuan corresponding Aachen DWI - Leibniz Institute for Interactive Materials Institute of Technical and Macromolecular Chemistry

   DWI – Leibniz Institute for Interactive Materials · Wenzhou Institute, University of Chinese Academy of Sciences · RWTH Aachen University

   Affiliation as printed

   DWI - Leibniz Institute for Interactive Materials, 52056, Aachen, Germany. xuan@wiucas.ac.cn

   Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, 52074, Aachen, Germany. xuan@wiucas.ac.cn

   Wenzhou Institute, University of Chinese Academy of Sciences, 325001, Wenzhou, China. xuan@wiucas.ac.cn

7. Robert Göstl corresponding Aachen DWI - Leibniz Institute for Interactive Materials Institute of Technical and Macromolecular Chemistry

   University of Wuppertal · DWI – Leibniz Institute for Interactive Materials · RWTH Aachen University

   Affiliation as printed

   DWI - Leibniz Institute for Interactive Materials, 52056, Aachen, Germany. goestl@uni-wuppertal.de

   Department of Chemistry and Biology, University of Wuppertal, 42119, Wuppertal, Germany. goestl@uni-wuppertal.de

   Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, 52074, Aachen, Germany. goestl@uni-wuppertal.de