Untitled

Liu, Hui-Hsiang; Chen, Wei-Tin; Wu, Fuh-Tsang

doi:10.1023/a:1021359903385

Cited by 9 publications

(1 citation statement)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This example is the only known mechanoacid reported to date. Because acid-catalyzed polymerization and cross-linking reactions such as polysiloxane formation, epoxy resin curing, novolac resin cross-linking, etc. are well-known, mechanoacids offer potential for designing mechanically triggered, autonomous self-healing materials when coupled with acid amplifier molecules.…”

Section: Timeline Of Polymer Mechanochemistry Developments In the Moo...mentioning

confidence: 99%

Polymer Mechanochemistry: From Destructive to Productive

Nagamani

Moore³

2015

Acc. Chem. Res.

592

513

View full text Add to dashboard Cite

When one brings "polymeric materials" and "mechanical action" into the same conversation, the topic of this discussion might naturally focus on everyday circumstances such as failure of fibers, fatigue of composites, abrasion of coatings, etc. This intuitive viewpoint reflects the historic consensus in both academia and industry that mechanically induced chemical changes are destructive, leading to polymer degradation that limits materials lifetime on both macroscopic and molecular levels. In the 1930s, Staudinger observed mechanical degradation of polymers, and Melville later discovered that polymer chain scission caused the degradation. Inspired by these historical observations, we sought to redirect the destructive mechanical energy to a productive form that enables mechanoresponsive functions. In this Account, we provide a personal perspective on the origin, barriers, developments, and key advancements of polymer mechanochemistry. We revisit the seminal events that offered molecular-level insights into the mechanochemical behavior of polymers and influenced our thinking. We also highlight the milestones achieved by our group along with the contributions from key comrades at the frontier of this field. We present a workflow for the design, evaluation, and development of new "mechanophores", a term that has come to mean a molecular unit that chemically responds in a selective manner to a mechanical perturbation. We discuss the significance of computation in identifying pairs of points on the mechanophore that promote stretch-induced activation. Attaching polymer chains to the mechanophore at the most sensitive pair and locating the mechanophore near the center of a linear polymer are thought to maximize the efficiency of mechanical-to-chemical energy transduction. We also emphasize the importance of control experiments to validate mechanochemical transformations, both in solution and in the solid state, to differentiate "mechanical" from "thermal" activation. This Account offers our first-hand perspective of the change-in-thinking in polymer mechanochemistry from "destructive" to "productive" and looks at future advances that will stimulate this growing field.

show abstract

Section: Timeline Of Polymer Mechanochemistry Developments In the Moo...mentioning

confidence: 99%

Polymer Mechanochemistry: From Destructive to Productive

Nagamani

Moore³

2015

Acc. Chem. Res.

592

513

View full text Add to dashboard Cite

show abstract

Release of Molecular Cargo from Polymer Systems by Mechanochemistry

Küng

Göstl

Schmidt

2022

Chemistry A European J

View full text Add to dashboard Cite

The design and manipulation of (multi)functional materials at the nanoscale holds the promise of fuelling tomorrow's major technological advances. In the realm of macromolecular nanosystems, the incorporation of force‐responsive groups, so called mechanophores, has resulted in unprecedented access to responsive behaviours and enabled sophisticated functions of the resulting structures and advanced materials. Among the diverse force‐activated motifs, the on‐demand release or activation of compounds, such as catalysts, drugs, or monomers for self‐healing, are sought‐after since they enable triggering pristine small molecule function from macromolecular frameworks. Here, we highlight examples of molecular cargo release systems from polymer‐based architectures in solution by means of sonochemical activation by ultrasound (ultrasound‐induced mechanochemistry). Important design concepts of these advanced materials are discussed, as well as their syntheses and applications.

show abstract

Preparation and characterization of chiral polyacrylates end‐capped with bornyl groups in the side chains

Liu

Hsieh

Wang

2004

J. Polym. Sci. A Polym. Chem.

View full text Add to dashboard Cite

Chiral polyacrylates with bornyl end‐capped side chains with four kinds of mesogenic moieties (azobenzene, biphenyl, benzoyloxy biphenyl, and phenyl benzoate) were prepared. The phase properties of the polymers were investigated with X‐ray diffraction, differential scanning calorimetry, and polarizing optical microscopy. The thermogravimetric characteristics, the glass‐transition temperatures and weight‐average molecular weights, of the homopolymers were evaluated. The optical properties of the synthesized polymers in diluted solutions and in the thin‐film state were also evaluated. The optical behavior of the composite films upon photoirradiation was investigated through the change in the transmittance of the probe light triggered by ultraviolet (365‐nm) irradiation. Ultraviolet irradiation and heat treatment caused a reversible intensity change of the probe light at λ = 400 nm. The shrinkage of the photoisomerization of the composite films was also investigated with atomic force microscopy. A spot contraction appeared on the surface when it was irradiated with a laser light spot. The contraction was recovered by heat treatment at 80 °C for 10 min. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1075–1092, 2004

show abstract

Untitled

Cited by 9 publications

References 8 publications

Polymer Mechanochemistry: From Destructive to Productive

Polymer Mechanochemistry: From Destructive to Productive

Release of Molecular Cargo from Polymer Systems by Mechanochemistry

Preparation and characterization of chiral polyacrylates end‐capped with bornyl groups in the side chains

Contact Info

Product

Resources

About