Mechanics of an Asymmetric Hard–Soft Lamellar Nanomaterial

Shi, Weichao; Fredrickson, Glenn H.; Krämer, Edward J.; Ntaras, Christos; Avgeropoulos, Apostolos; Demassieux, Quentin; Creton, Costantino

doi:10.1021/acsnano.5b06215

Cited by 23 publications

(24 citation statements)

References 57 publications

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“…A very efficient way to do so is to design a percolating hard domain into a predominantly soft material. [1][2][3][4][5] At small deformations the stress is carried by the stiff network while as the deformation increases, the percolating structure breaks and the load is sustained by the soft domains which can be very extensible.…”

Section: Introductionmentioning

confidence: 99%

Mechanical properties of nanostructured films with an ultralow volume fraction of hard phase

Chenal¹,

Véchambre²,

Chenal³

et al. 2017

Polymer

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We demonstrate in this paper how polymerization induced self-assembly (PISA) using RAFT can be used to synthesize very asymmetric but monodisperse poly(acrylic acid)-b-poly(nbutyl acrylate) block copolymers, PAA-b-PBA, with a short PAA block and a long PBA block. In the course of the surfactant-free emulsion polymerization, core-shell particles form in water, with the short hydrophilic block located at the water-particle interface, and the long hydrophobic block constituting the particle core. Drying at room temperature creates films possessing an out of equilibrium structure, where the glassy PAA block generates a percolating network of shells. When deformed in uniaxial elongation, these films combine a high stiffness in small strains (considering the low volume fraction of PAA, of only 3 wt%), a yield stress and a significant extensibility before failure. The modulus, yield stress and extensibility can be tuned by modifying the composition of the latex serum with cations or positively charged low molar mass polymers, or by changing the copolymer composition. Of particular interest was the synthesis by PISA of particles of triblock copolymer PAA-b-PBAb-PS. The out of equilibrium structure obtained had a very interesting combination of high stiffness, extensibility and high fracture toughness.

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Section: Introductionmentioning

confidence: 99%

Mechanical properties of nanostructured films with an ultralow volume fraction of hard phase

Chenal¹,

Véchambre²,

Chenal³

et al. 2017

Polymer

Self Cite

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“…For other molecular topologies, e.g., pentablock copolymers or star architectures, the phase diagrams are shifted. For example, for PS/PI miktoarm star block copolymer blends with PS, lamellar phase separation can be found even for a very low PI content of only ϕ PI = 3%. , …”

Section: Theorymentioning

confidence: 99%

“…For example, for PS/PI miktoarm star block copolymer blends with PS, lamellar phase separation can be found even for a very low PI content of only ϕ PI = 3%. 22,23 Besides the microstructure, the polymer chain alignment is also of high importance for the resulting mechanical properties of block copolymers. For an AB diblock, it is clear that each block is separated in its respective microdomain.…”

Section: Theorymentioning

confidence: 99%

Effect of Topology and Molecular Properties on the Rheology and Fatigue Behavior of Solid Polystyrene/Polyisoprene Di- and Triblock Copolymers

et al. 2020

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The effect of molecular properties on the rheological and fatigue behaviors of solid polystyrene (PS)/polyisoprene (PI) block copolymers was investigated. Linear model systems of PS–PI (SI), PS–PI–PS (SIS), and PI–PS–PI (ISI) block copolymers were synthesized via anionic polymerization with well-defined molecular structure variation such as block order, PI content, molecular weight, microstructure, and polydispersity. The different block sequences (SI vs SIS vs ISI) result, for similar PI contents, in different microdomain sizes, which correlate with the phase-separated morphologies as quantified via small-angle X-ray scattering (SAXS). The samples were mechanically characterized in the solid state via strain sweep tests to obtain their storage G′(γ0) and loss G″(γ0) moduli at room temperature as well as their nonlinear properties determined via the Fourier transform (FT) of the stress response. The fatigue behavior was determined via strain-controlled oscillatory torsion tests. First, the effect of strain amplitude on the number of cycles to failure was analyzed via Wöhler curves, specifically strain amplitude vs fatigue lifetime. A significant effect of the block sequence order, the microdomain size, and the chain dynamics on fatigue resistance was found. The fatigue resistance of SI diblock with 30 mol % PI outperforms the SIS or ISI triblock copolymer with a similar composition and, compared to neat PS, increases by a factor of 10 and even 4500, respectively. Second, the time-dependent stress response was analyzed via Fourier transform rheology to better quantify the time-dependent behavior of the nonlinear mechanical parameters and to determine quantitative parameters related to failure onset. Since the fatigue tests were performed under large amplitude oscillatory shear (LAOS), higher harmonics were detected and the time evolution was quantified in the FT spectra. Linear parameters such as the storage (G′) and loss (G″) moduli, as well as the third (I 3) harmonic over the fundamental one (I 1), were analyzed, leading to clear indications related to both brittle or ductile failure mechanisms.

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“…• Superconducting thin films, switches, memories [33] • SQUIDS (superconducting quantum interference devices) [34] Mechanics • "Hard" layers (e.g. on drill bits) [35] • Adhesion providers [36] • Friction reduction [37] Introductory Chapter: The Prominence of Thin Film Science in Technological Scale http://dx.doi.org/10.5772/67201 toxicity. Thus, it is figured out that this only evaluation is inadequate for building improvement, which leads to ecological preservation and to deep circumvention against human health.…”

Section: Technological Advancements In the Science Of Thin Filmsmentioning

confidence: 99%

Introductory Chapter: The Prominence of Thin Film Science in Technological Scale

Thirumalai¹

2017

Thin Film Processes - Artifacts on Surface Phenomena and Technological Facets

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Since antediluvian times, the term 'thin film coating technology' is more captivating towards mankind. More than 2000 eons ago, goldsmiths and silversmiths developed a variety of methods, including using mercury as an adhesive, to apply over thin films of metals to sculptures and other objects. The ancient mercury-based processes like fire gilding and silvering techniques were used for the surface coating of less precious substrates having thin layers made up of gold or silver. They developed the technology of thin-film coating that is unrivalled by today's process for manufacturing DVDs, electronic devices, solar cells and other relevant products and used it on statues, amulets, jewels and more common objects.

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Mechanics of an Asymmetric Hard–Soft Lamellar Nanomaterial

Cited by 23 publications

References 57 publications

Mechanical properties of nanostructured films with an ultralow volume fraction of hard phase

Mechanical properties of nanostructured films with an ultralow volume fraction of hard phase

Effect of Topology and Molecular Properties on the Rheology and Fatigue Behavior of Solid Polystyrene/Polyisoprene Di- and Triblock Copolymers

Introductory Chapter: The Prominence of Thin Film Science in Technological Scale

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