Rigid‐rod polymeric fibers

Chae, Han Gi; Kumar, Satish

doi:10.1002/app.22680

Cited by 320 publications

(192 citation statements)

References 112 publications

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“…As a proof-of-principle demonstration, we applied the polyester-derived calibration to find the Young's moduli (E) of two high performance fibers of known E: Nomex® (10-μm diameter), a stiffer fiber than polyester, and nylon (120-μm diameter), a more compliant fiber. We found E ¼ 18.9 AE 3.0 GPa and 4.3 AE 1.3 GPa for Nomex® and nylon, respectively, within the range of accepted values for these materials (23,24) (Fig. 2C).…”

Section: Resultssupporting

confidence: 77%

Luminescent nanocrystal stress gauge

Choi

Koski²,

Olson³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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Microscale mechanical forces can determine important outcomes ranging from the site of material fracture to stem cell fate. However, local stresses in a vast majority of systems cannot be measured due to the limitations of current techniques. In this work, we present the design and implementation of the CdSe-CdS core-shell tetrapod nanocrystal, a local stress sensor with bright luminescence readout. We calibrate the tetrapod luminescence response to stress and use the luminescence signal to report the spatial distribution of local stresses in single polyester fibers under uniaxial strain. The bright stress-dependent emission of the tetrapod, its nanoscale size, and its colloidal nature provide a unique tool that may be incorporated into a variety of micromechanical systems including materials and biological samples to quantify local stresses with high spatial resolution.nanoscience | semiconductor nanocrystals | fluorescence | luminescent stress gauge L ocal microscale stresses play a crucial role in inhomogeneous mechanical processes from cell motility to material failure. Stress is a tensor representing force per unit area and is directly related to strain-a tensor that represents change in size and/or shape-via the stiffness constants of a material. Contact-probe techniques that measure stiffness such as atomic force microscopy (1, 2), indentation testing (3), and optical coherence elastography (4), and noncontact techniques that measure stress such as micro-Raman spectroscopy (5), electron backscatter diffraction (6), and polymeric post arrays (7) have been used to quantify local mechanical behavior with high spatial resolution. However, these techniques remain limited to studies in specific material systems due to spectroscopic and geometric constraints. For example, although the mechanical behavior of cells can be indicative of significant aspects of their biology, including metastatic potential (8), the stresses exerted by cells in physiologic threedimensional culture systems cannot currently be quantified. A luminescent nanocrystal probe, with its small size, bright and narrow emission, and colloidal processability is ideally suited to measure local stresses in a variety of systems without spectroscopic requirements from or excessive perturbations to the material of interest.We present here the design and implementation of a luminescent nanocrystal stress gauge, the CdSe-CdS core-shell tetrapod. The tetrapod, with a CdSe quantum dot at its core, has the same advantages as its widely used quantum dot predecessor, including tunable quantum confinement and high fluorescence quantum yields (9). Four CdS arms protruding from the CdSe core confer a branched, three-dimensional structure on the tetrapod; these arms can act as dynamic levers to torque the CdSe core and alter its optical response. The tetrapod can be incorporated into many materials, yielding a local stress measurement through optical fluorescence spectroscopy of the electronically confined CdSe core states. In this report, we calibrate the stress...

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Section: Resultssupporting

confidence: 77%

Luminescent nanocrystal stress gauge

Choi

Koski²,

Olson³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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“…5 However, while these mechanical properties are impressive, they cannot compare to high performance rigid rod polymeric fibres such as ultra-high molecular weight polyethylene (DyneemaÒ), polyparaphenylene terephthalamide (KevlarÒ) and polypyridobisimidazole (PIPD) which can display modulus and strength as high as 330 GPa and 4 GPa respectively. 6 However, one advantage of polyester fibres is that they can be melt-spun, cheaply and in large quantities. Thus, there would be significant advantages to modifying existing polyesters to produce fibres with enhanced mechanical properties.…”

mentioning

confidence: 99%

High strength composite fibres from polyester filled with nanotubes and graphene

et al. 2012

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We have prepared composite fibres based on the polyester, polyethylene terephthalate (PET), filled with both single walled nanotubes and graphene by a combination of solution and melt processing. On addition of #2 wt% filler we observe increases in both modulus and strength by factors of between Â2 and Â4 for both fillers. For the nanotube-based fibres, the mechanical properties depend strongly on fibre diameter due to a combination of defect and nanotube orientation effects. For the graphene filled fibres, the modulus is approximately invariant with diameter while the strength is defect limited, scaling weakly with diameter. Using this production method, the best fibre we prepared had modulus and strength of 42 GPa and 1.2 GPa respectively (2 wt% SWNT). We attribute this reinforcement predominately to the dispersion quality resulting from the solvent exfoliation of both nanotubes and graphene. In general, marginally better reinforcement was observed for the nanotube filled fibres. However, because of the low cost of graphite, we suggest graphene to be the superior reinforcement material for polymer fibres.

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“…Such partition has recently been exploited in a fractionation process [122], which has relevance as the longer, straighter nanotubes are known to form stronger fibers, as is discussed further below. Liquid crystallinity is an example of self-organization, and such phases are known to be an excellent precursor for obtaining high orientation in fibers spun from the liquid, the process for making aramid fibers being the most important example, e.g., [123].…”

Section: Liquid Suspensions Of Carbon Nanotubesmentioning

confidence: 99%

Carbon Nanotube Synthesis and Organization

Joselevich

Dai

Liu

et al. 2007

Topics in Applied Physics

122

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Abstract. The synthesis, sorting and organization of carbon nanotubes are major challenges toward future applications. This chapter reviews recent advances in these topics, addressing both the bulk production and processing of carbon nanotubes, and their organization into ordered structures, such as fibers, and aligned arrays on surfaces. The bulk synthetic methods are reviewed with emphasis on the current advances toward mass production and selective synthesis. New approaches for the sorting of carbon nanotubes by structure and properties are described in the context of the specific physical or chemical interactions at play, and referring to the characterization methods described in the contribution by Jorio et al. Recent advances in the organization of carbon nanotubes into fibers are reviewed, including methods based on spinning from solution, from dry forests, and directly from the gas phase during growth. The organization of carbon nanotubes on surfaces, as a critical prerequisite toward future applications in nanoelectronics, is reviewed with particular emphasis given to the synthesis of both vertically and horizontally aligned arrays. Vertically aligned growth has been recently boosted by the development of highly efficient catalytic processes. Horizontally aligned growth on surfaces can yield a whole new array of carbon-nanotube patterns, with interesting physical properties and potential applications. Different mechanisms of horizontally aligned growth include field-and flow-directed growth, as well as recently developed methods of surface-directed growth on single-crystal substrates by epitaxial approaches. The proposed mechanisms pertinent to each technique are discussed throughout this review, as well as their potential applications and critical aspects toward future progress.

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Rigid‐rod polymeric fibers

Cited by 320 publications

References 112 publications

Luminescent nanocrystal stress gauge

Luminescent nanocrystal stress gauge

High strength composite fibres from polyester filled with nanotubes and graphene

Carbon Nanotube Synthesis and Organization

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