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Andrzej Galeski

Bio: Andrzej Galeski is an academic researcher from Polish Academy of Sciences. The author has contributed to research in topics: Crystallization & Deformation (engineering). The author has an hindex of 47, co-authored 198 publications receiving 8162 citations. Previous affiliations of Andrzej Galeski include Massachusetts Institute of Technology & Case Western Reserve University.


Papers
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Journal ArticleDOI
TL;DR: A revised morphological model for the crimp structure of tendon is presented and small bunches of collagen fibrils removed from the tendon are shown to exhibit the simple planar zig-zag morphology described in previous literature.
Abstract: A revised morphological model for the crimp structure of tendon is presented. The 300-500 mu diameter tendons of the mature rat tail are comprised of from one to more than ten substructures, called fascicles, of 80-320 mu diameter. Fascicles each possess a "crimp structure" demonstrable in the polarizing microscope and neighboring fascicles within a tendon usually exhibit crimp registry. The fascicle itself is shown to be a cylindrical array of planar-zig-zag crimped 500-5000 A diameter collagen fibrils. The approximate cylindrical symmetry of the fascicle is domonstrated by SEM not equal to and polarizing optical microscopy. A method of replacing native water with other liquids of refractive index near to that of collagen is utilized to reduce or eliminate light diffusion and therby greatly improve OM observations. Small bunches of collagen fibrils removed from the tendon are shown to exhibit the simple planar zig-zag morphology described in previous literature. The planar crimping of collagen fibrils and their assemblage into cylindrically symmetric fascicles is verified by small angle X-ray diffraction.

623 citations

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TL;DR: The role of crystal plasticity in achieving high toughness is addressed in this article, where two possibilities of the modification of crystal thickness are described: increase in the crystal thickness and a reduction in the number of mobile dislocations in polymer crystals, and two examples of efficient toughening in multicomponent polypropylene systems connected with cavitation are described.

479 citations

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TL;DR: In this article, the morphology and thermal properties of polylactide (PLA)/clay nanocomposites and microcomposites were compared with unfilled PLA, keeping the same thermomechanical history.
Abstract: Polylactide (PLA)/clay nanocomposites loaded with 3 wt % organomodified montmorillonite and PLA/clay microcomposites containing 3 wt % sodium montmorillonite were prepared by melt blending. We investigated the morphology and thermal properties of the nanocomposites and microcomposites and compared them with unfilled PLA, keeping the same thermomechanical history. The influence of the processing temperature on the structural characteristics of the investigated systems was determined. The investigations were performed with differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), size exclusion chromatography (SEC), and polarized light microscopy (LM). XRD showed that the good affinity between the organomodified clay and the PLA was sufficient to form intercalated structure in the nanocomposite. The microcomposite featured a phase-separated constitution. DSC and LM studies showed that the nature of the filler affected the ordering of the PLA matrix at the molecular and supermolecular levels. According to TGA, the PLA-based nanocomposites exhibited improvement in their thermal stability in air. Reduced flammability, together with char formation, was also observed for nanocomposites, compared to the microcomposites and pure PLA. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1497–1506, 2002

348 citations

Journal ArticleDOI
06 Feb 2009-Science
TL;DR: In this paper, the authors used an innovative layer-multiplying coextrusion process to obtain assemblies with thousands of polymer nanolayers, and discovered a morphology that emerges as confined polyethylene oxide (PEO) layers are made progressively thinner.
Abstract: The design and fabrication of ultrathin polymer layers are of increasing importance because of the rapid development of nanoscience and nanotechnology. Confined, two-dimensional crystallization of polymers presents challenges and opportunities due to the long-chain, covalently bonded nature of the macromolecule. Using an innovative layer-multiplying coextrusion process to obtain assemblies with thousands of polymer nanolayers, we discovered a morphology that emerges as confined polyethylene oxide (PEO) layers are made progressively thinner. When the thickness is confined to 20 nanometers, the PEO crystallizes as single, high-aspect-ratio lamellae that resemble single crystals. Unexpectedly, the crystallization habit imparts two orders of magnitude reduction in the gas permeability.

318 citations

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TL;DR: Nanocellulose has generated a great deal of interest as a source of nanometer-sized reinforcement, because of its good mechanical properties as discussed by the authors and its various preparation techniques.

301 citations


Cited by
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TL;DR: A review of the academic and industrial aspects of the preparation, characterization, materials properties, crystallization behavior, melt rheology, and processing of polymer/layered silicate nanocomposites is given in this article.

6,343 citations

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TL;DR: Polylactic acid is proving to be a viable alternative to petrochemical-based plastics for many applications It is produced from renewable resources and is biodegradable, decomposing to give H2O, CO2, and humus, the black material in soil as mentioned in this paper.
Abstract: Polylactic acid is proving to be a viable alternative to petrochemical-based plastics for many applications It is produced from renewable resources and is biodegradable, decomposing to give H2O, CO2, and humus, the black material in soil In addition, it has unique physical properties that make it useful in diverse applications including paper coating, fibers, films, and packaging (see Figure)

2,537 citations

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TL;DR: In this paper, the structure, preparation and properties of polymer-layered silicate nanocomposites are discussed in general, and detailed examples are also drawn from the scientific literature.

2,277 citations

Journal ArticleDOI
TL;DR: In this paper, the basic principles involved in designing hierarchical biological materials, such as cellular and composite architectures, adapative growth and as well as remodeling, are discussed, and examples that are found to utilize these strategies include wood, bone, tendon, and glass sponges.

2,274 citations

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TL;DR: A review of polymer blends and composites from renewable resources can be found in this article, where the progress of blends from three kinds of polymers from renewable sources (i.e., natural polymers such as starch, protein and cellulose), synthetic polymers, such as polylactic acid and polyhydroxybutyrate, are described with an emphasis on potential applications.

1,931 citations