On the >1 µm scale the morphology of semicrystalline plastics like polyethylene or Nylon features spherulites, “shish-kebabs”, cylinddrites and other crystalline aggregates which strongly affect mechanical and other material properties. Current imaging techniques give only a 2D picture of these objects. Here we show how they can be visualized in 3D using fluorescent labels and confocal microscopy. As a result, we see spherulites in 3D, both in neat polymers and their nanocomposites, and observe how unevenly nanoparticles and other additives are distributed in the material. Images of i-polypropylene and biodegradable poly(lactic acid) reveal previously unsuspected morphologies such as “vases” and “goblets”, nonspherical “spherulites” and, unexpectedly, “shish-kebabs” grown from quiescent melt. Also surprisingly, in nanocomposite sheets spherulite nucleation is seen to be copied from one surface to another, mediated by crystallization-induced pressure drop and local melt-flow. These first results reveal unfamiliar modes of self-assembly in familiar plastics and open fresh perspectives on polymer microstructure.

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Due to various production stages involved, textiles and clothing industry is known for causing carbon dioxide emissions, water pollution, soil erosion and huge waste generation. It is a need of the hour to seek for natural, renewable, and bio-degradable fabrication materials and environmentally friendly production methods. This study proposes an eco-friendly approach to prepare bacterial cellulose/electrospun nanofibers membrane-based hybrid non-woven fabrics using in-situ self-assembly method. This fabrication method enables bacterial cellulose cultivation on nanofibrous membrane support to create custom-made seamless tubular hybrid fabrics in desirable dimensions, to be used for various textile applications with minimized material wastage. As-prepared nano-composite fabric was characterized using SEM, X-ray diffraction, and FTIR. FTIR and X-ray diffraction results confirmed the presence of bacterial cellulose in the composite structure. SEM analysis showed as the bacterial cellulose cultivates, its nanofibrils penetrate and grow into empty voids of membrane's structure, which results in secure binding and interlocking of electrospun nonofibers. Sample thickness and weight gain measurements after the modification were found to be approx. 33.90% and 39.02%, respectively. Reduced surface hydrophobicity, water uptake, and increased tensile strength might contribute towards better fabric performance and comfort. Overall, this study suggests an eco-friendly approach to prepare nano-composite fabrics that might be used for bio-textiles and related applications.

Our research aim is to develop a new composite material via electrospinning and dip coating methodology. Among bioabsorbable polymers, Polylactic acid (PLA) is viewed as a suitable base material for biomedical usages such as drug delivery and wound dressing. Additionally, these bioabsorbable materials can be used for filtration applications in terms of antibacterial activity the integration of hexadecyl trimethyl ammonium chloride-modified montmorillonite (CTAC-MMT) into PLA fibers would improve mechanical and absorption properties of the PLA fibers. This research aimed to investigated a new method of combining electrospun PLA with dip coating of CTAC-MMT solution. Precisely, electrospun PLA nanofibers were treated with methanol and dipped in a CTAC-MMT suspension. The resultant layer composite of PLA nanofibers and CTAC-MMT was then characterized by elemental analysis. For material characterization and morphological structure analysis, we performed FTIR, SEM-EDS, XPS, DSC, and X-ray diffraction. Through mechanical testing and contact angle measurements, it was found that CTAC-MMT shows a slight improvement in mechanical and absorption properties. Results of characterization techniques have shown that CTAC-MMT can be used as a good filler for composites processed through the dip-coating method. Moreover, results also showed that the diameter of microfibers is affected by concentrations of PLA.

On the >1µm scale the morphology of semicrystalline plastics like polyethylene or Nylon features spherulites, “shish-kebabs”, cylinddrites and other crystalline aggregates which strongly affect mechanical and other material properties. Current imaging techniques give only a 2D picture of these objects. Here we show how they can be visualized in 3D using fluorescent labels and confocal microscopy. As a result, for the first time we see spherulites in 3D, both in neat polymers and their nanocomposites, and observe how unevenly nanoparticles and other additives are distributed in the material. Images of i-polypropylene and biodegradable poly(lactic acid) reveal previously unsuspected morphologies such as “vases” and “goblets”, nonspherical “spherulites” and, unexpectedly, “shish-kebabs” grown from quiescent melt. Also surprisingly, in nanocomposite sheets spherulite nucleation is seen to be copied from one surface to another, mediated by crystallization-induced pressure drop and local melt-flow. These first results reveal unfamiliar modes of self-assembly in familiar plastics and open new perspectives on polymer microstructure.