Interfacial interactions between the polymer and graphene are pivotal in determining the reinforcement efficiency in the graphene-enhanced polymer nanocomposites. Here, we report on the dynamic process of graphene-induced oriented interfacial crystals of isotactic polypropylene (iPP) in the single fiber polymer composites by means of polarized optical microscopy (POM) and scanning electron microscopy (SEM). The graphene fibers are obtained by chemical reduction of graphene oxide fibers, and the latter is produced from the liquid crystalline dispersion of graphene oxide via a wet coagulation route. The lamellar crystals of iPP grow perpendicular to the fiber axis, forming an oriented transcrystalline (TC) interphase surrounding the graphene fiber. Various factors including the diameter of graphene fibers, crystallization temperature, and time are investigated. The dynamic process of polymer transcrystallization surrounding the graphene fiber is studied in the temperature range 124-132 °C. The Lauritzen-Hoffman theory of heterogeneous nucleation is applied to analyze the transcrystallization process, and the fold surface free energy is determined. Study into microstructures demonstrates a cross-hatched lamellar morphology of the TC interphase and the strong interfacial adhesion between the iPP and graphene. Under appropriate conditions, the β-form transcrystals occur whereas the α-form transcrystals are predominant surrounding the graphene fibers.
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http://dx.doi.org/10.1021/acsami.5b03269 | DOI Listing |
Dalton Trans
December 2024
Key Laboratory of Microelectronics and Energy of Henan Province, Department of Physics and Electronic Engineering, Xinyang Normal University, Xinyang, 464000, P. R. China.
Energy storage devices have applications in large-scale portable and smart devices due to their high energy density and long lifespan, but the limited theoretical capacity of the graphite anode in lithium-ion batteries has slowed the development of portable electronic devices. Herein, we prepared porous fibers with heterogeneous FeN/FeO nanocrystals wrapped by a carbon layer. A series of measurements, such as TEM images, Raman spectra, XRD pattern and XPS analysis, were used to unveil the formation of FeN/FeO4 nanocrystals.
View Article and Find Full Text PDFChemosphere
December 2024
School of Materials Science and Engineering, Shijiazhuang Tiedao University, Hebei Key Laboratory of New Materials for Collaborative Development of Traffic Engineering and Environment. Electronic address:
Nanoscale FeWO/BiVO heterojunctions were directly grown on the graphite fiber felt (GF) with good conductivity to construct a FeWO/BiVO @GF solar photo-Fenton like wastewater treatment system. The removal effect of COD from phenolic wastewater and the mechanism of synergistic improvement of wastewater treatment efficiency by this system were investigated. The FeWO/BiVO heterojunction prepared by hydrothermal method exhibited higher photoelectric conversion efficiency and solar light utilization rate, thus endowing FeWO/BiVO with excellent solar-Fenton like reaction activity.
View Article and Find Full Text PDFAdv Colloid Interface Sci
December 2024
Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India. Electronic address:
Heightened levels of electromagnetic (EM) radiation emitted by electronic devices, communication equipment, and information processing technologies have become a significant concern recently. So, substantial efforts have been devoted for developing novel materials having high EM absorption properties. This critical review article provides an overview of the advancements in understanding and developing such materials.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Barrer Centre, Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
Graphene oxide (GO)-based membranes have demonstrated great potential in water treatment. However, microdefects in the framework of GO membranes induced by the imperfect stacking of GO nanosheets undermine their size-sieving ability and structural stability in aqueous systems. This study proposes a targeted growth approach by growing zeolitic imidazolate framework-8 (ZIF-8) nanocrystals precisely to patch microdefects as well as to cross-link the porous graphene oxide (PGO) flakes coated on the outer surface of the hollow fiber (HF) alumina substrate (named the hybrid PGO/ZIF-8 membrane).
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, třída Tomáše Bati 5678, 76001 Zlín, Czech Republic.
Bone tissue engineering demands advanced biomaterials with tailored properties. In this regard, composite scaffolds offer a strategy to integrate the desired functionalities. These scaffolds are expected to provide sufficient cellular activities while maintaining the required strength necessary for the bone repair for which they are intended.
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