scholarly journals Supramolecular Structure of Polypropylene Fibers Extruded with Addition of Functionalized Reduced Graphene Oxide

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 910 ◽  
Author(s):  
Jan Broda ◽  
Janusz Fabia ◽  
Marcin Bączek ◽  
Czesław Ślusarczyk
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Supramolecular Structure ◽  
Nucleating Agent ◽  
Polypropylene Fibers ◽  
Fiber Structure ◽  
X Ray Scattering ◽  
Reduced Graphene ◽  
The Impact ◽  
Spun Fibers

An effective β-nucleating agent for polypropylene crystallization was obtained by the functionalization of reduced graphene oxide with calcium pimelate. The nucleating ability of the modified reduced graphene oxide (rGO-CP) was confirmed during non-isothermal crystallization. In further examinations, the rGO-CP was used as an additive to modify polypropylene fibers. The fibers were extruded in laboratory conditions. Gravity spun fibers containing three different concentrations of the rGO-CP and fibers taken at three different velocities were obtained. The supramolecular structure of the fibers was examined by means of calorimetric and X-Ray Scattering methods (DSC, WAXS, and SAXS). The considerable amount of β-iPP was obtained only in the gravity spun fibers. In the fibers extruded at higher velocities, the diminishing impact of the additive on the fibers structure was revealed. The changes observed in the fiber structure in connection with the impact of the additive on polypropylene crystallization was discussed.

Supramolecular structure of polypropylene fibers formed with addition of functionalized graphene oxide

2020 ◽  
Vol 90 (19-20) ◽  
pp. 2322-2335 ◽  
Author(s):  
Jan Broda ◽  
Marcin Baczek ◽  
Janusz Fabia ◽  
Ryszard Fryczkowski
Keyword(s):  
Graphene Oxide ◽  
Polypropylene Fibers ◽  
Pimelic Acid ◽  
Functionalized Graphene ◽  
Fiber Structure ◽  
Scanning Calorimetry ◽  
Functionalized Graphene Oxide ◽  
X Ray ◽  
X Ray Scattering ◽  
Spun Fibers

Pimelic acid and calcium hydroxide were used to attach calcium pimelate to the surface of graphene oxide. The additive was mixed with isotactic polypropylene granulate. Neat polypropylene and polypropylene with functionalized graphene oxide was extruded into fibers under laboratory conditions. The gravity spun fibers containing different concentration of the additive and the fibers taken at various velocities were obtained. Morphology and elemental composition of functionalized graphene oxide were studied by means of scanning electron microscopy and energy dispersive X-ray spectroscopy. The structure of fibers was examined by means of differential scanning calorimetry and wide-angle X-ray scattering. The ability of calcium pimelate supported on the surface of the graphene oxide to nucleate the β-form of polypropylene was revealed. A considerable amount of the β-form crystals was obtained in the gravity spun fibers. In the fibers taken at moderate and higher velocities the β-form disappeared. The structure of the fibers extruded with the additive was similar to the structure of the fibers extruded from neat polypropylene. At moderate velocities, the content of mesophase in the structure was high. At higher velocities, the crystalline structure built only from α-form crystals was obtained. The paper presents a discussion of the changes observed in the fiber structure in connection with polypropylene nucleation.

scholarly journals Supermolecular Structure of Poly(Butylene Terephthalate) Fibers Formed with the Addition of Reduced Graphene Oxide

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1456
Author(s):  
Czesław Ślusarczyk ◽  
Marta Sieradzka ◽  
Janusz Fabia ◽  
Ryszard Fryczkowski
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Supermolecular Structure ◽  
Fiber Structure ◽  
Butylene Terephthalate ◽  
X Ray Scattering ◽  
Reduced Graphene ◽  
Smectic Mesophase ◽  
One Step ◽  
Nanocomposite Fibers

Nanocomposite fibers based on poly(butylene terephthalate) (PBT) and reduced graphene oxide (rGO) were prepared using a method able to disperse graphene in one step into a polymer matrix. The studies were performed for fibers containing four different concentrations of rGO at different take-up velocities. The supermolecular structures of the fibers at the crystallographic and lamellar levels were examined by means of calorimetric and X-ray scattering methods (DSC, WAXS, and SAXS). It was found that the fiber structure is mainly influenced by the take-up velocity. Fibers spun at low and medium take-up velocities contained a crystalline α-form, whereas the fibers spun at a high take-up velocity contained a smectic mesophase. During annealing, the smectic phase transformed into its α-form. The degree of transformation depended on the rGO content. Reduced graphene mainly hindered the crystallization of PBT by introducing steric obstacles confining the ordering of the macromolecules of PBT.

scholarly journals Manufacturing and Evaluation of Mechanical, Morphological, and Thermal Properties of Reduced Graphene Oxide-Reinforced Expanded Polystyrene (EPS) Nanocomposites

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Tomasz Rydzkowski ◽  
Kazimierz Reszka ◽  
Mieczysław Szczypiński ◽  
Michał Marek Szczypiński ◽  
Elżbieta Kopczyńska ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Carbon Nanoparticles ◽  
Bending Strength ◽  
Expanded Polystyrene ◽  
Thermal Conductivity Ratio ◽  
Reduced Graphene ◽  
Similar Density ◽  
The Impact

The aim of the present study is to examine the effect of the addition of carbon nanoparticles (σsp2 hybridization) on the mechanical properties of foamed polystyrene. In this work, we focus on the study of the impact of compressive stress, tensile strength, bending strength, thermal conductivity ratio (λ), and water absorption of expanded polystyrene (EPS) reinforced with reduced graphene oxide and graphite. The results were compared with pristine EPS and reduced graphene oxide-reinforced EPS. All the nanocomposite specimens used for testing had a similar density. The study reveals that the nanocomposites exhibit different thermal conductivities and mechanical properties in comparison to pristine EPS. The enhancement in the properties of the nanocomposite could be associated with a more extensive structure of elementary cells of expanded polystyrene granules.

scholarly journals Microbeam two-dimensional small-angle X-ray scattering investigating the effects of reduced graphene oxide on local microstructures of high-density polyethylene/reduced graphene oxide nanocomposite bars

2019 ◽  
Vol 6 (2) ◽  
pp. 181866 ◽  
Author(s):  
Guibin Yao ◽  
Tianchen Duan ◽  
Enyi Chi ◽  
Pengran Guo ◽  
Yiguo Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Small Angle ◽  
High Density Polyethylene ◽  
High Density ◽  
Two Dimensional ◽  
X Ray ◽  
X Ray Scattering ◽  
Reduced Graphene

It has been reported that the introduction of reduced graphene oxide (RGO) can enhance the crystallization and orientation of high-density polyethylene (HDPE) matrix and thus improve the mechanical properties of HDPE/RGO nanocomposites. In this study, the local microstructures and orientations in different regions of HDPE/RGO bars with varied RGO contents were further explored by two-dimensional small-angle X-ray scattering using a microbeam technique. It is unveiled that the orientation orderings of each position is intensified with increasing RGO amount, and of particular interest is the observation of the slight change of the ordering degrees in diverse zones of HDPE/RGO nanocomposite bars, indicating that RGO imposes a uniform enhancing effect upon HDPE matrix within different areas and consequently induces an effective increase of the mechanical properties of HDPE/RGO nanocomposites.

Functionalization and Chemical Linking of Reduced Graphene Oxide or Graphite onto Polyurethane and the Impact on the Tensile Strength and Sheet Resistance of Polymer Composites

2018 ◽  
Vol 26 (2) ◽  
pp. 141-153
Author(s):  
Yong-Chan Chung ◽  
Ho-Sung Kim ◽  
Byoung Chul Chun
Keyword(s):  
Tensile Strength ◽  
Graphene Oxide ◽  
Shape Memory ◽  
Reduced Graphene Oxide ◽  
Sheet Resistance ◽  
Sharp Decrease ◽  
Hydroxyl Groups ◽  
Functionalized Graphene Oxide ◽  
Reduced Graphene ◽  
The Impact

Reduced graphene oxide (RGO) or graphite is functionalized with hydroxyl groups for linking to the sides of polyurethane (PU) chains. Blended PU with RGO or graphite is prepared as a control for comparison. The PU composites are compared with respect to their spectroscopic, thermal, mechanical, shape memory, and sheet resistance properties. Scanning electron microscopy images demonstrate the good distribution of functionalized graphene oxide (FGO) or functionalized graphite (FG) particles on the inner surface of the PU. The linking of FGO or FG onto PU does not significantly affect the thermal behavior or shape memory properties but sharply improves the tensile strength of the PU composites without a noticeable decrease in tensile strain. The shape recovery of PU composites remains at approximately 90%, regardless of the FGO or FG content. The FG-linked PU composites exhibit a sharp decrease in sheet resistance as the FG content increases, whereas the sheet resistance of the FGO-linked PU composites does not decrease with increasing FGO content. The control PU composites with blended RGO or graphite show significant reductions in their sheet resistance. Considering the ease of functionalization of the graphite surface and the significant improvement in tensile strength, linking FG onto PU is advantageous for the development of PU composites with low sheet resistance.

scholarly journals Updating the Role of Reduced Graphene Oxide Ink on Field Emission Devices in Synergy with Charge Transfer Materials

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 137 ◽  
Author(s):  
Minas Stylianakis ◽  
George Viskadouros ◽  
Christos Polyzoidis ◽  
George Veisakis ◽  
George Kenanakis ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Field Emission ◽  
Large Scale ◽  
High Efficiency ◽  
Low Cost ◽  
Field Enhancement ◽  
Field Emitter ◽  
Reduced Graphene ◽  
The Impact

Hydroiodic acid (HI)-treated reduced graphene oxide (rGO) ink/conductive polymeric composites are considered as promising cold cathodes in terms of high geometrical aspect ratio and low field emission (FE) threshold devices. In this study, four simple, cost-effective, solution-processed approaches for rGO-based field effect emitters were developed, optimized, and compared; rGO layers were coated on (a) n+ doped Si substrate, (b) n+-Si/P3HT:rGO, (c) n+-Si/PCDTBT:rGO, and (d) n+-Si/PCDTBT:PC71BM:rGO composites, respectively. The fabricated emitters were optimized by tailoring the concentration ratios of their preparation and field emission characteristics. In a critical composite ratio, FE performance was remarkably improved compared to the pristine Si, as well as n+-Si/rGO field emitter. In this context, the impact of various materials, such as polymers, fullerene derivatives, as well as different solvents on rGO function reinforcement and consequently on FE performance upon rGO-based composites preparation was investigated. The field emitter consisted of n+-Si/PCDTBT:PC71BM(80%):rGO(20%)/rGO displayed a field enhancement factor of ~2850, with remarkable stability over 20 h and low turn-on field in 0.6 V/μm. High-efficiency graphene-based FE devices realization paves the way towards low-cost, large-scale electron sources development. Finally, the contribution of this hierarchical, composite film morphology was evaluated and discussed.

The Impact of Functionalization on the Stability, Work Function, and Photoluminescence of Reduced Graphene Oxide

ACS Nano ◽  
2013 ◽  
Vol 7 (2) ◽  
pp. 1638-1645 ◽  
Author(s):  
Priyank V. Kumar ◽  
Marco Bernardi ◽  
Jeffrey C. Grossman
Keyword(s):  
Graphene Oxide ◽  
Work Function ◽  
Reduced Graphene Oxide ◽  
Reduced Graphene ◽  
The Stability ◽  
The Impact

scholarly journals The Role of the Oxidation and Reduction Parameters on the Properties of the Reduced Graphene Oxide

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 166
Author(s):  
Marta Sieradzka ◽  
Czesław Ślusarczyk ◽  
Włodzimierz Biniaś ◽  
Ryszard Fryczkowski
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Structural Parameters ◽  
Mixing Time ◽  
Energy Dispersive Spectrometer ◽  
Process Conditions ◽  
X Ray Scattering ◽  
Reduced Graphene ◽  
Oxidation Stage

One of the methods of obtaining reduced graphene oxide (rGO) involves the oxidation of graphite to graphene oxide, which is then exfoliated and reduced. Each of these stages has a decisive influence on the properties of the produced nanoadditive, which determines its subsequent application. The process conditions which are examined during the oxidation stage are related to: The mixing time of the reactants before oxidation, sonication of the reaction mixture, and its composition. During reduction optimization, in turn, the form of the GO sample and the method of its purification, as well as the temperature at which this process took place, are examined. At each stage, the determined structural parameters of the produced materials (GO and rGO) are related to their morphology (SEM—scanning electron microscope), oxidation state (FTIR—Fourier transform infrared spectroscopy, EDS—energy-dispersive spectrometer), structure defect (Raman spectroscopy), as well as the number of layers and crystalline structure (WAXS—wide-angle X-ray scattering). The obtained results show that the shorter mixing time of the reactants determines the formation of more oxygen functional groups. On the basis of the obtained results, the process conditions that enable the production of multilayer, well-exfoliated reduced graphene oxide, with only a slightly defected structure, are established.

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