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Proceedings ArticleDOI: 10.1063/1.4947655

Optimized surface topography of thermoplastics blends modified by graphene

24 May 2016-Vol. 1731, Iss: 1, pp 050001
Abstract: Polyacrilonitrile (PAN)/ Polyvinylfloride (PVDF) blends were modified by loading the graphene (0.5 to 1.5 wt %). The presence of graphene reveals the interesting surface properties. The decrease in surface roughness as function of graphene loading was confirmed by the topographic method of recording (two and three dimensional images) with atomic force microscope (AFM). The blends become smoother in nature due to occupied smaller surface area of graphene. This property may be useful for several applications in the marine, naval, nuclear domain and engineering applications as barrier medium.

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Topics: Graphene oxide paper (62%), Graphene nanoribbons (61%), Graphene (58%) ...read more
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Journal ArticleDOI: 10.1080/03602559.2016.1233272
Abstract: Polymer composites made of carbon allotropes where highly crucial for various engineering applications. We demonstrated the successful modification of Polyacrilonitrile (PAN)/ Polyvinylfloride (PVDF) blends by reinforced graphene nano platelets (GNP). The atomic force microscopy (AFM) confirms the partial immiscible traces of polymer systems with asperities on the surface of the modified blends due to loading of graphene. The phase angle (Ɵ) measurement across the temperature (40 to 150 °C) with the broadband frequency (50 Hz to 35 MHz) done by using the Impedance analyzer. The results demonstrated the decrease in phase angle as a function of temperature. This investigation is highly suitable for the development of thermal sensor for engineering and health applications.

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Topics: Graphene (55%)

5 Citations

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Journal ArticleDOI: 10.1007/S10965-013-0286-2
Abstract: Graphene derivatives are intensively used as high performance nano fillers for the fabrication of polymer nanocomposites. The challenge is to achieve significant improvement in interfacial adhesion between polymer matrix and reinforcing filler. In the present work, we report the preparation of polyvinyl chloride (PVC) /Graphene Oxide (GO) composite by the colloidal blending method. PVC/GO composite films were further studied using fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and polarized optical microscopy (POM). The effect of GO loading on wettability of PVC/GO composites films were studied by measuring contact angle of composites films. Optical microscopy reveals that GO have been dispersed homogeneously throughout the PVC matrix. From morphological studies, a network of a denser stacking and randomly aggregate structure having rough surface was observed as a function of GO loading. The values of contact angle decrease with respect to GO loading for all the liquids used. The solid surface energy (SE) of composite films was estimated using contact angle measurements. The surface energies were measured and compared using Fowke’s and Good-Grifalco methods with respect to four different liquids having a wider range of surface tensions (44≤ lv ≤ 72. 8 mJ/m2). The composite film surfaces were tuned by controlling incorporation of GO in order to optimize the surface roughness.

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Topics: Contact angle (57%), Polymer nanocomposite (54%), Graphene (54%) ...read more

108 Citations


Open accessJournal ArticleDOI: 10.1038/SREP09141
Ye Ji Noh1, Han-Ik Joh1, Jaesang Yu1, Soon Hyoun Hwang2  +4 moreInstitutions (3)
16 Mar 2015-Scientific Reports
Abstract: Ultra-high dispersion of graphene in polymer composite via solvent free fabrication and functionalization

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Topics: Graphene oxide paper (60%), Graphene (56%), Dispersion (chemistry) (51%) ...read more

87 Citations


Journal ArticleDOI: 10.1002/PAT.592
Ting-Yu Liu1, Wen-Ching Lin2, Li-Ying Huang2, San-Yuan Chen1  +1 moreInstitutions (2)
Abstract: Polyacrylonitrile (PAN) was blended with polyvinylidine fluoride (PVDF) at various ratios and made into membranes. The hemocompatibility of the resulting membranes was evaluated based on human plasma proteins adsorption, platelet adhesion, thrombus formation, and blood coagulation time. The PAN/PVDF blends exhibited partial miscibility according to the inward shifting of their two glass transition temperatures. The microstructures of blend membranes examined using atomic force microscopy (AFM) indicated that the roughness increased with the PVDF content, and the phase separation was too severe to form a membrane when the PVDF content was more than 30%. The water contact angle of PAN/PVDF blend membranes increased with the PVDF content. By blending with 20wt% apolar PVDF the adsorption of blood proteins could be reduced, and hence the platelet adhesion and thrombus formation was also reduced. However, when the PVDF content was 30wt%, severe thrombogenicity was observed due probably to the more porous structure of blend membrane. These results demonstrated that the hemocompatibility would be improved for PAN/PVDF blend membranes with appropriate hydrophilicity and roughness. Copyright # 2005 John Wiley & Sons, Ltd.

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Topics: Membrane (54%), Polyacrylonitrile (51%)

84 Citations


Journal ArticleDOI: 10.1007/S11664-014-3010-Z
Girish M. Joshi1, Kalim Deshmukh1Institutions (1)
Abstract: Graphene oxide (GO)-reinforced polyvinyl chloride (PVC) composite films were prepared by solution blending. The homogeneity of GO dispersion with PVC was confirmed by an optical microscope. Quality factor (Q-factor) as a function of temperature (40–150 °C) was measured within a broadband frequency range of 50–35 MHz. The controlled GO loading demonstrates a crucial impact on the optimization of the Q-factor, resonance frequency (f 0) and wide bandwidth. This nanocomposite may be well suited for electronic applications. The further development of GO-reinforced polymer nanocomposites based on an optimized Q-factor may result in a material for electromagnetic frequency radiation shields for radar and communication towers/devices.

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Topics: Polymer nanocomposite (54%), Graphene (52%), Nanocomposite (52%)

27 Citations


Journal ArticleDOI: 10.1007/S11581-014-1111-6
Mayank Pandey1, Girish M. Joshi1, Kalim Deshmukh1, Kalim Deshmukh2  +2 moreInstitutions (3)
30 Mar 2014-Ionics
Abstract: Polyvinylidene fluoride (PVDF) and polyvinyl alcohol (PVA) composites were prepared by controlled loading of Nafion (5 to 15 wt%) by solution casting using water and dimethylformamide (DMF) as a solvent. The surface morphology of composite analyzed by atomic force microscopy (AFM) reveals the presence of Nafion ionomers. The increase in interlayer spacing of modified PVDF/PVA polymer system as a function of Nafion was detected by X-ray diffraction (XRD). The major change in Fourier transform infrared (FTIR) spectroscopy confirms the chemical bond C=O stretching around 1,700 cm−1 due to Nafion. Differential scanning calorimetry (DSC) demonstrates the thermal stability of polymer composites and the decrease in melting temperature (T m). The optimized AC conductivity (σ) of the prepared composite was evaluated by using an impedance analyzer as a function of temperature (40 to 150 °C) at constant 30-MHz frequency. The highest conductivity of 1.3 × 10−2 S m−1 was observed at 80 °C for 10 wt% of Nafion and correlated with structure, morphology and thermal properties of modified PVDF/PVA/Nafion composites. The experimental results may be useful for sensors, fuel cells and battery application domains.

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Topics: Nafion (62%), Differential scanning calorimetry (52%), Thermal stability (52%) ...read more

17 Citations