Mechanical, electrical and thermal properties of graphene oxide-carbon nanotube/ ABS hybrid polymer nanocomposites

Multiwalled carbon nanotubes (MWCNTs), functionalized carbon nanotubes (FCNTs) and graphene oxide-carbon nanotube (GCNTs) hybrid Bucky paper (BP) reinforced acrylonitrile-butadiene-styrene (ABS) composites are prepared via vacuum filtration followed by hot compression molding. The nanomechanical, electrical and thermal properties of these BP reinforced ABS composites are studied. The nanoindentation hardness and elastic modulus of GCNTs-ABS hybrid composites reached to 389.98 +/- 91.79 MPa and 7669.6 +/- 1179.12 MPa respectively. Other nanomechanical parameters such as plastic index parameter, elastic recovery, the ratio of residual displacement after load removal and displacement at maximum load are also investigated. The improved nanomechanical properties are correlated with Raman spectroscopy and scanning electron microscopy (SEM). It is found that GCNTs and their composites showed the higher value of defect density. The maximum value of defect density range for GCNTs and GCNTs-ABS is (297.4 to 159.6) and (16.0 to11.6), respectively. The higher defect density of GCNTs indicates that the interfacial interaction between the ABS, which was further correlated with electrical and thermal properties. Additionally, the through-plane electrical conductivities of MWCNTs, FCNTs and GCNTs based ABS composites were 6.5 +/- 0.6, 4.5 +/- 0.7 and 6.97 +/- 1.2 S/cm respectively and thermal conductivities of MWCNTs, FCNTs and GCNTs reinforced ABS composites; 1.80, 1.70 and 1.98 W/mK respectively. These GCNTs-ABS composites with this value of thermal conductivity can be used in various applications of efficient heat dissipative materials for electronic devices

The electrical properties of microwave sintered gadolinia doped ceria–alumina nano-composite electrolyte

Gadolinia doped ceria–alumina (GDC–Al2O3) nano composites have been prepared by chemical synthesis route and sintered using 2.45 GHz microwave energy as well as conventional technique. The electrical properties of the sintered samples are investigated by ac impedance spectroscopy. It has been observed that the conductivity of microwave sintered GDC–Al2O3 composite is higher than that of conventional sintered GDC–Al2O3 composite and pure GDC sample. Higher concentration of vacancies at the interfaces of GDC and Al2O3 phases may be responsible for the better conductivity of GDC–Al2O3 composite compared to pure GDC. The fine grain microstructure of microwave sintered samples creates more interfaces compared to conventional sintered sample which in turn responsible for the better performance of microwave sintered composite sample. The micro-structural results of microwave sintered samples also reveal the presence of elongated, needle like Al2O3 grains. The X-ray diffraction results have shown the formation of additional GdAlO3 phase

Tunable Mechanical, Electrical, and Thermal Properties of Polymer Nanocomposites through GMA Bridging at Interface

Polymer nanocomposites (PNCs) have become an exciting field of current research and have attracted a huge interest among both academia and industry during the last few decades. However, the multifunctional single-nanocomposite film exhibiting the combination of desired structure and properties still remains a big challenge. Herein, we report a novel strategy to address these problems by using versatile polymer glycidyl methacrylate (GMA) as a bridging medium between the filler and the polymer matrix, resulting in high density of interfaces as well as strong interactions, which lead to generation of tunable thermal, mechanical, and electrical properties in the materials. The nanocomposites prepared by GMA bridging exhibit the remarkable combination of thermal (T-d = 342.2 degrees C, T-g = 150.1 degrees C), mechanical (E = 7.6 Gpa and H = 0.45 Gpa) and electrical (sigma = 3.15 x 10(-5) S/cm) properties. Hence, the conjugation approaches related to GMA bridging facilitate a new paradigm for producing multifunctional polymer nanocomposites having a unique combination of multifunctional properties, which can be potentially used in next-generation polymer-based advanced functional devices

Synthesis and characterization of phosphorus doped hydrogenated silicon films by filtered cathodic vacuum arc technique

Phosphorous doped hydrogenated silicon thin film has been deposited by filtered cathodic vacuum arc technique at different substrate temperatures at a fixed hydrogen gas pressure. X-ray diffraction, electrical conductivity and optical band gap and scanning electron microscopy have been used to characterize the properties of film

Phosphorous doped hydrogenated amorphous silicon carbide films deposited by filtered cathodic vacuum arc technique

In the present work, we report the growth and characterization of phosphorous doped hydrogenated amorphous silicon carbide (a-SiC: H) films deposited by filtered cathodic vacuum arc technique using solid silicon target as cathode in presence of acetylene gas. The films have been characterized by x-ray diffraction, dark conductivity, activation energy, optical band gap, scanning electron microscopy, energy dispersive x-ray analysis and residual stress. The effect of arc current on the properties of P doped a-SiC: H films have been studie

Nanoindentation study on nitrogenated tetrahedral amorphous carbon thin films with ultra low load

543-550This paper reports the improved nanomechanical properties of as grown and nitrogen incorporated tetrahedral amorphous carbon (ta-C, ta-C: N) films deposited by S-bend filtered cathodic vacuum arc (FCVA) technique using nanoindentation. The effect of varying amount of nitrogen incorporation on the nanomechanical properties of ta-C films deposited at a high substrate bias of -300 V at ultra low load of 1.4 mN has been studied. It has been found that the nitrogenation has improved the mechanical properties of ta-C films. The hardness H of 27.8 GPa with improvement of ~30 % and plastic index parameter (ratio of H to elastic modulus E) (H/E) of 0.091 with improvement of ~ 25 % has been obtained for ta-C: N films deposited at a nitrogen partial pressure of 1.9x10-2 Pa. Improved H and H/E of ta-C: N films may be due to the better ionization and incorporation of nitrogen in a carbon matrix at the high negative substrate bias used in the deposition of FCVA technique

Synthesis of vertical graphene by microwave plasma enhanced chemical vapor deposition technique

Vertical graphene was synthesized on nickel substrate using microwave plasma enhanced chemical vapor deposition technique by varying gas pressure from 5 to 30 Torr under various mixing ratios of argon, hydrogen and methane. The Raman spectra show two major fingerprints of graphene, 2D peak at 2700 cm(-1) and G peak 1580 cm(-1). Scanning electron microscopy microstructure revealed flower like graphene structure which could find applications in gas sensing and field emission due to high surface-to-volume ratio

Improved nanomechanical properties of hydrogenated tetrahedral amorphous carbon films measured with ultra low indentation load

This paper reports the nanomechanical properties of as grown and hydrogenated tetrahedral amorphous carbon (ta-C, ta-C: H) films deposited by S-bend filtered cathodic vacuum arc technique measured with 1.4 mN load. It has been found that the hydrogenation of ta-C film improved the nanomechanical properties. Maximum hardness (H) of 38.15 GPa (with improvement of similar to 80%) has been obtained for ta-C: H film deposited at a hydrogen partial pressure of 1.4 x 10(-1) Pa and maximum elastic modulus (E) value of 410.1 GPa has been obtained when the hydrogen partial pressure reduced to 7.4 x 10(-3) Pa. The plastic index parameter (HIE) of ta-C: H film (0.11) is found to be superior to that of ta-C film (0.073), which is a measure of wear resistance for coating applications. The improved HIE of ta-C: H films may be due to the passivation of surface defects and favorable formation of sp(3) hybridized bonds

Nanoindentation study on nitrogenated tetrahedral amorphous carbon thin films with ultra low load

This paper reports the improved nanomechanical properties of as grown and nitrogen incorporated tetrahedral amorphous carbon (ta-C, ta-C: N) films deposited by S-bend filtered cathodic vacuum arc (FCVA) technique using nanoindentation. The effect of varying amount of nitrogen incorporation on the nanomechanical properties of ta-C films deposited at a high substrate bias of -300 V at ultra low load of 1.4 mN has been studied. It has been found that the nitrogenation has improved the mechanical properties of ta-C films. The hardness H of 27.8 GPa with improvement of ~30 % and plastic index parameter (ratio of H to elastic modulus E) (H/E) of 0.091 with improvement of ~ 25 % has been obtained for ta-C: N films deposited at a nitrogen partial pressure of 1.9 10-2 Pa. Improved H and H/E of ta-C: N films may be due to the better ionization and incorporation of nitrogen in a carbon matrix at the high negative substrate bias used in the deposition of FCVA technique

Growth and characterization of nitrogen incorporated amorphous carbon films haying embedded nanocrystallies

This paper reports the growth and characterization of nitrogen incorporated amorphous carbon films having embedded nanocrystallites deposited by filtered anodic jet carbon arc technique. The films are characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, Raman, residual stress and nanoindentation. The properties are found to depend on the substrate bias. The film deposited at -60 V substrate bias shows maximum hardness of 24 GPa and elastic modulus of 215 GPa