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In this article, we report advancement in structural, morphological and dielectric studies of PVA encapsulated titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles. PVA/(x)TiO2(15-x)ZnO nanocomposites are prepared using solvent casting ex-situ technique for x= 0wt%, 1wt%, 5wt%, 7.5wt%, 10wt%, 14wt% and 15wt% filling concentrations. FTIR spectroscopy reveals the formulation of complexes between the PVA main chain and nano fillers is due to inter/intra molecular hydrogen bonding. The AFM picture shows the uniform grain structure for pure PVA and changes in surface morphology for prepared PVA nanocomposites. The morphological and homogeneous distribution of nano fillers in PVA nanocomposites was observed using SEM and EDAX. AC conductivity studies spectacles that the conductivity increases for different filling concentrations with increase in frequency. The frequency dependent dielectric constants with different filling concentrations are recorded. [ABSTRACT FROM AUTHOR]

In this work, we report the synthesis of MWCNTs incorporated TiO2 nanotubes (TNTs) to make a hybrid nanocomposite of TNT - MWCNTs. The as-synthesized TNT - MWCNTs composite structural, optical, elemental analysis was characterized by using different techniques such as X-ray diffraction (XRD), UV-visible spectroscopy, and energy dispersive spectroscopy (EDAX), elemental mapping. The morphology and formation of TiO2 - MWCNTs composite nanotubes was confirmed from electron microscopy techniques viz., field emission scanning electron microscope (FE-SEM) and high-resolution transmission electron microscope (HR-TEM). The effect of concentration of MWCNTs in TNT-MWCNT photoanode on the performance for dye-sensitized solar cells (DSSCs) was investigated. The performance of DSSCs were evaluated by measuring photocurrent voltage (I-V) characteristics and electrochemical impedance spectroscopic (EIS) and found that the power conversion efficiency of DSSC depends on the concentration MWCNT in the photoanode. DSSC fabricated using 6 wt % of MWCNT with respect to TiO2 containing nanocomposite as photoanode has shown high power conversion efficiency (PCE) of 1.99%. [ABSTRACT FROM AUTHOR]

Polyaniline (PANI)/Cobalt oxide (Co3O4) hybrid nanocomposites (NCs) were synthesized by means of in-situ polymerization using Cobalt nitrate as metal precursor, Polyaniline as polymerizing agent and Aloe-Vera (A.V.) gel as a fuel. The prepared nano composites were characterized by different characterization techniques such as Powder XRD, SEM and TEM. The electrical properties of PANI/Co3O4 hybrid NCs are very unique in comparison to the pure phases, PANI and Co3O4 nanoparticles (NPs), which were ascribed to the interaction between the PANI and Co3O4 nano particles. DC conductivity is observed to be enhanced as the Co3O4 NPs concentration increased from 10 to 50 wt% in the hybrid NCs at the different temperature. From the obtained measurements and data, the synthesized hybrid nano composites may be used in electronic device applications such as LED devices, solar cells and optical devices. [ABSTRACT FROM AUTHOR]

In the present work, a novel polyaniline cerium vanadate nanocomposite was facilely prepared by in-situ polymerized sol-gel process. X-ray diffraction (XRD) pattern revealed the crystal planes and size of the synthesized nanocomposite. The morphological shape and the crystalline nature of the nanocomposite were examined by field emission scanning electron microscopy (FESEM). Fourier transform infrared spectroscopy (FT-IR) confirmed the conceivable stretching frequency on the surface of nanocomposite. Polyaniline cerium vanadate nanocomposite was used as a solid phase adsorbent for removing methylene blue (MB) from aqueous media. Besides, these nanocomposites evinced antimicrobial activity against E.coli and Staphylococcus aureus. The studies describing the synthesis of polyaniline cerium vanadate by simple in-situ polymerised sol-gel method followed by the investigation of adsorption and antibacterial activities may be useful for the research activities to open a new horizon in the field of nanotechnology. [ABSTRACT FROM AUTHOR]

In this work, we present the synthesis and characterization of nanoparticles suitable for semiconductor applications using a simple and economical sol-gel process. ZnO-CuO is the potential material because of its high thermal stability and low cost. Properties of the ZnO-CuO nanocomposites are size dependent and when the particle size is reduced to the nanometer scales it shows some novel properties. Sol-Gel method is a good method to synthesis ultrafine metallic oxide nanocomposites and has been widely used for preparing nanoparticles at very low temperatures. Nano- structured ZnO-CuO has been characterized by using various techniques like XRD, SEM, and DSC-TGA. The phase transformation was investigated by an X-ray diffractometer (XRD). The microstructure was characterized by a scanning electron microscope (SEM). DSC-TGA analysis was used to investigate the thermal properties of the material. [ABSTRACT FROM AUTHOR]

Enhancing the thermal conductivity of a heat transfer fluid with the incorporation of nanomaterial is a widely known technique to achieve an efficient cooling system where such fluid, incorporated with nanomaterial is popularly known as nanofluid. However, the complexities in synthesizing the desired nanomaterial sand difficulties in incorporating them to the heat transfer fluid due to their poor dispersion ability opens up huge scope for carrying out further research in this field. Therefore, in the current work, we report, a simply synthesized amorphous carbon nanotubes (ACNT) and alumina (Al2O3) nanoparticle based nanocomposite that can easily disperse in engine oil (a class of heat transfer fluid) and can significantly improve its thermal conductivity. In our work, ACNTs with the length of ⁓ 4 µm and diameter of ⁓ 200 nm was synthesized by simple solid state reaction method whereas alumina nanoparticles with the dimension of ⁓50 nm were separately synthesized by sol-gel method. Then the nanocomposite was prepared by simply mixing them in liquid medium, followed by drying. Structural characterizations were carried out through x-ray diffraction, field emission scanning electron microscopic and high resolution transmission electron microscopic studies. The nanofluid was formulated by dispersing the nanocomposite in the base fluid (engine oil) with variation in loading and subsequently thermal conductivity was measured by Transient Hot Wire (THW) method. The maximum improvement in the thermal conductivity of ⁓ 20% was obtained with 0.04 vol. % of nanocomposite loading. So, all in all, it can be stated that ACNT and alumina naoparticle based nanocomposite was successfully prepared and its application in enhancing thermal conductivity of engine oil has successfully been shown. [ABSTRACT FROM AUTHOR]

In the present work, ZnS/Graphene nanocomposite is prepared by solution mixing and sonication method. The thin films are prepared with homemade chemical spray pyrolysis system (CSP) by the colloidal spray coating method. ZnS/graphene nanocomposite thin film fabricated at the substrate temperature of 350°C. Uniform, adherent, highly crystalline, and transparent thin film obtained. The films characterised by UV-Visible spectroscopy, Photoluminescence, X-Ray diffraction (XRD), Energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM). The absorption spectrum of composite shows the blue shift in the absorption peak as compared to intrinsic ZnS thin film. The bandgap increased from 4.1eV (intrinsic ZnS at substrate temperature 350°C) to 4.9eV (ZnS/graphene composite at substrate temperature 350°C). The XRD and EDS analysis confirm the composite formation and purity of the samples. The SEM images show the uniformity of thin films with granules agglomerated structures. [ABSTRACT FROM AUTHOR]