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Yanhui Liu, Jicheng Zuo, Jie Qin and Chengwu Li

Abstract

Polypropylene/carbon nanotubes (PP/CNTs) nancomposites were prepared with a single screw extruder by adding maleic anhydride-grafted poplypropylene (PP-g-MAH) as compatibilizer to polypropylene (PP) with different amounts of carbon nanotubes (CNTs) in the range of 0.1–0.7 wt.%. Structure and morphology of the prepared samples were examined by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), polarizing light microscopy (PLM) and X-ray diffraction (XRD). The results showed that PP spherulites decreased in size when CNTs were introduced into the polymer. Mechanical properties of the samples were also studied. Tensile tests showed that with increasing amount of CNTs the strain at break decreased whereas the Young’s modulus was improved of 16.41 % to 36.05 % and tensile strength of 36.67 % to 64.70 % compared to pristine PP. The SEM microphotographs showed that majority of the CNTs were dispersed individually and oriented along the shear flow direction.

Open access

Durga Verma, R.P. Patel and Mohan L. Verma

Abstract

Dysprosium doped strontium silicate phosphor namely (Sr2SiO4:Dy3+) was prepared by low-temperature solution combustion method using urea (CO(NH2)2) as a fuel. The material was characterized by powder X-ray diffraction (XRD), FT-IR, SEM and EDX. The average crystallite sizes was calculated by Scherer formula. Thermoluminescence study was carried out for the phosphor which showed single glow curve. The kinetic parameter were calculated by using Chen’s glow curve method. Photoluminescence spectra revealed strong transition at 473 nm (blue), 571 nm (yellow) and weak transition at 645 nm (red). These peaks were assigned to transition 4F9/26H15/2, 13/2, 11/2. CIE graph of Sr2SiO4:Dy3+ phosphor is suitable for the generation of white light emission.

Open access

S. Reena Devi, S. Suresh, S. Kalaiyarasi, M. Nizammohideen and R. Mohan Kumar

Abstract

A novel 4-methylpyridinium 3-nitrophthalate (4MP3NP) was synthesized and the crystals were grown by using slow evaporation method. The structural data of the grown crystal was collected by single crystal X-ray diffraction. It revealed that the 4MP3NP crystal belongs to triclinic crystal system with a space group P1. Structure of the synthesized compound was established using SHELXL 97 program package. The crystalline nature and composition of the grown crystal was established using high resolution X-ray diffraction and FT-IR analyses. UV-Vis transmittance and photoluminescence studies revealed the optical transmission window and electronic transition mechanism of ions, respectively. The laser damage threshold of the grown crystal was estimated by Nd:YAG laser and these results were mutually related to specific heat capacity of the grown crystal. The third-order nonlinear optical susceptibility of the grown crystal was studied by Z-scan technique.

Open access

Mohamed Afqir, Amina Tachafine and Didier Fasquelle

Abstract

The main subject of the presented research is to investigate the dielectric properties of BaBi1.8Ln0.2Nb2O9 (Ln = Ce, Gd) ceramics prepared by conventional solid state reaction route. The materials were examined using XRD and FT-IR methods. Moreover, the AC conductivity, dielectric constant and dielectric loss of the ceramics were determined. X-ray diffraction confirmed that all these compounds crystallize in an orthorhombic structure. Fourier transform infrared spectroscopy study confirmed the presence of two characteristic vibration bands located at around 617 cm-1 and 818 cm-1 for BaBi2Nb2O9. The experimental results show that the substitution of Bi by Ce or Gd causes a decrease in Curie temperature, dielectric constant and dielectric loss.

Open access

Praveen Kumar and Kanupriya Sharma

Abstract

Organic/inorganic hybrid materials consisting of quantum dots and conjugate polymers are important for the application in light emitting devices. In the present work, we have studied the effect of CdS and CdS/ZnO nanoparticle addition on the structure and fluorescence properties of spin coated PVK (poly(N-vinyl carbozole)) nanocomposite films. CdS nanoparticles were synthesized by simple co-precipitation technique and ZnO shell was grown on the CdS nanoparticles by simple wet chemical approach. The nanoparticles and the hybrid nanocomposites have been characterized by using XRD, SEM, FT-IR, optical absorption and fluorescence spectroscopic techniques. The absorption peak for pure PVK remains at 345.5 nm accompanied with minor hump ~480 nm resulting from the incorporation of nanoparticles. It has been observed that the addition of nanoparticles to the hybrid material results in the enhancement of fluorescence intensity at 410 nm to 450 nm spectral regions. These results are important for the development of new light emitting devices at low fabrication costs.

Open access

Aseel A. Kareem

Abstract

Polyimide/polyaniline nanofiber composites were prepared by in situ polymerization with various weight percentages of polyaniline (PANI) nanofibers. X-ray diffraction (XRD) and Fourier transform infrared spectra (FT-IR), proved the successful preparation of PANI nanofiber composite films. In addition, thermal stability of PI/PANI nanofiber composites was superior relative to PI, having 10 % gravimetric loss in the range of 623 °C to 671 °C and glass transition temperature of 289 °C to 297 °C. Furthermore, the values of the loss tangent tanδ and AC conductivity σAC of the nanocomposite films were notably higher than those of pure polyimide. The addition of 5 wt.% to 15 wt.% PANI nanofiber filler enhanced the activation energy of PI composites from 0.37 eV to 0.34 eV.

Open access

Joshua A. Obaleye and Olufunso O. Abosede

Abstract

Three manganese complexes of the antibiotic doxycyline viz.: manganese doxycyline, [MnDox2]Cl2‧2H2O (1), and manganese doxycyline with bipyridine, [MnDox2(bpy)]Cl2‧8H2O (2), and phenanthroline, [MnDox2(phen)]Cl2‧8H2O (3), as the ancillary ligand were synthesized and characterized by FT-IR, elemental analysis and electrospray mass spectroscopy. The three complexes show good solubility in DMF and DMSO. Data obtained from spectroscopic techniques used show that doxycycline coordinates to the central manganese atom through the oxygen of the amide group and the carbonyl oxygen atom of ring A while bipyridine/phenanthroline coordinates through the two diimine nitrogen atoms. The stoichiometry of manganese-doxycycline is 1:2 and octahedral geometry is the preferred coordination in all the complexes.

Open access

Yifu Zhang

Abstract

Coordination of vanadyl (VO2+) ions with 8-hydroxyquinoline (8Hq) in the interlayer space of layered silicate magadiite (mag) was realized by solid-solid intercalation. Composition, structure and morphology of this compound were studied by X-ray diffraction (XRD), Fourier-transform infrared spectrometry (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The obtained results indicate that the basal spacing of decorated mag increased after intercalation and suggest that VO-8Hq decorated into the interlayer of mag (VO-mag-8Hq) was successfully synthesized for the first time. Optical properties of VO-mag-8Hq were studied by ultraviolet-visible (UV-Vis) and photoluminescence spectroscopy (PL). The findings reveal that VO-8Hq complexes in the interlayer space exhibit extraordinary fluorescence properties and the confined space of mag influences the optical properties of VO-8Hq complexes.

Open access

P. Sakthi, R. Rajasekaran and A. Arun

Abstract

An inorganic coordination complex of single crystal containing sodium and aluminum (SA) was grown at room temperature by slow evaporation technique. The crystal was characterized using single crystal X-ray diffraction (XRD), FT-IR, UV-Vis, SHG, SEM, EDX and TG/DTA analyses. The size of the grown crystal was around 17 mm × 15 mm × 5 mm. Both optical and SEM photographs confirmed that the crystal is transparent with smooth surface. The XRD data showed that the crystal belongs to the BCC crystal structure. The crystal shows excellent transparency in the entire region of visible light (cut-off value is 339 cm−1). The dielectric constant as well as dielectric loss of the sample was calculated by varying frequencies at different temperatures and the presence of low dielectric loss proved that this crystal can be used for the NLO application.

Open access

R. Vasanthakumar, W. Nirmala, R. Santhakumari, R. Meenakshi and A. Sinthiya

Abstract

4-aminopyridinium adipate monohydrate (4APA) was grown by slow evaporation solution growth technique. The functional groups in the grown crystal were identified from FT-IR spectral evaluation. The optical properties together with transmittance of the grown crystal were obtained from UV-Vis spectroscopic study. The mechanical and thermal properties of the grown crystal were studied using Vickers microhardness and TGA/DTA analyses, respectively. Microhardness test revealed that 4-aminopyridinium adipate monohydrate crystal is a soft category material. The density functional method (DFT) was performed using B3LYP with the 6-311G (d,p) basis set. The electronic charge distribution, reactivity of the molecules and the molecular electrostatic potential (MEP) of the grown crystal were analyzed using the B3LYP method. The intermolecular interactions that exist in the crystal structure of the 4APA have also been investigated by Hirshfeld surface analysis. The nonlinear optical properties of the 4APA crystal were confirmed by Kurtz-Perry technique.