scholarly journals Thermal and optical properties of new poly(amide-imide)-nanocomposite reinforced by layer silicate based on chiral n-trimellitylimido-L-valine

2012 ◽  
Vol 31 (1) ◽  
pp. 79
Author(s):  
Khalil Faghihi ◽  
Masoumeh Soleimani ◽  
Shabnam Nezami ◽  
Meisam Shabanian
Keyword(s):  
Main Chain ◽  
Nanocomposite Films ◽  
Direct Polycondensation ◽  
Polycondensation Reaction ◽  
X Ray Diffraction ◽  
Solution Intercalation ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Polymeric Chains ◽  
Morphology And Structure

Two new samples of poly(amide-imide)-montmorillonite reinforced nanocomposites containing N-trimellitylimido-L-valine moiety in the main chain were synthesized by a convenient solution intercalation technique. Poly(amide-imide) (PAI) 5 as a source of polymer matrix was synthesized by the direct polycondensation reaction of N-trimellitylimido-L-valine (3) with 4,4′-diaminodiphenyl ether 4 in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PA-nanocomposite films (5a) and (5b) with 10 and 20 % silicate particles were characterized by FTIR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of clay dispersion and the interaction between clay and polymeric chains on the properties of nanocomposite films were investigated by using Uv-vis spectroscopy,  thermogravimetric analysis (TGA) and water uptake measurements.

Synthesis and properties of new polyamide-organoclay nanocomposites containing pyrazine moiety in the main chain

2012 ◽  
Vol 19 (3) ◽  
pp. 215-220
Author(s):  
Khalil Faghihi ◽  
Mohammad Naderi-Ghomi ◽  
Mohsen Hajibeygi
Keyword(s):  
Main Chain ◽  
Nanocomposite Films ◽  
Triphenyl Phosphite ◽  
Direct Polycondensation ◽  
Polycondensation Reaction ◽  
X Ray Diffraction ◽  
Solution Intercalation ◽  
X Ray ◽  
Diaminodiphenyl Sulfone ◽  
Thermal Stability Of

AbstractA series of polyamide (PA)/montmorillonite nanocomposites containing pyrazine moiety in the main chain were synthesized by a convenient solution intercalation technique. PA 3 as a source of polymer matrix was synthesized by the direct polycondensation reaction of pyrazine-2,3-dicarboxylic acid 1 with 4,4′-diaminodiphenyl sulfone 2 in the presence of triphenyl phosphite, CaCl2, pyridine, and N-methyl-2-pyrrolidone. The resulting nanocomposite films were characterized by Fourier transform infrared spectra, X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis (TGA). The results showed that organo-modified clay was dispersed homogeneously in the PA matrix. TGA indicated an enhancement of thermal stability of new nanocomposites compared with the pure polymer.

New thermally stable poly(amide-imide)/montmorillonite reinforced nanocomposite based on N,N′-pyrromellitoyl-bis-l-valine: synthesis and characterization

2014 ◽  
Vol 21 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Khalil Faghihi ◽  
Narges Dehnavi ◽  
Mohsen Hajibeygi
Keyword(s):  
Main Chain ◽  
Diphenyl Ether ◽  
Nanocomposite Films ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
Scanning Calorimetry ◽  
Solution Intercalation ◽  
X Ray ◽  
Polymeric Chains ◽  
Uv Visible

AbstractTwo new samples of poly(amide-imide) (PAI)/nanocomposites reinforced montmorillonite containing N,N′-pyrromelitoyl-bis-l-valine moiety in the main chain were synthesized by a solution intercalation technique. PAI 3 as a source of polymer matrix was synthesized by the direct polycondensation reaction of N,N′-pyrromelitoyl-bis-l-valine 1 with 4,4′-diamino diphenyl ether 2 in the presence of triphenyl phosphite, CaCl2, pyridine and N-methyl-2-pyrrolidone. The morphology and structure of the resulting PAI-nanocomposite films 4a and 4b with 5% and 10% silicate particles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The effect of clay dispersion and the interaction between clay and polymeric chains on the properties of nanocomposites films were investigated by using UV-visible spectroscopy, thermogravimetric analysis and differential scanning calorimetry.

Photocatalytic Comparative Study of TiO2, ZnO, Ag-G-ZnO and Ag-G-TiO2 Nanocomposite Films

2017 ◽  
Vol 751 ◽  
pp. 825-830 ◽  
Author(s):  
Phuri Kalnaowakul ◽  
Tonghathai Phairatana ◽  
Aphichart Rodchanarowan
Keyword(s):  
Colloidal Solution ◽  
Nanocomposite Films ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Photocatalytic Activities ◽  
Xrd Patterns

In this study, the photocatalytic properties and morphology of TiO2, ZnO, Ag-graphene-zinc oxide (Ag-G-ZnO) and Ag-graphene-titanium dioxide (Ag-G-TiO2) nanocomposite were compared. The Ag-G-ZnO and Ag-G-TiO2 nanocomposite were successfully prepared by thermal decomposition of colloidal solution. These prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy and photocatalytic activities. The results from XRD patterns show that Ag-G-TiO2 composites and the Ag-G-ZnO nanocomposites were in the form of fcc and hcp crystal structure, respectively. The SEM images show that at calcination of 500 °C for 3 h, the composite thin film of Ag-G-ZnO and Ag-G-TiO2 were homogenous. In the case of the photocatalytic experiments using methylene blue dye (MB) under UV irradiation, the order of the photocatalytic activities from high to low performances are Ag-G-ZnO, Ag-G-TiO2, ZnO and TiO2, respectively.

scholarly journals Synthesis and Characterization of New Polyimide/Organoclay Nanocomposites Containing Benzophenone Moieties in the Main Chain

2017 ◽  
Vol 57 (2) ◽  
Author(s):  
Khalil Faghihi ◽  
Mostafa Ashouri ◽  
Akram Feyzi
Keyword(s):  
Main Chain ◽  
In Situ Polymerization ◽  
Clay Content ◽  
Nanocomposite Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

<p>A series of nanocomposites consist of organic polyimide and organo-modified clay content varying from 0 to 5 wt%, were successfully prepared by in situ polymerization. Polyimide used as a matrix of nanocomposite was prepared through the reaction of 1,4-bis [4-aminophenoxy] butane (APB) and 3،3΄،4،4΄-benzophenone tetra carboxylic dianhydride (BTDA) in N,N-dimethylacetamide (DMAc). The resulting nanocomposite films were characterized by FT-IR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA).</p>

scholarly journals PREPARATION OF BIO-NANOCOMPOSITE MEMBRANE FOR METHYLENE BLUE ADSORPTION

2018 ◽  
Vol 56 (2A) ◽  
pp. 174-178
Author(s):  
Nguyen Thai Ngoc Uyen
Keyword(s):  
Methylene Blue ◽  
Fourier Transform ◽  
X Ray Diffraction ◽  
Solution Intercalation ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Chitosan Films ◽  
Mb Adsorption ◽  
Scanning Electron

In this study, the bio-nanocomposite composed of chitosan and nanoclay was prepared by solution intercalation method. The membrane was subsequently fabricated by dry/wet phase separation technique. The structure of bio-nanocomposite was characterized by Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) and scanning electron microscope (SEM). The membrane was applied to adsorb methylene blue (MB) for water treatment. The adsorption of MB was monitored through UV-Vis spectroscopy. The results showed that bionanocomposite membrane could adsorb MB up to 97.9 % in 150 min. The MB adsorption of bionanocomposite membrane was 234 times as high as the adsorption of the conventional chitosan films that is promising for environmental applications.

scholarly journals Structural and Band Structure Investigation of Iron Oxide Nanoparticles Incorporated PVA Nanocomposite Films

2021 ◽  
Author(s):  
Muhammad Aslam ◽  
Muhammad Basit ◽  
Muhammad Ahmad ◽  
Zulfiqar Ali Raza
Keyword(s):  
Iron Oxide ◽  
Analytical Techniques ◽  
Nanocomposite Films ◽  
X Ray Diffraction ◽  
Band Tail ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Uv Visible ◽  
Fabrication And Characterization

Abstract The work reported here deals with the fabrication and characterization of iron oxide (Fe3O4) nanoparticles (NPs – IONPs) incorporated polyvinyl alcohol (PVA)-based nanocomposite films. The nanocomposite films, fabricated via solution casting route, have been characterized using advanced analytical techniques including x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and UV-visible (vis.) spectroscopy. There observed notable changes in the structural phases, crystallite size (2.3 to 2.1 nm), d-spacing (0.131 to 0.134 Å), optical absorption edge (5.12 to 4.84 eV), indirect bandgap (4.99 to 4.68 eV), direct bandgap (5.35 to 5.20 eV), and band tail (0.57 to 0.89 eV) from native PVA to nanocomposite films. The refractive index and optical conductivity enhancements were also observed on incorporating IONPs into the PVA matrix. It could be inferred that a minute loading of IONPs might induce significant alternation in opto-structural properties of the PVA-based nanocomposites for potential optoelectronic applications.

Nanocomposite synthesis by thermolysis of [Ag(hfac)(COD)] in amorphous polystyrene

2012 ◽  
Vol 19 (2) ◽  
pp. 195-197 ◽  
Author(s):  
Gianfranco Carotenuto ◽  
Mariano Palomba ◽  
Luigi Nicolais
Keyword(s):  
Polymer Matrix ◽  
Nanocomposite Films ◽  
Numerical Density ◽  
Silver Particles ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Yellow Coloration ◽  
Color Filters ◽  
Silver Atoms

AbstractLightfast color filters (intensively and brightly colored) can be easily produced by dying optical plastics with the surface plasmon resonance (SPR) of metal nanoparticles such as silver and gold. Here, color filters based on silver nanoparticles embedded in amorphous polystyrene have been prepared by dissolving and thermally decomposing (1,5-cyclooctadiene)(hexafluoro-acetylacetonate)silver(I) in amorphous polystyrene. The metal precursor quickly decomposes (10 s, at 180°C), leading to silver atoms that clusterize and produce a non-aggregated dispersion of silver particles in the polymer matrix. The intensity of the yellow coloration due to the SPR of nanoscopic silver can be widely tuned simply by varying the cluster numerical density in the polymer matrix that depends on the silver precursor concentration. The obtained nanocomposite films have been characterized by X-ray power diffraction, transmission electron microscopy, and UV-Vis spectroscopy.

Nanocrystalline Solutions as Precursors to The Spray Deposition of Cdte Thin Films

1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Cdte Nanoparticles ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Cdte Thin Films

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.

Salts of purine alkaloids caffeine and theobromine with 2,6-dihydroxybenzoic acid as coformer: structural, theoretical, thermal and spectroscopic studies

2021 ◽  
Vol 77 (11) ◽  
Author(s):  
Mateusz Gołdyn ◽  
Anna Komasa ◽  
Mateusz Pawlaczyk ◽  
Aneta Lewandowska ◽  
Elżbieta Bartoszak-Adamska
Keyword(s):  
Hydrogen Bonds ◽  
Water Solubility ◽  
Theoretical Calculations ◽  
Spectroscopic Studies ◽  
X Ray Diffraction ◽  
Dihydroxybenzoic Acid ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Purine Alkaloids ◽  
Vis Spectroscopy

The study of various forms of pharmaceutical substances with specific physicochemical properties suitable for putting them on the market is one of the elements of research in the pharmaceutical industry. A large proportion of active pharmaceutical ingredients (APIs) occur in the salt form. The use of an acidic coformer with a given structure and a suitable pK a value towards purine alkaloids containing a basic imidazole N atom can lead to salt formation. In this work, 2,6-dihydroxybenzoic acid (26DHBA) was used for cocrystallization of theobromine (TBR) and caffeine (CAF). Two novel salts, namely, theobrominium 2,6-dihydroxybenzoate, C7H9N4O2 +·C7H5O4 − (I), and caffeinium 2,6-dihydroxybenzoate, C8H11N4O2 +·C7H5O4 − (II), were synthesized. Both salts were obtained independently by slow evaporation from solution, by neat grinding and also by microwave-assisted slurry cocrystallization. Powder X-ray diffraction measurements proved the formation of the new substances. Single-crystal X-ray diffraction studies confirmed proton transfer between the given alkaloid and 26DHBA, and the formation of N—H...O hydrogen bonds in both I and II. Unlike the caffeine cations in II, the theobromine cations in I are paired by noncovalent N—H...O=C interactions and a cyclic array is observed. As expected, the two hydroxy groups in the 26DHBA anion in both salts are involved in two intramolecular O—H...O hydrogen bonds. C—H...O and π–π interactions further stabilize the crystal structures of both compounds. Steady-state UV–Vis spectroscopy showed changes in the water solubility of xanthines after ionizable complex formation. The obtained salts I and II were also characterized by theoretical calculations, Fourier-transform IR spectroscopy (FT–IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and elemental analysis.

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