scholarly journals PVA/Gd2O3@Zno Nanocomposite Films as New Uv-Blockers: Structure and Optical Revealations

2021 ◽  
Author(s):  
H.S Vedhavathi ◽  
Divya U S ◽  
Madhukar B S ◽  
Pradeep Reddy Vanga ◽  
Kumara Swamy N
Keyword(s):  
Band Gap ◽  
Dopant Concentration ◽  
Combustion Method ◽  
Optical Characteristics ◽  
Nanocomposite Films ◽  
Solution Combustion ◽  
Scanning Calorimetry ◽  
Solution Intercalation ◽  
Oh Groups ◽  
Vis Spectroscopy

Abstract Herein we have synthesised Gadolinium oxide doped Zinc oxide (Gd 2 O 3 @ZnO) by solution combustion method and incorporated it as a nanofiller into Polyvinyl alcohol (PVA) polymer matrix using solution intercalation technique to get PVA/Gd 2 O 3 @ZnO nanocomposite film. The X-ray diffraction (XRD), Scanning electron microscopy (SEM), Differential scanning calorimetry (DSC) and UV-Vis spectroscopy were used to investigate the structural, morphological, glass transition temperature and optical properties of synthesized nanocomposites respectively. The optical propertiesof PVA/Gd 2 O 3 @ZnO film shows the interaction of –OH groups in PVA and dopant. From DSC, it is clear that Tg of prepared nano composites increases with increasing in dopant concentration. XRD analysis showed that the crystalline characteristics of the nanocomposites increases with increase in dopant concentration. The UV-Visible spectra reveals that there is decrease in indirect band gap of PVA from 4.94 eV to 3.12 eV and direct band gap from 4.90eV to 3.03 eV compared to pristine PVA Gd 2 O 3 @ZnO doped nanocomposite films showed multifold enhancement in optical characteristics such as refractive index of PVA doped nanocomposites compared pristine PVA, optical conductivity, finess coefficient, extinction coefficient on increasing in dopant concentration (0%, 2%, 4%, 6% and 8wt%). The optical characteristics of PVA/Gd 2 O 3 @ZnO nanocomposite films show excellent UV-blocking behaviour suggesting that, they are promising materials for optical devices.

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.

Refractive Index Tailoring of Poly(methylmethacrylate) Thin Films by Embedding Silver Nanoparticles

2012 ◽  
Vol 585 ◽  
pp. 134-138 ◽  
Author(s):  
Alisha Goyal ◽  
Jyoti Rozra ◽  
Isha Saini ◽  
Pawan K. Sharma ◽  
Annu Sharma
Keyword(s):  
Thin Films ◽  
Silver Nanoparticles ◽  
Refractive Index ◽  
Band Gap ◽  
Ag Nanoparticles ◽  
Nanocomposite Films ◽  
Ex Situ ◽  
Plasmon Resonance Peak ◽  
Pmma Matrix ◽  
Vis Spectroscopy

Nanocomposite films of Poly (methylmethacrylate) with different concentration of silver nanoparticles were prepared by ex-situ method. Firstly, silver nanoparticles were obtained by reducing the aqueous solution of silver nitrate with sodium borohydride then Ag-PMMA films were prepared by mixing colloidal solution of silver nanoparticles with solution of polymer. Thin solid films were structurally characterized using UV-VIS spectroscopy and TEM. The appearance of surface plasmon resonance peak, characteristic of silver nanoparticles at 420 nm in UV-VIS absorption spectra of Ag-PMMA films confirms the formation of Ag-PMMA nanocomposite. TEM showed Ag nanoparticles of average size 8 nm embedded in PMMA matrix. Analysis of absorption and reflection data indicates towards the reduction in optical band gap and increase in refractive index of the resulting nanocomposite. The synthesized Ag-PMMA nanocomposite has been found to be more conducting than PMMA as ascertained using I-V studies. The decrease in band gap and increase in conductivity can be correlated due to the formation of localized electronic states in PMMA matrix due to insertion of Ag nanoparticles. The PMMA thin films with dispersed silver nanoparticles may be useful for nanophotonic devices.

Laser Damage Threshold of Hydrophobic Up-Conversion Carboxylated Nanocellulose/SrF2:Hо Composite Films Functionalized With 3-Aminopropyltriethoxysilane

2021 ◽  
Author(s):  
Anna A. Luginina ◽  
Sergey V. Kuznetsov ◽  
Vladimir K. Ivanov ◽  
Valery V. Voronov ◽  
Alexey D. Yapryntsev ◽  
...  
Keyword(s):  
Cellulose Nanofibrils ◽  
Damage Threshold ◽  
Nanocomposite Films ◽  
Laser Damage Threshold ◽  
Laser Damage ◽  
Homogeneous Distribution ◽  
Scanning Calorimetry ◽  
Long Distance ◽  
Oh Groups ◽  
X Ray

Abstract Luminescent nanocomposite films, containing SrF 2 :Но up-conversion particles, were prepared by two different protocols from aqueous dispersions of TEMPO-oxidized cellulose nanofibrils (TOCNF) functionalized with 3-aminopropyltriethoxysilane (APS) without the use of organic solvents at pH = 4.0-4.5 and 9.0-9.5, respectively. Proposed synthetic protocols included formation of the films by drying the dispersions containing pre-hydrolyzed APS adsorbed onto TOCNF and SrF 2 :Но particles followed by heating at 105 °C. Hydrophobic (water contact angle 101 ± 2°), strong, and translucent TOCNF/SrF 2 :Но-APS films were prepared by casting from a solution at pH = 4.0-4.5. Scanning electron microscopy, energy-dispersive X-ray spectroscopy with element mapping, Fourier-transform infrared spectroscopy, X-ray diffraction methods confirmed homogeneous distribution of up-conversion particles in TOCNF matrices as well as the grafting of linear polysiloxanes via the condensation of silanol groups and OH-groups on the surface of TOCNF. Differential scanning calorimetry and thermogravimetry data confirmed an increase in thermal stability of the APS modified nanocomposite films obtained at pH = 4.0-4.5. Hydrophobic TOCNF/SrF 2 :Но-APS nanocomposite films exhibited an intense red luminescence in the visible spectrum range ( 5 I 7 level excitation of Ho 3+ ions with 1912 nm laser irradiation) as well as two-times higher laser damage threshold compared to unmodified TOCNF/SrF 2 :Но films. TOCNF/SrF 2 :Но films can be used for visualization 2 μm laser radiation in medicine and long-distance atmosphere monitoring.

scholarly journals Transparent Polyimide/Organoclay Nanocomposite Films Containing Different Diamine Monomers

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 135 ◽  
Author(s):  
Hyeon Il Shin ◽  
Jin-Hae Chang
Keyword(s):  
Mechanical Properties ◽  
Critical Concentration ◽  
Amic Acid ◽  
Optical Transparency ◽  
Nanocomposite Films ◽  
Hybrid Films ◽  
Solution Intercalation ◽  
Oh Groups ◽  
Cloisite 30B ◽  
Intercalation Polymerization

Poly (amic acid) s (PAAs) were synthesized using 4,4′-(hexafluoroisopropyl-idene) diphthalic anhydride (6FDA) and two types of diamines—bis(3-aminophenyl) sulfone (BAS) and bis(3-amino-4-hydroxyphenyl) sulfone (BAS-OH). Two series of transparent polyimide (PI) hybrid films were synthesized by solution intercalation polymerization and thermal imidization using various concentrations (from 0 to 1 wt%) of organically modified clay Cloisite 30B in PAA solution. The thermo-mechanical properties, morphology, and optical transparency of the hybrid films were observed. The transmission electronic microscopy (TEM) results showed that some of the clays were agglomerated, but most of them showed dispersed nanoscale clay. The effects of -OH groups on the properties of the two PI hybrids synthesized using BAS and BAS-OH monomers were compared. The BAS PI hybrids were superior to the BAS-OH PI hybrids in terms of thermal stability and optical transparency, but the BAS-OH PI hybrids exhibited higher glass transition temperatures (Tg) and mechanical properties. Analysis of the thermal properties and tensile strength showed that the highest critical concentration of organoclay was 0.50 wt%.

Effectiveness assessment of TiO2-Al2O3 nano-mixture as a filler material for improvement of packaging performance of PLA nanocomposite films

2020 ◽  
Vol 40 (10) ◽  
pp. 848-858
Author(s):  
Fatima Zohra Yakdoumi ◽  
Assia Siham Hadj-Hamou
Keyword(s):  
Polylactic Acid ◽  
Nanocomposite Film ◽  
Food Packaging ◽  
Antimicrobial Properties ◽  
Young Modulus ◽  
Nanocomposite Films ◽  
Vapor Permeability ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Vis Spectroscopy

AbstractThe main objective of this study was to assess the effectiveness of TiO2-Al2O3 nano-mixture used as filler in improving packaging films performance. Polylactic acid/titanium dioxide (PLA/TiO2), polylactic acid/alumina (PLA/Al2O3) and polylactic acid/TiO2-Al2O3 (PLA/TiO2-Al2O3) nanocomposite films were successfully prepared via melt mixing process and thoroughly characterized by FTIR spectroscopy, X-ray diffraction (XRD), UV–vis spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The properties such as heat resistant, barrier, mechanical and antimicrobial properties, required for food packaging have also been investigated. As compared to the neat PLA film, the developed PLA nanocomposites have displayed superior properties particularly the PLA/ TiO2-Al2O3 nanocomposite film. This resulted material has showed a 22 °C increase in its thermal stability versus 14 and 2 °C in the cases of PLA/TiO2 and PLA/Al2O3 respectively, and a 54% reduction of its water vapor permeability in comparison with 47% for PLA/TiO2 and 39% for PLA/Al2O3. In addition, the PLA/TiO2-Al2O3 had a significant enhancement of its mechanical properties. Its Young modulus increased by 102% unlike 23.60% for the PLA/TiO2 and 44.66% for the PLA/Al2O3. It was also noticed that this nanocomposite film demonstrated stronger antibacterial activity than the two others. The bacterial growth inhibition effect of TiO2-Al2O3 nano-mixture against Pseudomonas aeruginosa and Escherichia coli bacteria was more effective than that of its two constituents.

Swift Heavy Ion Induced Modification in Physical Properties of Poly Methylmethacrylate (PMMA)/Nickel (Ni) Nanocomposites

2013 ◽  
Vol 341 ◽  
pp. 51-68
Author(s):  
N.L. Singh ◽  
Chaitali Gavade ◽  
P.K. Khanna
Keyword(s):  
Differential Scanning Calorimetry ◽  
Band Gap ◽  
Quantum Interference ◽  
Ion Beam ◽  
Magnetic Hysteresis ◽  
Heavy Ion ◽  
Nanocomposite Films ◽  
Zero Field ◽  
Scanning Calorimetry ◽  
Swift Heavy Ion

We have These films were irradiated with 85 MeV C-ions at the fluences of 1 x 1011 and 1 x 1012 ions/cm2. Changes in the optical, structural, dielectric, magnetic and thermal properties of (PMMA)/Ni nanocomposites of different concentrations of nickel nanoparticles (5%, 10%, 15%) due to swift heavy ion irradiation were studied by means of UVvisible spectroscopy, X-ray diffraction, impedance gain phase analyzer, SQUID and differential scanning calorimetry. Optical properties like band gap were estimated for pure polymer and nanocomposite films from their optical absorption spectra in the wavelength range 200-800 nm. It was found that the band gap value shifted to lower energy on doping with metal nanoparticles. Differential scanning calorimetry analysis revealed a decrease in the glass transition temperature upon irradiation, which may be attributed to the scissioning of polymer chain due to ion beam irradiation which is also corroborated with XRD analysis. Surface morphology of the pristine and irradiated films was studied by scanning electron microscopy (SEM). The breakage of chemical bonds resulted in an increase of free radicals, unsaturation etc. as revealed from FTIR analysis. The dielectric properties were observed to enhance with an increase in metal compound concentration as well as with irradiation dose. This may be due to metal/polymer bonding and conversion of polymeric structure into hydrogen-depleted carbon network. Zero-Field-Cooled (ZFC)/Field-Cooled (FC) magnetization and magnetic hysteresis measurements were performed using a superconducting quantum interference device (SQUID) magnetometer from temperatures ranging from 5 K to 300 K, to investigate the magnetic properties of nanocomposites. The changes in topography of surfaces were also observed upon irradiation.

scholarly journals Enhancing the Optical Properties of Chitosan, Carboxymethyl Cellulose, Sodium Alginate Modified with Nano Metal Oxide and Graphene Oxide

2022 ◽  
Author(s):  
Amina Omar ◽  
Rania Badry ◽  
Maroof A. Hegazy ◽  
Ibrahim S. Yahia ◽  
Hanan Elhaes ◽  
...  
Keyword(s):  
Optical Properties ◽  
Graphene Oxide ◽  
Band Gap ◽  
Sodium Alginate ◽  
Carboxymethyl Cellulose ◽  
Optical Band Gap ◽  
Filler Content ◽  
Nanocomposite Films ◽  
Absorption Bands ◽  
Vis Spectroscopy

Abstract The solution casting method was utilized to synthesize nanocomposite films of chitosan (Cs)/CuO, Cs/graphene oxide (GO), carboxymethyl cellulose (CMC)/TiO2, CMC/GO, sodium alginate (Na Alg)/TiO2, and Na-Alg/GO owing to their various applications. The influence of CuO, TiO2 and GO concentration on the optical properties of Cs, CMC and Na-Alg films was studied by UV-Vis Spectroscopy. The absorbance of Cs, CMC and Na-Alg increased with increasing the filler content, thus reflecting the dependence of Cs, CMC, and Na-Alg properties on the nanofiller content, and confirming the interactions between individual polymers and CuO, TiO2 and GO nanoparticles. The obtained absorbance values were then used to calculate the absorption coefficient and, hence, the optical band gap values. The characteristic absorption bands of CuO and TiO2 underwent a redshift by increasing the filler content. The results showed that the optical band gap of Cs, CMC, and Na-Alg decreased with filler content, and they possessed 1, 2 and 2 band gaps respectively. The obtained results recommended that Cs, CMC, and Na-Alg nanocomposites can be used in optoelectronic devices.

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.

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