scholarly journals Understanding the effects of montmorillonite and sepiolite on the properties of solution‐cast chitosan and chitosan/silk peptide composite films

2020 ◽  
Author(s):  
Pei Chen ◽  
Fengwei Xie ◽  
Tony McNally
Keyword(s):  
Composite Films ◽  
Solution Cast ◽  
Silk Peptide

Silver-Polyimide Nanocomposite Films Yielding Highly Reflective Surfaces

2001 ◽  
Vol 707 ◽  
Author(s):  
Robin E. Southward ◽  
C. J. Dean ◽  
J. L. Scott ◽  
S. T. Broadwater ◽  
D. W. Thompson
Keyword(s):  
Composite Films ◽  
Weight Percent ◽  
Amic Acid ◽  
Nanocomposite Films ◽  
Polyimide Films ◽  
Electrically Conductive ◽  
Reflective Surface ◽  
Solution Cast ◽  
Surface Metal ◽  
Polyimide Nanocomposite

ABSTRACTHighly reflective surface-metallized flexible polyimide films have been prepared by the incorporation of the soluble silver ion complex (1,1,1-trifluoroacetylacetonato)silver(I) into dimethylacetamide solutions of the poly(amic acid) prepared from 2,2-bis(3,4-dicarboxyphenyl)-hexafluoropropane dianhydride (6FDA) and 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoro-propane (4-BDAF). Thermal curing of solution cast silver(I)-poly(amic acid) films leads to cycloimidization of the amic acid with concommitant silver(I) reduction and formation of a reflective surface-silvered film at 8 and 13 weight percent silver. The metallized films are thermally stable and flexible with mechanical properties similar to those of the parent polyimide. TEM reveals that the bulk (interior) of the polyimide composite films have 5-20 nanometer-sized silver particles with a surface layer of silver metal ca. 80 nm thick. Neither the bulk nor the surface of the films is electrically conductive. Adhesion of the surface metal to polyimide is excellent.

scholarly journals Attenuation parameters of polyvinyl alcohol-tungsten oxide composites at the photon energies 5.895, 6.490, 59.54 and 662 keV

2020 ◽  
Vol 26 (2) ◽  
pp. 77-85
Author(s):  
M V Muthamma ◽  
Bubbly S Gudennavar ◽  
Shivappa B Gudennavar
Keyword(s):  
Polyvinyl Alcohol ◽  
Direct Method ◽  
Composite Films ◽  
Effective Atomic Number ◽  
X Ray Diffraction ◽  
X Ray ◽  
Noticeable Increase ◽  
Conductivity Property ◽  
Solution Cast ◽  
Γ Ray

AbstractThe growing demand for lightweight, non-toxic and effective X- and γ-ray shielding materials in various fields has led to the exploration of various polymer composites for shielding applications. In this study, tungsten filled polyvinyl alcohol (PVA) composites of varying WO3 concentrations (0 - 50 wt%) were prepared by solution cast technique. The structural, morphological, and thermal properties of the prepared composite films were studied using X-ray diffraction technique (XRD), Scanning electron microscopy (SEM) and Thermogravimetric analysis (TGA). The AC conductivity studies showed the low conductivity property of the composites. The X-ray (5.895 and 6.490 keV) and γ-ray (59.54 and 662 keV) attenuation studies performed using CdTe and NaI(Tl) detector spectrometers revealed a noticeable increase in shielding efficiency with increase in filler wt%. The effective atomic number (Zeff) calculated by the direct method agreed with the values obtained using Auto-Zeff software. The % heaviness showed that tungsten filled polyvinyl alcohol composites are lighter than traditional shielding materials.

Enhanced Dielectric Permittivity of Nh4H2Po4/Polyvinyl Alcohol Composites at Low Percolation Threshold

2013 ◽  
Vol 665 ◽  
pp. 74-75
Author(s):  
Jamal Uddin ◽  
B.K. Chaudhuri
Keyword(s):  
Dielectric Permittivity ◽  
Polyvinyl Alcohol ◽  
Percolation Threshold ◽  
Composite Films ◽  
Threshold Value ◽  
Dihydrogen Phosphate ◽  
Two Phase ◽  
Dielectric Data ◽  
Solution Cast ◽  
Dependent Transport

A new kind of two phase ammonium dihydrogen phosphate (NH4H2PO4 or ADP)/polyvinyl alcohol (PVA) composite films have been prepared by solution cast technique. Significant enhancement of dielectric permittivity (~442) of ADP/PVA composites are observed at low ADP concentration (fADP fC ~5 wt %) which is the percolation threshold value estimated from the concentration dependent transport and dielectric data. Nearly 85 times increase in dielectric permittivity compared to that of the bare PVA film in the composite film around fC with low loss (~0.14) at 1 kHz and room temperature is observed. The present ADP based PVA composite material might be processed for application in devices.

PREPARATION OF CARBON–NITROGEN NANOTUBES (CNNTs)–POLY ETHYLENE OXIDE (PEO) COMPOSITES FILMS AND THEIR ELECTRICAL CONDUCTIVITY MEASUREMENT

2011 ◽  
Vol 10 (04n05) ◽  
pp. 1091-1094 ◽  
Author(s):  
RAM MANOHAR YADAV ◽  
RAJESH KUMAR ◽  
KALPANA AWASTHI ◽  
O. N. SRIVASTAVA
Keyword(s):  
Electrical Conductivity ◽  
Room Temperature ◽  
Composite Films ◽  
Conductivity Measurement ◽  
Electrical Conductivity Measurement ◽  
Solution Cast ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Cast Technique ◽  
Film Conductivity

The present work describes the preparation characterization and electrical conductivity measurement of carbon–nitrogen (C–N) nanotubes–PEO composites films. CNNTs–PEO composite films have been prepared by using the solution cast technique and characterized by scanning electron microscope (SEM PHILIPS XL-20). The DC electrical conductivity measurements of the composite films revealed that for PEO film conductivity has been found to be ~ 7.5 × 10-8 Scm-1, and for C–N nanotubes (~ 20 wt.%)–PEO film it was found to be ~6.2 Scm-1 at room temperature. Thus, compared to the PEO film, the conductivity of the C–N nanotubes (~ 20 wt.%)–PEO composite film is eight orders of magnitude higher. The same conductivity of ~ 6.2 Scm-1 for the carbon nanotubes (CNT)–PEO composites comes out at 50 wt.% of CNT in PEO as reported earlier by our group. The conductivity increases with the increase of temperature, confirming the semiconducting nature of the C–N nanotubes–PEO composites.

scholarly journals Hydrogen evolution at conjugated polymer nanoparticle electrodes

2018 ◽  
Vol 96 (2) ◽  
pp. 148-157 ◽  
Author(s):  
Patrick Fortin ◽  
Subash Rajasekar ◽  
Pankaj Chowdhury ◽  
Steven Holdcroft
Keyword(s):  
Thin Films ◽  
Hydrogen Evolution ◽  
Bulk Heterojunction ◽  
Composite Films ◽  
Organic Thin Films ◽  
Phase Segregation ◽  
Organic Polymer ◽  
Acidic Solutions ◽  
Solution Cast ◽  
Conventional Solution

Organic polymer nanoparticles have been gaining attention in photovoltaics as a means to control the morphology of polymer composite films for the purpose of studying bulk heterojunction, photoactive layers. This work investigates the preparation of nanostructured organic thin films from P3HT:PC61BM nanoparticles and their characterization as photoelectrodes for the photoelectrochemical reduction of hydrogen in acidic solutions. The morphology and optoelectronic properties of the nanostructured photocathodes are compared with conventional, solution-cast thin films of P3HT:PC61BM. The nanostructured photoelectrodes provide increased surface area compared with solution-cast films through control of the nanoscale morphology within each nanoparticle, leading to enhanced P3HT:PC61BM phase segregation. The photo-assisted deposition of platinum nanoparticles as hydrogen evolution reaction (HER) catalysts onto the nanostructured P3HT:PC61BM photocathodes facilitates the photoreduction of protons to H2.

MWNT Polymer Nanocomposites Based on P3HT

2007 ◽  
Vol 29-30 ◽  
pp. 291-294 ◽  
Author(s):  
A.W. Musumeci ◽  
G.G. Silva ◽  
J.W. Liu ◽  
L. Rintoul ◽  
E.R. Waclawik ◽  
...  
Keyword(s):  
Polymer Nanocomposites ◽  
Conjugated Polymer ◽  
Composite Films ◽  
Weight Percent ◽  
Heat Of Fusion ◽  
Covalent Interaction ◽  
Carbon Nanotube Network ◽  
Solution Cast ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Thin and short multi walled carbon nanotubes (MWNTs) were used to prepare nanocomposites based on poly(3-hexylthiophene) (P3HT). The MWNTs were characterized by TEG, SEM, TEM and Raman spectroscopy following deposition of films from stable dispersions of MWNT in chloroform. Non-covalent interaction between MWNT and P3HT dissolved in chloroform allowed the preparation of solution-cast composite films. Composite thermal events such as glass transition, melting temperature and heat of fusion were investigated by DSC and compared with pure polymer. Conductivity of composite bulk films was measured as a function of temperature by 2-point probe DC-resistance measurements. Loadings of MWNTs above 0.1 weight percent (wt%) in the conjugated polymer significantly increased the conductivity of P3HT composites. Interplay between charge transport through the semiconductor polymer and carbon nanotube network allowed the increase of conductivity after percolation to values close to 10-2 S cm-1, an improvement of four orders of magnitude over that of films cast from pure P3HT.

scholarly journals Crystallographic Textures and Morphologies of Solution Cast Ibuprofen Composite Films at Solid Surfaces

2014 ◽  
Vol 11 (11) ◽  
pp. 4084-4091 ◽  
Author(s):  
Thomas Kellner ◽  
Heike M. A. Ehmann ◽  
Simone Schrank ◽  
Birgit Kunert ◽  
Andreas Zimmer ◽  
...  
Keyword(s):  
Composite Films ◽  
Solid Surfaces ◽  
Solution Cast

Thermal conductive performance of organosoluble polyimide/BN and polyimide/(BN + ALN) composite films fabricated by a solution-cast method

2013 ◽  
Vol 34 (2) ◽  
pp. 252-258 ◽  
Author(s):  
D.H. Kuo ◽  
C.Y. Lin ◽  
Y.C. Jhou ◽  
J.Y. Cheng ◽  
G.S. Liou
Keyword(s):  
Composite Films ◽  
Solution Cast ◽  
Solution Cast Method

Silver-Polyimide Nanocomposite Films Yielding Highly Reflective Surfaces

2001 ◽  
Vol 703 ◽  
Author(s):  
Robin E. Southward ◽  
C. J. Dean ◽  
J. L. Scott ◽  
S. T. Broadwater ◽  
D. W. Thompson
Keyword(s):  
Composite Films ◽  
Weight Percent ◽  
Amic Acid ◽  
Nanocomposite Films ◽  
Polyimide Films ◽  
Electrically Conductive ◽  
Reflective Surface ◽  
Solution Cast ◽  
Surface Metal ◽  
Polyimide Nanocomposite

ABSTRACTHighly reflective surface-metallized flexible polyimide films have been prepared by the incorporation of the soluble silver ion complex (1,1,1-trifluoroacetylacetonato)silver(I) into dimethylacetamide solutions of the poly(amic acid) prepared from 2,2-bis(3,4-dicarboxyphenyl)-hexafluoropropane dianhydride (6FDA) and 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoro-propane (4-BDAF). Thermal curing of solution cast silver(I)-poly(amic acid) films leads to cycloimidization of the amic acid with concommitant silver(I) reduction and formation of a reflective surface-silvered film at 8 and 13 weight percent silver. The metallized films are thermally stable and flexible with mechanical properties similar to those of the parent polyimide. TEM reveals that the bulk (interior) of the polyimide composite films have 5-20 nanometer-sized silver particles with a surface layer of silver metal ca. 80 nm thick. Neither the bulk nor the surface of the films is electrically conductive. Adhesion of the surface metal to polyimide is excellent.

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