Photosensitive PVA Polarizing Film

2006 ◽  
Vol 11-12 ◽  
pp. 351-354
Author(s):  
Jie Wei ◽  
Xiao Mei Ji ◽  
Xiao Wang ◽  
Xiao Ming Dong
Keyword(s):  
Vinyl Alcohol ◽  
Uv Light ◽  
Light Transmittance ◽  
Poly Vinyl Alcohol ◽  
X Ray ◽  
Series Of Experiments ◽  
Uv Visible ◽  
Crystallization Degree

In order to analyze the polarization of Poly(vinyl alcohol) (PVA) film, both the polarizing film and polarizing film exposed to UV light were prepared and investigated by X-ray diffractometer (XRD) and polarized UV-Visible Spectrometer. Through a series of experiments, it was found that the crystallization degree of the unirradiated PVA film was higher than that of the UV-irradiated PVA film. Furthermore, the transmittance of both unirradiated PVA film and UV-irradiated PVA film was selective, different wavelength and different polarizing angles parallelism different light transmittance.

scholarly journals Synthesis of Silver Nanoparticles from Mimusops elengi Extract of Raw Fruits and Characterization of PVA-Silver Polymer Nanocomposite Films

2021 ◽  
Vol 33 (4) ◽  
pp. 762-766
Author(s):  
BHABANI SHANKAR PANDA ◽  
MOHAMMED ANSAR AHEMAD
Keyword(s):  
Silver Nanoparticles ◽  
Vinyl Alcohol ◽  
Thermal Studies ◽  
Polymer Nanocomposite ◽  
Nanocomposite Films ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Visible ◽  
Mimusops Elengi

The present work concerns on the synthesis of silver nanoparticles at 25 ºC using raw fruits extract of Bakul (Mimusops elengi) tree via chemical reduction route development of poly(vinyl alcohol) PVA-silver polymer nanocomposite films. The nanocomposite films were subjected to characterization by UV-visible, FTIR, X-ray diffraction, field emission scanning electron microscope (FESEM) and thermal studies. The UV-visible spectrum shows a characteristic broad absorption band observed near 465 nm suggesting presence of silver nanoparticles in polymer nanocomposites (PNCs) film. The vibrational band shift of –OH group of poly(vinyl alcohol) in the presence of nanoparticle designated the chemical interaction between –OH group of poly(vinyl alcohol) and silver nanoparticles. The FESEM study confirmed that PVA is not only acted as a capping agent, but also a cross-linking agent. X-ray diffraction study shows that the existence of AgNPs in the poly nanocomposite film and nanoaparticles are crystalline in nature. Thermal studies suggest that the enhanced thermal stability is because of the good packing of the polar crystallites in β-PVA composites as compared to the non-polar α-phase of neat poly(vinyl alcohol) (PVA).

TiO2 nanofibers fabricated by electrospinning technique and degradation of MO dye under UV light

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Naveen Thakur ◽  
Nikesh Thakur ◽  
Viplove Bhullar ◽  
Saurabh Sharma ◽  
Aman Mahajan ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Fiber Diameter ◽  
Uv Light ◽  
Rutile Phase ◽  
Powder Form ◽  
X Ray Diffraction ◽  
Electrospinning Technique ◽  
Tio2 Nanofibers ◽  
X Ray ◽  
Uv Visible

Abstract Titanium dioxide (TiO2) nanofibers were synthesized by electrospinning to optimize the photocatalytic action efficiency. The synthesis of the fibers was carried out at four different wt% concentrations: 8, 9, 10 & 11% of polymer polyvinylpyrrolidone (PVP). The TiO2 fibers were further calcined at 700 °C to get powder form. The uncalcinated and calcined TiO2 nanofibers were characterized by using X-Ray diffraction (XRD), Raman spectroscopy, Scanning electron microscopy (SEM) and UV-Visible spectroscopy. Raman spectroscopy confirmed the rutile phase of the calcined TiO2nanofibers in powder form with a crystallite size of 34–38 nm. The surface morphology of the uncalcinated and calcined TiO2 nanofibers was examined by SEM and the fiber diameter found to be 360–540 nm. The optical bandgap of the calcined TiO2 nanofibers was found in the range of 3.29–3.24 eV. The photocatalytic activity of the TiO2 nanofibers as examined for uncalcinated and calcined nanofibers, methyl orange (MO) dye degraded up to 98 and 78%, respectively in 180 min under the exposure of UV light. Uncalcinated TiO2 nanofibers were found more suitable for degradation of MO dye as compared to calcined nanofibers.

scholarly journals PREPARATION AND CHARACTERIZATION OF POLY (VINYL ALCOHOL)–POLY (VINYL PYRROLIDONE) MUCOADHESIVE BUCCAL PATCHES FOR DELIVERY OF LIDOCAINE HCL

2018 ◽  
Vol 10 (1) ◽  
pp. 115 ◽  
Author(s):  
Napaphak Jaipakdee ◽  
Thaned Pongjanyakul ◽  
Ekapol Limpongsa
Keyword(s):  
Vinyl Alcohol ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Casting Technique ◽  
In Vitro Permeation ◽  
Lidocaine Hcl ◽  
Poly Vinyl Pyrrolidone

Objective: The objectives of this study were to prepare and characterize a buccal mucoadhesive patch using poly (vinyl alcohol) (PVA), poly (vinyl pyrrolidone) (PVP) as a mucoadhesive matrix, Eudragit S100 as a backing layer, and lidocaine HCl as a model drug.Methods: Lidocaine HCl buccal patches were prepared using double casting technique. Molecular interactions in the polymer matrices were studied using attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC) and X-ray diffractometry. Mechanical and mucoadhesive properties were measured using texture analyzer. In vitro permeation of lidocaine HCl from the patch was conducted using Franz diffusion cell.Results: Both of the free and lidocaine HCl patches were smooth and transparent, with good flexibility and strength. ATR-FTIR, DSC and X-ray diffractometry studies confirmed the interaction of PVA and PVP. Mechanical properties of matrices containing 60% PVP were significantly lower than those containing 20% PVP (*P<0.05). Mucoadhesive properties had a tendency to decrease with the concentration of PVP in the patch. The patch containing 60% PVP had significantly lower muco-adhesiveness than those containing 20% PVP (*P<0.05). In vitro permeation revealed that the pattern of lidocaine HCl permeation started with an initial fast permeation, followed by a slower permeation rate. The initial permeation fluxes follow the zero-order model of which rate was not affected by the PVP concentrations in the PVA/PVP matrix.Conclusion: Mucoadhesive buccal patches fabricated with PVA/PVP were successfully prepared. Incorporation of PVP in PVA/PVP matrix affected the strength of polymeric matrix and mucoadhesive property of patches.

scholarly journals Preparation and Assessment of Heat-Treated α-Chitin Nanowhiskers Reinforced Poly(viny alcohol) Film for Packaging Application

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1883 ◽  
Author(s):  
Chao Peng ◽  
Guangxue Chen
Keyword(s):  
Heat Treatment ◽  
Composite Films ◽  
Barrier Properties ◽  
Mechanical Tests ◽  
Light Transmittance ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Chitin Nanowhiskers

In this study, poly(vinyl alcohol) (PVA) composite films enhanced by α-chitin nanowhiskers (ChWs) were prepared through heat treatment. The obtained membranes were assessed by means of FTIR spectroscopy, X-ray diffraction, thermogravimetric analysis, regular light transmittance, mechanical tests, permeability and water absorption. The influence of the nano-component and heat treatment on the mechanical, thermal and water-resistant properties of the composite membrane were analyzed. From the results of the work, the produced films with excellent barrier properties and inexpensive raw processed materials have great prospects in packaging applications.

Preparation of electrospun silver/poly(vinyl alcohol) fibrous membranes and characterization of the effect of sterilization processes on the antibacterial activity

2020 ◽  
pp. 152808372091334 ◽  
Author(s):  
Wen-Cheng Chen ◽  
Chia-Ying Ko ◽  
Kai-Chi Chang ◽  
Chih-Hua Chen ◽  
Dan-Jae Lin
Keyword(s):  
Vinyl Alcohol ◽  
Antimicrobial Agents ◽  
Uv Light ◽  
Silver Ions ◽  
Composite Membranes ◽  
Antibacterial Activities ◽  
Poly Vinyl Alcohol ◽  
Preheat Treatment ◽  
Fibrous Membranes

Silver ions (Ag+) and silver nanoparticles (AgNPs) are effective antimicrobial agents that act against a broad spectrum of bacteria. The releasing quantitation of free Ag+ is exclusively responsible for the biological toxicity, while limiting the free Ag+ in AgNPs or in polymers would largely ease the conditions. In this study, the different concentrations of silver nitrate (AgNO3) in poly(vinyl alcohol) (PVA) and an optional preheat treatment on the spinning solution before electrospinning to form the Ag+/AgNPs/PVA fibrous membranes through electrospinning technology were investigated. The morphologies, AgNPs dispersity within the PVA matrix, and the sterilizations (UV irradiation and autoclave) for Ag+/AgNPs/PVA fibrous membranes were characterized. The antibacterial activities of Ag/PVA composite membranes combined with the in-house prepared light-cured resin were also investigated. Results showed that the AgNPs/PVA fibrous membranes with antibacterial capability can be produced with the addition of at least 5 wt.% of AgNO3 to PVA. The antibacterial activities of Ag content in the PVA matrix were increased in the high presence of Ag. Noteworthy, the antibacterial enhancing effect was observed for the spinning solution groups after preheating treatment at 100°C for 1 h. The result suggests that Ag/PVA fibrous membranes sterilized by autoclave hindered antibacterial effectiveness due to the significant particle size changes in the generation of large-sized AgNPs. Nevertheless, the direct application of UV light irradiation to Ag/PVA fibrous membranes preserves their active antibacterial profile against Staphylococcus aureus and Escherichia coli. We also demonstrated that these designed AgNPs/PVA composite membranes can equip the resin with an active antibacterial capability, could benefit from the prevented bacteria breeding in microleakages and thus further reduce the possibility for secondary caries.

Free volume and lamellar structure of poly vinyl alcohol-nanosized BaTiO3 composite: Positron annihilation and small angle X-ray scattering study

2016 ◽  
Vol 84 ◽  
pp. 100-110 ◽  
Author(s):  
Sandeep K. Sharma ◽  
Jyoti Prakash ◽  
Jitendra Bahadur ◽  
Manjulata Sahu ◽  
Subhashish Mazumder ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Free Volume ◽  
Small Angle ◽  
Vinyl Alcohol ◽  
Lamellar Structure ◽  
Poly Vinyl Alcohol ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering

Defining Structure in Electrospun Polymer Fibres

2008 ◽  
Vol 55-57 ◽  
pp. 33-36
Author(s):  
G.R. Mitchell ◽  
M. Belal ◽  
F.J. Davis ◽  
D.E. Elliott ◽  
M. Kariduraganavar ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Polyethylene Oxide ◽  
Self Assembly ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
X Ray ◽  
Amorphous System ◽  
Composite Systems ◽  
X Ray Scattering ◽  
Nano Size

We use a combination of microscopy, x-ray scattering and neutron scattering to show how structure develops in micro and nano-size polymer fibres prepared by electrospinning. The technique has been applied to a range of different polymers, an amorphous system (polystyrene), a crystallisable polymer (poly-ε-caprolactone), a composite systems (polyethylene oxide or poly vinyl alcohol containing polypyrrole) and consider the possibility of self assembly (gelatin).

Surface Modified Poly(vinyl alcohol) Nanofiber for the Artificial Corneal Stroma

2007 ◽  
Vol 342-343 ◽  
pp. 209-212 ◽  
Author(s):  
Hisatoshi Kobayashi
Keyword(s):  
Corneal Epithelium ◽  
Vinyl Alcohol ◽  
Type I Collagen ◽  
Corneal Stroma ◽  
Light Transmittance ◽  
Poly Vinyl Alcohol ◽  
Type I ◽  
Nanofiber Sheets

Previously we have found that the immobilization of Type I collagen on the poly(vinyl alcohol)(PVA) hydrogel disc was effective in supporting adhesion and growth of the corneal epithelium and stromal cell in vitro. But the durability of the produced corneal epithelium layer in vivo has some problem. We hypothesized the cell construction force is much stronger than the force of the cell adhesion on the flat modified PVA surfaces. Therefore the improvement of mechanical anchoring force between the substrate and formed corneal cell layer maybe become one of the solving methods. In this study, we prepared the PVA nanofiber mat by using the electrospinning method and the surface modification of the PVA nanofiber was studied to improve the durability of the corneal epithelium layer. The collagen-immobilized PVA nanofiber sheets could support the adhesion and proliferation of rabbit corneal epithelial cells. And the stratified corneal epithelium structure was observed on the PVA nanofiber sheets when the epithelium was co-cultured with rabbit corneal stromal cells. It means that the corneal epithelium was well differentiated on the collagen immobilized PVA nanofiber sheet. The stability of the corneal epithelium layer on the PVA was dramatically improved; the stratified epithelium layer was kept for two weeks after the differentiation introduction, totally after one month. A light transmittance of these materials is not yet enough. Further study to improve the transmission of light, is required.

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