Experimental Studies of UV Irradiation Induced Changes in Optical, Mechanical and Microstructural Properties of PVA/Modified Cellulose Composite

2017 ◽  
Vol 14 (1) ◽  
pp. 41-52
Author(s):  
Sunil G Rathod R F Bhajantri
Keyword(s):  
Uv Irradiation ◽  
Chemical Interaction ◽  
Irradiation Time ◽  
Composite Films ◽  
Experimental Studies ◽  
Morphological Properties ◽  
Poly Vinyl Alcohol ◽  
Increase With Increase ◽  
Cellulose Composite ◽  
Modified Cellulose

Poly(vinyl alcohol) (PVA)/modified Cellulose composite films with 85:15 wt.% were prepared by solution casting method and subjected to UV irradiation for different intervals of time. The UV irradiation induced modifications in optical, mechanical and morphological properties were studied. The FTIR results confirm the chemical interaction between PVA and Cellulose. The optical absorption also supports the formation of crosslinked network in the polymer composite. The XRD result shows an increase in the amorphousness with increase in UV irradiation time. The Young’s modulus (YM), tensile strength (TS), stiffness and percentage (%) elongation at break (% EB) of the composite films increase with increase in UV irradiation time. The Scanning Electron microscope (SEM)    images    confirm the

scholarly journals Preparation and Properties of Biodegradable Film Composites Using Modified Cellulose Fibre-Reinforced with PVA

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Sandeep S. Laxmeshwar ◽  
D. J. Madhu Kumar ◽  
S. Viveka ◽  
G. K. Nagaraja
Keyword(s):  
Moisture Absorption ◽  
Composite Films ◽  
Cellulose Fibre ◽  
Barrier Properties ◽  
Poly Vinyl Alcohol ◽  
Biodegradable Film ◽  
Biodegradable Composite ◽  
Ir Studies ◽  
Modified Cellulose ◽  
Film Composites

Cellulose has a potential to become a key resource in the development of biodegradable film composites. In this work, cellulose was modified by using 2-(Trifluromethyl)benzoylchloride by base-catalyzed reaction. Modification of cellulose was confirmed by IR studies. The biodegradable composite films were developed by film casting method using modified cellulose with Poly(vinyl alcohol) in different compositions. The film composites were characterized by mechanical, moisture absorption, gas barrier, and biodegradable properties. Obtained films have shown transparency and flexibility and displayed good mechanical properties. Film composites also showed good biodegradability. Better barrier properties showed by film composites as the percentage of modified cellulose increased. This indicates the importance of modified cellulose as a reinforcing agent. After evaluating these properties of film composites, we came to conclusion that these biocomposites can be used to membrane and packaging applications.

Surface properties, thermal, and mechanical characteristics of poly(vinyl alcohol)-starch-bacterial cellulose composite films

2017 ◽  
Vol 135 (6) ◽  
pp. 45800 ◽  
Author(s):  
Ioana Chiulan ◽  
Adriana Nicoleta Frone ◽  
Denis Mihaela Panaitescu ◽  
Cristian Andi Nicolae ◽  
Roxana Trusca
Keyword(s):  
Bacterial Cellulose ◽  
Surface Properties ◽  
Vinyl Alcohol ◽  
Mechanical Characteristics ◽  
Composite Films ◽  
Poly Vinyl Alcohol ◽  
Cellulose Composite

scholarly journals Green Synthesis and Characterization of Pullulan Mediated Silver Nanoparticles through Ultraviolet Irradiation

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2382 ◽  
Author(s):  
Muhammad Jamshed Khan ◽  
Suriya Kumari ◽  
Kamyar Shameli ◽  
Jinap Selamat ◽  
Awis Qurni Sazili
Keyword(s):  
Silver Nanoparticles ◽  
Uv Irradiation ◽  
Irradiation Time ◽  
Edible Films ◽  
Crystallographic Structure ◽  
Face Centered Cubic ◽  
Selected Area Electron Diffraction ◽  
Vis Spectroscopy ◽  
Face Centered ◽  
Average Lattice

Nanoparticles (NPs) are, frequently, being utilized in multi-dimensional enterprises. Silver nanoparticles (AgNPs) have attracted researchers in the last decade due to their exceptional efficacy at very low volume and stability at higher temperatures. Due to certain limitations of the chemical method of synthesis, AgNPs can be obtained by physical methods including sun rays, microwaves and ultraviolet (UV) radiation. In the current study, the synthesis of pullulan mediated silver nanoparticles (P-AgNPs) was achieved through ultraviolet (UV) irradiation, with a wavelength of 365 nm, for 96 h. P-AgNPs were formed after 24 h of UV-irradiation time and expressed spectra maxima as 415 nm, after 96 h, in UV-vis spectroscopy. The crystallographic structure was “face centered cubic (fcc)” as confirmed by powder X-ray diffraction (PXRD). Furthermore, high resolution transmission electron microscopy (HRTEM) proved that P-AgNPs were covered with a thin layer of pullulan, with a mean crystalline size of 6.02 ± 2.37. The average lattice fringe spacing of nanoparticles was confirmed as 0.235 nm with quasi-spherical characteristics, by selected area electron diffraction (SAED) analysis. These green synthesized P-AgNPs can be utilized efficiently, as an active food and meat preservative, when incorporated into the edible films.

scholarly journals Enhanced antibacterial activity through the controlled alignment of graphene oxide nanosheets

2017 ◽  
Vol 114 (46) ◽  
pp. E9793-E9801 ◽  
Author(s):  
Xinglin Lu ◽  
Xunda Feng ◽  
Jay R. Werber ◽  
Chiheng Chu ◽  
Ines Zucker ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Antibacterial Activity ◽  
Graphene Oxide ◽  
Direct Electron Transfer ◽  
Composite Films ◽  
Experimental Studies ◽  
Cross Linking ◽  
Vertical Orientation ◽  
Electron Transfer Mechanism ◽  
Vertically Aligned

The cytotoxicity of 2D graphene-based nanomaterials (GBNs) is highly important for engineered applications and environmental health. However, the isotropic orientation of GBNs, most notably graphene oxide (GO), in previous experimental studies obscured the interpretation of cytotoxic contributions of nanosheet edges. Here, we investigate the orientation-dependent interaction of GBNs with bacteria using GO composite films. To produce the films, GO nanosheets are aligned in a magnetic field, immobilized by cross-linking of the surrounding matrix, and exposed on the surface through oxidative etching. Characterization by small-angle X-ray scattering and atomic force microscopy confirms that GO nanosheets align progressively well with increasing magnetic field strength and that the alignment is effectively preserved by cross-linking. When contacted with the model bacteriumEscherichia coli, GO nanosheets with vertical orientation exhibit enhanced antibacterial activity compared with random and horizontal orientations. Further characterization is performed to explain the enhanced antibacterial activity of the film with vertically aligned GO. Using phospholipid vesicles as a model system, we observe that GO nanosheets induce physical disruption of the lipid bilayer. Additionally, we find substantial GO-induced oxidation of glutathione, a model intracellular antioxidant, paired with limited generation of reactive oxygen species, suggesting that oxidation occurs through a direct electron-transfer mechanism. These physical and chemical mechanisms both require nanosheet penetration of the cell membrane, suggesting that the enhanced antibacterial activity of the film with vertically aligned GO stems from an increased density of edges with a preferential orientation for membrane disruption. The importance of nanosheet penetration for cytotoxicity has direct implications for the design of engineering surfaces using GBNs.

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