scholarly journals Synthesis and Optical Properties of Chitosan/polypyrrole Composite for Biological Applications

2021 ◽  
Vol 10 (4) ◽  
pp. 2742-2749
Keyword(s):  
Mechanical Properties ◽  
Optical Properties ◽  
Electrostatic Interaction ◽  
Electrical Conduction ◽  
Biomedical Applications ◽  
Optical Band Gap ◽  
Composite Films ◽  
Biological Applications ◽  
Chitosan Matrix ◽  
Polypyrrole Composite

Polypyrrole conducting polymers have become significant in different biomedical applications, but unfortunately, they are insoluble with poor mechanical properties. A natural soluble polymer (Chitosan) can be used to improve such properties. Chitosan/polypyrrole composites were synthesized by dispersing the different doped amounts of polypyrrole into the chitosan matrix. The physical properties of the synthesized composite films were investigated using different techniques. The results obtained from FTIR, XRD show the electrostatic interaction between chitosan and polypyrrole. UV/Vis analysis implies that the optical band gap of composite films decreases with increasing polypyrrole concentration, which can be assumed to increase the electrical conduction in the composite films.

Preparation and Properties of Biocomposite Film with Gelatin and Poly(Vinyl Alcohol)

2011 ◽  
Vol 287-290 ◽  
pp. 302-305
Author(s):  
Xi Ping Gao ◽  
Ke Yong Tang ◽  
Yu Qing Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Optical Properties ◽  
Vinyl Alcohol ◽  
Composite Films ◽  
Poly Vinyl Alcohol ◽  
Elongation At Break ◽  
Biocomposite Film

The mechanical properties, swelling, solubility, and optical properties of composite films with poly(vinyl alcohol) (PVA) and gelatin were studied. With increasing the PVA content in the composite films, the tensile strength (TS) and elongation at break (EB) of the films increase. The swelling and solubility are different with different gelatin/PVA ratios, with the lowest at 1:5.

Spinach Ferredoxin (Fdx) as an Organic Material to Improve Optical Band Gap of Chitosan (Cs) Biofilm

2015 ◽  
Vol 754-755 ◽  
pp. 939-943
Author(s):  
Devi Shantini Chandrasakaran ◽  
Irwana Nainggolan ◽  
Mohd Nazree Derman ◽  
Tulus Ikhsan Nasution
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Spin Coating ◽  
Organic Material ◽  
Optical Band Gap ◽  
Band Gaps ◽  
Coating Technique ◽  
Optical Band Gaps ◽  
Chitosan Matrix ◽  
Straight Line

In this study, the effect of spinach-ferredoxin addition in chitosan matrix towards optical band gap was investigated. 5 distinct solutions were prepared by blending chitosan and spinach-ferredoxin (Cs-Fdx) with the volume to volume ratios of 100:0, 95:5, 90:10, 85:15 and 80:20 respectively. The solutions were cast into film via spin coating technique. The optical properties in terms of absorbance for these films were investigated using UV-Vis Spectrometer. UV-Vis result showed that the absorbance increased as the spinach-ferredoxin content increases. Finally, the optical band gaps of the films were determined by extrapolating a straight line of (αhν)2vs. hν curves. Band gap value of 3.48 eV, 3.25 eV, 3.2 eV, 3.0 eV, and 2.8 eV were observed for (Cs-Fdx) films with 100:0, 95:5, 90:10, 85:15 and 80:20 respectively.

scholarly journals Plasticized Starch/Agar Composite Films: Processing, Morphology, Structure, Mechanical Properties and Surface Hydrophilicity

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 311
Author(s):  
Yabin Guo ◽  
Binjia Zhang ◽  
Siming Zhao ◽  
Dongling Qiao ◽  
Fengwei Xie
Keyword(s):  
Mechanical Properties ◽  
Biomedical Applications ◽  
Composite Films ◽  
Elongation At Break ◽  
Surface Hydrophilicity ◽  
Lamellar Structures ◽  
Agar Film ◽  
Tissue Scaffolding ◽  
Chain Interaction ◽  
Starch Agar

Natural biopolymers, which are renewable, widely available, biodegradable, and biocompatible, have attracted huge interest in the development of biocomposite materials. Herein, formulation–property relationships for starch/agar composite films were investigated. First, rapid visco analysis was used to confirm the conditions needed for their gelation and to prepare filmogenic solutions. All the original crystalline and/or lamellar structures of starch and agar were destroyed, and films with cohesive and compact structures were formed, as shown by SEM, XRD, and SAXS. All the plasticized films were predominantly amorphous, and the polymorphs of the composite films were closer to that of the agar-only film. FTIR results suggest that the incorporation of agar restricted starch chain interaction and rearrangement. The addition of agar to starch increased both tensile strength and elongation at break, but the improvements were insignificant after the agar content was over 50 wt.%. Contact angle results indicate that compared with the other samples, the 4:6 (wt./wt.) starch/agar film was less hydrophilic. Thus, this work shows that agar dominates the structure and properties of starch/agar composites, and the best properties can be obtained with a certain starch/agar ratio. Such composite polysaccharide films with tailored mechanical properties and surface hydrophilicity could be useful in biodegradable packaging and biomedical applications (wound dressing and tissue scaffolding).

The Nanostructure and Properties of the Nano TiO2/PVA Composite Film

2013 ◽  
Vol 320 ◽  
pp. 611-614
Author(s):  
Wei Hong ◽  
Qing Shan Li ◽  
Jing Sun ◽  
Xin Chun Wang ◽  
Guo Wei Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Optical Properties ◽  
Infrared Spectroscopy ◽  
Polyvinyl Alcohol ◽  
Composite Film ◽  
Composite Films ◽  
Solution Casting ◽  
Uv Shielding

In order to improve the performance of polyvinyl alcohol (PVA), the nanometer TiO2/PVA composite film prepared by solution casting, effects of nanotitanium dioxide (TiO2) PVA film. The structures, mechanical properties, and optical properties of the composite films were detected by infrared spectroscopy, TG, DSC, XRD. The results show that: nanoTiO2 fill added to the PVA matrix to improve the mechanical properties of PVA, thermal stability and UV shielding performance.

How SIMS microscopy can be used in medicine

1992 ◽  
Vol 50 (2) ◽  
pp. 1602-1603
Author(s):  
Philippe Fragu
Keyword(s):  
Mass Spectrometry ◽  
Biomedical Applications ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Elements ◽  
Biological Applications ◽  
The Past ◽  
Potential Source ◽  
Secondary Ion ◽  
Chemical Integrity ◽  
Scientific Endeavour

The identification, localization and quantification of intracellular chemical elements is an area of scientific endeavour which has not ceased to develop over the past 30 years. Secondary Ion Mass Spectrometry (SIMS) microscopy is widely used for elemental localization problems in geochemistry, metallurgy and electronics. Although the first commercial instruments were available in 1968, biological applications have been gradual as investigators have systematically examined the potential source of artefacts inherent in the method and sought to develop strategies for the analysis of soft biological material with a lateral resolution equivalent to that of the light microscope. In 1992, the prospects offered by this technique are even more encouraging as prototypes of new ion probes appear capable of achieving the ultimate goal, namely the quantitative analysis of micron and submicron regions. The purpose of this review is to underline the requirements for biomedical applications of SIMS microscopy.Sample preparation methodology should preserve both the structural and the chemical integrity of the tissue.

Cellulose Nanofibrils-based Hydrogels for Biomedical Applications: Progresses and Challenges

2020 ◽  
Vol 27 (28) ◽  
pp. 4622-4646 ◽  
Author(s):  
Huayu Liu ◽  
Kun Liu ◽  
Xiao Han ◽  
Hongxiang Xie ◽  
Chuanling Si ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Metal Ion ◽  
Biomedical Applications ◽  
Biomedical Application ◽  
Cellulose Nanofibrils ◽  
Wound Dressings ◽  
Preparation Methods ◽  
Tissue Scaffold ◽  
Surface Areas ◽  
Mechanical Methods

Background: Cellulose Nanofibrils (CNFs) are natural nanomaterials with nanometer dimensions. Compared with ordinary cellulose, CNFs own good mechanical properties, large specific surface areas, high Young's modulus, strong hydrophilicity and other distinguishing characteristics, which make them widely used in many fields. This review aims to introduce the preparation of CNFs-based hydrogels and their recent biomedical application advances. Methods: By searching the recent literatures, we have summarized the preparation methods of CNFs, including mechanical methods and chemical mechanical methods, and also introduced the fabrication methods of CNFs-based hydrogels, including CNFs cross-linked with metal ion and with polymers. In addition, we have summarized the biomedical applications of CNFs-based hydrogels, including scaffold materials and wound dressings. Results: CNFs-based hydrogels are new types of materials that are non-toxic and display a certain mechanical strength. In the tissue scaffold application, they can provide a micro-environment for the damaged tissue to repair and regenerate it. In wound dressing applications, it can fit the wound surface and protect the wound from the external environment, thereby effectively promoting the healing of skin tissue. Conclusion: By summarizing the preparation and application of CNFs-based hydrogels, we have analyzed and forecasted their development trends. At present, the research of CNFs-based hydrogels is still in the laboratory stage. It needs further exploration to be applied in practice. The development of medical hydrogels with high mechanical properties and biocompatibility still poses significant challenges.

Sol-gel growth of Ni doped CdS on glass substrates: effect of spin coating speed and dopant concentration

2020 ◽  
Vol 10 ◽  
Author(s):  
Atefeh Nazari Setayesh ◽  
Hassan Sedghi
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spin Coating ◽  
Optical Band Gap ◽  
Dopant Concentration ◽  
Rotation Speed ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Glass Substrates

Background: In this work, CdS thin films were synthesized by sol-gel method (spin coating technique) on glass substrates to investigate the optical behavior of the film. Methods: Different substrate spin coating speeds of 2400, 3000, 3600 rpm and different Ni dopant concentrations of 0 wt.%, 2.5 wt.%, 5 wt.%) were investigated. The optical properties of thin films such as refraction index, extinction coefficient, dielectric constant and optical band gap energy of the layers were discussed using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. Results: It can be deduced that substrate rotation speed and dopant concentration has influenced the optical properties of thin films. By decreasing rotation speed of the substrate which results in films with more thicknesses, more optical interferences were appeared in the results. Conclusion: The samples doped with Ni comparing to pure ones have had more optical band gap energy.

Doping-induced modulation of optical properties of PFO/PMMA composite films

2020 ◽  
Author(s):  
Vinayak S. Bhat ◽  
S. B. Kapatkar ◽  
N. H. Ayachit ◽  
Ishwar Naik ◽  
M. S. Murari
Keyword(s):  
Optical Properties ◽  
Composite Films
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