scholarly journals Silver Nanoparticles Embedded in Polyvinyl Alcohol Based Passive Saturable Absorber

2021 ◽  
Vol 2075 (1) ◽  
pp. 012004
Author(s):  
N N M Rashid ◽  
M Q Lokman ◽  
N A Nordin ◽  
H Yahaya ◽  
F Ahmad
Keyword(s):  
Silver Nanoparticles ◽  
Polyvinyl Alcohol ◽  
Saturable Absorber ◽  
Chemical Reduction ◽  
Single Pulse ◽  
Laser Cavity ◽  
Noble Metal Nanoparticles ◽  
Fibre Laser ◽  
Laser Applications ◽  
Average Size

Abstract Silver nanoparticles (AgNP), a novel candidate of noble metal nanoparticles, which has great potential for pulsed laser applications due to strong saturation absorption behaviour. This study demonstrated the passively Q-switched laser operating within an Erbium-doped fibre laser cavity using AgNP saturable absorber (SA). The AgNP was synthesized via the chemical reduction method and the average size of nanoparticles was around 52.39 nm. The AgNP was incorporated with polyvinyl alcohol (PVA) polymer to form an AgNP-PVA composite SA. The proposed experimental works generated single pulse energy and peak power of about 66.14 nJ and 18.71 mW corresponds to the repetition rate and pulse width of 62.89 kHz and 3.32 µs.

Antimicrobial and Cytotoxic Activity of Silver Nanoparticles Stabilized by Natural Biopolymer Arabinogalactan

2020 ◽  
Vol 19 (04) ◽  
pp. 1950029
Author(s):  
A. G. Demchenko ◽  
V. S. Sadykova ◽  
A. V. Lyundup ◽  
N. E. Sedyakina ◽  
T. I. Gromovykh ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antifungal Activity ◽  
Cytotoxic Activity ◽  
Chemical Reduction ◽  
Antitumor Agent ◽  
Escherichia Coli Bacteria ◽  
Trichoderma Citrinoviride ◽  
Average Size ◽  
Antibacterial And Antifungal ◽  
Dose Dependent

Silver nanoparticles were synthesized by chemical reduction of silver nitrate using arabinogalactan polysaccharide as a reducing agent and a stabilizer. The average size of nanoparticles, obtained by analyzing TEM-images, was 10.8[Formula: see text]nm; zeta potential [Formula: see text][Formula: see text]mV. A study of the sol by electron diffraction showed that silver in the sample is in metallic form. The resulting preparation of silver nanoparticles showed both antibacterial and antifungal activity. A pronounced antibacterial activity of silver nanoparticles was demonstrated both in relation to conditionally pathogenic gram-positive (Bacillus subtilis and B. coagulans) and gram-negative (Escherichia coli) bacteria. Silver nanoparticles also possess antifungal activity against macromycete Fomitopsis sp., as well as two strains of micromycetes Trichoderma citrinoviride and Fusarium sporotrichioides. Using the methods of light and fluorescence microscopy, MTT-analysis and Real-time cell analysis, the cytotoxic activity of silver nanoparticles was investigated on HepG2 human hepatocellular carcinoma cells. It was demonstrated that nanoparticles cause a suppression of cell metabolic and proliferative activity, as well as dose-dependent induction of cell death (average relative EC[Formula: see text] value was [Formula: see text]g/ml). The preparation of silver nanoparticles stabilized by arabinogalactan can be used in medicine, as a potential antimicrobial and antitumor agent.

scholarly journals Fabrication, Characterization, and Antibacterial Properties of Electrospun Membrane Composed of Gum Karaya, Polyvinyl Alcohol, and Silver Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Vinod Vellora Thekkae Padil ◽  
Nhung H. A. Nguyen ◽  
Alena Ševců ◽  
Miroslav Černík
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Polyvinyl Alcohol ◽  
Food Packaging ◽  
Chemical Reduction ◽  
Antibacterial Properties ◽  
Hydroxyl Groups ◽  
Ag Nps ◽  
Gum Karaya ◽  
Nanofiber Membranes

Gum karaya (GK), a natural hydrocolloid, was mixed with polyvinyl alcohol (PVA) at different weight ratios and electrospun to produce PVA/GK nanofibers. An 80 : 20 PVA/GK ratio produced the most suitable nanofiber for further testing. Silver nanoparticles (Ag-NPs) were synthesised through chemical reduction of AgNO3(at different concentrations) in the PVA/GK solution, the GK hydroxyl groups being oxidised to carbonyl groups, and Ag+cations reduced to metallic Ag-NPs. These PVA/GK/Ag solutions were then electrospun to produce nanofiber membranes containing Ag-NPs (Ag-MEMs). Membrane morphology and other characteristics were analysed using scanning electron microscopy coupled with energy dispersive X-ray analysis, transmission electron microscopy, and UV-Vis and ATR-FTIR spectroscopy. The antibacterial activity of the Ag-NP solution and Ag-MEM was then investigated against Gram-negativeEscherichia coliandPseudomonas aeruginosaand Gram-positiveStaphylococcus aureus. Our results show that electrospun nanofiber membranes based on natural hydrocolloid, synthetic polymer, and Ag-NPs have many potential uses in medical applications, food packaging, and water treatment.

Preparing and Applying Silver Nanoparticles in Conductive Ink and Inkjet Painting

2021 ◽  
Vol 21 (12) ◽  
pp. 5979-5986
Author(s):  
Gui Bing Hong ◽  
Yi Hua Luo ◽  
Kai Jen Chuang ◽  
Chih Ming Ma
Keyword(s):  
Silver Nanoparticles ◽  
Inkjet Printing ◽  
Chemical Reduction ◽  
Flexible Substrate ◽  
High Surface ◽  
High Surface Area ◽  
Reducing Agent ◽  
Noble Metal Nanoparticles ◽  
Conductive Ink ◽  
Uniform Size

Noble metal nanoparticles have special properties in optical, electronic, and physical chemistry due to their high surface area and volume. With the development of electronic printing technology, inkjet printing has gradually replaced traditional spin coating and blade coating, since it leads to more material savings and a faster batch production, and the pattern can be easily designed by a computer. In this study, Ag nanoparticles were prepared by a chemical reduction method. Non-toxic, environment-friendly agents were selected to fabricate a single-shape, uniform-size, crystal-form, and monodisperse product. The effects of the reducing agent ratio and the stabilizer ratio on the size, shape, and stability of the nanoparticles are discussed. The silver nanoparticles were characterized by an ultraviolet-visible spectrophotometer (UV-vis) and a transmission electron microscope (TEM). In addition, in order to prepare conductive ink that can stably disperse for a long time and that can be applied to inkjet printing on a PET flexible substrate at a lower sintering temperature, a sintering agent and a commercial surfactant were added. The experimental results show that the best addition ratio of the precursor to the reducing agent and the stabilizer is 1:6:1. The conductive silver ink was printed and treated by a70 mM NaCl solution, and the electric resistivity was 5.17×10−4 Ω· cm.

scholarly journals Observation of dark and bright pulses in q-switched erbium doped fiber laser using graphene nano-platelets as saturable absorber

2019 ◽  
Vol 8 (4) ◽  
Author(s):  
Nur Hidayah Muhamad Apandi ◽  
Siti Nur Fatin Zuikafly ◽  
Nabilah Kasim ◽  
Mohd Ambri Mohamed ◽  
Sulaiman Wadi Harun ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Fiber Laser ◽  
Saturable Absorber ◽  
Signal To Noise Ratio ◽  
Ring Cavity ◽  
Laser Cavity ◽  
Laser Generation ◽  
Output Peak Power ◽  
Erbium Doped ◽  
Cavity Configuration

In this paper, a passively Q-switched Erbium doped fiber laser (EDFL) by residing Graphene nanoplatelets (GnPs) embedded in polyvinyl alcohol (PVA) based saturable absorber (SA) is demonstrated. To aid the dispersion of GNPs, a surfactant is used and then it is mixed with polyvinyl alcohol (PVA) as host polymer to develop GnPs-PVA film based passive SA. The GnPs-PVA based film then integrated in laser cavity in ring cavity configuration for pulse laser generation. The experimental works show that the proposed passive SA operates at input pump power range from 77 mW to 128 mW with a tunable repetition rate from 78.4 kHz to 114.8 kHz and a shortest pulse width of 3.69 µs. The laser produces maximum instantaneous output peak power and pulse energy of 7.3 mW and 30.46 nJ, respectively and accompanied by signal to noise ratio (SNR) of 64 dB.

scholarly journals Silver Nanoparticles AgNPs Preparation by Chemical Method to Obtain Optimal Characteristics of The Pharmaceutical Form and Study Their Effect on The Leishmania Parasite in Laboratory: تحضير جسيمات الفضة النانوية AgNPs بالطريقة الكيميائية للحصول على الخصائص المثلى للشكل الصيدلاني المعتمد ودراسة تأثيرها على طفيلي الليشمانيا مختبريا

2021 ◽  
Vol 5 (3) ◽  
pp. 41-28
Author(s):  
Rama Muhamad Sattout, Ahmad Kamari, Muhamad Muayyad Bilal Rama Muhamad Sattout, Ahmad Kamari, Muhamad Muayyad Bilal
Keyword(s):  
Silver Nanoparticles ◽  
Chemical Reduction ◽  
Leishmania Parasite ◽  
Force Microscopy ◽  
Atomic Force ◽  
Yellow Color ◽  
Artificial Environment ◽  
Pharmaceutical Form ◽  
Average Size ◽  
Hierarchical Morphology

This study aimed first to prepare silver nanoparticles AgNPs in a chemical reduction, The silver nanoparticles AgNPs properties were characterized using spectroscopy of Vision and UV- Visible (UV- Vis), and atomic force microscopy (AFM) and a ZetaSizer device. This study also aimed to study the results effect of preparing Silver nanoparticles on the Leishmania parasite using an artificial environment. The results of the spectrophotometer of the secondary silver solution with yellow color, showed maximum absorption at a wavelength of 400 mm, while the image of atomic force microscope (AFM) showed the hierarchical morphology shape of the prepared Silver nanoparticles with an average size of (10- 30 nm). Silver secondary particles were estimated with a diameter ranging from (12- 60 nm) and with good dispersion in water by ZetaSizer device. The results illustrated that the number of Promastigotes of the Leishmania parasite decreased after adding the Silver nanoparticles AgNPs in varying proportions, as the concentration of 500 μg/ml had the highest effect after 72 hours from incubation, and the percentage of remaining parasites was 5.2% comparing with the control percentage of 14.99%, while the value of IC50 was 253.075 μg/ml, The value of R2 = 0.8809, slope = 0.0478 after 24 hours from incubation.

scholarly journals Nanofibrillated Cellulose and Copper Nanoparticles Embedded in Polyvinyl Alcohol Films for Antimicrobial Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Tuhua Zhong ◽  
Gloria S. Oporto ◽  
Jacek Jaczynski ◽  
Changle Jiang
Keyword(s):  
Polyvinyl Alcohol ◽  
Copper Nanoparticles ◽  
Chemical Reduction ◽  
Antimicrobial Properties ◽  
Nanofibrillated Cellulose ◽  
Microbial Reduction ◽  
Nanocomposite Films ◽  
Transmission Electron ◽  
Average Size ◽  
Thermoplastic Resins

Our long-term goal is to develop a hybrid cellulose-copper nanoparticle material as a functional nanofiller to be incorporated in thermoplastic resins for efficiently improving their antimicrobial properties. In this study, copper nanoparticles were first synthesized through chemical reduction of cupric ions on TEMPO nanofibrillated cellulose (TNFC) template using borohydride as a copper reducing agent. The resulting hybrid material was embedded into a polyvinyl alcohol (PVA) matrix using a solvent casting method. The morphology of TNFC-copper nanoparticles was analyzed by transmission electron microscopy (TEM); spherical copper nanoparticles with average size of 9.2 ± 2.0 nm were determined. Thermogravimetric analysis and antimicrobial performance of the films were evaluated. Slight variations in thermal properties between the nanocomposite films and PVA resin were observed. Antimicrobial analysis demonstrated that one-week exposure of nonpathogenicEscherichia coliDH5αto the nanocomposite films results in up to 5-log microbial reduction.

scholarly journals Mode-locked Thulium Ytterbium co-Doped Fiber Laser with Graphene Saturable Absorber

2016 ◽  
Vol 8 (4) ◽  
pp. 104 ◽  
Author(s):  
Sulaiman Wadi Harun ◽  
Mukul C. Paul ◽  
Shyamal Das ◽  
Anirban Dhar ◽  
Harith Ahmad
Keyword(s):  
Graphene Oxide ◽  
Fiber Laser ◽  
Saturable Absorber ◽  
Pulse Generation ◽  
Fibre Laser ◽  
Laser Mode ◽  
Laser Applications ◽  
Erbium Doped ◽  
Output Laser ◽  
Co Doped

A passively mode-locked Thulium Ytterbium co-doped fiber laser (TYDFL) is demonstrated using a graphene polyvinyl alcohol saturable absorber as the mode-locker. With 980 nm multimode pumping, the laser operates at 1942.95 nm with repetition rate of 11.76 MHz. The pulse width is calculated to be around 52.85 ps. The maximum pulse energy of 1190.5 pJ is achieved at pump power of 1750 mW. Full Text: PDF ReferencesJ. Sotor et al., "Ultrafast thulium-doped fiber laser mode locked with black phosphorus", Opt. Lett. 40, 3885-3888 (2015) CrossRef J. Wang et al., "152 fs nanotube-mode-locked thulium-doped all-fiber laser", Nature Scientific Reports 6, 28885 (2016) CrossRef I. M. Babar et al., "Double-clad thulium/ytterbium co-doped octagonal-shaped fibre for fibre laser applications", Ukr. J. Phys. Opt. 15, 173-183 (2014) CrossRef Harun et al., "Mode-locked bismuth-based erbium-doped fiber laser with stable and clean femtosecond pulses output", Laser Phys. Lett. 8, 449-452 (2011) CrossRef M. A. Ismail et al., "Nanosecond soliton pulse generation by mode-locked erbium-doped fiber laser using single-walled carbon-nanotube-based saturable absorber", Applied Optics 51, 8621-8624 (2012) CrossRef G. Sobon et al., "Graphene Oxide vs. Reduced Graphene Oxide as saturable absorbers for Er-doped passively mode-locked fiber laser", Opt. Express 20, 19463-19473 (2012) CrossRef G. Sobon et al., "Thulium-doped all-fiber laser mode-locked by CVD-graphene/PMMA saturable absorber", Opt. Express 21, 12797-12802 (2013) CrossRef

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