Evolution of Silver Nanoparticles within an Aqueous Dispersion of Nanosized Zeolite Y: Mechanism and Applications

2014 ◽  
Vol 118 (49) ◽  
pp. 28580-28591 ◽  
Author(s):  
Michael Severance ◽  
Prabir K. Dutta
Keyword(s):  
Silver Nanoparticles ◽  
Zeolite Y ◽  
Aqueous Dispersion ◽  
Nanosized Zeolite

SDA-Free Hydrothermal Synthesis of High-Silica Ultra-nanosized Zeolite Y

2017 ◽  
Vol 17 (3) ◽  
pp. 1173-1179 ◽  
Author(s):  
Maeva Borel ◽  
Mathias Dodin ◽  
T. Jean Daou ◽  
Nicolas Bats ◽  
Bogdan Harbuzaru ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Zeolite Y ◽  
High Silica ◽  
Nanosized Zeolite

Nanocomposite cellulose fabrics with in situ generated silver nanoparticles by bioreduction method

2020 ◽  
pp. 152808372092473 ◽  
Author(s):  
Suchart Siengchin ◽  
Pawinee Boonyasopon ◽  
Vajja Sadanand ◽  
Anumakonda Varada Rajulu
Keyword(s):  
Silver Nanoparticles ◽  
Size Range ◽  
Low Cost ◽  
Aqueous Dispersion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gram Positive Bacteria ◽  
Bed Materials ◽  
Cellulose Fabrics

In the present work, nanocomposite cellulose fabrics with in situ generated silver nanoparticles were prepared by bioreduction method employing aqueous dispersion of low-cost natural turmeric powder as a reducing agent and different concentrated aqueous AgNO3 as source solutions. The prepared nanocomposite cellulose fabrics were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and antibacterial tests. The nanocomposite cellulose fabrics had roughly spherical silver nanoparticles in the size range of 41–130 nm with an overall average of 78 nm. The X-ray analysis indicated the generation of both silver nanoparticles and Ag2O nanoparticles in the nanocomposite cellulose fabrics. The nanocomposite cellulose fabrics retained the generated AgNPs even after repeated detergent washings. The prepared nanocomposite cellulose fabrics exhibited excellent antibacterial activity against both the Gram-negative and Gram-positive bacteria and hence can be considered as antibacterial hospital-bed materials, apparels, etc.

Fabrication of Polydiacetylene Nanocrystals Deposited with Silver Nanoparticles for a Nonlinear Optical Material

2004 ◽  
Vol 846 ◽  
Author(s):  
Tsunenobu Onodera ◽  
Hidetoshi Oikawa ◽  
Hitoshi Kasai ◽  
Hachiro Nakanishi ◽  
Takashi Sekiguchi
Keyword(s):  
Silver Nanoparticles ◽  
Optical Properties ◽  
Nonlinear Optical ◽  
Aqueous Dispersion ◽  
Red Shift ◽  
Localized Surface Plasmon ◽  
Nonlinear Optical Susceptibility ◽  
Seed Growth ◽  
Reduction Methods ◽  
Linear Optical Properties

ABSTRACTNoble metal-coated polydiacetylene (PDA) nanocrystals are expected to enlarge effective third-order nonlinear optical susceptibility, owing to the enhancement of optical electric field induced by localized surface plasmon. The surface of PDA nanocrystals was decorated with silver nanoparticles, and the linear optical properties were investigated. The well-defined PDA nanocrystals were first prepared by the conventional reprecipitation method as an aqueous dispersion. The following two-steps of reduction methods, namely, seed deposition and seed growth, enabled higher silver coverage on the surface of PDA nanocrystals. Silver fine seeds were successfully deposited on the PDA surface by particularly employing an anionic surfactant as a binder. The extinction spectra of the PDA nanocrystals covered with silver exhibited the red-shift and broadening of surface plasmonic peak for silver nanoparticles, which would indicate the interaction among silver nanoparticles on the same PDA nanocrystal. In addition, the red-shift of excitonic peak for PDA nanocrystals was observed, resulting from the changes of dielectric properties around PDA nanocrystal. Both spectral changes would have an influence on nonlinear optical properties of PDA nanocrystal.

The role of nanosized zeolite Y in the H2-free catalytic deoxygenation of triolein

2019 ◽  
Vol 9 (3) ◽  
pp. 772-782 ◽  
Author(s):  
Min-Yee Choo ◽  
Joon Ching Juan ◽  
Lee Eng Oi ◽  
Tau Chuan Ling ◽  
Eng-Poh Ng ◽  
...  
Keyword(s):  
Crystal Size ◽  
Zeolite Y ◽  
Conversion Yield ◽  
Catalytic Deoxygenation ◽  
Nanosized Zeolite

The reduction in zeolite Y crystal size has improved the triolein conversion, yield of deoxygenated product and diesel range hydrocarbon selectivity.

scholarly journals Functionalized-AgNPs for Long-Term Stability and Its Applicability in the Detection of Manganese Ions

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Van-Tuan Hoang ◽  
Mai Mai ◽  
Le Thi Tam ◽  
Ngoc Phan Vu ◽  
Nguyen Tien Khi ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Aqueous Dispersion ◽  
Tween 80 ◽  
Strong Interactions ◽  
Electrostatic Repulsion ◽  
Practical Applications ◽  
Term Stability ◽  
Long Term Stability ◽  
Long Time

In this study, silver nanoparticles (AgNPs) were functionalized by various molecules, including sodium borohydride (NaBH4), polyhexamethylene biguanide hydrochloride (PHMB), and Tween 80 to investigate the long-term stabilization of AgNPs in an aqueous dispersion. PHMB-functionalized silver nanoparticles (AgNPs/PHMB) exhibited better stability than others and could be stored at ambient temperature for at least 180 days. In addition to creating stabilization based on the electrostatic repulsion, the use of PHMB helped to increase the degree of stability of the colloidal AgNPs for a long time owing to strong interactions between Ag atoms on AgNPs with nitrogen (N) positions in PHMB molecules. The formed bond led to improving maintenance ability of the electrostatic repulsion layer among independent nanoparticles. The applicability of the as-prepared AgNPs/PHMB was also examined for Mn2+ detection via a colorimetric approach. The calibration curve was found to be linear over the range of 0–100 mM with a correlation coefficient of 0.97. The amine groups of PHMB brought out a cooperative effect to form of ion-templated chelation with Mn2+, which caused the aggregation of AgNPs/PHMB. This suggested that the AgNPs/PHMB could be used as a potential probe in the detection of Mn2+ ions. More importantly, the long-term stability of AgNPs/PHMB paved a great promising path to provide many further solutions for the producer in practical applications.

scholarly journals Deposition of NiO Nanoparticles on Nanosized Zeolite NaY for Production of Biofuel via Hydrogen-Free Deoxygenation

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3104
Author(s):  
Min-Yee Choo ◽  
Lee Eng Oi ◽  
T. Jean Daou ◽  
Tau Chuan Ling ◽  
Yu-Chuan Lin ◽  
...  
Keyword(s):  
Crystal Size ◽  
Zeolite Y ◽  
Lewis Acidity ◽  
One Pot ◽  
Preparation Methods ◽  
Green Diesel ◽  
Zeolite Nay ◽  
Yield And Quality ◽  
Nanosized Zeolite

Nickel-based catalysts play an important role in the hydrogen-free deoxygenation for the production of biofuel. The yield and quality of the biofuel are critically affected by the physicochemical properties of NiO supported on nanosized zeolite Y (Y65, crystal size of 65 nm). Therefore, 10 wt% NiO supported on Y65 synthesized by using impregnation (IM) and deposition–precipitation (DP) methods were investigated. It was found that preparation methods have a significant effect on the deoxygenation of triolein. The initial rate of the DP method (14.8 goil·h−1) was 1.5 times higher than that of the IM method (9.6 goil·h−1). The DP-Y65 showed the best deoxygenation performance with a 80.0% conversion and a diesel selectivity of 93.7% at 380 °C within 1 h. The outstanding performance from the DP method was due to the smaller NiO particle size (3.57 ± 0.40 nm), high accessibility (H.F value of 0.084), and a higher Brönsted to Lewis acidity (B/L) ratio (0.29), which has improved the accessibility and deoxygenation ability of the catalyst. The NH4+ released from the decomposition of the urea during the DP process increased the B/L ratio of zeolite NaY. As a result, the pretreatment to convert Na-zeolite to H-zeolite in a conventional zeolite synthesis can be avoided. In this regard, the DP method offers a one-pot synthesis to produce smaller NiO-supported nanosized zeolite NaY with a high B/L ratio, and it managed to produce a higher yield with selectivity towards green diesel via deoxygenation under a hydrogen-free condition.

scholarly journals Influence of Polysaccharides’ Molecular Structure on the Antibacterial Activity and Cytotoxicity of Green Synthesized Composites Based on Silver Nanoparticles and Carboxymethyl-Cellulose

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1164 ◽  
Author(s):  
María de los Ángeles Martínez-Rodríguez ◽  
Elizabeth Madla-Cruz ◽  
Victor H. Urrutia-Baca ◽  
Myriam A. de la Garza-Ramos ◽  
Virgilio A. González-González ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Aqueous Solutions ◽  
Carboxymethyl Cellulose ◽  
Aqueous Dispersion ◽  
Human Gingival Fibroblast ◽  
Spectroscopic Techniques ◽  
Gingival Fibroblast ◽  
Coordination Bonds

In this paper we report on the influence of polysaccharides’ molecular structure on the antibacterial activity and cytotoxicity of composites based on silver nanoparticles (AgNPs) immobilized into carboxymethyl-cellulose (CMC). These composites were green synthesized from the reduction of silver ions into aqueous solutions of the polysaccharide, using CMC with different degree of substitution (DS) and molecular weight (Mw). The composites were characterized by transmission electron microscopy (TEM), as well as infrared (ATR-FTIR), ultraviolet (UV-Vis), Raman, and X-ray photo-electron (XPS) spectroscopic techniques. The antibacterial activity was evaluated with minimum inhibitory concentration against Enterococcus faecalis. The cytotoxicity of composites was assessed against human gingival fibroblast. Experimental evidence suggests that particle size distribution and morphology of AgNPs change according to the quantity of silver precursor added to the reaction, as well as the DS and Mw of CMC used for composites preparation. This is related to the dispersion of silver precursor into aqueous solutions of the polysaccharide and the formation of Ag-O coordination bonds among AgNPs and COO− moieties of CMC. Moreover, these coordination bonds modify the ability of nanoparticles to produce and release Ag+ into aqueous dispersion, adjusting their antibacterial activity and the induction of cytotoxicity into the tested biological environments.

scholarly journals Synthesis and characterization of stable aqueous dispersion of silver nanoparticle from citrullus vulgaris seed oil via lecithin

NanoNEXT ◽  
2021 ◽  
pp. 16-25
Author(s):  
Henry L. Barnabas ◽  
Ngoshe A.M ◽  
Joshua A Gidigbi
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nanoparticle ◽  
Peroxide Value ◽  
Seed Oil ◽  
Waste Product ◽  
Chemical Properties ◽  
Aqueous Dispersion ◽  
Acid Value ◽  
Visual Assessment ◽  
Physico Chemical

Nanoparticles are known to be of wide applications in various fields of human endeavours. Many methods of syntheses such as physical, chemical are harmful to the environment, thus, this study utilised green production of nanoparticles via waste product such as Citrulus vulgaris seed. Oil was extracted using soxhlet extractor from the prepared Citrulus vulgaris seed. Physico-chemical properties such as percentage yield, acid value, peroxide value were carried out on the Citrulus vulgaris seed oil. Citrulus vulgaris was further processed to form lecithin. The lecithin extracted was characterized for colour, Peroxide Value, Acetone Insoluble (AI), Acid Value, solubility in water and organic solvents. The result of the physico-chemical parameters was in conformity with the standard and various literatures. Therefore, lecithin is processed into dispersed aqueous silver nanoparticles by the addition of silver nitrate. The chemical reaction was monitored progressively using visual assessment, UV-visible and FTIR Spectroscopy. The size and surface of the dispersed silver nanoparticles produced was analysed using Atomic Force Microscopy. Therefore, a dispersed aqueous silver nanoparticle was produced from lecithin made from Citrulus vulgaris seed oil.

scholarly journals Determination of silver in tissues and organs of broiler chickens after oral and aerosol administration of an aqueous dispersion of silver nanoparticles

2019 ◽  
Vol 95 (2) ◽  
pp. 207-211
Author(s):  
Yuriy A. Krutyakov ◽  
V. Yu. Koptev ◽  
A. A. Kudrinsky ◽  
A. I. Klimov ◽  
M. A. Titova ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Body Weight ◽  
Broiler Chickens ◽  
Retention Rate ◽  
Aqueous Dispersion ◽  
The Body ◽  
Veterinary Drug ◽  
Brand Name ◽  
Gastrointestinal Infections

An aqueous dispersions of silver nanoparticles (10 ppm, 50 ppm, 300 ppm) stabilized with 100-600 ppm of chloride benzyldimethyl[3-(myristoylamino)propyl]ammonium monohydrate (miramistin) have been used in the experiment. These compositions were registered in Russia in 2014 as a veterinary drug under the brand name Argumistin®. One of the indications for oral and aerosol administration of Argumistin® is respiratory and gastrointestinal infections of broiler chickens. Miramistin-stabilized silver nanoparticles administered at a dose of 0.32 pg of silver per 1 kg of body weight per day almost completely retained in the body of broilers, while the increasing of the administered dose up to 1.92 pg of silver per 1 kg of body weight per day reduced the retention rate up to 30%. With taking into account WHO recommendations and Russian regulations the oral administration of 10 ppm of silver at above mentioned doses can be concluded to fail to cause accumulation of silver in the tissue and organs of broiler chickens in concentrations dangerous for humans.

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