Biosynthesis of silver nanoparticles through tandem hydrolysis of silver sulfate and cellulose under hydrothermal conditions

2013 ◽  
Vol 89 (12) ◽  
pp. 1817-1824 ◽  
Author(s):  
Xianxue Li ◽  
Tareque Odoom-Wubah ◽  
Huimei Chen ◽  
Xiaolian Jing ◽  
Bingyun Zheng ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Hydrothermal Conditions ◽  
Silver Sulfate ◽  
Hydrolysis Of

scholarly journals Biosynthesis of Ag–Pd bimetallic alloy nanoparticles through hydrolysis of cellulose triggered by silver sulfate

RSC Advances ◽  
2018 ◽  
Vol 8 (53) ◽  
pp. 30340-30345 ◽  
Author(s):  
Xianxue Li ◽  
Tareque Odoom-Wubah ◽  
Jiale Huang
Keyword(s):  
Alloy Nanoparticles ◽  
Hydrothermal Conditions ◽  
Bimetallic Alloy ◽  
Silver Sulfate ◽  
Hydrolysis Of Cellulose ◽  
Pd Alloy ◽  
Hydrolysis Of

We report a simple but efficient biological route based on the hydrolysis of cellulose to synthesize Ag–Pd alloy nanoparticles (NPs) under hydrothermal conditions.

Topotactic route to synthesis of novel hydroxylated phases: I. Trioctahedral Micas

Clay Minerals ◽  
1986 ◽  
Vol 21 (2) ◽  
pp. 125-131 ◽  
Author(s):  
S. Komarneni ◽  
R. Roy
Keyword(s):  
Ion Exchange ◽  
Alkaline Earth ◽  
Water Molecules ◽  
Hydration Energy ◽  
Hydrothermal Conditions ◽  
Potential Applications ◽  
Clay Layers ◽  
First Time ◽  
Hydrolysis Of ◽  
Alkaline Earth Cations

AbstractK-depleted phlogopite mica was used as a topotactic precursor and treated with alkali (Li+, K+, , Rb+, Cs+), alkaline-earth (Mg2+, Ca2+, Sr2+, Ba2+) and trivalent (Al3+) cations under hydrothermal conditions of 200°C and 30 MPa pressure. K-, NH4-, Rb- and Cs-aluminosilicate micas were synthesised at 200°C in one day. The synthesis of Cs-aluminosilicate mica, with potential applications in the management of nuclear wastes, has been achieved for the first time by this approach. Ion exchange by Li+, Na+ and alkaline-earth cations under hydrothermal conditions did not produce anhydrous mica phases but resulted in hydrous phases with one or two layers of water molecules between the clay layers. The formation of hydrous phases may be attributed to the high hydration energy of the above cations compared to K+, , RB+ and Cs+. Ion exchange with Al3+ produced a chlorite-like phase because of the hydrolysis of Al3+ under these hydrothermal conditions. These studies are of relevance in the immobilization of wastes where hazardous ions can be fixed in highly stable insoluble phases like mica or chlorite.

Hydrolysis of Acetals in Water under Hydrothermal Conditions.

ChemInform ◽  
2004 ◽  
Vol 35 (10) ◽  
Author(s):  
Kimihiko Sato ◽  
Tsutomu Kishimoto ◽  
Minoru Morimoto ◽  
Hiroyuki Saimoto ◽  
Yoshihiro Shigemasa
Keyword(s):  
Hydrothermal Conditions ◽  
Hydrolysis Of

Quantitative relationships between boehmite and γ-alumina crystallite sizes

2004 ◽  
Vol 19 (5) ◽  
pp. 1499-1503 ◽  
Author(s):  
J. Sánchez-Valente ◽  
F. Hernández-Beltrán ◽  
M.L. Guzman-Castillo ◽  
J.J. Fripiat ◽  
X. Bokhimi
Keyword(s):  
Pore Diameter ◽  
Lower Surface ◽  
Order Kinetic ◽  
Hydrothermal Conditions ◽  
Structural Units ◽  
Fresh Sample ◽  
First Order ◽  
Main Variable ◽  
Crystallite Sizes ◽  
Hydrolysis Of

Nanocrystalline boehmite obtained by limited hydrolysis of aluminum tri-sec-butoxide or aluminum chloride was aged under different conditions before being calcined above the dehydroxylation temperature. When aging was carried out under hydrothermal conditions, the condensation of the structural units obeyed a first-order kinetic law with apparent activation energy of 12.2 kcal/mol. Under dehydroxylation conditions, the boehmite fragmentation is accounted for by a simple power law that links its volume to that of the resulting γ-alumina. The main variable is the volatile compounds content (water for instance) in the fresh sample. In terms of texture, a better organization of the initial nanoparticles in the boehmite means a lower surface area and larger pore diameter in the corresponding γ-alumina.

Effect of Niobium on the Structure and Photoactivity of Anatase (TiO2) Nanoparticles

2006 ◽  
Vol 6 (3) ◽  
pp. 762-770 ◽  
Author(s):  
Masanori Hirano ◽  
Kazumasa Matsushima
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Solid Solutions ◽  
Uv Light ◽  
Anatase Tio2 ◽  
Hydrothermal Conditions ◽  
Niobium Content ◽  
Uv Light Irradiation ◽  
Adsorption Amount ◽  
Hydrolysis Of

Anatase-type TiO2 nanoparticles doped with 0–30 mol% niobium were directly formed from precursor solutions of TiOSO4 and NbCl5 under mild hydrothermal conditions at 120–180 °C for 5 h using the hydrolysis of urea. When the niobium content increased from 0 to 30 mol%, the crystallite size of anatase increased from 8.5 to 19 nm. The band gap of anatase was slightly decreased by making solid solutions with niobium. Their photocatalytic activity and adsorptivity were evaluated separately by the measurement of the concentration of methylene blue (MB) remained in the solution after maintained in the dark or under UV-light irradiation. To form anatase-type solid solutions by doping 5–15 mol% niobium into TiO2 was effective for improvement of the photoactivity of TiO2. The photocatalytic activity (the photooxidation rate) and the adsorption amount of MB for the sample containing 15 mol% niobium became more than approximately nine times and six times as much as those of the hydrothermal anatase-type pure TiO2, respectively.

scholarly journals Involvement of Intermediate Sulfur Species in Biological Reduction of Elemental Sulfur under Acidic, Hydrothermal Conditions

2013 ◽  
Vol 79 (6) ◽  
pp. 2061-2068 ◽  
Author(s):  
Eric S. Boyd ◽  
Gregory K. Druschel
Keyword(s):  
Elemental Sulfur ◽  
Solid Phase ◽  
Sulfide Concentration ◽  
Hydrothermal Conditions ◽  
Dialysis Tubing ◽  
Biological Reduction ◽  
Content Type ◽  
Pore Sizes ◽  
Production Of Hydrogen ◽  
Hydrolysis Of

ABSTRACTThe thermoacidophile and obligate elemental sulfur (S80)-reducing anaerobeAcidilobus sulfurireducens18D70 does not associate with bulk solid-phase sulfur during S80-dependent batch culture growth. Cyclic voltammetry indicated the production of hydrogen sulfide (H2S) as well as polysulfides after 1 day of batch growth of the organism at pH 3.0 and 81°C. The production of polysulfide is likely due to the abiotic reaction between S80and the biologically produced H2S, as evinced by a rapid cessation of polysulfide formation when the growth temperature was decreased, inhibiting the biological production of sulfide. After an additional 5 days of growth, nanoparticulate S80was detected in the cultivation medium, a result of the hydrolysis of polysulfides in acidic medium. To examine whether soluble polysulfides and/or nanoparticulate S80can serve as terminal electron acceptors (TEA) supporting the growth ofA. sulfurireducens, total sulfide concentration and cell density were monitored in batch cultures with S80provided as a solid phase in the medium or with S80sequestered in dialysis tubing. The rates of sulfide production in 7-day-old cultures with S80sequestered in dialysis tubing with pore sizes of 12 to 14 kDa and 6 to 8 kDa were 55% and 22%, respectively, of that of cultures with S80provided as a solid phase in the medium. These results indicate that the TEA existed in a range of particle sizes that affected its ability to diffuse through dialysis tubing of different pore sizes. Dynamic light scattering revealed that S80particles generated through polysulfide rapidly grew in size, a rate which was influenced by the pH of the medium and the presence of organic carbon. Thus, S80particles formed through abiological hydrolysis of polysulfide under acidic conditions appeared to serve as a growth-promoting TEA forA. sulfurireducens.

Formation mechanism of fine anatase crystals from amorphous titania under hydrothermal conditions

1998 ◽  
Vol 13 (4) ◽  
pp. 825-829 ◽  
Author(s):  
Kazumichi Yanagisawa ◽  
Yuichi Yamamoto ◽  
Qi Feng ◽  
Nakamichi Yamasaki
Keyword(s):  
Growth Rate ◽  
Solid State ◽  
Epitaxial Growth ◽  
Deposition Process ◽  
Hydrothermal Conditions ◽  
Slow Growth Rate ◽  
Amorphous Titania ◽  
Two Stages ◽  
Short Time ◽  
Hydrolysis Of

Crystallization of amorphous titania prepared by hydrolysis of ethoxide was accelerated even by a small amount of water in the vapor phase. The existence of water promoted the change of localized structure of the amorphous titania to anatase structure, which resulted in acceleration of anatase nucleation. The anatase crystals grew in steam by solid-state epitaxial growth, but stopped growing in a short time. The growth of anatase crystals under hydrothermal conditions could be divided into the following two stages: the first stage with fast growth rate by the solid-state epitaxial growth and the second stage with slow growth rate by the dissolution and deposition process.

scholarly journals Morphological comparative assessment of in vivo 2-week oral exposure of silver nanoparticles and silver sulfate on the mice liver

2019 ◽  
Vol 95 (9) ◽  
pp. 899-902
Author(s):  
Natalia N. Belyaeva ◽  
L. P. Sycheva
Keyword(s):  
Silver Nanoparticles ◽  
Comparative Evaluation ◽  
Comparative Assessment ◽  
Oral Exposure ◽  
Silver Sulfate ◽  
Mice Liver ◽  
The Impact ◽  
Functional Indices ◽  
Different Doses

Currently the problem of the impact of nanoparticles and nanomaterials on human health remains to be poorly understood. As in our studies of the impact of silver nanoparticles on rats liver as well in works of other researchers there were investigated morphofunctional indices under peroral exposure. Although all researchers took different sizes, doses and concentrations of silver nanoparticles, various exposure time and different stabilizers, the same effects had been obtained, which, however, were occurred under both different doses and time of exposure. However, it was interesting to compare the impact of silver nanoparticles with reference substance - silver sulfate on the mice liver with the previously evaluated effect produced on the rats ’ liver. By ourselves there was executed the morphological comparative evaluation of in vivo oral 2-weeks exposure of 4 concentrations (0.1; 5; 50 and 500 mg/l) of silver nanoparticles with size of 14 nm, stable arabian gum 1:7 by weight, and of 4 similar concentrations of silver sulfate on the liver of male mice СВАхС57В1/6 weighing 25-35g. 2 groups were considered as control: intact mice and mice received gum in water. Results of the exposure were assessed according to 10 morphological and functional indices. The impact of nanosilver was shown to initiate from its concentration of 50 mg/l and to express in the gain of the index of alteration of the cytoplasm of hepatocytes with the increasing in both severity of steatosis and the number of micronecroses, persisting at the same level at concentrations of 500 mg/l and with the elevation of the index of alteration of nuclei of hepatocytes, while the similar effect develops under the influence of silver sulfate at a concentration of 500 mg/l only. The remaining investigated morphofunctional indices did not differ significantly in all groups of mice. Unlike previously executed studies on rats, mice appeared to be sensitive to the effects of nano-silver more than to silver sulfate.

Kinetic Study of Hydrolysis of Chlorpyrifos Using Gallic Acid Coated Silver Nanoparticles

2016 ◽  
Vol 8 (12) ◽  
pp. 941-946 ◽  
Author(s):  
Sandeep Sharma ◽  
Nitish Panchal ◽  
Surinder Kumar Sharma ◽  
Rakesh Kumar Sharma ◽  
Phool Kumar Patanjali
Keyword(s):  
Silver Nanoparticles ◽  
Kinetic Study ◽  
Gallic Acid ◽  
Hydrolysis Of
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