Displaying publications 1 - 20 of 130 in total

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  1. Zamiri R, Zakaria A, Ahangar HA, Sadrolhosseini AR, Mahdi MA
    Int J Mol Sci, 2010;11(11):4764-70.
    PMID: 21151470 DOI: 10.3390/ijms11114764
    In this study we used a laser ablation technique for preparation of silver nanoparticles. The fabrication process was carried out by ablation of a silver plate immersed in palm oil. A pulsed Nd:YAG laser at a wavelength of 1064 nm was used for ablation of the plate at different times. The palm coconut oil allowed formation of nanoparticles with very small and uniform particle size, which are dispersed very homogeneously within the solution. The obtained particle sizes for 15 and 30 minute ablation times were 2.5 and 2 nm, respectively. Stability study shows that all of the samples remained stable for a reasonable period of time.
    Matched MeSH terms: Silver/chemistry*
  2. Schönrath I, Tsvetkov VB, Zatsepin TS, Aralov AV, Müller J
    J Biol Inorg Chem, 2019 08;24(5):693-702.
    PMID: 31263954 DOI: 10.1007/s00775-019-01682-1
    1,3-Diaza-2-oxophenoxazine (X) has been introduced as a ligand in silver(I)-mediated base pairing in a parallel DNA duplex. This fluorescent cytosine analog is capable of forming stabilizing X-Ag(I)-X and X-Ag(I)-C base pairs in DNA duplexes, as confirmed by temperature-dependent UV spectroscopy and luminescence spectroscopy. DFT calculations of the silver(I)-mediated base pairs suggest the presence of a synergistic hydrogen bond. Molecular dynamics (MD) simulations of entire DNA duplexes nicely underline the geometrical flexibility of these base pairs, with the synergistic hydrogen bond facing either the major or the minor groove. Upon silver(I) binding to the X:X or X:C base pairs, the luminescence emission maximum experiences a red shift from 448 to 460 nm upon excitation at 370 nm. Importantly, the luminescence of the 1,3-diaza-2-oxophenoxazine ligand is not quenched significantly upon binding a silver(I) ion. In fact, the luminescence intensity even increases upon formation of a X-Ag(I)-C base pair, which is expected to be beneficial for the development of biosensors. As a consequence, the silver(I)-mediated phenoxazinone base pairs represent the first strongly fluorescent metal-mediated base pairs.
    Matched MeSH terms: Silver/chemistry*
  3. Zulkifli FH, Hussain FSJ, Zeyohannes SS, Rasad MSBA, Yusuff MM
    Mater Sci Eng C Mater Biol Appl, 2017 Oct 01;79:151-160.
    PMID: 28629002 DOI: 10.1016/j.msec.2017.05.028
    Green porous and ecofriendly scaffolds have been considered as one of the potent candidates for tissue engineering substitutes. The objective of this study is to investigate the biocompatibility of hydroxyethyl cellulose (HEC)/silver nanoparticles (AgNPs), prepared by the green synthesis method as a potential host material for skin tissue applications. The substrates which contained varied concentrations of AgNO3(0.4%-1.6%) were formed in the presence of HEC, were dissolved in a single step in water. The presence of AgNPs was confirmed visually by the change of color from colorless to dark brown, and was fabricated via freeze-drying technique. The outcomes exhibited significant porosity of >80%, moderate degradation rate, and tremendous value of water absorption up to 1163% in all samples. These scaffolds of HEC/AgNPs were further characterized by SEM, UV-Vis, ATR-FTIR, TGA, and DSC. All scaffolds possessed open interconnected pore size in the range of 50-150μm. The characteristic peaks of Ag in the UV-Vis spectra (417-421nm) revealed the formation of AgNPs in the blend composite. ATR-FTIR curve showed new existing peak, which implies the oxidation of HEC in the cellulose derivatives. The DSC thermogram showed augmentation in Tgwith increased AgNO3concentration. Preliminary studies of cytotoxicity were carried out in vitro by implementation of the hFB cells on the scaffolds. The results substantiated low toxicity of HEC/AgNPs scaffolds, thus exhibiting an ideal characteristic in skin tissue engineering applications.
    Matched MeSH terms: Silver/chemistry*
  4. Jamila N, Khan N, Hwang IM, Saba M, Khan F, Amin F, et al.
    Int J Biol Macromol, 2020 Mar 15;147:853-866.
    PMID: 31739066 DOI: 10.1016/j.ijbiomac.2019.09.245
    Gums; composed of polysaccharides, carbohydrates, proteins, and minerals, are high molecular weight hydrophilic compounds with several biological applications. This study describes the nutritional and toxic elements content, chemical composition, synthesis of silver nanoparticles (G-AgNPs), and pharmacological and catalytic properties of Prunus armeniaca (apricot), Prunus domestica (plums), Prunus persica (peaches), Acacia modesta (phulai), Acacia arabica (kikar), and Salmalia malabarica (silk cotton tree) gums. The elemental contents were analyzed by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and ICP-mass spectrometry (ICP-MS). NMR spectroscopy was used for the identification of class of compounds in the mixture, their functional groups were determined through FTIR techniques, and plasmon resonance and size of G-AgNPs through UV-Vis spectroscopic technique and transmission electron microscopy (TEM). From the results, nutritional elements were present at appreciable concentrations, whereas toxic elements showed content below the maximum permissible ranges. Using the elemental data, linear discriminant and principal component analyses classified the gums to 99.9% variability index. Furthermore, G-AgNPs exhibited significant antioxidant, antibacterial, and redox catalytic potential. Hence, the subject G-AgNPs could have promising nutritional, therapeutic and environmental remediation applications.
    Matched MeSH terms: Silver/chemistry*
  5. Dang F, Li C, Nunes LM, Tang R, Wang J, Dong S, et al.
    Environ Int, 2023 Jun;176:107990.
    PMID: 37247467 DOI: 10.1016/j.envint.2023.107990
    Food security and sustainable development of agriculture has been a key challenge for decades. To support this, nanotechnology in the agricultural sectors increases productivity and food security, while leaving complex environmental negative impacts including pollution of the human food chains by nanoparticles. Here we model the effects of silver nanoparticles (Ag-NPs) in a food chain consisting of soil-grown lettuce Lactuca sativa and snail Achatina fulica. Soil-grown lettuce were exposed to sulfurized Ag-NPs via root or metallic Ag-NPs via leaves before fed to snails. We discover an important biomagnification of silver in snails sourced from plant root uptake, with trophic transfer factors of 2.0-5.9 in soft tissues. NPs shifts from original size (55-68 nm) toward much smaller size (17-26 nm) in snails. Trophic transfer of Ag-NPs reprograms the global metabolic profile by down-regulating or up-regulating metabolites for up to 0.25- or 4.20- fold, respectively, relative to the control. These metabolites control osmoregulation, phospholipid, energy, and amino acid metabolism in snails, reflecting molecular pathways of biomagnification and pontential adverse biological effects on lower trophic levels. Consumption of these Ag-NP contaminated snails causes non-carcinogenic effects on human health. Global public health risks decrease by 72% under foliar Ag-NP application in agriculture or through a reduction in the consumption of snails sourced from root application. The latter strategy is at the expense of domestic economic losses in food security of $177.3 and $58.3 million annually for countries such as Nigeria and Cameroon. Foliar Ag-NP application in nano-agriculture has lower hazard quotient risks on public health than root application to ensure global food safety, as brought forward by the United Nations Sustainable Development Goals.
    Matched MeSH terms: Silver/chemistry
  6. Shanmugam P, Parasuraman B, Boonyuen S, Thangavelu P, AlSalhi MS, Zheng ALT, et al.
    Environ Geochem Health, 2024 Feb 17;46(3):92.
    PMID: 38367085 DOI: 10.1007/s10653-024-01871-1
    A facile and cost-effective hydrothermal followed by precipitation method is employed to synthesize visible light-driven ZnS-Ag ternary composites supported on carbon aerogel (CA). Extensive studies were conducted on the structural, morphological, and optical properties, confirming the successful formation of ternary nanocomposites. The obtained results evidently demonstrate the successful loading of ZnS and Ag onto the surface of the CA. High-resolution transmission electron microscopy analysis revealed that ZnS and Ag nanoparticles (AgNPs) were uniformly distributed on the surface of the CA with an average diameter of 18 nm. The biomass-derived CA, containing a hierarchical porous nano-architecture and an abundant number of -NH2 functional groups on the surface, can greatly prevent the agglomeration, stability and reduce particle size. Brunauer-Emmett-Teller analysis results indicated specific surface areas of 4.62 m2 g-1 for the CA, 48.50 m2 g-1 for the CA/ZnS composite, and 62.62 m2 g-1 for the CA/ZnS-Ag composite. These values demonstrate an increase in surface area upon the incorporation of ZnS and Ag into the CA matrix. Under visible light irradiation, the synthesized CA/ZnS-Ag composites displayed remarkably improved photodegradation efficiency of methylene blue (MB). Among the tested samples, the CA/ZnS-Ag composites exhibited the highest percentage of photodegradation efficiency, surpassing ZnS, CA, and CA/ZnS. The obtained percentages of degradation efficiency for CA, ZnS, CA/ZnS, and CA/ZnS-Ag composites were determined as 26.60%, 52.12%, 68.39%, and 98.64%, respectively. These results highlight the superior photocatalytic performance of the CA/ZnS-Ag composites in the degradation of MB under visible light conditions. The superior efficiency of the CA/ZnS-Ag composite can be attributed to multiple factors, including its elevated specific surface area, inhibition of electron-hole pair recombination, and enhanced photon absorption within the visible light spectrum. The CA/ZnS-Ag composites displayed consistent efficiency over multiple cycles, confirming their stable performance, reusability, and enduring durability, thereby showcasing the robust nature of this composite material.
    Matched MeSH terms: Silver/chemistry
  7. Ahmad MB, Tay MY, Shameli K, Hussein MZ, Lim JJ
    Int J Mol Sci, 2011;12(8):4872-84.
    PMID: 21954331 DOI: 10.3390/ijms12084872
    This paper presents the green synthesis of silver nanoparticles (Ag NPs) in aqueous medium. This method was performed by reducing AgNO(3) in different stirring times of reaction at a moderate temperature using green agents, chitosan (Cts) and polyethylene glycol (PEG). In this work, silver nitrate (AgNO(3)) was used as the silver precursor while Cts and PEG were used as the solid support and polymeric stabilizer. The properties of Ag/Cts/PEG nanocomposites (NCs) were studied under different stirring times of reaction. The developed Ag/Cts/PEG NCs were then characterized by the ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy.
    Matched MeSH terms: Silver/chemistry*
  8. Darroudi M, Ahmad MB, Abdullah AH, Ibrahim NA, Shameli K
    Int J Mol Sci, 2010;11(10):3898-905.
    PMID: 21152307 DOI: 10.3390/ijms11103898
    Silver nanoparticles (Ag-NPs) were successfully synthesized in the natural polymeric matrix. Silver nitrate, gelatin, glucose, and sodium hydroxide have been used as silver precursor, stabilizer, reducing agent, and accelerator reagent, respectively. This study investigated the role of NaOH as the accelerator. The resultant products have been confirmed to be Ag-NPs using powder X-ray diffraction (PXRD), UV-vis spectroscopy, and transmission electron microscopy (TEM). The colloidal sols of Ag-NPs obtained at different volumes of NaOH show strong and different surface plasmon resonance (SPR) peaks, which can be explained from the TEM images of Ag-NPs and their particle size distribution. Compared with other synthetic methods, this work is green, rapid, and simple to use. The newly prepared Ag-NPs may have many potential applications in chemical and biological industries.
    Matched MeSH terms: Silver/chemistry*
  9. Bhatia S, Abdullah AZ, Wong CT
    J Hazard Mater, 2009 Apr 15;163(1):73-81.
    PMID: 18649998 DOI: 10.1016/j.jhazmat.2008.06.055
    Adsorption behaviours of butyl acetate in air have been studied over silver-loaded Y (Si/Al=40) and ZSM-5 (Si/Al=140) zeolites. The silver metal was loaded into the zeolites by ion exchange (IE) and impregnation (IM) methods. The adsorption study was mainly conducted at a gas hourly space velocity (GHSV) of 13,000 h(-1) with the organic concentration of 1000 ppm while the desorption step was carried out at a GHSV of 5000 h(-1). The impregnated silver-loaded adsorbents showed lower uptake capacity and shorter breakthrough time by about 10 min, attributed to changes in the pore characteristics and available surface for adsorption. Silver exchanged Y (AgY(IE)) with lower hydrophobicity showed higher uptake capacity of up to 35%, longer adsorbent service time and easier desorption compared to AgZSM-5(IE). The presence of water vapour in the feed suppressed the butyl acetate adsorption of AgY(IE) by 42% due to the competitive adsorption of water on the surface and the effect was more pronounced at lower GHSV. Conversely, the adsorption capacity of AgZSM-5(IE) was minimally affected, attributed to the higher hydrophobicity of the material. A mathematical model is proposed to simulate the adsorption behaviour of butyl acetate over AgY(IE) and AgZSM-5(IE). The model parameters were successfully evaluated and used to accurately predict the breakthrough curves under various process conditions with root square mean errors of between 0.05 and 0.07.
    Matched MeSH terms: Silver/chemistry*
  10. Lee SY, Fazlina N, Tye GJ
    Anal Biochem, 2019 09 15;581:113352.
    PMID: 31260647 DOI: 10.1016/j.ab.2019.113352
    DNA-templated silver nanocluster (AgNC), a new promising fluorescence probe has gained importance in biosensing and bioimaging in recent years. We employed a label-free AgNC to detect an intracellular transcription factor known as forkhead box p3 (FOXP3), which is the master regulator of regulatory T cells (Tregs) suppressive function. We developed an optimized method for the detection of messenger ribonucleic acid (mRNA) of FOXP3 by hybridizing AgNC and G-rich to the target FOXP3 mRNA of a MCF-7 cells. MCF-7 cells are chosen as a model as it readily expresses FOXP3. The hybridized samples were examined with UV illuminator and further verified with fluorescence spectroscopy, fluorescence microscope and flow cytometry. The successful hybridization of a three-way junction with AgNC, G-rich and mRNA FOXP3 target generated an improved fluorescence intensity with a spectral shift. We have successfully delivered the green fluorescing AgNC and G-rich into MCF-7 cells, producing a shift to red fluorescing cells corroborated by flow cytometry results. In summary, our approach enables the detection of intracellular FOXP3 nucleic acid and holds considerable potential in establishing a non-lethal intracellular detection system which would be crucial for the isolation of regulatory T-cells (Tregs) when combined with other cell surface markers.
    Matched MeSH terms: Silver/chemistry*
  11. Abdurabu Thabit H, Ismail AK, Kabir NA, Abu Mhareb MH, Al Mutairi AM, Bafaqeer A, et al.
    Luminescence, 2024 Feb;39(2):e4683.
    PMID: 38332469 DOI: 10.1002/bio.4683
    This work explores the thermoluminescence (TL) and photoluminescence (PL) properties of Ag/Y co-doped zinc oxide (ZnO) nanophosphor. The proposed dosimeter was prepared by the coprecipitation method and sintered at temperatures from 400°C to 1000°C in an air atmosphere. Raman spectroscopy was studied to investigate the structural features of this composition. The new proposed dosimeter revealed two peaks at 150°C and 175°C with a small shoulder at high temperature (225°C). The PL spectrum showed strong green emissions between 500 to 550 nm. The Raman spectrum showed many bands related to the interaction between ZnO, silver (Ag), and yttrium oxide (Y2 O3 ). The rising sintering temperature enhanced the TL glow curve intensity. The Ag/Y co-doped ZnO nanophosphor showed an excellent linearity index within a dose from 1 to 4 Gy. The minimum detectable dose (MDD) of the Ag/Y co-doped ZnO nanopowder (pellets) equaled 0.518 mGy. The main TL properties were achieved in this work as follows: thermal fading (37% after 45 days at 1 and 4 Gy), optical fading (53% after 1 h and 68% after 6 h by exposure to sunlight), effective atomic number (27.6), and energy response (flat behavior from 0.1 to 1.3 MeV). Finally, the proposed material shows promising results nominated to be used for radiation measurements.
    Matched MeSH terms: Silver/chemistry
  12. Zamiri R, Zakaria A, Husin MS, Wahab ZA, Nazarpour FK
    Int J Nanomedicine, 2011;6:2221-4.
    PMID: 22114485 DOI: 10.2147/IJN.S23830
    In the present work, we prepared silver nanoparticles by laser ablation of pure silver plate in ethanol and then irradiated the silver nanoparticles using a 532 nm Q-switched Nd:YAG pulsed laser. Transmission electron microscopic images of the sample after irradiation clearly showed formation of big structures, such as microrods and microbelts in ethanol. The obtained microbelts had a width of about 0.166 μm and a length of 1.472 μm. The reason for the formation of such a big structure is the tendency of the nanoparticles to aggregate in ethanol before irradiation, which causes fusion of the nanoparticles.
    Matched MeSH terms: Silver/chemistry*
  13. Tajdidzadeh M, Azmi BZ, Yunus WM, Talib ZA, Sadrolhosseini AR, Karimzadeh K, et al.
    ScientificWorldJournal, 2014;2014:324921.
    PMID: 25295298 DOI: 10.1155/2014/324921
    The particle size, morphology, and stability of Ag-NPs were investigated in the present study. A Q-Switched Nd: YAG pulsed laser (λ = 532 nm, 360 mJ/pulse) was used for ablation of a pure Ag plate for 30 min to prepare Ag-NPs in the organic compound such as ethylene glycol (EG) and biopolymer such as chitosan. The media (EG, chitosan) permitted the making of NPs with well dispersed and average size of Ag-NPs in EG is about 22 nm and in chitosan is about 10 nm in spherical form. Particle size, morphology, and stability of NPs were compared with distilled water as a reference. The stability of the samples was studied by measuring UV-visible absorption spectra of samples after one month. The result indicated that the formation efficiency of NPs in chitosan was higher than other media and NPs in chitosan solution were more stable than other media during one month storage. This method for synthesis of silver NPs could be as a green method due to its environmentally friendly nature.
    Matched MeSH terms: Silver/chemistry*
  14. Han TK, Fen LB, Nee NM, Johan MR
    ScientificWorldJournal, 2014;2014:847806.
    PMID: 24995365 DOI: 10.1155/2014/847806
    We report the synthesis of amorphous carbon nanotubes/silver (αCNTs/Ag) nanohybrids via simple chemical route without additional reactant and surfactant at low temperature. Field emission scanning microscope (FESEM) and transmission electron microscope (TEM) confirmed formation of CNTs. X-ray diffraction (XRD) pattern confirmed the amorphous phase of carbon and the formation of Ag nanoparticles crystalline phase. Raman spectra revealed the amorphous nature of α CNTs. UV-visible spectroscopy showed enhancement of optical properties of α CNTs/Ag nanohybrids.
    Matched MeSH terms: Silver/chemistry*
  15. Tan ST, Ali Umar A, Balouch A, Nafisah S, Yahaya M, Yap CC, et al.
    ACS Comb Sci, 2014 Jul 14;16(7):314-20.
    PMID: 24919039 DOI: 10.1021/co400157m
    This Research Article reports an unusually high efficiency heterogeneous photodegradation of methyl orange (MO) in the presence of Ag nanoparticle-loaded ZnO quasi-nanotube or nanoreactor (A-ZNRs) nanocatalyst grown on FTO substrate. In typical process, photodegradation efficiency of as high as 21.6% per μg per Watts of used catalyst and UV power can be normally obtained within only a 60-min reaction time from this system, which is 10(3) order higher than the reported results. This is equivalent to the turnover frequency of 360 mol mol(-1) h(-1). High-density hexagonal A-ZNRs catalysts were grown directly on FTO substrate via a seed-mediated microwave-assisted hydrolysis growth process utilizing Ag nanoparticle of approximately 3 nm in size as nanoseed and mixture aqueous solution of Zn(NO3)·6H2O, hexamethylenetetramine (HMT), and AgNO3 as the growth solution. A-ZNRs adopts hexagonal cross-section morphology with the inner surface of the reactor characterized by a rough and rugged structure. Transmission electron microscopy imaging shows the Ag nanoparticle grows interstitially in the ZnO nanoreactor structure. The high photocatalytic property of the A-ZNRs is associated with the highly active of inner side's surface of A-ZNRs and the oxidizing effect of Ag nanoparticle. The growth mechanism as well as the mechanism of the enhanced-photocatalytic performance of the A-ZNRs will be discussed.
    Matched MeSH terms: Silver/chemistry*
  16. Saion E, Gharibshahi E, Naghavi K
    Int J Mol Sci, 2013;14(4):7880-96.
    PMID: 23579953 DOI: 10.3390/ijms14047880
    Size-controlled and monodispersed silver nanoparticles were synthesized from an aqueous solution containing silver nitrate as a metal precursor, polyvinyl alcohol as a capping agent, isopropyl alcohol as hydrogen and hydroxyl radical scavengers, and deionized water as a solvent with a simple radiolytic method. The average particle size decreased with an increase in dose due to the domination of nucleation over ion association in the formation of the nanoparticles by gamma reduction. The silver nanoparticles exhibit a very sharp and strong absorption spectrum with the absorption maximum λmax blue shifting with an increased dose, owing to a decrease in particle size. The absorption spectra of silver nanoparticles of various particle sizes were also calculated using a quantum physics treatment and an agreement was obtained with the experimental absorption data. The results suggest that the absorption spectrum of silver nanoparticles possibly derived from the intra-band excitations of conduction electrons from the lowest energy state (n = 5, l = 0) to higher energy states (n ≥ 6; Δl = 0, ±1; Δs = 0, ±1), allowed by the quantum numbers principle. This demonstrates that the absorption phenomenon of metal nanoparticles based on a quantum physics description could be exploited to be added into the fundamentals of metal nanoparticles and the related fields of nanoscience and nanotechnology.
    Matched MeSH terms: Silver/chemistry*
  17. Darroudi M, Ahmad MB, Zamiri R, Zak AK, Abdullah AH, Ibrahim NA
    Int J Nanomedicine, 2011;6:677-81.
    PMID: 21556342 DOI: 10.2147/IJN.S17669
    The application of "green" chemistry rules to nanoscience and nanotechnology is very important in the preparation of various nanomaterials. In this work, we successfully developed an eco-friendly chemistry method for preparing silver nanoparticles (Ag-NPs) in natural polymeric media. The colloidal Ag-NPs were synthesized in an aqueous solution using silver nitrate, gelatin, and glucose as a silver precursor, stabilizer, and reducing agent, respectively. The properties of synthesized colloidal Ag-NPs were studied at different reaction times. The ultraviolet-visible (UV-vis) spectra were in excellent agreement with the obtained nanostructure studies performed by transmission electron microscopy (TEM) and their size distributions. The prepared samples were also characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). The use of eco-friendly reagents, such as gelatin and glucose, provides green and economic attributes to this work.
    Matched MeSH terms: Silver/chemistry*
  18. Zamiri R, Zakaria A, Abbastabar H, Darroudi M, Husin MS, Mahdi MA
    Int J Nanomedicine, 2011;6:565-8.
    PMID: 21698083 DOI: 10.2147/IJN.S16384
    Silver nanoparticles were fabricated by ablation of a pure silver plate immersed in castor oil. A Nd:YAG-pulsed Q-switch laser with 1064-nm wavelength and 10-Hz frequency was used to ablate the plate for 10 minutes. The sample was characterized by ultraviolet-visible, atomic absorption, Fourier transform-infrared spectroscopies, and transmission electron microscopy. The results of the fabricated sample showed that the nanoparticles in castor oil were about 5-nm in diameter, well dispersed, and showed stability for a long period of time.
    Matched MeSH terms: Silver/chemistry*
  19. Zamiri R, Azmi BZ, Sadrolhosseini AR, Ahangar HA, Zaidan AW, Mahdi MA
    Int J Nanomedicine, 2011;6:71-5.
    PMID: 21289983 DOI: 10.2147/IJN.S14005
    Laser ablation of a silver plate immersed in virgin coconut oil was carried out for fabrication of silver nanoparticles. A Nd:YAG laser at wavelengths of 1064 nm was used for ablation of the plate at different times. The virgin coconut oil allowed formation of nanoparticles with well-dispersed, uniform particle diameters that were stable for a reasonable length of time. The particle sizes and volume fraction of nanoparticles inside the solutions obtained at 15, 30, 45 min ablation times were 4.84, 5.18, 6.33 nm and 1.0 × 10(-8), 1.6 × 10(-8), 2.4 × 10(-8), respectively. The presented method for preparation of silver nanoparticles in virgin coconut oil is environmentally friendly and may be considered a green method.
    Matched MeSH terms: Silver/chemistry*
  20. Wong CT, Abdullah AZ, Bhatia S
    J Hazard Mater, 2008 Sep 15;157(2-3):480-9.
    PMID: 18294771 DOI: 10.1016/j.jhazmat.2008.01.012
    The performance of silver-loaded zeolite (HY and HZSM-5) catalysts in the oxidation of butyl acetate as a model volatile organic compound (VOC) was studied. The objective was to find a catalyst with superior activity, selectivity towards deep oxidation product and stability. The catalyst activity was measured under excess oxygen condition in a packed bed reactor operated at gas hourly space velocity (GHSV)=15,000-32,000 h(-1), reaction temperature between 150 and 500 degrees C and butyl acetate inlet concentration of 1000-4000 ppm. Both AgY and AgZSM-5 catalysts exhibited high activity in the oxidation of butyl acetate. Despite lower silver content, AgY showed better activity, attributed to better metal dispersion, surface characteristics and acidity, and its pore system. Total conversion of butyl acetate was achieved at above 400 degrees C. The oxidation of butyl acetate followed a simple power law model. The reaction orders, n and m were evaluated under differential mode by varying the VOC partial pressure between 0.004 and 0.018 atm and partial pressure of oxygen between 0.05 and 0.20 atm. The reaction rate was independent of oxygen concentration and single order with respect to VOC concentration. The activation energies were 19.78 kJ/mol for AgY and 32.26 kJ/mol for AgZSM-5, respectively.
    Matched MeSH terms: Silver/chemistry*
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