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Nano-silver clay was utilized to be the alternative material for hand making jewelry products. Silver nanoparticles were synthesized in aqueous solution by the chemical reduction method. The clay-liked feature of silver nanopartic...
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Nano-silver clay was utilized to be the alternative material for hand making jewelry products. Silver nanoparticles were synthesized in aqueous solution by the chemical reduction method. The clay-liked feature of silver nanoparticles was accomplished by mixing the nano-sized silver with organic binders and water. Analysis of the firing transformation and microstructure of nano-silver clay was carried by differential thermal profile and SEM. The results revealed that the sintering temperature of the nano-silver clay was initiated at lower temperature (ca. 250℃) than that of bulk silver metal. The optimal condition of the heating process of nano-silver clay for jewelry application was investigated. The optimal condition of the firing temperature was above 600℃ with the heating rate of 10℃/min and the holding time 60 min. Herein, nano-silver clay offers not only clay-liked feature, which is proper for molded jewelry body by hand, but also the mechanical property is good enough for wearable jewelry body.
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A simple, rapid, and environmentally friendly process using hydrogen peroxide, was developed for recovering high purity silver directly from industry and laboratory wastes. Silver ammine complex, [Ag(NH3)(2)]+CI-, derived from AgC...
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A simple, rapid, and environmentally friendly process using hydrogen peroxide, was developed for recovering high purity silver directly from industry and laboratory wastes. Silver ammine complex, [Ag(NH3)(2)]+CI-, derived from AgCI were generated and then directly reduced using H2O2 to reliably turn into high purity microcrystalline silver (99.99%) examined by EDS and XRD. Morphology of the recovered silver microcrystals could be selectively tuned by an addition of poly(vinyl pyrrolidone). The main parameters in the recovering process including pH, concentration of Ag+ and the mole ratio of H2O2:Ag+ were carefully optimized though the central composite design (CCD). The optimized condition was employed for a trial recovery of 50 L silver ammine complex prepared from a collection of silver-wastes during 3-year research on industrial nanoparticle production. The recovered silver microcrystals >700 g could be recovered with 91.27%. The remaining solution after filtering of the recovered silver micro crystals can be used repeatedly (at least 8 cycles) without losing recovery efficiency. Matrix interferences including Pb2+ and Cl play a minimal role in our silver recovery process. Furthermore, the direct usage of the recovered silver microcrystals was demonstrated by using as a raw material of silver clay for creating a set of wearable silver jewelries. (C) 2017 Elsevier Ltd. All rights reserved.
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The performance of Polyethylene (PE)/Clay/Silver nanocomposites is dependent to a great extent on the properties of filler-matrix interface. To improve the interfacial properties in PE/Clay/Silver composites, different types of co...
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The performance of Polyethylene (PE)/Clay/Silver nanocomposites is dependent to a great extent on the properties of filler-matrix interface. To improve the interfacial properties in PE/Clay/Silver composites, different types of compatibilizers or adhesion promoters were introduced. The compatibilization provided by maleic anhydride (MA), itaconic acid (IA) and 2-[2-(dimethylamine)-ethoxy] ethanol (DMAE) functionalized PEs for forming PE-based nanocomposites was studied and compared. IA was grafted into PE by melt mixing to obtain PEgIA (compatibilizer 1), thereafter, PEgIA and PEgMA (compatibilizer 2) were reacted with DMAE also by melt mixing to obtain PEgI-DMAE (compatibilizer 3) and PEgM-DMAE (compatibilizer 4). These compatibilizers were reacted using ultrasound with a solution of AgNO3 0.04M and ethylene glycol. Ammonium hydroxide was added in a ratio of 2:1M with respect to silver nitrate. These silver coated compatibilizers were mixed with PE and with a quaternary ammonium modified montmorillonite clay (Nanomer I28E), thus forming the different hybrid PE/Clay/Silver nanocomposites. FTIR confirmed the formation of these compatibilizers. All the DMAE compatibilized nanocomposites had better filler (clay and silver) dispersion and exfoliation. XRD, oxygen and water transmission rate as well as antimicrobial properties attained showed that the PEgI-DMAE produced the better dispersed PE, clay and silver nanocomposites. The obtained nanocomposites showed enhanced barrier properties and outstanding antimicrobial properties against bacteria, E. coli. PEgI-DMAE offers an outstanding capability for preparing nanocomposites with highly exfoliated and dispersed filler into the PE matrix that offers a new option for obtaining hybrid nanocomposites with enhanced properties to be used in packaging applications.
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Polyethylene grafted with maleic anhydride (PEgMA) was used as one type of compatibilizer and it was reacted by reactive extrusion with 2 [2 (dimethylamine) ethoxy] ethanol (DMAE) to obtain other type of compatibilizer PEgDMAE. Sy...
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Polyethylene grafted with maleic anhydride (PEgMA) was used as one type of compatibilizer and it was reacted by reactive extrusion with 2 [2 (dimethylamine) ethoxy] ethanol (DMAE) to obtain other type of compatibilizer PEgDMAE. Synthesis and deposition of silver nanoparticles (Ag-NP) was done by two different methods: In one method (method A), silver nanoparticles were synthetized using ethylene glycol (EG) and pre mixed with compatibilizers using ultrasound with the aim of inducing an interaction between AgNP and polar groups of compatibilizer. Then they were incorporated in a blend with PE and Clay by melt mixing. In other method (method B) silver nanoparticles, were synthetized using EG, premixed with the Clay in a solvent suspension, and then incorporated with PE and compatibilizers. Characterization techniques indicated that an increase in the content of Ag-NPs, filler dispersion (clay and silver), mechanical and antimicrobial properties were strongly affected by the type and concentration of the compatibilizer and preparation method used. The using of PEgDMAE resulted in a better particle distribution of both sliver and clay into PE. The obtained nanocomposites showed enhanced mechanical and antimicrobial properties with highly exfoliated and dispersed filler into the PE matrix that offers a better option for obtaining hybrid nanocomposites for different applications.
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Polyethylene grafted with maleic anhydride (PEgMA) was used as one type of compatibilizer and it was reacted by reactive extrusion with 2 [2 (dimethyl‐amine) ethoxy] ethanol (DMAE) to obtain other type of comp
Polyethylene grafted with maleic anhydride (PEgMA) was used as one type of compatibilizer and it was reacted by reactive extrusion with 2 [2 (dimethyl‐amine) ethoxy] ethanol (DMAE) to obtain other type of compatibilizer PEgDMAE. Synthesis and deposition of silver nanoparticles (Ag‐NP) was done by two different methods: In one method (method A), silver nanoparticles were synthetized using ethylene glycol (EG) and pre mixed with compatibilizers using ultrasound with the aim of inducing an interaction between AgNP and polar groups of compatibilizer. Then they were incorporated in a blend with PE and Clay by melt mixing. In other method (method B) silver nanoparticles, were synthetized using EG, premixed with the Clay in a solvent suspension, and then incorporated with PE and compatibilizers. Characterization techniques indicated that an increase in the content of Ag‐NPs, filler dispersion (clay and silver), mechanical and antimicrobial properties were strongly affected by the type and concentration of the compatibilizer and preparation method used. The using of PEgDMAE resulted in a better particle distribution of both sliver and clay into PE. The obtained nanocomposites showed enhanced mechanical and antimicrobial properties with highly exfoliated and dispersed filler into the PE matrix that offers a better option for obtaining hybrid nanocomposites for different applications.
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A novel clay mineral-based adsorbent for Ag(Ⅰ) ions extraction was obtained by modifying hectorite with 2-(3-(2-aminoethylthio)propylthio)ethanamine (AEPE-hectorite). The modified hectorite was used to recover Ag(Ⅰ) ions from wa...
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A novel clay mineral-based adsorbent for Ag(Ⅰ) ions extraction was obtained by modifying hectorite with 2-(3-(2-aminoethylthio)propylthio)ethanamine (AEPE-hectorite). The modified hectorite was used to recover Ag(Ⅰ) ions from wastewater for further preparation of silver nanoparticles supported hectorite. The parameters affecting silver ions extraction by AEPE-hectorite were investigated. The adsorbent could extract Ag(Ⅰ) ions from solution in a wide pH range (1-8) and high extraction efficiencies were achieved in the solution pH ranged from 4 to 9. AEPE-hectorite showed a good selectivity toward Ag(Ⅰ) ions over Co(Ⅱ), Ni(Ⅱ) and Cd(Ⅱ) ions and the solution ionic strength had no significant effect on extraction efficiency. The adsorption of Ag(Ⅰ) ions onto AEPE-hectorite followed the Freundlich isotherm model with maximum adsorption capacity observed in the experiment of 49.5 mg g~(-1). The adsorbent was successfully used to recover silver ions from a wastewater containing high concentration of silver and silver nanoparticles supported hectorite was obtained after reducing with NaBH_4. These results show an alternative in the preparation of silver nanoparticles supported clay.
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In order to enhance silver effectiveness for oxygen reduction reaction, pillared clay was used as a support for silver nanodispersion. Silver particles incorporation into pillared clay pores was attempted by impregnation/ thermal ...
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In order to enhance silver effectiveness for oxygen reduction reaction, pillared clay was used as a support for silver nanodispersion. Silver particles incorporation into pillared clay pores was attempted by impregnation/ thermal degradation technique. X-ray diffraction as well as adsorption-desorption isotherms confirmed that pillaring procedure was successful. Scanning electron microscopy evidenced that a part of silver appeared outside the pillared clay cavities. Ag-pillared clay composite homogenized with 10 wt.% of nanodispersed carbon black (Vulcan), was applied on a flat glassy carbon surface and used as an electrode material. Oxygen reduction reaction was investigated in an O _2-saturated aqueous 0.1 M NaOH solution.
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Aim: To evaluate the effectiveness of novel nanohybrids, composed of silver nanoparticles and nanoscale silicate platelets, to clear Pseudomonas aeruginosa biofilms. Materials & methods: The nanohybrids were manufactured from an in situ reduction of silver salts in the silicate platelet dispersion, and then applied to biofilms in vitro and in vivo. Results: In reference to the biocidal effects of gentamycin, the nanohybrids mitigated the spreading of the biofilms, and initiated robust cell death and exfoliation from the superficial layers of the biofilms in vitro. In vivo, the nanohybrids exhibited significant therapeutic effects by eliminating established biofilms from infected corneas and promoting the recovery of corneal integrity. Conclusion: All of the evaluations indicate the high potency of the newly developed silver nanoparticle/nanoscale silicate platelet nanohybrids for eliminating biofilms. Original submitted 6 June 2012; revised submitted 13 February 201....
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Aim: To evaluate the effectiveness of novel nanohybrids, composed of silver nanoparticles and nanoscale silicate platelets, to clear Pseudomonas aeruginosa biofilms. Materials & methods: The nanohybrids were manufactured from an in situ reduction of silver salts in the silicate platelet dispersion, and then applied to biofilms in vitro and in vivo. Results: In reference to the biocidal effects of gentamycin, the nanohybrids mitigated the spreading of the biofilms, and initiated robust cell death and exfoliation from the superficial layers of the biofilms in vitro. In vivo, the nanohybrids exhibited significant therapeutic effects by eliminating established biofilms from infected corneas and promoting the recovery of corneal integrity. Conclusion: All of the evaluations indicate the high potency of the newly developed silver nanoparticle/nanoscale silicate platelet nanohybrids for eliminating biofilms. Original submitted 6 June 2012; revised submitted 13 February 201.
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Highly electrically conductive films were prepared by coating organic/inorganic nanohybrid solutions with a polymeric dispersant and exfoliated mica nanosheets (Mica) on which silver nanoparticles (AgNPs) had been dispersed in var...
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Highly electrically conductive films were prepared by coating organic/inorganic nanohybrid solutions with a polymeric dispersant and exfoliated mica nanosheets (Mica) on which silver nanoparticles (AgNPs) had been dispersed in various components. Transmission electronic microscopy showed that the synthesized AgNPs had a narrow size distribution and a diameter of approximately 20 nm. Furthermore, a 60 mu m thick film with a sheet resistance as low as 4.5 x 10(-2) Omega/sq could be prepared by controlling the heating temperature and by using AgNPs/POE-imide/Mica in a weight ratio of 20:20:1. During the heating process, the surface color of the hybrid film changed from dark golden to white, suggesting the accumulation of the AgNPs through surface migration and their melting to form an interconnected network. These nanohybrid films have potential for use in various electrically conductive devices.
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The aim of this work is to investigate the ability of an adsorbent of a clay mineral composite to remove and recover gold and silver ions from wastewater. The composite was prepared by mixing phosphogypsum (PG), obtained from an i...
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The aim of this work is to investigate the ability of an adsorbent of a clay mineral composite to remove and recover gold and silver ions from wastewater. The composite was prepared by mixing phosphogypsum (PG), obtained from an industrial waste, and a natural clay mineral. The materials were characterized before and after use in adsorption by several techniques. Batch adsorption experiments were carried out, and the effects of the contact time and the pH and temperature of solution on the removal processes were investigated. The optimum pH for the adsorption was found to be 4. The adsorption of these metal ions reached equilibrium after 2 h of contact. The pseudo-first- and the pseudo-second-order kinetic models, as well as the Freundlich and the Langmuir isotherm equations, were considered to describe the adsorption results. The maximum adsorbed amount of 85 mgg(-1) Ag(I) and 108.3 mgg(-1) Au(III) was found. The recovery of the adsorbed gold and silver ions from the adsorbent was also analyzed. Strong acids appeared to be the best desorption agents to recover gold and silver ions. The use of aqua regia gave regeneration rates close to 95.3% and 94.3% for Ag(I) and Au(III), respectively. Finally, the removal of gold and silver ions from an industrial wastewater was tested in batch experiments, and percentage recoveries of 76.5% and 79.9% for Ag(I) and Au(III), respectively, were obtained. To carry out the industrial application of the proposed methodology, an economic viability study is required.
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