Synthesis, stabilization, growth behavior, and catalytic activity of highly concentrated silver nanoparticles using a multifunctional polymer in an aqueous-phase

Shahzad, Aasim; Kim, Woo‐Sik; Yu, Taekyung

doi:10.1039/c5ra00610d

Cited by 37 publications

(53 citation statements)

References 67 publications

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“…Average sizes of the Ag NPs were (15.8±3.5), (24.2±5.9), and (42.9±12.4) nm at weight ratios of 5, 7, and 11, respectively (Figure b–d and Figure S6 b–d in the Supporting Information). In previous works on the synthesis of Ag NPs with PEI as a stabilizer, it was demonstrated that the Ag ion and PEI could make a PEI−Ag complex; thus modulating the reaction rate …”

Section: Resultsmentioning

confidence: 99%

“…The catalytic reactions are of tremendous interest because of a fundamental significance and broad technological applications. Metal NPs with small sizes and narrow distributions are most attractive because of their low cost and high electrocatalytic activity owing to their large surface‐to‐volume ratios . In the catalytic reaction, the stability of the catalyst is of prime interest because catalysts often lose their catalytic activity owing to the formation of aggregates or surface poisoning under harsh reaction conditions .…”

Section: Resultsmentioning

confidence: 99%

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A Simple and Fast Aqueous‐Phase Synthesis of Ultra‐Highly Concentrated Silver Nanoparticles and Their Catalytic Properties

Shahzad

Chung

et al. 2015

Chemistry An Asian Journal

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A simple and fast synthetic route to ultra-highly concentrated silver nanoparticles with long-term stability by reducing AgNO3 with ascorbic acid in the presence of polyethyleneimine (PEI) as a stabilizer in an aqueous phase is reported. The concentration of silver precursor was as high as 2000 mm (200 g of Ag nanoparticle per liter of water) and the reaction time was less than 10 min. The resulting silver nanoparticles show long-term stability after two months of storage at room temperature without any signs of particle aggregation or precipitation in an aqueous phase. The successful ligand exchange of PEI-stabilized silver nanoparticles to polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP) without particle aggregation is also demonstrated. In addition, the catalytic activities of silver nanoparticles stabilized by various stabilizers prepared by the ligand exchange method was investigated. The PEI-stabilized silver nanoparticles exhibited a higher stability than those of PEG- and PVP-stabilized silver nanoparticles in the diffusion-controlled catalytic reduction of 4-nitrophenol to 4-aminophenol by NaBH4 .

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

A Simple and Fast Aqueous‐Phase Synthesis of Ultra‐Highly Concentrated Silver Nanoparticles and Their Catalytic Properties

Shahzad

Chung

et al. 2015

Chemistry An Asian Journal

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“…Because BPEI is known as a weak reducing agent, we believe that BPEI prevented the surface oxidation of the Cu NWs. 21,24,25 In previous research on the synthesis of Ag nanoparticles using BPEI in an aqueous-phase, we reported that the protonated amine groups of BPEI have a weaker ability to stabilize Ag nanoparticles under strong acidic conditions. After several washing and storing 40 days at room temperature, we found that thin CuO layer were formed on the surface of NWs.…”

Section: Introductionmentioning

confidence: 99%

“…21 We could partially remove the BPEI by several washing the Cu NWs using ethanol. 21 When the synthesis was conducted under strong acidic conditions (pH = 1.8), thick and short Cu NWs were observed, showing the weak stabilization ability of BPEI ( Fig. XRD and XPS results show the presence of CuO layer on the surface of NWs while major crystal structure was still metallic Cu (Fig.…”

Section: Introductionmentioning

confidence: 99%

Cost-effective aqueous-phase synthesis of long copper nanowires

et al. 2015

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This work describes a simple and aqueous-phase route for synthesis of Cu nanowires (Cu NWs) having a long length of 140−180 µm, a high aspect ratio of more than 350, and long-term stability. High-quality Cu NWs were synthesized by reduction of CuCl 2 with ascorbic acid in the presence of branched polyethyleneimine (BPEI) in an aqueous solution at 90 °C. The synthesized uniform Cu NWs showed long-term stability without the formation of Cu oxides on the surface of the NWs after being stored at room temperature for 40 days. Interestingly, we found that Cl − in the reacting solution played a key role in the formation of long Cu NWs. We also investigated the influence of various experimental conditions including the weight ratio of BPEI/CuCl 2 , the pH of the reacting solution, and the reaction temperature on the length, morphology, and stability of Cu NWs.branched polyethyleneimine (BPEI) in an aqueous-phase at 90 °C. The synthesized uniform Cu NWs showed long-term stability without formation of Cu oxides on the surface of the NWs after being stored at room temperature for 40 days. Interestingly, we found that Cl − in the reacting solution played a key role in the formation of long Cu NWs. We also investigated the influence of various experimental conditions including the weight ratio of BPEI/CuCl 2 , the pH of the reacting solution, and the reaction temperature on the length, morphology, and stability of Cu NWs. Experimental SectionMaterials. BPEI (MW = 750,000, 50 wt.% solution in water), cupric chloride (CuCl 2 , ≥99%), copper(II) nitrate (Cu(NO 3 ) 2 ), ascorbic acid (C 6 H 8 O 6, purity ≥99%), sodium hydroxide (NaOH, ≥98%),and nitric acid (HNO 3 , ~ 70 %) were purchased from Aldrich and were used without further purification. Synthesis of Cu NWs.In a typical synthesis, 0.135g of CuCl 2 and 0.04g of BPEI were dissolved in 2 mL of deionized water in air under magnetic stirring at room temperature. Meanwhile, 3mL of 0.167 M aqueous ascorbic acid was added to the reaction solution using a micropipette (final volume of the solution was 5 ml and the weight ratio of BPEI/CuCl 2 was 0.3). The pH of the resulting solution was 2.9. The resulting mixture was aged at 90°C for 3 h, and was then cooled down to room temperature. The product was collected by repeated centrifugation and washing with water three times to remove the excess reagents.Characterization. TEM and high-resolution TEM (HRTEM) images were captured using a JEM-2100F microscope operating at 200 kV. Scanning electron microscopy (SEM) images were obtained using a LEO SUPRA 55 microscope. Powder X-ray diffraction (XRD) patterns were obtained using a Rigaku D-MAX/A diffractometer at 35 kV and 35 mA. Fourier transform infrared spectroscopy (FTIR) analysis was performed using a Jasco FTIR-6100 equipped with an ATR assembly in transmission mode. X-ray photoelectron spectroscopy (XPS) data was obtained using a Thermo Scientific K-Alpha spectrometer. Results and Discussion 5We observed a growth behavior of the Cu NWs by taking samples at various reaction stages and a...

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“…[1,2] In comparison with other metal nanoparticles with catalytic activity, [3][4][5] such as Pt and Pd nanoparticles, [6,7] AgNPs can be prepared more readily and inexpensively, so they have attractive application prospect in catalysis. [8] However, like other colloidal metal nanoparticles, colloidal AgNPs dispersed in aqueous medium are prone to self-aggregation and settling down owing to their high surface energy and great density, [9] In recent years, stimulus-responsive nanofibrous hydrogel consisting of randomly or orderly aligned nanofibers with the diameters of less than 1000 nm has attracted more and more attention, which overcome the above-mentioned disadvantages of smart bulky hydrogels and microgels. [23] First, it is able to respond rapidly to external stimulus due to very small diameters of their constituent nanofibers and porous structure, which facilitates the transfer of the stimulus to the whole material.…”

Section: Introductionmentioning

confidence: 99%

Silver Nanoparticles Loaded Thermoresponsive Hybrid Nanofibrous Hydrogel as a Recyclable Dip‐Catalyst with Temperature‐Tunable Catalytic Activity

Wang

Chen

Zhou

et al. 2017

Macro Materials & Eng

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Silver nanoparticles (AgNPs) loaded thermoresponsive nanofibrous hydrogel is fabricated by electrospinning the aqueous solution containing the metal nanoparticles and poly((N‐isopropylacrylamide)‐co‐(N‐hydroxymethylacrylamide)) copolymer, followed by heat treatment. To avoid negative effect of the stabilizer or the residual reductant on their performances, the AgNPs of less than 5 nm size are synthesized through reducing Ag+ ions in the spinning solution by UV irradiation. The prepared nanofibrous hydrogel with desirable stability in aqueous medium has significant thermoresponsive property, and can reach its swelling or deswelling equilibrium state within 15 s with the medium temperature changing between 25 and 50 °C alternately. The smart nanofibrous hydrogel as a dip‐catalyst has the catalysis for the reduction of 4‐nitrothiophenol to 4‐aminothiophenol by NaBH4, and its catalytic activity can be rapidly tuned by temperature. Moreover, it can be facilely recycled from the reaction system at least four times, without any loss of its catalytic activity.

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Synthesis, stabilization, growth behavior, and catalytic activity of highly concentrated silver nanoparticles using a multifunctional polymer in an aqueous-phase

Abstract: Highly concentrated Ag nanoparticles (above 20 g L−1) synthesized by the reaction AgNO3 with BPEI exhibited long-term stability over more than 40 days.

Cited by 37 publications

References 67 publications

A Simple and Fast Aqueous‐Phase Synthesis of Ultra‐Highly Concentrated Silver Nanoparticles and Their Catalytic Properties

A Simple and Fast Aqueous‐Phase Synthesis of Ultra‐Highly Concentrated Silver Nanoparticles and Their Catalytic Properties

Cost-effective aqueous-phase synthesis of long copper nanowires

Silver Nanoparticles Loaded Thermoresponsive Hybrid Nanofibrous Hydrogel as a Recyclable Dip‐Catalyst with Temperature‐Tunable Catalytic Activity

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