Green Synthesis of Smart Metal/Polymer Nanocomposite Particles and Their Tuneable Catalytic Activities

Tan, Noel Peter Bengzon; Lee, Cheng Hao; Li, Pei

doi:10.3390/polym8040105

Cited by 51 publications

(25 citation statements)

References 38 publications

(53 reference statements)

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“…The zeta potential of Au NPs relies on the surface modification of the nanoparticles [43]. The Au NPs zeta potential has a negative value of −39.2 mV due to the charge stabilization through the electrostatic interaction between the Au NPs and citrate ions [45]. Meanwhile, the zeta potentials of the bimetallic Au-Ag NPs were −31.5 mV and −20.9 mV for 2.0 mL and 5.0 mL Au seed, respectively.…”

Section: Zeta Potential Analysismentioning

confidence: 99%

Synthesis of Bimetallic Gold-Silver (Au-Ag) Nanoparticles for the Catalytic Reduction of 4-Nitrophenol to 4-Aminophenol

et al. 2018

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Bimetallic gold-silver nanoparticles as unique catalysts were prepared using seed colloidal techniques. The catalytic capabilities of the nanoparticles were ascertained in the reduction of 4-nitrophenol to 4-aminophenol in the presence of sodium borohydride. Our results clearly showed that the rate of 4-NP reduction to 4-AP increased with a corresponding decrease in the diameter of the bimetallic NPs. The Au-Ag nanoparticles prepared with 5.0 mL Au seed volume indicated higher reduction activity, which was approximately 1.2 times higher than that of 2.0 mL Au seed volume in the reductive conversion of 4-NP to 4-AP. However, the monometallic NPs showed relatively less catalytic activity in the reductive conversion of 4-NP to 4-AP compared to bimetallic Au-Ag nanoparticles. Our studies also reinforced the improved catalytic properties of the bimetallic Au-Ag nanoparticles structure with a direct impact of the size or diameter and relative composition of the bimetallic catalytic nanoparticles.

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Section: Zeta Potential Analysismentioning

confidence: 99%

Synthesis of Bimetallic Gold-Silver (Au-Ag) Nanoparticles for the Catalytic Reduction of 4-Nitrophenol to 4-Aminophenol

et al. 2018

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“…Au@Ag bimetallic nanoparticle synthesis was carried out through a progressive reduction of Au and Ag metal ions as performed previously by Tan et al [58]. Gold metal ions were first reduced to the shell component of the microgel.…”

Section: Synthesis Of Au@ag/core-shell Pnipam/pei Microgel Composite mentioning

confidence: 99%

Environment-Friendly Approach in the Synthesis of Metal/ Polymeric Nanocomposite Particles and Their Catalytic Activities on the Reduction of p-Nitrophenol to p-Aminophenol

Tan¹,

Lee²

2017

Green Chemical Processing and Synthesis

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In this chapter, an environment-friendly approach in synthesizing Au and Au@Ag metal nanoparticles using a microgel is demonstrated. Poly(N-isopropyl acrylamide)/polyethyleneimine microgel was used as a multifunctional template to reduce metal ions to metal nanoparticles, stabilize and immobilize these metal nanoparticles, and regulate their accessibility within the template. Such multifunctional roles of microgel template were possible due to their unique properties (i.e., amino groups reducing capability, electrostatic and steric stabilizing properties, and swelling/deswelling properties). Characterizations of these metal/polymeric composite particles were also performed, such as scanning electron microscope (SEM), transmission electron microscope (TEM), Zeta-potential, UV-vis spectroscopy, X-ray Diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). To test the catalytic activities of both gold and gold@silver nanoparticles in the microgel template, a model reaction (i.e., reduction of p-nitrophenol to p-aminophenol) was performed. Results showed that bimetallic gold@silver gave 10 times higher catalytic activity compared to monometallic gold nanoparticles. With the simple one-step synthesis, a highly scalable process is possible.

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“…Another approach has been to immobilize metal nanoparticles within polyelectrolyte-brushes synthesized on a polystyrene core [14]. The polymer microenvironment of these systems can lead to increased local concentrations of reactants, which can accelerate reactions, facilitate reactions of otherwise non-reactive species [9,10,15,16,17], confer temperature or pH dependent catalytic activity [18], and/or provide specificity based on hydrophobicity [15].…”

Section: Introductionmentioning

confidence: 99%

Rapid Self-Assembly of Metal/Polymer Nanocomposite Particles as Nanoreactors and Their Kinetic Characterization

et al. 2019

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Self-assembled metal nanoparticle-polymer nanocomposite particles as nanoreactors are a promising approach for performing liquid phase reactions using water as a bulk solvent. In this work, we demonstrate rapid, scalable self-assembly of metal nanoparticle catalyst-polymer nanocomposite particles via Flash NanoPrecipitation. The catalyst loading and size of the nanocomposite particles can be tuned independently. Using nanocomposite particles as nanoreactors and the reduction of 4-nitrophenol as a model reaction, we study the fundamental interplay of reaction and diffusion. The induction time is affected by the sequence of reagent addition, time between additions, and reagent concentration. Combined, our experiments indicate the induction time is most influenced by diffusion of sodium borohydride. Following the induction time, scaling analysis and effective diffusivity measured using NMR indicate that the observed reaction rate are reaction- rather than diffusion-limited. Furthermore, the intrinsic kinetics are comparable to ligand-free gold nanoparticles. This result indicates that the polymer microenvironment does not de-activate or block the catalyst active sites.

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Green Synthesis of Smart Metal/Polymer Nanocomposite Particles and Their Tuneable Catalytic Activities

Cited by 51 publications

References 38 publications

Synthesis of Bimetallic Gold-Silver (Au-Ag) Nanoparticles for the Catalytic Reduction of 4-Nitrophenol to 4-Aminophenol

Synthesis of Bimetallic Gold-Silver (Au-Ag) Nanoparticles for the Catalytic Reduction of 4-Nitrophenol to 4-Aminophenol

Environment-Friendly Approach in the Synthesis of Metal/ Polymeric Nanocomposite Particles and Their Catalytic Activities on the Reduction of p-Nitrophenol to p-Aminophenol

Rapid Self-Assembly of Metal/Polymer Nanocomposite Particles as Nanoreactors and Their Kinetic Characterization

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