Preparation of Gold Nanoparticles in Inorganic Suspension and Clay Gel Solution.

Nakamura, Keitarou; Mori, Yasushige

doi:10.1252/jcej.34.1538

Cited by 13 publications

(8 citation statements)

References 25 publications

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“…An example is given for nanodispersions based on gold nanoparticles obtained by the impregnation in water in Figure 3. This figure plots the dynamic viscosity of the ternary systems at a high frequency of ω = 100 s −1 , as a function of the AuNPs contents, for the three studied temperatures (20,30, and 40 o C). The dynamic viscosity of the 3 wt % clay−epoxy dispersions slightly decreases when a clay decorated with gold is used, but it is not significantly changed by increasing the AuNPs content within 0.06−0.6 wt %.…”

Section: Langmuirmentioning

confidence: 99%

“…Patel et al suggested a method for preparation of gold nanoparticles anchored on surfactant intercalated montmorillonite, where the organic surfactant was exchanged with gold salt; the latter was then reduced to obtain gold nanoparticles. Other attempts to make gold nanoparticle–clay nanocomposites were made recently. − …”

Section: Introductionmentioning

confidence: 99%

“…Dynamic viscosity of gold−clay−epoxy nanodispersions at ω = 100 s −1 , as a function of the gold content at three temperatures(20,30, and 40 o C). The synthesis method of AuNPs is IM wt.…”

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confidence: 99%

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EPR and Rheological Study of Hybrid Interfaces in Gold–Clay–Epoxy Nanocomposites

et al. 2014

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With the aim to obtain new materials with special properties to be used in various industrial and biomedical applications, ternary "gold-clay-epoxy" nanocomposites and their nanodispersions were prepared using clay decorated with gold nanoparticles (AuNPs), at different gold contents. Nanocomposites structure was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Rheology and electron paramagnetic resonance (EPR) techniques were used in order to evaluate the molecular dynamics in the nanodispersions, as well as dynamics at interfaces in the nanocomposites. The percolation threshold (i.e., the filler content related to the formation of long-range connectivity of particles in the dispersed media) of the gold nanoparticles was determined to be ϕp = 0.6 wt % at a fixed clay content of 3 wt %. The flow activation energy and the relaxation time spectrum illustrated the presence of interfacial interactions in the ternary nanodispersions around and above the percolation threshold of AuNPs; these interfacial interactions suppressed the global molecular dynamics. It was found that below ϕp the free epoxy polymer chains ratio dominated over the chains attracted on the gold surfaces; thus, the rheological behavior was not significantly changed by the presence of AuNPs. While, around and above ϕp, the amount of the bonded epoxy polymer chains on the gold surface was much higher than that of the free chains; thus, a substantial increase in the flow activation energy and shift in the spectra to higher relaxation times appeared. The EPR signals of the nanocomposites depended on the gold nanoparticle contents and the preparation procedure thus providing a fingerprint of the different nanostructures. The EPR results from spin probes indicated that the main effect of the gold nanoparticles above ϕp, was to form a more homogeneous, viscous and polar clay-epoxy mixture at the nanoparticle surface. The knowledge obtained from this study is applicable to understand the role of interfaces in ternary nanocomposites with different combinations of nanofillers.

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Section: Langmuirmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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EPR and Rheological Study of Hybrid Interfaces in Gold–Clay–Epoxy Nanocomposites

et al. 2014

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“…One of the main drawbacks with nanoparticles lies in the fact that they cannot be reused, unless it is supported on a substrate for their reusability. Among the various supports studied such as metal oxides (TiO 2 , CeO 2 , Fe 2 O 3 , ZrO 2 , Al 2 O 3 , ZnO and SiO 2 ) (Zhen and Sheng, 2011), carbon materials (Tan et al, 2009, Muszynski et al, 2008 (carbon nanotubes, carbon fibers, and graphene sheet), and clays (montmorillonite, laponite, sepiolate, and kaolinite) (Chen and Kuo, 2006, Nakamura and Mori, 2001, Zhu et al, 2009, LDH have also attracted a great deal of interest in recent years bidimensional support for nanoparticles because of its inherent properties. For instance, gold nanoparticles were successfully immobilized on LDH using different strategies in-situ reduction (Varade and Haraguchi, 2012), homogenous deposition precipitation (Zhang et al, 2011), polyol reduction (Ballarin et al, 2011), calcination-reconstruction (Carja et al, 2013 to develop efficient catalyst for epoxidation of styrene, electrooxidation of methanol, and hydrogen generation.…”

Section: Introductionmentioning

confidence: 99%

Layered double hydroxides decorated with Au-Pd nanoparticles to photodegradate Orange II from water

Sobhana

Sarakha

Prevot

et al. 2016

Applied Clay Science

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“…(materials with at least one dimension < 100 nm) can be produced, and immobilized on substrates, introducing new properties to the end product. [4][5][6][7][8] Particular emphasis has been placed on the production of self-cleaning materials by means of surface modification with self-cleaning, anti-stain or anti-microbial coatings. Self-cleaning surfaces have been designed through the use of titanium dioxide nanoparticles which have the ability to act as photocatalysts under ultra violet light.…”

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confidence: 99%

Gold and silver nanoparticles as high-value colourants and multi-functional entities for natural fibres and minerals

Burridge¹

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<p>Significant opportunities exist in both the scientific and industrial sectors for the development of novel multi-functional materials that combine the inherent properties of all precursor components in a synergistic manner, thereby providing new products and opportunities. Processes that add value to natural materials in a facile and refined manner are particularly sought after. Thus this research combines useable substrates, notably natural protein fibres and minerals with gold or silver nanoparticles, producing high value, multi-functional materials that display the strength, softness and shine (of the protein fibres), or high surface area and dispersibility (of the minerals) with the high value and wealth associated with the noble metal nanoparticles, their broad spectrum of intense colours, anti-microbial, insecticide and anti-static properties. This adds significant worth to the substrates, transforming them from commodities to valuable materials. Silk, merino wool and crossbred wool were the natural fibres employed kaolinite and halloysite clays the minerals. They were combined with gold and silver nanoparticles of various sizes and shapes (and hence colours) producing the following composite materials: • Gold nanoparticle-merino wool composites • Gold nanoparticle-crossbred wool composites • Gold nanoparticle-silk composites • Silver nanoparticle-kaolinite composites • Silver nanoparticle-halloysite composites The most successful method for producing silver nanoparticle-clay composites involved the external preparation of silver nanoparticles and their subsequent attachment to the clay substrates by means of a layer-by-layer deposition approach, which capitalised on electrostatic interactions between oppositely charged polyelectrolytes capping the nanoparticles and bound to the clay surfaces. Three general approaches were employed in the production of the gold nanoparticle-natural fibre composite materials. The nanoparticles were either synthesised ex-situ and subsequently attached to the fibres, or the natural fibres were utilised as redox active biotemplates in which the wool or silk absorbed and subsequently reduced Au³⁺ to nanoparticulate Au⁰ on and within the fibres. Thirdly, a seed mediated growth approach was employed in which additional Au³⁺ was reduced to nanoparticulate Au⁰ on the surface of gold nanoparticles already bound to the fibres. This was facilitated by an external reductant.</p>

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Preparation of Gold Nanoparticles in Inorganic Suspension and Clay Gel Solution.

Cited by 13 publications

References 25 publications

EPR and Rheological Study of Hybrid Interfaces in Gold–Clay–Epoxy Nanocomposites

EPR and Rheological Study of Hybrid Interfaces in Gold–Clay–Epoxy Nanocomposites

Layered double hydroxides decorated with Au-Pd nanoparticles to photodegradate Orange II from water

Gold and silver nanoparticles as high-value colourants and multi-functional entities for natural fibres and minerals

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