Synthesis of NiS nanoparticles using a sugar-ester nonionic water-in-oil microemulsion

Khiew, Poi Sim; Huang, N. M.; Radiman, Shahidan; Ahmad, Soot

doi:10.1016/j.matlet.2003.07.006

Cited by 71 publications

(35 citation statements)

References 24 publications

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“…40-50 nm; see Supporting Information) suggesting that the nanoparticle size is determined by the water nanodroplet size, which in turn is manipulated by controlling the water/surfactant ratio. [19,22,23] X-ray diffraction patterns of as-prepared nanoparticles confirm the presence of trigonal Bi 2 Te 3 ( Fig. 2a).…”

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confidence: 69%

Molecularly Protected Bismuth Telluride Nanoparticles: Microemulsion Synthesis and Thermoelectric Transport Properties

et al. 2006

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The efficiency of thermoelectric devices is a function of the non-dimensional figure of merit ZT [1] of the material, whereT is the absolute temperature and Z = ra 2 /j; a = thermoelectric power or the Seebeck coefficient, r = electrical conductivity, j = thermal conductivity; the numerator of Z is referred to as the power factor. State-of-the-art thermoelectric materials usable for cooling and power generation have a ZT ∼ 1, whereas a ZT ∼ 4 is necessary to surpass competing technologies.[2] Factorial enhancements in ZT may be obtained by introducing nanoscopic geometrical confinement in one, two, or three dimensions, for example, nanolayered quantum-well superlattices, nanowires, and quantum-dot superlattices, respectively. [3][4][5][6] Increased scattering of heat carriers at interfaces and nanostructure boundaries are thought to decrease j, while changes in charge carrier density near the Fermi level offers possibilities for increasing r and a. [3,6,[7][8][9][10][11] Decreases in j have been observed across Bi 2 Te 3 /Sb 2 Te 3 nanolayer superlattices, [3] giving rise to approximately twofold increase of ZT (highest reported ZT ∼ 2.3). Even larger ZT increases (approximately fivefold compared with the bulk value) due mainly to the reduction of j have been observed in PbSeTe/ PbTe quantum-dot superlattices.[6] However, the magnitude of ZT is only ca. 1.6 since PbSeTe/PbTe bulk has a lower ZT than Bi 2 Te 3 /Sb 2 Te 3 . Lowering the thermal conductivity of materials with an inherently high ZT in the bulk form (e.g., bismuth telluride), by introducing 3D confinement, that is, producing nanoparticles, is expected to yield higher ZT values. This approach could also allow the tuning of quantum effects by tailoring the nanoparticle size and shape, to facilitate additional mechanisms for increasing ZT. Indeed, power-factor increases have been predicted to arise from such effects in wellorganized Si/Ge nanoparticle arrays.[11] Hence, synthesis and assembly of nanoparticles of bismuth telluride is of interest to enable the development of higher efficiency devices for thermoelectric cooling and power generation. Bismuth telluride nanoparticles with diameters of ca. 100 nm have been synthesized by several routes. Examples include melting the constituent elements in sealed vessels above 600°C; [12] low-temperature (ca. 30°C) precipitation by reacting tris(dimethylamine) bismuthine and bis(trimethylsilyl) telluride in hexane, and subsequent annealing at 160°C; [13] co-precipitation of bismuth and tellurium oxides in water followed by hydrogen reduction; [14] or through reduction of organometallic complexes. [15] Smaller (e.g., 20-40 nm) nanostructures can be realized by solvothermal techniques [16,17] using precursors in solvents such as N,N-dimethylformamide or water at 100-180°C in reducing ambients. The high temperatures or long reaction times in these reactions, however, are not conducive for obtaining nanostructures smaller than 20 nm, which is the size regime where quantumconfinement effects are expected to be signif...

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confidence: 69%

Molecularly Protected Bismuth Telluride Nanoparticles: Microemulsion Synthesis and Thermoelectric Transport Properties

et al. 2006

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“…Particularly, in a quaternary W/O microemulsion system, the water nanodroplets stabilized by both surfactant and cosurfactant provide confined reaction space, which can be actually utilized as microreactors for the synthesis of nanoparticles [7]. These microreactors provide not only the suitable reaction media but also an efficient method to define the size of nanoparticles by restricting the excess particle growth as the size of particles approaches to that of water nanodroplets [8]. However, the confining effect would be inevitably diminished when the microemulsions become unstable or prone to breaking during the reaction, and the size of nanoparticles turns out to become larger.…”

Section: Introductionmentioning

confidence: 99%

Effect of the thermodynamic properties of W/O microemulsions on samarium oxide nanoparticle size

Zhu

et al. 2009

Journal of Colloid and Interface Science

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“…Det. 53 (2016) 1 sion system in the presence of as hort chain alcohol as coemulsifier,while Khiew et al found that sucrose ester-based microemulsions provide as uitable microenvironment for the preparation of nanomaterials [130,131].…”

Section: Sugar Estersmentioning

confidence: 99%

An Overview of Novel Surfactants for Formulation of Cosmetics with Certain Emphasis on Acidic Active Substances

Lukić¹,

Pantelić²,

Savić³

2016

Tenside Surfactants Detergents

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Novel surfactants which are nowadays available for incorporation into various formulations of personal care and cosmetic products are numerous, implying a permanent need for their classification. This overview provides essential information relating to synthesis, basic physicochemical characteristics, application and other relevant data on surfactants currently used in cosmetic products. In the second part of the paper an outline of acidic active substances with significant application in cosmetic products is given, as well as the problems that arise during preparation/manufacture of the containing formulations, accompanied with the review of scientific publications and other available reliable data dealing with the incorporation of these actives in the cosmetic formulations stabilized with novel (mainly natural) surfactants.

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Synthesis of NiS nanoparticles using a sugar-ester nonionic water-in-oil microemulsion

Cited by 71 publications

References 24 publications

Molecularly Protected Bismuth Telluride Nanoparticles: Microemulsion Synthesis and Thermoelectric Transport Properties

Molecularly Protected Bismuth Telluride Nanoparticles: Microemulsion Synthesis and Thermoelectric Transport Properties

Effect of the thermodynamic properties of W/O microemulsions on samarium oxide nanoparticle size

An Overview of Novel Surfactants for Formulation of Cosmetics with Certain Emphasis on Acidic Active Substances

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