Continuous synthesis of Zn2SiO4:Mn2+ fine particles in supercritical water at temperatures of 400–500°C and pressures of 30–35MPa

Shibuki, Kazuaki; Takesue, Masafumi; Aida, Taku Michael; Watanabe, Masaru; Hayashi, Hiromichi; Smith, Richard L.

doi:10.1016/j.supflu.2010.05.007

Cited by 21 publications

(11 citation statements)

References 37 publications

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“…This is including the conventional sol–gel technique [16,17,18] and solid state method [19,20,21,22]. In addition, other researchers reported the production of willemite by hydrothermal method [23,24], co–precipitation method [25], sonochemical method [26], spray drying method [27], spray pyrolysis method [28,29], super critical water methods [30,31] and solvothermal method [32]. It was inferred that the sol–gel technique is one the famous methods for producing semiconductor nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

Effects of Calcination Holding Time on Properties of Wide Band Gap Willemite Semiconductor Nanoparticles by the Polymer Thermal Treatment Method

et al. 2018

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Willemite is a wide band gap semiconductor used in modern day technology for optoelectronics application. In this study, a new simple technique with less energy consumption is proposed. Willemite nanoparticles (NPs) were produced via a water–based solution consisting of a metallic precursor, polyvinylpyrrolidone (PVP), and underwent a calcination process at 900 °C for several holding times between 1–4 h. The FT–IR and Raman spectra indicated the presence of metal oxide bands as well as the effective removal of PVP. The degree of the crystallization and formation of the NPs were determined by XRD. The mean crystallite size of the NPs was between 18.23–27.40 nm. The morphology, particle shape and size distribution were viewed with HR-TEM and FESEM analysis. The willemite NPs aggregate from the smaller to larger particles with an increase in calcination holding time from 1–4 h with the sizes ranging between 19.74–29.71 nm. The energy values obtained from the experimental band gap decreased with increasing the holding time over the range of 5.39 eV at 1 h to at 5.27 at 4 h. These values match well with band gap obtained from the Mott and Davis model for direct transition. The findings in this study are very promising and can justify the use of these novel materials as a potential candidate for green luminescent optoelectronic applications.

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Section: Introductionmentioning

confidence: 99%

Effects of Calcination Holding Time on Properties of Wide Band Gap Willemite Semiconductor Nanoparticles by the Polymer Thermal Treatment Method

et al. 2018

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“…For example, in photonic devices [19,20], laser crystals [21,22], optoelectronics [23,24], as well as adsorbents [25,26]. Several investigations regarding the synthesis techniques of willemite have been reported by numerous researchers, including the sol-gel technique [27,28], solid-state route [18,[29][30][31], co-precipitation method [32], spray pyrolysis method [33] spray drying method [34], hydrothermal method [35,36], supercritical methods [37,38], solvothermal method [39] and sonochemical method [40]. Conventional sol-gel and solid-state technique are often used methods for producing willemite NPs for phosphor application.…”

Section: Introductionmentioning

confidence: 99%

Effects of polyvinylpyrrolidone on structural and optical properties of willemite semiconductor nanoparticles by polymer thermal treatment method

Alibe

Матори

Sidek

et al. 2018

J Therm Anal Calorim

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Willemite is an inorganic semiconductor material used for optoelectronic applications. The present study purposes a new polymer thermal treatment method involving calcination temperature to fabricate the willemite nanoparticles. The effects of polyvinylpyrrolidone (PVP) on the structural and optical properties of the material were thoroughly investigated. Thermogravimetric and its derivative confirmed the decomposition behavior of PVP. The minimum calcination temperature to decompose PVP was appraised at 740°C. The FTIR and the Raman analyses confirmed the presence of organic source before the calcination process and the formation of the crystalline structure of the willemite nanoparticles after the heat treatment. The optimum PVP concentration in this study based on the FTIR results was found to be 40 g L-1. This is the minimum concentration at which the willemite nanoparticles remained pure with homogenous distribution. X-ray diffraction analysis of the PVP samples before calcination was confirmed to be amorphous, and upon calcination between 800 and 1000°C, an a-willemite phase was obtained. The morphology and the average particle size were determined with FESEM and HR-TEM analysis. The average particle size is between 23.8 and 36.7 nm. The optical energy band was found to be increasing from 5.24 to 5.32 eV with the corresponding increase in PVP concentration from 20 to 50 g L-1. The findings in this study provides a new pathway to understand the effects of PVP concentrations on the structural and optical properties of willemite semiconductor nanoparticles as it may have key potential applications for future optoelectronic devices.

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“…Due to the rapid heating rate of microwave, the nucleation rate is faster than the growth rate, so the new nuclei will rapidly form on the surface of the previously‐formed nuclei. Rodlike ZS bundles preferred to form in the hydrothermal environment, including the solvothermal and supercritical water method . However, submicrometer ellipsoidal ZS crystals were obtained under the MH condition in this study.…”

Section: Resultsmentioning

confidence: 68%

“…In the past, willemite phase zinc silicate (Zn 2 SiO 4 , ZS) has been widely applied to the luminescent materials owing to its high chemical and physical stability, but fewer reports about the use of ZS as biomaterials can be found. As it has previously been determined, ion release from well‐crystallized ZS is limited.…”

Section: Introductionmentioning

confidence: 99%

Microwave‐Assisted Hydrothermal Synthesis of Submicrometer Willemite Phase Zinc Silicate and Its Zinc Ion Release Behavior

Xiong

Liu

et al. 2012

J. Am. Ceram. Soc.

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As an important trace element in human bone, zinc (Zn) has a great influence on bone metabolism. The aim of this work was to prepare a Zn-containing material that can release Zn ions. For this purpose, submicrometer willemite phase zinc silicate (Zn 2 SiO 4 , ZS) with poor crystallinity was synthesized at 110°C via the microwave-assisted hydrothermal (MH) method. Under the MH condition, the growth of ZS was consistent with "multicore growth" mechanism. Moreover, the influences of the reaction temperature and the reactant concentration on the final products were investigated in detail. The inductively coupled plasma atomic emission spectroscopy (ICP) data indicated that the poor crystallinity ZS could successfully release Zn for at least 28 d as soaking in the simulated body fluid (SBF). Without the replenishment of SBF,~333 lM Zn was released from ZS synthesized at 110°C (ZS-110). If SBF was periodically replenished once a day, more Zn was released from ZS-110, and the parascholzite phase calcium zinc phosphate hydrate (CaZn 2 (PO 4 ) 2 Á2H 2 O) formed during the soaking process of ZS-110. Under the concentration of 6.25 mg/mL, the extract of ZS-110 was proved to be nontoxic by assessing with mouse osteoblast cells (MC3T3). Therefore, the poor crystallinity ZS has potential to be incorporated into the orthopedic reconstructive materials as a source of Zn ions, which can improve the bioactivity of the materials.

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Continuous synthesis of Zn2SiO4:Mn2+ fine particles in supercritical water at temperatures of 400–500°C and pressures of 30–35MPa

Cited by 21 publications

References 37 publications

Effects of Calcination Holding Time on Properties of Wide Band Gap Willemite Semiconductor Nanoparticles by the Polymer Thermal Treatment Method

Effects of Calcination Holding Time on Properties of Wide Band Gap Willemite Semiconductor Nanoparticles by the Polymer Thermal Treatment Method

Effects of polyvinylpyrrolidone on structural and optical properties of willemite semiconductor nanoparticles by polymer thermal treatment method

Microwave‐Assisted Hydrothermal Synthesis of Submicrometer Willemite Phase Zinc Silicate and Its Zinc Ion Release Behavior

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