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Synthesis and Characterization of Nanorods in Sucrose Ester Water-in-Oil Microemulsion  [PDF]
N. M. Huang
Journal of Nanomaterials , 2011, DOI: 10.1155/2011/815709
Abstract: We report the synthesis of nanorods in a nonionic sugar-based water-in-oil (w/o) microemulsion system using food grade sucrose ester as biosurfactant. was formed by mixing indium (III) chloride and thioacetamide in the water core of the microemulsion system. The as-prepared yellowish was characterized by X-ray diffractometry (XRD), UV-visible absorption spectroscopy (UV-Vis), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR). Formation of spherical or rod-like nanomaterials was dependent on reaction time. Rod-like , arranged in bundles, was formed only after 2 days of reaction time. Upon longer aging time, a mixture of rod-like and spherical was formed. A plausible formation mechanism of the nanorods in the sucrose ester microemulsion was postulated. The diameter of the nanorods was found to be very small, which is ?nm with aspect ratio of 20?:?1 (length?:?diameter). 1. Introduction Due to the toxicity of transition metals like Cd and Pb, alternative metals have been studied for the production of metal sulfides like ZnS, SnS2, and In2S3 [1, 2]. In2S3 is an interesting semiconductor with band gap energy of ~2.0?eV for bulk material [3, 4]. In2S3 is a metal sulfide group III–VI with potential application in optoelectronic, solar cells, and photoelectric [5, 6]. Many different types of techniques have been introduced for the synthesis of In2S3 in thin film or powder form with various morphologies [7, 8]. Conventionally, In2S3 was synthesized through direct reaction between indium and sulfur in a quartz chamber under high temperature [9], thermal treatment by In2O3 in the presence of H2S gas at high temperature, thermal degradation of butylindium at the temperature of 300°C [10], or self-propagation with metathesis reaction between InCl3 and Li2S at the temperature of 500°C [11]. There are a lot of reports on the solution synthesis method, which includes precipitation in aqueous solution that yields amorphous or low crystalline indium sulfide from reaction between InCl3 and H2S, (NH4)2S [5], or NaHS [12], In2S3 formation in sodium polysulfide solution using laser ablation technique; In2S3 nanoparticles precipitation method by adding Na2S into the InCl3 solution in the presence of polymeric stabilizing agent [13], injection of H2S into the In(ClO4)3 solution [14], and precipitation of In2S3 nanoparticles in microemulsion system. However, few works reported on the formation of 1-D In2S3 nanomaterials [15], thus, synthesis of 1-D In2S3 remains a great challenge. W/o microemulsion systems have been employed for some time
Effects of cosurfactant on ZnS nanoparticle synthesis in microemulsion
Tawatchai Charinpanitkul, Amornsak Chanagul, Joydeep Dutta, Uracha Rungsardthong and Wiwut Tanthapanichakoon
Science and Technology of Advanced Materials , 2005,
Abstract: ZnS nanoparticles with different morphology; spherical, ellipsoidal particles' nanotubes and nanorods, could be successfully synthesized from quaternary W/O microemulsion system. The morphology of the final products could be clearly confirmed by the scanning electron microscopy (SEM) and the transmission electron microscopy (TEM). The effect of cosurfactant on size and morphology of the obtained products have been explored in this work. The key controlling parameters such as the molar ratio of water to surfactant (wo) and the reactant concentration, which affect the product characteristics, have also been investigated.
Synthesis, Characterization, and Low Temperature Sintering of Nanostructured BaWO4 for Optical and LTCC Applications  [PDF]
S. Vidya,Sam Solomon,J. K. Thomas
Advances in Condensed Matter Physics , 2013, DOI: 10.1155/2013/409620
Abstract: Synthesis of nano-BaWO4 by a modified combustion technique and its suitability for various applications are reported. The structure and phase purity of the sample analyzed by X-ray diffraction, Fourier transform Raman, and infrared spectroscopy show that the sample is phase pure with tetragonal structure. The particle size from the transmission electron microscopy is 22?nm. The basic optical properties and optical constants of the nano BaWO4 are studied using UV-visible absorption spectroscopy which showed that the material is a wide band gap semiconductor with band gap of 4.1?eV. The sample shows poor transmittance in ultraviolet region while maximum in visible-near infrared regions. The photoluminescence spectra show intense emission in blue region. The sample is sintered at low temperature of 810°C, without any sintering aid. Surface morphology of the sample is analyzed by scanning electron microscopy. The dielectric constant and loss factor measured at 5?MHz are 9 and . The temperature coefficient of dielectric constant is ?22?ppm/°C. The experimental results obtained in the present work claim the potential use of nano BaWO4 as UV filters, transparent films for window layers on solar cells, antireflection coatings, scintillators, detectors, and for LTCC applications. 1. Introduction The ever increasing scientific and technological demand for novel materials with unique properties poses challenges to scientific research. Nanomaterials have caught the interest of researchers because of its exceptional properties which are completely different from its bulk material. Synthesis of advanced functional materials in nanoscale is one of the prime fields of interest. Generally, AWO4 (A = Ba, Sr, Ca, Pb) tetragonal scheelite-type crystals of divalent metal ion tungstate have been of immense interest because of their remarkable properties such as luminescence, nonlinear optical activity, photocatalysis, and scintillation [1–7]. Among them, BaWO4 is a significant material due to its excellent PL emission and stimulated Raman scattering active crystal. The reasons for blue and green PL emissions of BaWO4 are discussed in many different aspects ranging from defect centers by interstitial oxygen atoms to structural disorder in the crystal lattice [8–11]. BaWO4 also serves as a potential material for designing all solid-state lasers, especially that it has been considered as a unique Raman crystal for a wide variety of pump pulse durations in Raman laser pulses [12–17]. Its other applications include nuclear spin optical hole burning hosts [6], radiation detection
Synthesis and properties of ZnO nanorods by modified Pechini process
Ramasamy Devaraj,Krishnamoorthy Karthikeyan,Kadarkaraithangam Jeyasubramanian
Applied Nanoscience , 2013, DOI: 10.1007/s13204-012-0072-1
Abstract: Zinc oxide (ZnO) nanorods have been successfully synthesized by modified Pechini process. The as-synthesized ZnO nanorods were characterized by X-ray diffraction, scanning electron microscope, Raman spectrum, ultraviolet–visible (UV–vis) spectrum. X-ray diffraction result shows that the ZnO nanorods are oriented in wurtzite phase. Raman spectroscopy measurements revealed the presence of E2 (high) mode at 437 cm 1 indicating the high crystallinity of the as-synthesized ZnO nanorods. The optical property of the ZnO nanorods were studied from their UV–vis spectroscopy analysis which exhibits the absorbance at 373 nm corresponds to the Zn–O absorption. A mechanism for modified Pechini process for the synthesis of ZnO nanorods using citric acid–ethylene glycol precursor has also been proposed.
Synthesis of copper nanorods using electrochemical methods
Journal of the Serbian Chemical Society , 2003,
Abstract: Copper nanorods were synthesized using controlled-current electrochemical methods. The surfactants in the electrolyte served as both a templates and stabilizers during the synthesis procedure. TEM images show that the products consist mainly of nanosized rod-like structures. The current density applied during the electrodeposition was found to have an effect on the shape and yield of the copper nanorods.
Solvothermal Synthesis of Boehmite and γ-Alumina Nanorods
Mingguo MA,Yingjie ZHU,Guofeng CHENG,Yuehong HUANG,

材料科学技术学报 , 2008,
Abstract: Boehmite nanorods were synthesized by a solvothermal method using AlCl3-6H2O in mixed solvents of water and aniline. The solvothermal time, heating temperature and the concentration of aniline have effects on the morphology of boehmite. γ-alumina nanorods were prepared by a simple thermal transformation of boehmite nanorods. A rational mechanism based on the oriented attachment is proposed for the formation of boehmite nanorods. The products were characterized by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). Photoluminescence (PL) spectrum of the boehmite nanorods was also investigated.
Hydrothermal Synthesis of Ni/Al Layered Double Hydroxide Nanorods  [PDF]
Yun Zhao,Fenfei Xiao,Qingze Jiao
Journal of Nanotechnology , 2011, DOI: 10.1155/2011/646409
Abstract: Ni/Al layered double hydroxide (LDH) nanorods were successfully synthesized by the hydrothermal reaction. The crystal structure of the products was characterized by X-ray diffraction (XRD). The morphology of the products was observed using transmission electron microscopy (TEM) and field emission scanning electron microscopy (SEM). The influences of reaction time and pH value on the morphology of the Ni/Al LDHs were investigated. The result showed that the well-crystallized nanorods of Ni/Al LDHs could be obtained when the pH value was about 10.0 with a long reaction time (12–18?h) at 180°C. 1. Introduction Layered double hydroxides (LDHs) or LDH-type compounds belong to a large class of anionic clays. They can be represented by the general formula [M(II)1-x M(III)x(OH)2]x+[An?]x/nmH2O [1], where M(II) is a divalent metal cation, such as Mg, Mn, Ni, Zn, and Cu; M(III) is a trivalent metal cation, such as Al, Fe, Co, and Cr; [1] An? is an exchangeable anion, such as F?, Cl?, NO3?, CO32?, SO42?, and PO43? [2, 3]. The value of x is between 0.2 and 0.34 generally. LDHs are a layered structure with positively charged brucite-like sheets, where M(II) and M(III) are octahedrally coordinated. The excess charge is balanced by anions in the interlayer, together with water molecules. Recently, LDHs have attracted much attention because of their unique applications in many fields. For example, they can be used as catalysts, catalyst supports, ion exchangers, adsorbents, and pigments and also be used in sensor and magnetic technologies [1, 4, 5]. Scotter and ken B, prepared Ni/Al, Mg/Al, Co/Al, Cu/Al LDHs and used them as the catalysts of the steam reforming of methanol to produce hydrogen [6]. Alejandre et al. used Cu/Ni/Al LDHs as precursors of catalysts for the wet air oxidation of phenol aqueous solutions [7]. Most of these advanced functions depend strongly on the composition, size, and morphology. So nanostructures of LDHs will be of particular interest for the applications. In the last decade, 1-D nanostructures have been paid more attention due to their unique physical and chemical properties and their potential applications in science and engineering. The successful synthesis of nanotubes such as BN, WS2, and MoS2 has been reported [8]. Many hydroxide and oxide nanorods or nanotubes have also been prepared [9–15]. However, there is little report relating to LDH nanorods. A variety of Ni-based LDHs such as Ni/Al, Ni/Co, Ni/Fe, and Ni/Mn have been studied as cathode materials and catalysts [16, 17]. If Ni/Al LDHs were fabricated in the form of a
Size Controlled Synthesis of Starch Nanoparticles by a Microemulsion Method  [PDF]
Suk Fun Chin,Aressa Azman,Suh Cem Pang
Journal of Nanomaterials , 2014, DOI: 10.1155/2014/763736
Abstract: Controllable particles sizes of starch nanoparticles were synthesized via a precipitation in water-in-oil microemulsion approach. Microemulsion method offers the advantages of ultralow interfacial tension, large interfacial area, and being thermodynamically stable and affords monodispersed nanoparticles. The synthesis parameters such as stirring rates, ratios of oil/cosurfactant, oil phases, cosurfactants, and ratios of water/oil were found to affect the mean particle size of starch nanoparticles. Starch nanoparticles with mean particles sizes of 109?nm were synthesized by direct nanoprecipitation method, whereas by using precipitation in microemulsion approach, starch nanoparticles with smaller mean particles sizes of 83?nm were obtained. 1. Introduction Starch is one of the most commonly used biopolymers in industries because of nontoxicity, biodegradability, biocompatibility, low cost, and being renewable and abundantly available in nature [1–3]. There is a growing interest in making use of starch as precursor material for synthesizing starch-based nanoparticles for various biomedical and industry applications such as drug delivery carriers [4–7], plastic fillers [8], and biodegradable packaging materials [6, 9, 10]. Various synthetic methods for synthesis of starch nanoparticles such as high-pressure homogenization and miniemulsion cross-linking [11], nanoprecipitation [2, 12, 13], emulsion [14, 15], and microemulsion [16–18] have been explored by researchers. High-pressure homogenization is a simple technique and useful for diluted and concentrated samples; however it requires high number of homogenization cycles and possible contamination of product could occur from metal ions coming off from the wall of the homogenizers [19]. Nanoprecipitation method is a favorable method as it is very simple and straightforward method. However, in order to avoid nanoparticles aggregate formation during the precipitation process, only very low concentration of starting materials can be used [13] and large amount of nonsolvent was required in order to obtain spherical shape nanoparticles [2]. Interest in using microemulsion for nanoparticles synthesis arises mainly from the versatile nature of microemulsion system such as mild reaction conditions, simple procedure [20], cost effectiveness, and formation of very small droplet size [21–24]. Besides, microemulsion route is known to be one of the most efficient methods for stabilization of nanodroplets and controlling of particle size, morphology, and homogeneity [20, 22]. Components of microemulsion consist of water
A Novel Hydrothermal Synthesis of Single Crystalline PbS Nanorods and Their Characterization
Hongliang ZHU,Deren YANG,Hui ZHANG,
Hongliang ZHU
,Deren YANG and Hui ZHANG Center of Materials Engineering,Zhejiang Sci-Tech University,Hangzhou,China State Key Lab of Silicon Materials,Zhejiang University,Hangzhou,China

材料科学技术学报 , 2005,
Abstract: Lead sulfide (PbS) nanorods with a high aspect ratio were prepared by a novel thioglycolic acid assisted hydrothermal method. X-ray diffraction and transmission electron microscopy revealed that the product was rod-like PbS with cubic rock-salt structure. Further characterizations by selected area electron diffraction and high-resolution transmission electron microscopy showed that the PbS nanorods were single crystalline in nature. Furthermore, the mechanism and critical factors for the hydrothermal synthesis of the nanorods have been discussed.
Facile Synthesis of ZnO Nanorods by Microwave Irradiation of Zinc–Hydrazine Hydrate Complex  [cached]
Bhat DenthajeKrishna
Nanoscale Research Letters , 2007,
Abstract: ZnO nanorods have been successfully synthesized by a simple microwave-assisted solution phase approach. Hydrazine hydrate has been used as a mineralizer instead of sodium hydroxide. XRD and FESEM have been used to characterize the product. The FESEM images show that the diameter of the nanorods fall in the range of about 25–75 nm and length in the range of 500–1,500 nm with an aspect ratio of about 20–50. UV–VIS and photoluminescence spectra of the nanorods in solution have been taken to study their optical properties. A mechanism for microwave synthesis of the ZnO nanorods using hydrazine hydrate precursor has also been proposed.
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