Synthesis of Magnesium Oxychloride Nanowhisker by Microemulsion Method

2012 ◽  
Vol 535-537 ◽  
pp. 357-361
Author(s):  
Lin Qing Qin ◽  
Chuang Bin Wang ◽  
Zhi Yang Qin
Keyword(s):  
Magnesium Chloride ◽  
Average Diameter ◽  
Soft Template ◽  
Ammonium Bromide ◽  
Mass Ratio ◽  
Microemulsion Method ◽  
Transmission Electron ◽  
Chloride Hexahydrate ◽  
Magnesium Oxychloride ◽  
Cetyltrimethyl Ammonium

Magnesium oxychloride (MOC,5Mg(OH)2•MgCl2•8H2O,phase 5) nanowhiskers were synthesized via a reverse microemulsion method by suing cetyltrimethyl ammonium bromide (CTAB)/n-butanol (C4H10O)/cyclohexane (C6H12)/water as soft-template. Aqueous solution of magnesium chloride (MgCl2) and MgO powder were suing as reactants. The products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). Results indicated that MOC nanowhiskers can be obtained when the mass ratio of MgO, magnesium chloride hexahydrate and water is 1:1:0.64. The aspect ratio of MOC nanowhisker is more than 100 with an average diameter of 50-90 nm. The influence of size of MgO particles and mass ratio of MgCl2 solution to CTAB on morphology of whiskers was investigated. The growth mechanism of the MOC nanowhisker was also supposed in this study.

SYNTHESIS OF CaWO4 AND CaWO4:Eu MICROSPHERES BY PRECIPITATION

NANO ◽  
2014 ◽  
Vol 09 (01) ◽  
pp. 1450008 ◽  
Author(s):  
YUGUO YANG ◽  
XUPING WANG ◽  
BING LIU
Keyword(s):  
Electron Microscopy ◽  
Emission Band ◽  
Large Scale ◽  
Blue Emission ◽  
Average Diameter ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Blue Emission Band ◽  
Transmission Electron ◽  
Cetyltrimethyl Ammonium

Nearly monodisperse CaWO 4 and CaWO 4: Eu 3+ microspheres have been synthesized in large scale by a surfactant-assisted solution route, in which cetyltrimethyl ammonium bromide (CTAB) is used. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and photoluminescence (PL) were used to characterize the resulting samples. The results of XRD indicate that the CaWO 4 and CaWO 4: Eu 3+ samples have the scheelite structures. The growth process of these nearly monodisperse spheres with an average diameter around 3.2 μm has been examined. The results of FTIR indicate that CTAB plays an important role in the formation of microspheres. The CaWO 4 microspheres exhibit a blue emission band with a maximum at 423 nm. But the CaWO 4: Eu 3+ microspheres exhibit a red emission band with a maximum at 623 nm.

Synthesis and Characterization of γ-Al2O3 Nanowires by a Surfactant Assisted Precipitation Method

2014 ◽  
Vol 602-603 ◽  
pp. 93-96 ◽  
Author(s):  
Fan Cheng Meng ◽  
Cheng Liu ◽  
Xiao Lei Zhang ◽  
Hai Shen Ren ◽  
Tie Kun Jia
Keyword(s):  
Raw Materials ◽  
Sodium Aluminate ◽  
Precipitation Method ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Structure Directing Agent ◽  
Ctab Concentration ◽  
Transmission Electron ◽  
Cetyltrimethyl Ammonium ◽  
Surfactant Assisted

In this study, the γ-Al2O3 nanowires were prepared by a simple surfactant assisted precipitation method using the cetyltrimethyl ammonium bromide (CTAB) as a structure-directing agent (SDAs). Homemade sodium aluminate (NaAlO2) and H2O2 were used as raw materials. The influences of CTAB concentration and calcination temperature on the morphology of product were discussed. The obtained samples were investigated using transmission electron microscopy, X-ray diffraction analysis and TG-DSC. In the end, a possible formation mechanism of wire-like γ-Al2O3 is proposed.

scholarly journals Synthesis and Properties of Electrochemically Deposited Vertical Mesoporous Silica Thin Films

2015 ◽  
Vol 18 (3) ◽  
pp. 169-175
Author(s):  
Yuan Zhou ◽  
Qiming Liu ◽  
Ye Feng ◽  
Min Tan
Keyword(s):  
Thin Films ◽  
Mesoporous Silica ◽  
Self Assembly ◽  
Ammonium Bromide ◽  
Silica Thin Films ◽  
Transmission Electron ◽  
Hydroxyl Ion ◽  
Mesoporous Film ◽  
Electrochemically Deposited ◽  
Cetyltrimethyl Ammonium

Electrochemical deposition was successfully used to prepare mesoporous silica thin films with highly ordered and vertically oriented pores. Tetraethyl orthosilicate was used as the inorganic silicon source and cetyltrimethyl ammonium bromide was the template. A negative potential was applied to the working electrode, which was initially immersed in collosol and then in hydroxyl at the electrode/solution interface. Hydroxyl ion served as the catalyst that promoted the polycondensation and self-assembly of the silicon precursor, as well as the formation of thin films with pores which are highly ordered and vertically oriented with respect to the panel.The pore arrangement of the mesoporous film was hexagonal, and its aperture was 2 nm to 3 nm. The verticality of the thin film pore was demonstrated through permeability and transmission electron microscopy analyses. The prepared mesoporous film possessed good optical amorphous antireflective property with ordered and vertically oriented pores.

scholarly journals Morphologies Tuning of Polypyrrole and Thermoelectric Properties of Polypyrrole Nanowire/Graphene Composites

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1143 ◽  
Author(s):  
Yong Du ◽  
Hao Niu ◽  
Jun Li ◽  
Yunchen Dou ◽  
Shirley Shen ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Oxidative Polymerization ◽  
Soft Template ◽  
Ammonium Bromide ◽  
Measured Temperature ◽  
Cetyltrimethyl Ammonium ◽  
Polymerization Method

Polypyrrole (PPy) with different morphologies (e.g., particles, nanotubes, and nanowires) were successfully prepared by adding or without adding different kinds of surfactants through a chemical oxidative polymerization method, respectively. The results show that the morphologies of PPy can be effectively controlled and have a significantly effects on their thermoelectric properties. The PPy nanowires exhibit the highest electrical conductivity and Seebeck coefficient among the various PPy morphologies, such as particles, nanotubes, and nanowires, so PPy nanowires were chosen to prepare PPy nanowire/graphene thermoelectric composites via a soft template polymerization method using cetyltrimethyl ammonium bromide as the template. Both electrical conductivity and Seebeck coefficient of the PPy nanowire/graphene composites increased as the content of graphene increases from 0 to 20 wt %, and as the measured temperature increases from 300 K to 380 K, which leds to the same trend for the power factor. A highest power factor of 1.01 μWm−1K−2 at ~380 K was obtained for the PPy nanowire/graphene composites with 20 wt % PPy nanowire, which is about 3.3 times higher than that of the pure PPy nanowire.

On the Performance of Metal Supported Catalysts Prepared by Microemulsion: Sol Gel and Precipitation of the Support Precursor

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Gustavo Pérez ◽  
J. Luis Suaste ◽  
César Barrales ◽  
J. Antonio De los Reyes ◽  
Juan Pérez-Sea ◽  
...  
Keyword(s):  
Supported Catalysts ◽  
Sol Gel ◽  
Synthesis Method ◽  
Active Phase ◽  
Catalytic Performance ◽  
Ammonium Bromide ◽  
Microemulsion Method ◽  
Structure Sensitive ◽  
Cetyltrimethyl Ammonium

Ni/SiO2, NiMo/Al2O3 and CoMo/Al2O3 were prepared by microemulsion method. Precipitation and sol-gel of the support precursor allowed the synthesis of catalysts with differences in textural, structural and catalytic properties. The main difference between the precipitation and sol-gel microemulsion routes is the role of surfactant (Cetyltrimethyl Ammonium Bromide) in each synthesis method. The aggregation mechanism of support is modified by the synthesis route. There are differences in the catalytic performance of Ni/SiO2 microemulsion catalysts by the precipitation or sol-gel of support precursor. The hydrogenation of benzene, a low structure-sensitive reaction, showed that the precipitation 9%Ni/SiO2 microemulsion catalyst is more active than the sol-gel 9%Ni/SiO2 microemulsion catalyst. On other hand, these catalysts showed opposite result in the hydrogenation of C=C double bond of crotonaldehyde molecule. These results are indicative of the effects of nanostructured support and nanostructured active-phase in the hydrogenation activity. NiMo/Al2O3 and CoMo/Al2O3 catalysts prepared by sol-gel-microemulsion method were used in the hydrodesulphurization (HDS) of dibenzothiophene and 4,6-dimethyldibenzothiophene. The HDS activity was improved as a function of metal content and it motivates the study of NiMo and CoMo microemulsion catalysts with higher contents of metals to enhance the HDS of 4,6-dimethyldibenzothiophene.

A Facile One-Step Hydrothermal Synthesis of Graphene/CeO2 Nanocomposite and its Catalytic Properties

2013 ◽  
Vol 747 ◽  
pp. 242-245 ◽  
Author(s):  
Manish Srivastava ◽  
Ashok Kumar Das ◽  
Partha Khanra ◽  
Nam Hoon Kim ◽  
Joong Hee Lee
Keyword(s):  
Catalytic Activity ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Cetyltrimethyl Ammonium Bromide ◽  
Xrd Pattern ◽  
Transmission Electron ◽  
One Step ◽  
Ft Ir ◽  
Cetyltrimethyl Ammonium

Graphene/CeO2 nanocomposite has been successfully prepared by directly growing CeO2 nanoparticles on graphene sheets via in-situ reduction of graphene oxide containing the metal precursor. The presence of cetyltrimethyl ammonium bromide (CTAB) results the formation of CeO2 nanoparticles with a narrow size distribution. The structural, morphological, particles size and optical properties of the synthesized products were investigated through X-ray diffraction (XRD), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FT-IR) and UVvis absorbance spectroscopy, respectively. The XRD pattern shows that graphene/CeO2 nanocomposite is highly crystalline in nature. Growth of CeO2 nanoparticles with size in range of 5-18 nm on the graphene sheet were observed by TEM measurement. Optical energy band gap was calculated to be ~3.30 eV corresponding to direct transition. The catalytic activity of the synthesized nanocomposite was investigated taking hydrazine hydrate as a model system. Significant enhancement in the peak current with respect to CeO2 was observed on graphene/CeO2 nanocomposite-based electrode demonstrating the higher catalytic activity of graphene/CeO2 nanocomposite-based electrode.

scholarly journals Efficient Hydrolysis of Chitin in a Deep Eutectic Solvent Synergism for Production of Chitin Nanocrystals

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 869 ◽  
Author(s):  
Shu Hong ◽  
Yang Yuan ◽  
Kaitao Zhang ◽  
Hailan Lian ◽  
Henrikki Liimatainen
Keyword(s):  
Deep Eutectic Solvent ◽  
Average Diameter ◽  
Molar Ratio ◽  
High Yield ◽  
Mass Ratio ◽  
Synthesis Conditions ◽  
Chloride Hexahydrate ◽  
Low Energy Consumption ◽  
Ferric Chloride Hexahydrate ◽  
Hydrolysis Of

A deep eutectic solvent (DES) derived from ferric chloride hexahydrate and betaine chloride (molar ratio of 1:1) was used as hydrolytic media for production of chitin nanocrystals (ChNCs) with a high yield (up to 88.5%). The synergistic effect of Lewis acid and released Brønsted acid from betaine hydrochloride enabled the efficient hydrolysis of chitin for production of ChNCs coupled with ultrasonication with low energy consumption. The obtained ChNCs were with an average diameter of 10 nm and length of 268 nm, and a crystallinity of 89.2% with optimal synthesis conditions (at 100 °C for 1 h with chitin-to-DES mass ratio of 1:20). The ChNCs were further investigated as efficient emulsion stabilizers, and they resulted in stable o/w emulsions even at a high oil content of 50% with a low ChNC dosage of 1 mg/g. Therefore, a potential approach based on a DES on the production of chitin-based nanoparticles as emulsifiers is introduced.

Preparation and Properties and Application of Renewable Source (Palm Oil Polyol) Based Polyurethanes Coatings and its Thermal Stability Improvement by Clay Nanocomposites

2014 ◽  
Vol 887-888 ◽  
pp. 566-569 ◽  
Author(s):  
Teuku Rihayat ◽  
Salim Suryani ◽  
X Zaimahwati
Keyword(s):  
Thermal Stability ◽  
Palm Oil ◽  
Layered Silicate ◽  
Ammonium Bromide ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
New Class ◽  
Transmission Electron ◽  
Cetyltrimethyl Ammonium

A thermal study (using TGA) was carried out on polyurethane (PU) paint modified with layered silicate (organoclay) nanocomposites. The result showed that by adding clay, the PU paint/organoclaynanocomposites demonstrated better thermal stability than the virgin polyurethanepaint. The PU paint was synthesized with polyol prepared from palm oil i.e. a renewable resource.Whilst polyurethane modified with layered silicate (organoclay) nanocomposite is considered a new class of material. A tremendous improvement of the nanocompositecompared to pure polymers, although the filler content is just 2-5 wt%.The unmodified layered silicate (kunipia-F) was treated with cetyltrimethyl ammonium bromide (CTAB-mont) and octadodecylamine (ODA-mont) were used as swelling agents to treat Na+-montmorillonite and forming organoclay through ion exchange.The morphology of the nanocomposites was characterized by X-ray diffraction (X-RD) and transmission electron microscopic (TEM) and the pattern showed that all of the nanocomposites produced from this work are intercalated type.

Synthesis of Spindle-Like Hollow Mesoporous Silicas with Tunable Wall Thickness

2013 ◽  
Vol 643 ◽  
pp. 72-75
Author(s):  
Yan Xiao Li ◽  
Zhan Fang Ma
Keyword(s):  
Electron Microscopy ◽  
Mesoporous Silica Nanoparticles ◽  
Mesoporous Silicas ◽  
Ammonium Bromide ◽  
Hard Template ◽  
Cetyltrimethyl Ammonium Bromide ◽  
Transmission Electron ◽  
Acid Aqueous Solution ◽  
Cetyltrimethyl Ammonium ◽  
Hollow Mesoporous Silica

Spindle-like hollow mesoporous silica nanoparticles (spindle-like HMSNs) were fabricated via the template-sacrificial technique using hematite (Fe2O3) spindles as hard template, tetraethylorthosilicate (TEOS) as precursor and cetyltrimethyl ammonium bromide (CTAB) as the pore directing agent. The Fe2O3core and CTAB were selectively removed by hydrochoric acid aqueous solution etching. Transmission electron microscopy results revealed that spindle-like HMSNs with thickness of shell range from 8 to 47 nm were prepared by changing the concentration of the reactant. This methodology provides a facile and robust route for preparation of hollow mesoporous materials.

Sign in / Sign up

Export Citation Format

Share Document