scholarly journals Nanocomposites of Magnetite and Layered Double Hydroxide for Recyclable Chromate Removal

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Gyeong-Hyeon Gwak ◽  
Min-Kyu Kim ◽  
Jae-Min Oh
Keyword(s):  
Layered Double Hydroxide ◽  
Magnetite Nanoparticles ◽  
X Ray Diffraction ◽  
Potential Measurement ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
House Of Cards ◽  
Double Hydroxide ◽  
Scanning Electron

Nanocomposites containing magnetic iron oxide (magnetite) nanoparticles and layered double hydroxide (LDH) nanosheets were prepared by two different methods, exfoliation-reassembly and coprecipitation, for aqueous chromate adsorbent. According to X-ray diffraction, scanning electron microscopy, and atomic force microscopy, both nanocomposites were determined to develop different nanostructures; LDH nanosheets well covered magnetite nanoparticles with house-of-cards-like structure in exfoliation-reassembly method, while coprecipitation resulted in LDH particle formation along with magnetite nanoparticles. Zeta-potential measurement also revealed that the magnetite surface was effectively covered by LDH moiety in exfoliation-reassembly compared with coprecipitation. Time, pH, concentration dependent chromate adsorption tests, and magnetic separation experiments exhibited that both nanocomposites effectively adsorb and easily collect chromate. However, exfoliation-reassembly nanocomposite was determined to be slightly effective in chromate removal by ~10%. Chromate adsorbed nanocomposites could be regenerated by treating with bicarbonate and the regenerated nanocomposites preserved ~80% of chromate adsorption efficacy after three times of recycling.

Lateral Size of Self-Patterned Nanostructures Controlled by Multi-Step Deposition

2005 ◽  
Vol 106 ◽  
pp. 117-122 ◽  
Author(s):  
Izabela Szafraniak ◽  
Dietrich Hesse ◽  
Marin Alexe
Keyword(s):  
Electron Microscopy ◽  
Ultrathin Films ◽  
Lateral Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Non Volatile Memory ◽  
Ferroelectric Capacitors ◽  
Scanning Electron

Self-patterning presents an appealing alternative to lithography for the production of arrays of nanoscale ferroelectric capacitors for use in high density non-volatile memory devices. Recently a self-patterning method, based on the use of the instability of ultrathin films during hightemperature treatments, was used to fabricate nanosized ferroelectrics. This paper reports the use of the method for the preparation of PZT nanoislands on different single crystalline substrates - SrTiO3, MgO and LaAlO3. Moreover, a multi-step deposition procedure in order to control lateral the dimension of the crystals was introduced. The nanostructures obtained were studied by atomic force microscopy, scanning electron microscopy and X-ray diffraction.

Wettability and Nanotribological Response of Silicon Surfaces Functionalized by Ion Implantation

2012 ◽  
Vol 730-732 ◽  
pp. 257-262
Author(s):  
Bruno Nunes ◽  
Sergio Magalhães ◽  
Nuno Franco ◽  
Eduardo Alves ◽  
Ana Paula Serro ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ion Implantation ◽  
Silicon Surfaces ◽  
Iron Ions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Scanning Electron

Aiming to improve the nanotribological response of Si-based materials we implanted silicon wafers with different fluences of iron ions (up to 2x1017 cm-2). Implantation was followed by annealing treatments at temperatures from 550°C to 1000°C. The implanted surfaces were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM) and wettability tests. Then, samples were submitted to AFM-based nanowear tests. We observe an increase of both hidrophobicity and and wear resistance of the implanted silicon, indicating that ion implantation of Si can be a route to be deeper explored in what concerns tribomechanical improvement of Si.

Preparation of ZnAl2O4 Spinel Directly from Zinc Aluminum Layered Double Hydroxide Precursor

2012 ◽  
Vol 567 ◽  
pp. 127-130
Author(s):  
Jian Ye Song ◽  
Ming Zhe Leng ◽  
Xing Qi Fu ◽  
Jian Qiang Liu
Keyword(s):  
Layered Double Hydroxide ◽  
Single Phase ◽  
Structural Characteristics ◽  
Atomic Level ◽  
X Ray Diffraction ◽  
Simple Route ◽  
X Ray ◽  
Znal2o4 Spinel ◽  
Double Hydroxide ◽  
Scanning Electron

Single-phase ZnAl2O4 spinel has been prepared by a novel simple route using layered double hydroxide as a precursor. ZnAl2O4 spinel is directly obtained by calcination of zinc aluminum layered double hydroxide (Zn/Al molar radio is 0.5) without further chemical treatment. The key feature of this method is that it affords uniform distribution of all metal cations on an atomic level in the precursor. The structural characteristics of the as-synthesized precursor and the resulted calcined products are obtained by X-ray diffraction and scanning electron microscope.

Grain Size Effect on Lattice of Ni Nanocrystals Prepared Through Polyol Method

2008 ◽  
Vol 8 (8) ◽  
pp. 4127-4131 ◽  
Author(s):  
G. S. Okram ◽  
Kh. Namrata Devi ◽  
H. Sanatombi ◽  
Ajay Soni ◽  
V. Ganesan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
Polyol Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Scanning Electron

Nanocrystalline nickel powders were prepared with grain size 'd' in the range 40–100 nm diameters through polyol method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used for characterization. XRD of the prepared samples consistently matched with standard fcc structure of nickel without any impurity peak. Detailed analysis and calculations using Scherrer equation for (111) peak revealed systematic increase in line width and peak shifting towards lower diffraction 2θ angles with decrease in nickel to ethylene glycol mole ratio. Different values of d estimated from various peaks of each sample suggested associated microstrains in the nanograins. Values of d estimated from X-ray diffraction patterns were compared with those obtained from atomic force microscopy and scanning electron microscopy results, and discussed. Observed lattice expansion is explained, on the basis of a theoretical model of linear elasticity.

scholarly journals The Influence of the Preparation and Stability of Nanofluids for Heat Transfer

2019 ◽  
Vol 25 (4) ◽  
pp. 45-54 ◽  
Author(s):  
Noor Sabih Majeed ◽  
Basma A. Abdulmajeed ◽  
Anwar Khudhur Yaseen
Keyword(s):  
Heat Transfer ◽  
Electron Microscopy ◽  
Base Fluid ◽  
X Ray Diffraction ◽  
Step Method ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Stability ◽  
Scanning Electron

Recently the use of nanofluids represents very important materials. They are used in different branches like medicine, engineering, power, heat transfer, etc. The stability of nanofluids is an important factor to improve the performance of nanofluids with good results. In this research two types of nanoparticles, TiO2 (titanium oxide) and γ-Al2O3 (gamma aluminum oxide) were used with base fluid water. Two-step method were used to prepare the nanofluids. One concentration 0.003 vol. %, the nanoparticles were examined. Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and X-ray diffraction (XRD) were used to accomplish these tests. The stability of the two types of nanofluids is measured by zeta potential and UV-vis spectrophotometer. The results showed that γ-Al2O3/water has more stable than TiO2/ water for the same period of time.  

Fabrication and Characterization of Polyaniline–ZnO Hybrid Nanocomposite Thin Films

2008 ◽  
Vol 8 (4) ◽  
pp. 1757-1761 ◽  
Author(s):  
Ajeet Kaushik ◽  
Jitendra Kumar ◽  
M. K. Tiwari ◽  
R. Khan ◽  
B. D. Malhotra ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Atomic Force Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nanocomposite Thin Films ◽  
Scanning Electron

Polyaniline (PANI)–ZnO nanocomposite thin film has been successfully fabricated on glass substrates by using vacuum deposition technique. The as-grown PANI–ZnO nanocomposite thin films have been characterized using X-ray diffraction, Scanning Electron Microscopy, Atomic Force Microscopy, UV-visible spectrophotometer and Fourier Transform Infrared (FTIR) spectroscopy, respectively. X-ray diffraction of as-grown film shows the reflection of ZnO nanoparticles along with a broad peak of PANI. The surface morphology of nanocomposite films has been investigated using scanning electron microscopy and atomic force microscopy. The hypsochromic shift of the UV absorption band corresponding to π–π* transition in polymeric chain of PANI and a band at 504 cm –1 due to ZnO nanoparticles has been observed in the FTIR spectra. The hydrogen bonding between the imine group of PANI and ZnO nanoparticle has been confirmed from the presence of the absorbance band at 1151 cm–1 in the FTIR spectra of the nanocomposite thin films.

Influence of pH on Phosphate Intercalation in Zinc-Aluminum Layered Double Hydroxide

1998 ◽  
Vol 63 (5) ◽  
pp. 741-748 ◽  
Author(s):  
Mohamed Badreddine ◽  
Ahmed Legrouri ◽  
Allal Barroug ◽  
André De Roy ◽  
Jean-Pierre Besse
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Layered Double Hydroxide ◽  
Chloride Ion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phosphate Ions ◽  
Double Hydroxide ◽  
Influence Of Ph ◽  
Scanning Electron

The exchange of chloride ion by phosphate ions in [Zn-Al-Cl] layered double hydroxide was investigated using X-ray diffraction and infrared spectroscopy. The effects of the pH of the solution containing the phosphate ions on the ion exchange was studied. The best sample in terms of crystallinity, was obtained at pH 8. This sample was further characterized by scanning electron microscopy and microanalysis.

Structural and Surface Studies of Undoped Porous GaN Grown on Sapphire

2012 ◽  
Vol 620 ◽  
pp. 45-49
Author(s):  
Mahmood Ainorkhilah ◽  
Hassan Zainuriah ◽  
Yusof Yushamdan ◽  
Fong Kwong Yam ◽  
Lee Siang Chuah ◽  
...  
Keyword(s):  
Electrochemical Etching ◽  
Optoelectronic Devices ◽  
Pore Morphology ◽  
X Ray Diffraction ◽  
Porous Sample ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Sem Micrograph ◽  
Scanning Electron

Owing to its great potential in optoelectronic devices, structural and surface properties of porous GaN prepared by UV electrochemical etching has been investigated. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and high resolution X-ray diffraction (HR-XRD) phi-scan and rocking curves measurements revealed the nature of the pore morphology and nanostructures. SEM micrograph indicated that the shapes of pores for porous sample are nearly hexagonal. The AFM measurements revealed that the surface roughness increased in the porous sample. X-ray diffraction phi-scan showed that porous GaN sample maintained the epitaxial feature.

scholarly journals Hydrothermal Synthesis of Ni/Al Layered Double Hydroxide Nanorods

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Yun Zhao ◽  
Fenfei Xiao ◽  
Qingze Jiao
Keyword(s):  
Electron Microscopy ◽  
Reaction Time ◽  
Layered Double Hydroxide ◽  
Hydrothermal Reaction ◽  
Ph Value ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Double Hydroxide ◽  
Scanning Electron

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.

Preparation of Photocatalytic Nanostructured TiO2 Thin Films

2008 ◽  
Vol 587-588 ◽  
pp. 795-799 ◽  
Author(s):  
A. Di Paola ◽  
M. Addamo ◽  
M. Bellardita ◽  
E. García-López ◽  
G. Marcì ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dip Coating ◽  
Coating Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Glass Slides ◽  
Scanning Electron

Photoactive films consisting of pure anatase, brookite or rutile were deposited on glass slides by a dip coating process from water dispersions or solutions obtained by using TiCl4 as the precursor. The films were characterized by X-ray diffraction, scanning electron microscopy and atomic force microscopy. The photocatalytic activity of the various samples was evaluated by using the photooxidation of 2-propanol in gas solid regime as probe reaction. Brookite and anatase films showed a good photoactivity degrading the substrate and the propanone produced during the reaction.

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