Preparation and characterization of Ni(OH)2 nanoparticles coated with dialkyldithiophosphate

2000 ◽  
Vol 15 (2) ◽  
pp. 541-545 ◽  
Author(s):  
Junyan Zhang ◽  
Shengrong Yang ◽  
Qunji Xue
Keyword(s):  
Thermal Stability ◽  
Surface Modification ◽  
Photoelectron Spectroscopy ◽  
Chemical Interaction ◽  
Average Diameter ◽  
Resonance Spectroscopy ◽  
X Ray ◽  
Chemical Surface ◽  
Transmission Electron ◽  
Thermal Stability Of

Ni(OH)2 nanoparticles modified with di-n-hexadecyldithiophosphate (DDP) were prepared by a chemical surface modification method. The structure of the nanocluster was investigated using infrared spectroscopy, x-ray photoelectron spectroscopy, x-ray diffraction, transmission electron microscopy, and 31P nuclear magnetic resonance spectroscopy. The thermal stability of DDP coating on the Ni(OH)2 nanoparticles was compared to that of pyridinium di-n-hexadecyldithiophosphate (PyDDP) using thermogravimetric analysis. It was found that coated Ni(OH)2 nanoparticles had an average diameter of about 5 nm. Surface modification with DDP prevented water adsorption and effectively improved the dispersive capacity and antioxidative stability of Ni(OH)2 nanoparticles. The thermal stability of DDP coatings on the surface of nano-Ni(OH)2 particles was higher than that of PyDDP coatings because of the chemical interaction between PyDDP and Ni(OH)2 during the coating process.

Study on the structure of PbS nanoparticles coated with dialkyldithiophosphate

1999 ◽  
Vol 14 (5) ◽  
pp. 2147-2151 ◽  
Author(s):  
Shuang Chen ◽  
Weimin Liu ◽  
Laigui Yu
Keyword(s):  
Thermal Stability ◽  
Surface Modification ◽  
Photoelectron Spectroscopy ◽  
Chemical Interaction ◽  
Average Diameter ◽  
Resonance Spectroscopy ◽  
Pbs Nanoparticles ◽  
X Ray ◽  
Chemical Surface ◽  
Thermal Stability Of

PbS nanoparticles modified with di-n-hexadecyldithiophosphate (DDP) were prepared by the chemical surface modification method. The structure of the PbS nanoparticles coated with DDP was investigated by means of infrared spectroscopy (ir), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), transmission electron microscopy (TEM), and 31P nuclear magnetic resonance spectroscopy (31P NMR). The thermal stability of DDP coating on the PbS nanoparticles was compared with that of pyridinium di-n-hexadecyldithiophosphate (PyDDP) using a thermogravimetric analyzer (TGA). It was found that coated PbS nanoparticles had an average diameter of about 5 nm. Surface modification with DDP prevented water adsorption and effectively improved the dispersive capacity and antioxidative stability of PbS nanoparticles. The thermal stability of DDP coating on the surface of nano-PbS particles was higher than that of modifier PyDDP because of the chemical interaction between PyDDP and PbS during the coating process.

Synthesis and Thermal Stability of Nontransformable Tetragonal (ZrO2)0.96(REO1.5)0.04 (Re=Sc3+, Y3+) Nanocrystals

2013 ◽  
Vol 334-335 ◽  
pp. 60-64 ◽  
Author(s):  
Mohammad Reza Loghman-Estark ◽  
Reza Shoja Razavi ◽  
Hossein Edris
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Sol Gel ◽  
Average Diameter ◽  
X Ray ◽  
Transmission Electron ◽  
20 Nm ◽  
Thermal Stability Of ◽  
Scanning Electron

Scandia, yttria doped zirconia ((ZrO2)0.96(REO1.5)0.04(RE=Sc3+, Y3+)) nanoparticles were prepared by the modified sol-gel method. The microstructure of the products was characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Thermal stabillity of SYSZ nanocrystals were also investigated. The SYSZ nanocrystals synthesized with EGM:Zr+4mole ratio 4:1, calcined at 700°C, have average diameter of ~20 nm.

scholarly journals Improvement of the thermal stability of dendritic silver-coated copper microparticles by surface modification based on molecular self-assembly

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Tae Hyeong Kim ◽  
Hyeji Kim ◽  
Hyo Jun Jang ◽  
Nara Lee ◽  
Kwang Hyun Nam ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Electrically Conductive ◽  
X Ray ◽  
Alkyl Chains ◽  
Conductive Film ◽  
Initial Resistance ◽  
Thermal Stability Of ◽  
Scanning Electron

AbstractIn the study reported herein, silver-coated copper (Ag/Cu) powder was modified with alkanethiols featuring alkyl chains of different lengths, namely butyl, octyl, and dodecyl, to improve its thermal stability. The modification of the Ag/Cu powders with adsorbed alkanethiols was confirmed by scanning electron microscopy with energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Each powder was combined with an epoxy resin to prepare an electrically conductive film. The results confirmed that the thermal stability of the films containing alkanethiol-modified Ag/Cu powders is superior to that of the film containing untreated Ag/Cu powder. The longer the alkyl group in the alkanethiol-modified Ag/Cu powder, the higher the initial resistance of the corresponding electrically conductive film and the lower the increase in resistance induced by heat treatment.

Formation and Thermal Stability of Nd0.32Y0.68Si1.7 Layers Formed by Channeled Ion Beam Synthesis

1998 ◽  
Vol 514 ◽  
Author(s):  
M. F. Wu ◽  
A. Vantomne ◽  
S. Hogg ◽  
H. Pattyn ◽  
G. Langouche ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ion Beam ◽  
Hexagonal Structure ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Good Crystalline Quality ◽  
Ion Beam Synthesis ◽  
Thermal Stability Of

ABSTRACTThe Nd-disilicide, which exists only in a tetragonal or an orthorhombic structure, cannot be grown epitaxially on a Si(111) substrate. However, by adding Y and using channeled ion beam synthesis, hexagonal Nd0.32Y0.68Si1.7 epilayers with lattice constant of aepi = 0.3915 nm and cepi = 0.4152 nm and with good crystalline quality (χmin of Nd and Y is 3.5% and 4.3 % respectively) are formed in a Si(111) substrate. This shows that the addition of Y to the Nd-Si system forces the latter into a hexagonal structure. The epilayer is stable up to 950 °C; annealing at 1000 °C results in partial transformation into other phases. The formation, the structure and the thermal stability of this ternary silicide have been studied using Rutherford backscattering/channeling, x-ray diffraction and transmission electron microscopy.

Immobilization of hemoglobin on stable mesoporous multilamellar silica vesicles and their activity and stability

2005 ◽  
Vol 20 (10) ◽  
pp. 2682-2690 ◽  
Author(s):  
Yufang Zhu ◽  
Weihua Shen ◽  
Xiaoping Dong ◽  
Jianlin Shi
Keyword(s):  
Thermal Stability ◽  
Pore Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Practical Applications ◽  
Silica Material ◽  
Transmission Electron ◽  
Mesoporous Support ◽  
Adsorption Desorption ◽  
Thermal Stability Of

A stable mesoporous multilamellar silica vesicle (MSV) was developed with a gallery pore size of about 14.0 nm. A simulative enzyme, hemoglobin (Hb), was immobilized on this newly developed MSV and a conventional mesoporous silica material SBA-15. The structures and the immobilization of Hb on the mesoporous supports were characterized with x-ray diffraction, transmission electron microscopy, N2 adsorption-desorption isotherms, Fourier transform infrared, ultraviolet-visible spectroscopy, and so forth. MSV is a promising support for immobilizing Hb due to its large pore size and high Hb immobilization capacity (up to 522 mg/g) compared to SBA-15 (236 mg/g). Less than 5% Hb was leached from Hb/MSV at pH 6.0. The activity study indicated that the immobilized Hb retained most peroxidase activity compared to free Hb. Thermal stability of the immobilized Hb was improved by the proctetive environment of MSV and SBA-15. Such an Hb-mesoporous support with high Hb immobilization capacity, high activity, and enhanced thermal stability will be attractive for practical applications.

scholarly journals Thermal Stability of Octadecyltrichlorosilane and Perfluorooctyltriethoxysilane Monolayers on SiO2

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 210
Author(s):  
Xiangdong Yang ◽  
Haitao Wang ◽  
Peng Wang ◽  
Xuxin Yang ◽  
Hongying Mao
Keyword(s):  
Thermal Stability ◽  
Thermal Behavior ◽  
Work Function ◽  
Photoelectron Spectroscopy ◽  
Vacuum Annealing ◽  
Moderate Temperature ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
X Ray ◽  
Thermal Stability Of

Using in situ ultraviolet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS) measurements, the thermal behavior of octadecyltrichlorosilane (OTS) and 1H, 1H, 2H, and 2H-perfluorooctyltriethoxysilane (PTES) monolayers on SiO2 substrates has been investigated. OTS is thermally stable up to 573 K with vacuum annealing, whereas PTES starts decomposing at a moderate temperature between 373 K and 423 K. Vacuum annealing results in the decomposition of CF3 and CF2 species rather than desorption of the entire PTES molecule. In addition, our UPS results reveal that the work function (WF)of OTS remains the same after annealing; however WF of PTES decreases from ~5.62 eV to ~5.16 eV after annealing at 573 K.

Thermal stability of magnetic tunnel junctions studied by x-ray photoelectron spectroscopy

2001 ◽  
Vol 78 (2) ◽  
pp. 234-236 ◽  
Author(s):  
David J. Keavney ◽  
Sungkyun Park ◽  
Charles M. Falco ◽  
J. M. Slaughter
Keyword(s):  
Thermal Stability ◽  
Photoelectron Spectroscopy ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
X Ray ◽  
Thermal Stability Of

Thermal stability of carbon nitride thin films

2001 ◽  
Vol 16 (11) ◽  
pp. 3188-3201 ◽  
Author(s):  
Niklas Hellgren ◽  
Nian Lin ◽  
Esteban Broitman ◽  
Virginie Serin ◽  
Stefano E. Grillo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Amorphous Structure ◽  
X Ray ◽  
Bonding Structure ◽  
Higher Temperature ◽  
Electron Energy Loss ◽  
Thermal Stability Of

The thermal stability of carbon nitride films, deposited by reactive direct current magnetron sputtering in N2 discharge, was studied for postdeposition annealing temperatures TA up to 1000 °C. Films were grown at temperatures of 100 °C (amorphous structure) and 350 and 550 °C (fullerenelike structure) and were analyzed with respect to thickness, composition, microstructure, bonding structure, and mechanical properties as a function of TA and annealing time. All properties investigated were found to be stable for annealing up to 300 °C for long times (>48 h). For higher TA, nitrogen is lost from the films and graphitization takes place. At TA = 500 °C the graphitization process takes up to 48 h while at TA = 900 °C it takes less than 2 min. A comparison on the evolution of x-ray photoelectron spectroscopy, electron energy loss spectroscopy and Raman spectra during annealing shows that for TA > 800 °C, preferentially pyridinelike N and –C≡N is lost from the films, mainly in the form of molecular N2 and C2N2, while N substituted in graphite is preserved the longest in the structure. Films deposited at the higher temperature exhibit better thermal stability, but annealing at temperatures a few hundred degrees Celsius above the deposition temperature for long times is always detrimental for the mechanical properties of the films.

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