The effect of particle size on the dispersion and wear protection ability of MoS2 particles in polyalphaolefin and trimethylolpropane ester

2017 ◽  
Vol 232 (8) ◽  
pp. 987-998 ◽  
Author(s):  
M Gulzar ◽  
Khalid Mahmood ◽  
Rehan Zahid ◽  
Abdullah Alabdulkarem ◽  
HH Masjuki ◽  
...  
Keyword(s):  
Particle Size ◽  
Sliding Wear ◽  
Base Oil ◽  
Force Microscopy ◽  
Wear Protection ◽  
Atomic Force ◽  
Nominal Size ◽  
Load Carrying ◽  
Effect Of Particle Size ◽  
20 Nm

The effect of particle size and surfactant on dispersion stability and wear protection ability was experimentally evaluated for polyalphaolefin (PAO 10) and bio-based base oil (palm trimethylolpropane ester) added with molybdenum disulfide (MoS2) particles. Nanolubricants were developed by adding 1 wt% of MoS2 particles that varied in size. In addition to the variation in particle size, an anionic surfactant was also used to analyze its interaction with both types of nanoparticles for stable suspensions and for the related effects on the antiwear characteristics. The wear protection characteristics of the formulations were evaluated by four-ball extreme pressure tests and piston ring on cylinder sliding wear tests. The wear surfaces were analyzed by scanning electron microscopy along with an energy-dispersive X-ray and an atomic force microscopy. The MoS2 nanoparticles with a nominal size of 20 nm exhibited a better load-carrying capacity, while better sliding wear protection was provided by nanoparticles with a nominal size of 50 nm.

ATOMIC FORCE MICROSCOPY AND XRD ANALYSIS OF SILVER FILMS DEPOSITED BY THERMAL EVAPORATION

2006 ◽  
Vol 20 (02) ◽  
pp. 217-231 ◽  
Author(s):  
MUHAMMAD MAQBOOL ◽  
TAHIRZEB KHAN
Keyword(s):  
Atomic Force Microscopy ◽  
Grain Size ◽  
Surface Characterization ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Xrd Analysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Average Grain Size ◽  
20 Nm

Thin films of pure silver were deposited on glass substrate by thermal evaporation process at room temperature. Surface characterization of the films was performed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Thickness of the films varied between 20 nm and 72.8 nm. XRD analysis provided a sharp peak at 38.75° from silver. These results indicated that the films deposited on glass substrates at room temperature are crystalline. Three-dimension and top view pictures of the films were obtained by AFM to study the grain size and its dependency on various factors. Average grain size increased with the thickness of the deposited films. A minimum grain size of 8 nm was obtained for 20 nm thick films, reaching 41.9 nm when the film size reaches 60 nm. Grain size was calculated from the information provided by the XRD spectrum and averaging method. We could not find any sequential variation in the grain size with the growth rate.

Spectroscopic Characterization of Flame-Generated 2-D Carbon Nano-Disks

2015 ◽  
Vol 1726 ◽  
Author(s):  
Patrizia Minutolo ◽  
Mario Commodo ◽  
Gianluigi De Falco ◽  
Rosanna Larciprete ◽  
Andrea D'Anna
Keyword(s):  
Carbon Nanostructures ◽  
Functional Materials ◽  
Building Blocks ◽  
Spectroscopic Characterization ◽  
Molecular Compound ◽  
Force Microscopy ◽  
Atomic Force ◽  
Thin Carbon ◽  
On Line ◽  
20 Nm

ABSTRACTIn this work we produce atomically thin carbon nanostructures which have a disk-like shape when deposited on a substrate. These nanostructures have intermediate characteristics between a graphene island and a molecular compound and have the potentiality to be used either as they are, or to become building blocks for functional materials or to be manipulated and engineered into composite layered structures.The carbon nanostructures are produced in a premixed ethylene/air flame with a slight excess of fuel with respect to the stoichiometric value. The size distribution of the produced compounds in aerosol phase has been measured on line by means of a differential mobility analyzer (DMA) and topographic images of the structures deposited on mica disks were obtained by Atomic Force Microscopy. Raman spectroscopy and XPS have been used to characterize their structure and the electronic and optical properties were obtained combining on-line photoionization measurements with Cyclic Voltammetry, light absorption and photoluminescence.When deposited on the mica substrate the carbon compounds assume the shape of an atomically thin disk with in plane diameter of about 20 nm. Carbon nano-disks consist of a network of small aromatic island with in plane length, La, of about 1 nm. Raman spectra evidence a significant amount of disorder which is in a large part due to the quantum confinement in the aromatic islands. Nano-disks contain small percentage of sp3 and the O/C ratio is lower than 6%. They furthermore present interesting UV and visible photoluminescence properties.

Characterization and Optimization of The Tco/a-Si:H(,B) Interface for Solar Cells by In-Situ Ellipsometry and Sims/XPS Depth Profiling

1994 ◽  
Vol 336 ◽  
Author(s):  
H.N. Wanka ◽  
E. Lotter ◽  
M.B. Schubert
Keyword(s):  
Solar Cells ◽  
Light Trapping ◽  
Hydrogen Plasma ◽  
Depth Profiling ◽  
Trapping Efficiency ◽  
Force Microscopy ◽  
Hydrogen Plasmas ◽  
Atomic Force ◽  
20 Nm

ABSTRACTThe chemical reactions at the surface of transparent conductive oxides (SnO2, ITO and ZnO) have been studied in silane and hydrogen plasmas by in-situ ellipsometry and by SIMS as well as XPS depth profiling. SIMS and XPS of the interface reveal an increasing amount of metallic phases upon lowering a-Si:H growth rates (controlled by plasma power), indicating that the ion and radical impact is more than compensated by protecting the surface by a rapidly growing a-Si:H film. Hence, optical transmission of TCO films as well as the efficiency of solar cells can be improved if the first few nanometers of the p-layer are grown at higher rates. Comparing a-Si:H deposition on top of different TCOs, reduction effects on ITO and SnO2 have been detected whereas ZnO appeared to be chemically stable. Therefore an additional shielding of the SnO2 surface by a thin ZnO layer has been investigated in greater detail. Small amounts of H are detected close to the ZnO surface by SIMS after hydrogen plasma treatment, but no significant changes occur to the optical and electrical properties. In-situ ellipsometry indicates that a ZnO layer as thin as 20 nm completely protects SnO2 from being reduced to metallic phases. This provides for shielding of textured TCOs, and hence rising solar cell efficiencies, too. Regarding light trapping efficiency we additionally investigated the smoothing of initial TCO texture when growing a-Si:H on top by combining atomic force microscopy and spectroscopie ellipsometry.

SURFACE PLASMON ENHANCED OPTICAL SECOND HARMONIC GENERATION IN ULTRA-THIN METALLIC FILMS

1999 ◽  
Vol 08 (04) ◽  
pp. 503-518 ◽  
Author(s):  
JUH-TZENG LUE ◽  
CHIA-SHY CHANG
Keyword(s):  
Second Harmonic ◽  
Angular Position ◽  
Field Enhancement ◽  
Surface Scattering ◽  
Metallic Films ◽  
Silver Films ◽  
Force Microscopy ◽  
Atomic Force ◽  
Peak Intensity ◽  
20 Nm

Internal reflection of second-harmonic generations from silver films with thickness ranging from 5 nm to 50 nm are enhanced by the excitation of surface plasmons under Kretschmann configuration. Enhancement of the SHG was observed at a film thickness of 20 nm resulting from the field enhancement of granular structure. For thinner films, the surface reveals disconnected islands as inspected by the atomic force microscopy. The incident angular position to find the peak intensity and the change of linewidth of the SHG can almost satisfactorily be predicted by the theory based on surface scattering.

scholarly journals Effects of Size and Dispersity of Microcrystalline Celluloses on Size, Structure and Stability of Nanocrystalline Celluloses Extracted by Acid Hydrolysis

Nano LIFE ◽  
2014 ◽  
Vol 04 (04) ◽  
pp. 1441014 ◽  
Author(s):  
Qi Liu ◽  
Weiping Hao ◽  
Yongguang Yang ◽  
Aurore Richel ◽  
Canbin Ouyang ◽  
...  
Keyword(s):  
Particle Size ◽  
Acid Hydrolysis ◽  
Size Structure ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Sonication Treatment

Nanocrystalline celluloses (NCCs) were separated from four commercial microcrystalline celluloses (MCCs) by an acid hydrolysis–sonication treatment. Transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectrum, X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were conducted to investigate the NCCs. MCCs with different morphologies and particle sizes showed different aggregation degrees. The aggregation of MCCs followed the order MCC1 > MCC3 > MCC2 > MCC4, which is the same order of the heights of the resulting NCCs. The best uniformity and thermal stability were characterized for NCC3, which was produced by MCC3 with smallest original particle size and good dispersity among the four MCCs. This result suggests that both the original particle size and dispersity of MCCs had significant effects on separated NCCs.

Mechanical Stress, Grain-boundary Relaxation, and Oxidation of Sputtered CuNi(Mn) Films

1999 ◽  
Vol 14 (4) ◽  
pp. 1286-1294 ◽  
Author(s):  
W. Brückner ◽  
W. Pitschke ◽  
S. Baunack ◽  
J. Thomas
Keyword(s):  
Grain Boundary ◽  
Microstructural Characterization ◽  
Excess Vacancy ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Boundary Relaxation ◽  
20 Nm ◽  
Atomic Rearrangement

This paper focuses on understanding stress development in CuNi42Mn1 thin films during annealing in Ar. In addition to stress-temperature measurements, resistance-temperature investigations and chemical and microstructural characterization by Auger electron spectroscopy, scanning and transmission electron microscopy, x-ray diffraction, and atomic force microscopy were also carried out. The films are polycrystalline with a grain size of 20 nm up to 450 °C. To explain the stress evolution above 120 °C, atomic rearrangement (excess-vacancy annihilation, grain-boundary relaxation, and shrinkage of grain-boundary voids) and oxidation were considered. Grain-boundary relaxation was found to be the dominating process up to 250–300 °C. A sharp transition from compressive to tensile stress between 300 and 380 °C is explained by the formation of a NiO surface layer due to reaction with the remaining oxygen in the Ar atmosphere. This oxidation is masking the inherent structural relaxation above 300 °C.

Interrogation of Alumina Grain Boundaries using Atomic Force Microscopy

1999 ◽  
Vol 580 ◽  
Author(s):  
P.A. Tibble ◽  
B.R. Heywood ◽  
R. Richardson ◽  
P. Barnes
Keyword(s):  
Particle Size ◽  
Atomic Force Microscopy ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Preferential Growth ◽  
Polycrystalline Alumina ◽  
Present Evidence ◽  
Force Microscopy ◽  
Atomic Force ◽  
Uniform Growth

AbstractA number of MgO doped (3wt%) polycrystalline alumina samples were prepared. The preparation of these samples varied; different regimes for annealing (1500 – 1600°C) and a range of dwell times were examined. Atomic force microscopy (AFM) was used to study surface features. Information on grain boundary dimensions (depth, width) is presented along with a study of grain particle size. The growth of the grain boundaries was found to contradict Mullins' theory of uniform growth with time. We also present evidence for Ostwalds' ripening and the preferential growth of [001] oriented grains.

Antiwear Behavior of CuO Nanoparticles as Additive in Bio-Based Lubricant

2017 ◽  
Vol 748 ◽  
pp. 166-170 ◽  
Author(s):  
Mubashir Gulzar ◽  
H.H. Masjuki ◽  
M.A. Kalam ◽  
M. Varman ◽  
N.W.M. Zulkifli
Keyword(s):  
Cylinder Liner ◽  
Cuo Nanoparticles ◽  
Ultrasonic Probe ◽  
Base Oil ◽  
Wear Protection ◽  
Nominal Size ◽  
Nanoparticle Suspensions ◽  
Surface Modified ◽  
Worn Surface ◽  
Wear Tests

This work presents and discusses the anitwear characteristics of surface modified CuO nanoparticle suspensions in bio-based lubricant. 1.0 wt% unmodified as well as surface modified CuO nanoparticles (nominal size of 50 nm), were dispersed in base oil using an ultrasonic probe. Wear protection was evaluated by using Four-Ball Extreme Pressure (EP) testing and sliding wear tests. The scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) analysis of the worn surface shows that: surface modification helped to improve the dispersion stability of CuO nanoparticles and related suspension show high EP characteristics in terms of load wear index and low cylinder liner wear due to surface mending effect of nanoparticles.

Microdispersion of Carbon Blacks in Rubber, Part I: Some Quantitative Aspects by AFM Image Analysis

2006 ◽  
Vol 79 (5) ◽  
pp. 783-789 ◽  
Author(s):  
C. C. Wang ◽  
S. H. Wu ◽  
J. B. Donnet ◽  
T. K. Wang
Keyword(s):  
Particle Size ◽  
Atomic Force Microscopy ◽  
Image Analysis ◽  
Force Microscopy ◽  
Carbon Blacks ◽  
Surface Fraction ◽  
Atomic Force ◽  
Distance Distributions ◽  
Rubber Part ◽  
Afm Image

Abstract The microdispersion state of carbon blacks in an emulsion SBR matrix has been observed by atomic force microscopy (AFM) and the images analyzed quantitatively. The fillers were well dispersed in the rubber samples. Different parameters, such as the surface fraction of fillers in images, particle size distance distributions, have been extracted and the main results are presented.

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