scholarly journals Removal Mechanism Investigation of Ultraviolet Induced Nanoparticle Colloid Jet Machining

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 68
Author(s):  
Xiaozong Song ◽  
Gui Gao
Keyword(s):  
Tio2 Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Material Removal ◽  
Density Functional ◽  
Hydroxyl Groups ◽  
Removal Mechanism ◽  
The Density Functional Theory ◽  
Point Injection ◽  
Ultra Precision ◽  
Nanoparticle Colloid

Ultraviolet induced nanoparticle colloid jet machining is a new ultra-precision machining technology utilizing the reaction between nanoparticles and the surface of the workpiece to achieve sub-nanometer ultra-smooth surface manufacturing without damage. First-principles calculations based on the density functional theory (DFT) were carried out to study the atomic material removal mechanism of nanoparticle colloid jet machining and a series of impacting and polishing experiments were conducted to verify the mechanism. New chemical bonds of Ti-O-Si were generated through the chemical adsorption between the surface adsorbed hydroxyl groups of the TiO2 cluster and the Si surface with the adsorption energy of at least −4.360 eV. The two Si-Si back bonds were broken preferentially and the Si atom was removed in the separation process of TiO2 cluster from the Si surface realizing the atomic material removal. A layer of adsorbed TiO2 nanoparticles was detected on the Si surface after 3 min of fixed-point injection of an ultraviolet induced nanoparticle colloid jet. X-ray photoelectron spectroscopy results indicated that Ti-O-Si bonds were formed between TiO2 nanoparticles and Si surface corresponding to the calculation result. An ultra-smooth Si workpiece with a roughness of Rq 0.791 nm was obtained by ultraviolet induced nanoparticle colloid jet machining.

A Review of Material Removal Mechanism in Ultra-Precision Polishing of Optical Glass

2021 ◽  
Vol 48 (4) ◽  
pp. 0401014
Author(s):  
蒋小为 Jiang Xiaowei ◽  
龙兴武 Long Xingwu ◽  
谭中奇 Tan Zhongqi
Keyword(s):  
Material Removal ◽  
Optical Glass ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Ultra Precision

The Mechanism Research of Collector and Hemimorphite

2014 ◽  
Vol 1073-1076 ◽  
pp. 2163-2167
Author(s):  
Kang Kang Li ◽  
Xiao Lin Zhang ◽  
Shi Ming Cao ◽  
Dian Wen Liu
Keyword(s):  
Zinc Oxide ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Adsorption Mechanism ◽  
Efficient Utilization ◽  
Functional Theory ◽  
X Ray ◽  
The Density Functional Theory ◽  
Mechanism Research ◽  
Drying Up

As the zinc minerals of easy separation drying up, efficient utilization of refractory zinc oxide ores is getting more and more attention, especially for siliceous zinc oxide ore is quite difficult to separate, and it is a challenge for worldwide mineral processing industry. This article mainly used the density functional theory and X-ray photoelectron spectroscopy to study the adsorption mechanism of amine collectors on hemimorphite, when the composite activator was working.

XPS and Electrochemical Studies on Tungsten-Oxidizer Interaction in Chemical Mechanical Polishing

1999 ◽  
Vol 566 ◽  
Author(s):  
Dnyanesh Tamboli ◽  
Sudipta Seal ◽  
Vimal Desai
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Electrochemical Measurements ◽  
Electrochemical Studies ◽  
Removal Mechanism ◽  
Tungsten Oxides ◽  
X Ray ◽  
Static Solutions

Electrochemical interaction between the oxidizer and the metal is believed to play a key role in material removal in tungsten CMP. In this study, we use X-ray Photoelectron Spectroscopy (XPS) in conjunction with electrochemical measurements in both in-situ polishing conditions as well as in static solutions, to identify the passivation and dissolution modes of tungsten. Dissolution of tungsten oxides was found to be the primary non-mechanical tungsten removal mechanism in CMP.

scholarly journals SIMULATION OF POLYMORPHIC VARIETIES OF HEXAGONAL GRAPHENE FUNCTIONALIZED BY HYDROXYL GROUPS

2021 ◽  
pp. 541-551
Author(s):  
Максим Евгеньевич Беленков ◽  
Владимир Михайлович Чернов
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Density Functional Theory Method ◽  
Hydroxyl Groups ◽  
Functional Theory ◽  
Graphene Layers ◽  
Sublimation Energy ◽  
The Density Functional Theory ◽  
Direct Band ◽  
Oxygen Bond

Моделирование кристаллической и электронной структуры слоев гексагонального графена, на поверхность которых были химически адсорбированы гидроксильные группы, было выполнено методом теории функционала плотности. В результате расчетов была установлена возможность устойчивого существования пяти структурных разновидностей COH - L слоев. Слоевая плотность изменяется от 1,62 до 1,72 мг/м. Длина водород-кислородной связи варьируется в диапазоне от 1,046 до 1,079 Å, а углерод-кислородной связи - от 1,455 до 1,465 Å. Ориентация O - H связей относительно плоскости слоев может варьироваться в зависимости от выбора элементарной ячейки слоя. Минимальной энергией сублимации и равной 18,69 эВ/(COH) обладает слой COH-L - T4, а максимальную энергию сублимации 18,93 эВ/(COH) имеет слой COH - L - T1. Электронная структура всех COH слоев характеризуется наличием прямой запрещенной зоны на уровне энергии Ферми, изменяющейся в диапазоне от 3,02 до 4,56 эВ. Computer simulation of the crystal and electronic structure of hexagonal graphene layers, on the surface of which hydroxyl groups, chemically adsorbed, was performed by the density functional theory method. As a result of calculations, the possibility of the stable existence of five structural varieties of COH - L layers was established. The layer density varies from 1,62 to 1,72 mg/m. The length of the hydrogen-oxygen bond varies in the range from 1,046 to 1,079 Å, and the carbon-oxygen bond-from 1,455 to 1,465 Å. The orientation of the -OH bonds relative to the surface of the layers can vary depending on the choice of the unit cell of the layer. Layer COH - L - T4 has the minimum sublimation energy equal to 18,69 eV/(COH), and layer COH - L - T1 has the maximum sublimation energy 18,93 eV/(COH). The electronic structure of all COH layers is characterized by the presence of a direct band gap at the Fermi energy level, varying in the range from 3,02 to 4,56 eV.

A Review of Material Removal Mechanism in Ultra-Precision Polishing of Optical Glass

2021 ◽  
Vol 48 (4) ◽  
pp. 0402014
Author(s):  
蒋小为 Jiang Xiaowei ◽  
龙兴武 Long Xingwu ◽  
谭中奇 Tan Zhongqi
Keyword(s):  
Material Removal ◽  
Optical Glass ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Ultra Precision

DFT study of the physicochemical properties of A- and B-type procyanidin oligomers

2016 ◽  
Vol 15 (08) ◽  
pp. 1650069 ◽  
Author(s):  
Ana María Mendoza-Wilson ◽  
Francisco Javier Carmelo-Luna ◽  
Humberto Astiazarán-García ◽  
Bertha I. Pacheco-Moreno ◽  
Iván Anduro-Corona ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Density Functional ◽  
Molecular Size ◽  
Potential Effect ◽  
Degree Of Polymerization ◽  
Hydroxyl Groups ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Hydrophilic Character ◽  
Pass Through

The objective of this study was to determine the physicochemical properties of the oligomers of procyanidins (PCs) including PA1, PA2, PB1, PB2, PC1 and a B-type tetramer, taking into account of their conformations related to the interflavan links using the density functional theory (DFT). This information may provide useful insight into the potential effect of physicochemical properties on the absorption of PCs. The results indicate that A-type and B-type PCs in all of their conformations tend to be more stable in water than in octanol, showing a hydrophilic character due to their negative log [Formula: see text] values, which increase with the degree of polymerization (DP). The studied PCs, including the B-type tetramer, can achieve an appropriate molecular size (i.e. width and length) that can allow them to pass through the pores in the paracellular route in the human small intestine. The factor that could limit the absorption of the PC oligomers with increases in size is the higher number of hydroxyl groups exposed to the outside of the molecule due to their potential to interact with other molecules, which is based on electrostatic potential maps.

Experimental Study on the Ultra-Precision Polishing for the Quartz Substrates

2013 ◽  
Vol 797 ◽  
pp. 135-139 ◽  
Author(s):  
Lei Sun ◽  
Wei Gang Guo ◽  
Ju Long Yuan ◽  
Qian Fa Deng ◽  
Ming Feng ◽  
...  
Keyword(s):  
Experimental Study ◽  
Material Removal ◽  
Smooth Surface ◽  
Quartz Substrate ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Polishing Process ◽  
Ultra Precision ◽  
Quartz Substrates

The Quartz substrates are widely used in various fields, and the requirement for the surface quality of quartz substrate is higher than ever before. This paper focuses on the ultra-precision polishing technology for the quartz substrates, and the material removal mechanism in the process of ultra-precision polishing is discussed. The results showed that an extremely smooth surface of quartz substrate was obtained in the ultra-precision polishing process, and the best surface roughness reached Ra 0.82nm. Meanwhile, the thickness can be controlled very well.

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