Surface modified precipitated calcium carbonates at a high degree of dispersion

1993 ◽  
Vol 271 (11) ◽  
pp. 1091-1099 ◽  
Author(s):  
L. Domka
Keyword(s):  
Calcium Carbonates ◽  
Degree Of Dispersion ◽  
Surface Modified ◽  
High Degree

scholarly journals Preparation and Application of Conductive Textile Coatings Filled with Honeycomb Structured Carbon Nanotubes

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Filip Govaert ◽  
Myriam Vanneste
Keyword(s):  
Carbon Nanotubes ◽  
Screen Printing ◽  
Honeycomb Structure ◽  
Sheet Resistivity ◽  
Knitted Fabrics ◽  
Electrically Conductive ◽  
Degree Of Dispersion ◽  
Conductive Textile ◽  
High Degree ◽  
Textile Coating

Electrical conductive textile coatings with variable amounts of carbon nanotubes (CNTs) are presented. Formulations of textile coatings were prepared with up to 15 wt % of CNT, based on the solid weight of the binder. The binders are water based polyacrylate dispersions. The CNTs were mixed into the binder dispersion starting from a commercially available aqueous CNT dispersion that is compatible with the binder dispersion. Coating formulations with variable CNT concentrations were applied on polyester and cotton woven and knitted fabrics by different textile coating techniques: direct coating, transfer coating, and screen printing. The coatings showed increasing electrical conductivity with increasing CNT concentration. The coatings can be regarded to be electrically conductive(sheet resistivity<103 Ohm/sq)starting at 3 wt% CNT. The degree of dispersion of the carbon nanotubes particles inside the coating was visualized by scanning electron microscopy. The CNT particles form honeycomb structured networks in the coatings, proving a high degree of dispersion. This honeycomb structure of CNT particles is forming a conductive network in the coating leading to low resistivity values.

scholarly journals DEVELOPMENT AND CHARACTERIZATION OF SURFACE-MODIFIED NANOPARTICLES USING FLUORINE-BASED CHEMICALS

2020 ◽  
Vol 2 (1) ◽  
pp. 12-16
Author(s):  
Kenny Ganie ◽  
Dzeti Farhah Mohshim ◽  
Ismail Mohd Saaid ◽  
Wan Rosli Wan Sulaiman ◽  
Ahmad Kamal Idris
Keyword(s):  
Chemical Treatment ◽  
Research Direction ◽  
Wettability Alteration ◽  
Future Research ◽  
Future Research Direction ◽  
Surface Modified ◽  
Coating Agents ◽  
High Degree ◽  
Surface Modified Nanoparticles

Scientist have been using chemical treatment to alter the wettability of near wellbore region for condensate banking removal. However, this technique performed unsatisfactorily as the chemical treatment only reduce the surface free energy without modifying the surface roughness and affects the gas relative permeability negatively. Hence, in the present study, an alternative surface-modified nanoparticle using fluorine-based chemicals was developed as a new wettability alteration agent since fluorine exhibits high degree of water and oil repellency. The new wettability alteration agent was evaluated based on FTIR, DLS and TGA characterization. The results show that the surface of nanoparticles has been modified with fluorine-based chemicals coating and this is proven from: FTIR spectra with new peaks observed; DLS characterization with incremental size of surface-modified nanoparticles; and TGA with decomposition rate of coating agents. Implications of the results will path the way for future research direction in using fluorine-surface-modified-nanoparticles as a wettability alteration agent.

scholarly journals Study of the rheological properties of the highly-filled paste-like fuel composition based on oligomeric rubber and dispersed fillers

2021 ◽  
pp. 111-117
Author(s):  
A.B. Surovtsev ◽  
◽  
I.A. Mandzyuk ◽  
D.O. Chervakov ◽  
M.F. Seferova ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Shear Stresses ◽  
Butadiene Rubber ◽  
Unsaturated Methyl Ester ◽  
Surface Active ◽  
The Individual ◽  
Surface Modified ◽  
High Degree ◽  
Rotary Viscometer ◽  
Degree Of Filling

We present the results of creation of paste-like fuel compositions with a high degree of filling (up to 90 wt.%) and investigation of their rheological properties. The developed composition contained the following components: a polymer matrix (type SNBR-N butadiene rubber) and a mixture of inorganic fillers (preliminarily surface-modified highly disperse potassium chloride, that was microencapsulated by using oligomeric products of polyehtyleneterepthalate glycerolize, and highly dispersed aluminum powder. A surface-active compound (oligomeric polioxypropylene glycol) and plasticizers of different natures were used as additional components, which were introduced in order to increase the degree of filling of the resulting paste-like compositions while maintaining a low level of their viscosity. The dynamic viscosity of the compositions was evaluated in the range of the shear stresses of 1 to 30 kPa and the temperatures of 293 to 323 K by using a rotary viscometer (cone–plane system). The viscosity of the composition which is a mixture of saturated and unsaturated methyl ester fatty acids at the maximum degree of filling (90 wt.%) was at the level of viscosity of the individual binder.

Kinetics of High Density Functional Polymer Nanocomposite formation by Tuning Enthalpic and Entropic Barriers

Soft Matter ◽  
2022 ◽  
Author(s):  
Aparna Swain ◽  
Nimmi A. Das ◽  
Sivasurender Chandran ◽  
Jaydeep Kumar Basu
Keyword(s):  
Polymer Nanocomposites ◽  
Density Functional ◽  
Polymer Nanocomposite ◽  
High Density ◽  
Functional Polymer ◽  
Novel Materials ◽  
Degree Of Dispersion ◽  
High Degree ◽  
Kinetics Of

High density functional polymer nanocomposites (PNCs) with high degree of dispersion have recently emerged as novel materials for various thermo-mechanical, optical and electrical applications. The key challenge is to attain...

scholarly journals MODIFIED SORBENTS AND THEIR APPLICATION FOR EXTRACTION OF METAL IONS

2021 ◽  
pp. 75-79
Author(s):  
N. C. Murzakassymova ◽  
N. A. Bektenov ◽  
M. A. Gavrilenko
Keyword(s):  
Metal Ion ◽  
Maximum Permissible Concentration ◽  
Carbon Materials ◽  
Water Supply Systems ◽  
Technological Properties ◽  
Surface Modified ◽  
High Degree ◽  
Supply Systems ◽  
Modified Sorbents ◽  
Significant Factors

The data on accumulated mining waste in the territory of Kazakhstan are presented. Their processing has become very important in our time. The structure of surface-modified carbon materials with a grafted layer is given. New modified carbon sorbents were obtained, oleum was used as a modifying agent. It was revealed that the capacitive characteristics of the modified sorbent are significantly higher than that of the original one, which will make it possible to more efficiently extract the metal ion from wastewater and technogenic formations. Sorption is an effective method of extracting valuable components from wastewater and man-made formations. This method allows you to recover valuable substances with a high degree of wastewater treatment, which can be purified to the maximum permissible concentration of pollutants and then used in technological processes or in recycling water supply systems. Processing involves ores characterized by a low content of valuable components, fine dissemination and similar technological properties of minerals. The existing technologies for the development of minerals make it possible to use only a small part of the valuable mineral mass extracted from the subsoil, and the rest forms waste, which, as it accumulates and is stored, becomes one of the most significant factors of anthropogenic changes in the environment.

scholarly journals Avaliando a Volatilidade Diária dos Ativos: a Hora da Negociação Importa?

2014 ◽  
Vol 12 (1) ◽  
pp. 41
Author(s):  
José Valentim Machado Vicente ◽  
Gustavo Silva Araujo ◽  
Paula Baião Fisher de Castro ◽  
Felipe Noronha Tavares
Keyword(s):  
Financial Models ◽  
Point Of View ◽  
Practical Point ◽  
Degree Of Dispersion ◽  
Standard Deviations ◽  
High Degree ◽  
Daily Returns

The aim of this study is to examine whether investors who trade daily but at different times have distinct perceptions about the risk of an asset. In order to capture the uncertainty faced by these investors, we define the volatility perceived by investors as the distribution of standard deviations of daily returns calculated from intraday prices collected randomly. We find that this distribution has a high degree of dispersion. This means that different investors may not share the same opinion regarding the variability of returns of the same asset. Moreover, the close-to-close volatility is often less than the median of the volatility distribution perceived by investors while the open-to-open volatility is greater than that statistic. From a practical point of view, our results indicate that volatilities estimated using traditional samples of daily returns (i.e., close-to-close and open-to-open returns) may not do a good job when used as inputs in financial models since they may not properly capture the risk investors are exposed.

scholarly journals Synthesis and Characterization of a New Surface-Modified Nanoparticle Using Fluoroalkanoic Acids as a Wettability Alteration Agent

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Kenny Ganie ◽  
Dzeti Farhah Mohshim ◽  
Ismail Mohd Saaid ◽  
Wan Rosli Wan Sulaiman ◽  
Ahmad Kamal Idris
Keyword(s):  
Silica Nanoparticles ◽  
High Surface ◽  
Research Direction ◽  
Wettability Alteration ◽  
Future Research ◽  
Chemical Treatments ◽  
Surface Modified ◽  
Liquid Repellency ◽  
High Degree ◽  
Surface Modified Nanoparticles

Previously, condensate banking removal in gas reservoir is mitigated using chemical treatments to alter the wettability of the near-wellbore region. However, this technique performed unsatisfactorily as it reduces the surface free energy and affects the gas relative permeability negatively. Hence, alternative surface-modified nanoparticles using fluorine-based chemicals were developed as wettability alteration agents since fluorine exhibits a high degree of liquid repellency and nanoparticles introduce high surface roughness. The newly synthesized surface-modified nanoparticles were characterized using FTIR, DLS, FESEM, and TGA. FTIR results highlight the characteristic absorption of Si-O-C group at peak 1105 and 1106 cm-1 in both fluoroalkanoic acids, demonstrating that fluorochemical molecules have been successfully coated onto silica nanoparticles. Nanoparticle sizes measured by DLS reported higher value than FESEM due to agglomeration, and the DLS measurement was done in hydrodynamic conditions. TGA analysis reveals decomposition at temperature between 100 and 150°C, indicating that these surface-modified nanoparticles can be utilized in an environment below 100°C. Higher decomposition was perceived on PFNA-modified nanoparticles as a thicker coating of PFNA is shrouding the silica nanoparticles compared to PFOA. Implications of the results will path the way for future research direction in using fluorine-based surface-modified nanoparticles as wettability alteration agents.

Tissue section lifting for electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 86-87
Author(s):  
Adrian F. van Dellen
Keyword(s):  
Infectious Disease ◽  
Electron Microscopy ◽  
Tissue Culture ◽  
Organ System ◽  
Surrounding Tissue ◽  
Paraffin Sections ◽  
Surface Areas ◽  
Specific Determination ◽  
High Degree ◽  
Accuracy And Repeatability

The morphologic pathologist may require information on the ultrastructure of a non-specific lesion seen under the light microscope before he can make a specific determination. Such lesions, when caused by infectious disease agents, may be sparsely distributed in any organ system. Tissue culture systems, too, may only have widely dispersed foci suitable for ultrastructural study. In these situations, when only a few, small foci in large tissue areas are useful for electron microscopy, it is advantageous to employ a methodology which rapidly selects a single tissue focus that is expected to yield beneficial ultrastructural data from amongst the surrounding tissue. This is in essence what "LIFTING" accomplishes. We have developed LIFTING to a high degree of accuracy and repeatability utilizing the Microlift (Fig 1), and have successfully applied it to tissue culture monolayers, histologic paraffin sections, and tissue blocks with large surface areas that had been initially fixed for either light or electron microscopy.

Electron Microscopy in Molecular Biology

1967 ◽  
Vol 25 ◽  
pp. 2-3
Author(s):  
Cecil E. Hall
Keyword(s):  
Electron Microscopy ◽  
Molecular Biology ◽  
Noise Level ◽  
Molecular Structures ◽  
Material Structure ◽  
The Arts ◽  
Shadow Casting ◽  
Electron Image ◽  
High Degree ◽  
Very High

The visualization of organic macromolecules such as proteins, nucleic acids, viruses and virus components has reached its high degree of effectiveness owing to refinements and reliability of instruments and to the invention of methods for enhancing the structure of these materials within the electron image. The latter techniques have been most important because what can be seen depends upon the molecular and atomic character of the object as modified which is rarely evident in the pristine material. Structure may thus be displayed by the arts of positive and negative staining, shadow casting, replication and other techniques. Enhancement of contrast, which delineates bounds of isolated macromolecules has been effected progressively over the years as illustrated in Figs. 1, 2, 3 and 4 by these methods. We now look to the future wondering what other visions are waiting to be seen. The instrument designers will need to exact from the arts of fabrication the performance that theory has prescribed as well as methods for phase and interference contrast with explorations of the potentialities of very high and very low voltages. Chemistry must play an increasingly important part in future progress by providing specific stain molecules of high visibility, substrates of vanishing “noise” level and means for preservation of molecular structures that usually exist in a solvated condition.

A High Angle, Double Tilting Cold Stage for the AEI EM7

1974 ◽  
Vol 32 ◽  
pp. 450-451
Author(s):  
P.R. Swann ◽  
A.E. Lloyd
Keyword(s):  
Habit Plane ◽  
Temperature Control ◽  
Tilt Angle ◽  
Cooling System ◽  
Thermal Drift ◽  
High Angle ◽  
Cold Stage ◽  
High Degree ◽  
Better Than

Figure 1 shows the design of a specimen stage used for the in situ observation of phase transformations in the temperature range between ambient and −160°C. The design has the following features a high degree of specimen stability during tilting linear tilt actuation about two orthogonal axes for accurate control of tilt angle read-out high angle tilt range for stereo work and habit plane determination simple, robust construction temperature control of better than ±0.5°C minimum thermal drift and transmission of vibration from the cooling system.

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