Stability of High Polymer Latexes and Their Electrokinetic Potentials

1958 ◽  
Vol 31 (5) ◽  
pp. 1105-1141 ◽  
Author(s):  
S. S. Voyutskiĭ ◽  
R. M. Panich
Keyword(s):  
Colloidal Particles ◽  
Electrokinetic Potential ◽  
Point Of View ◽  
Boundary Line ◽  
Colloidal System ◽  
Colloidal Systems ◽  
Long Time ◽  
The Stability ◽  
Colloid Systems

Abstract The stability of colloid systems is a central problem of colloid chemistry. Therefore, many papers have been devoted to studies of coagulation and to the development of criteria of stability for colloid systems. For a long time a prevalent opinion was that the stability of colloidal particles could be explained by the fact that like charge on the particles prevents agglomeration of particles which collide due to Brownian motion. This opinion was first expressed by Hardy and later developed by Powis, Ellis and a number of other scientists. According to this point of view, electrokinetic potential (ζ potential) is the measure of stability. However, after detailed investigation of coagulation phenomena and accumulation of experimental data the correctness of this point of view became less obvious, and the statement that the electrokinetic potential is a criterion of stability of colloidal systems underwent vigorous criticism. The reasons for the measured values of electrokinetic potentials not always corresponding to the stability of certain systems are as follows: firstly, the exact determination of electrokinetic potential is work of great experimental difficulty which seems to some investigators insuperable. Some of these difficulties are (1) the necessity of performing the mocroelectrophoresis in a medium which has the same characteristics as the colloidal system under investigation, (2) the influence on electrophoresis of the simultaneously occurring electrolysis (3) the wash out of the boundary line between the solution and the colloidal system, and a number of others. In the case of microelectrophoresis, these difficulties are replaced by others, which are not less difficult to overcome.

USING MALIC ACID SOLUTIONS FOR THE HYDRATION OF VEGETABLE OILS AND LECITHIN PRODUCTION

2020 ◽  
Author(s):  
Л.А. МАРЧЕНКО ◽  
Т.Н. БОКОВИКОВА ◽  
Е.В. ЛИСОВАЯ ◽  
С.А. ИЛЬИНОВА ◽  
Е.П. ВИКТОРОВА
Keyword(s):  
Malic Acid ◽  
Complex Compounds ◽  
Point Of View ◽  
Magnesium Ions ◽  
Ph Values ◽  
Calcium And Magnesium ◽  
The Stability ◽  
The Cost ◽  
Calcium And Magnesium Ions

Исследована возможность применения яблочной кислоты (ЯК) в качестве гидратирующего агента для перевода негидратируемых форм фосфолипидов в гидратируемые. Выбор ЯК обусловлен ее стоимостью, которая в 1,5 раза меньше стоимости янтарной кислоты, широко применяемой в качестве гидратирующего агента, а также большей доступностью с точки зрения промышленного производства. Исследование процесса комплексообразования и определение состава комплексных соединений ЯК с ионами кальция и магния осуществляли методом потенциометрического титрования. Установлено, что внесение в раствор ЯК ионов кальция и магния приводит к снижению значений рН, что свидетельствует о наличии комплексообразования в указанных системах. Наиболее устойчивыми являются комплексы ионов кальция и магния с непротонированным лигандом при соотношении Ме2 : лиганд 1 : 1. В процессе комплексообразования ионы Ca2 и Mg2 вытесняют протоны только карбоксильных групп ЯК, которая с ионами кальция образует более устойчивые комплексы, чем с ионами магния. Показано, что устойчивость комплексов ЯК с ионами кальция и магния значительно выше, чем устойчивость комплексов фосфатидилсеринов и фосфатидных кислот с указанными ионами. Использование водных растворов ЯК в качестве гидратирующего агента позволит повысить эффективность процесса гидратации и увеличить выход фосфолипидов и, следовательно, готового продукта лецитина. The possibility of using malic acid (MA) as a hydrating agent for converting non-hydrated forms of phospholipids into hydrated ones has been investigated. The choice of MA is due to its cost, which is 1,5 times less than the cost of succinic acid, as well as greater availability from the point of view of industrial production. The study of the complexation process and determination of the composition of complex compounds of MA with calcium and magnesium ions was carried out by the method of potentiometric titration. It was found that the introduction of calcium and magnesium ions into the MA solution leads to a decrease in pH values, which indicates the presence of complexation in these systems. Complexes of calcium and magnesium ions with an unprotected ligand at a ratio of ME2 : ligand 1 : 1 are the most stable. In the process of complexing, Ca2 and Mg2 ions displace protons only of the carboxyl groups of MA, which forms more stable complexes with calcium ions than with magnesium ions. It is shown that the stability of MA complexes with calcium and magnesium ions is significantly higher than the stability of phosphatidylserine and phosphatidic acid complexes with these ions. Using water solutions of MA as a hydrating agent will increase the efficiency of the hydration process and increase the yield of phospholipids and, consequently, the finished product lecithin.

scholarly journals Electric double layer and electrokinetic potential of pectic macromolecules in sugar beet

2008 ◽  
pp. 21-28
Author(s):  
Tatjana Kuljanin ◽  
Ljubinko Levic ◽  
Nevena Misljenovic ◽  
Gordana Koprivica
Keyword(s):  
Sugar Beet ◽  
Double Layer ◽  
Electric Double Layer ◽  
Colloidal Particles ◽  
Colloidal Particle ◽  
Electrokinetic Potential ◽  
Shear Plane ◽  
Colloidal System ◽  
Cu Ions ◽  
Measurable Property

Electrokinetic potential is an important property of colloidal particles and, regarding the fact that it is a well defined and easily measurable property, it is considered to be a permanent characteristic of a particular colloidal system. In fact, it is a measure of electrokinetic charge that surrounds the colloidal particle in a solution and is in direct proportion with the mobility of particles in an electric field. Gouy-Chapman-Stern-Graham's model of electric double layer was adopted and it was proven experimentally that the addition of Cu++ ions to sugar beet pectin caused a reduction in the negative electrokinetic potential proportional to the increase of Cu++ concentration. Higher Cu++ concentrations increased the proportion of cation specific adsorption (Cu++ and H+) with regard to electrostatic Coulombic forces. Consequently, there is a shift in the shear plane between the fixed and diffuse layers directed towards the diffuse layer, i.e. towards its compression and decrease in the electrokinetic potential or even charge inversion of pectin macromolecules.

The issue of "oil shrinkage" during the compounding of oils in the processes of production, collection, preparation and transportation of hydrocarbon raw materials

2021 ◽  
pp. 104-113
Author(s):  
O. P. Deryugina ◽  
E. A. Trapeznikov
Keyword(s):  
Raw Materials ◽  
Raw Material ◽  
Colloidal System ◽  
Main Pipelines ◽  
Different Types ◽  
Preliminary Study ◽  
The Stability ◽  
Mixed Oil

The article discusses the issue of industrial compounding, which improves the quality of the raw materials supplied to the main pipelines. Compounding from "to compound" (English) - to mix. When mixing different types of oil obtained, "incompatibility" is possible, which is expressed in the precipitation of a solid sediment and violation of the stability of the colloidal system and due to the differing properties of oils. Attention to this problem is due to the tightening of requirements for the quality of raw materials that must comply with modern standards. The article discusses the causes of the problem of "incompatibility" of oil during compounding and effective ways of solving it, substantiates the need for a preliminary study of the properties of mixed oil in order to identify possible incompatibility of various types of oil. The standard tests for determination of incompatibility indices characterizing the ability of raw materials to mix are considered. The article substantiates the need to develop methods for diagnosing the incompatibility of oils as the most important task of modern chemical science, the solution of which will improve the quality of the raw material obtained and solve many technological problems in the compounding process.

scholarly journals Anomalous Long-Range Attraction in Colloidal Binary Mixtures at Fluid–Fluid Interfaces

2020 ◽  
Vol 4 (3) ◽  
pp. 36
Author(s):  
Zonglin Yi ◽  
To Ngai
Keyword(s):  
Long Range ◽  
Colloidal Particles ◽  
Experimental Result ◽  
Colloidal System ◽  
Fluid Interfaces ◽  
Water Interface ◽  
Two Dimensional ◽  
Colloidal Systems ◽  
Oil Water ◽  
Theoretical Side

The properties of binary colloidal systems have gained the interest of researchers because they have much richer structures than their one-component counterpart. Continuing efforts are being made on the theoretical side on binary colloidal systems, while many issues remained unsolved for the lack of solid experimental supports, especially for study in the field of two-dimensional (2D) binary colloids system. Oil–water interfaces can serve as a good stringent 2D confinement for colloidal particles and can avoid anomalous problems caused by the quasi-two-dimensional environment in previous experimental reports. In this work, we conduct experimental research of binary colloids system in an oil–water interface to revisit theoretical predication. We measure an ultra-long-range attraction and discuss the possible mechanism of this attraction by comparing the experimental result with existing model and theory. This study could contribute more understanding of the binary colloidal system in both experimental aspects and theoretical aspects.

On Protecting and Sensitising Colloidal Sols

1924 ◽  
Vol 22 (2) ◽  
pp. 101-104
Author(s):  
Eric K. Rideal
Keyword(s):  
Isoelectric Point ◽  
Electrokinetic Potential ◽  
Colloidal System ◽  
Disperse Systems ◽  
The Stability

Stable colloidal sols are always charged, and disperse systems in water appear in most cases to acquire a constant electrokinetic potential of 70 m.v. When the electrokinetic potential falls to 30 m.v. coagulation commences and the rate of coagulation is, as Hardy first pointed out, most rapid at the isoelectric point. Thus the question on what the stability of a colloidal system rests must ultimately be referred to the magnitude of the electrokinetic potential and the methods by which this is increased or decreased in solution.

scholarly journals Proposal for the Evaluation of the Stability Level of Periodic Timetable in Terms of Operation and Infrastructure

2021 ◽  
Vol 17 (1) ◽  
pp. 25-33
Author(s):  
Lukáš Čechovič ◽  
Adrián Šperka ◽  
Jozef Gašparík
Keyword(s):  
Rail Transport ◽  
Point Of View ◽  
Passenger Transport ◽  
Railway Transport ◽  
Scientific Methods ◽  
Practical Point ◽  
Railway Networks ◽  
Transport Path ◽  
The Stability

Abstract The introduction of tact timetable in rail passenger transport is currently a new evolving trend that increases the efficiency of rail transport. This article seeks to contribute in this area of the issue and thus to raise and improve this system of organizing transport in railway transport. The aim is to propose a methodology that assesses the level of stability of tact timetable based on operational and infrastructural factors. The methodology identifies operational-infrastructural factors that affect the stability and reliability of tact timetable. Using scientific methods, it presents the method of their quantification and determination of the weights of these factors, which evaluate the line sections and transport points of the examined transport path. From a practical point of view, the methodology is generally tact applicable to other European railway networks. In the final part of the work, this methodological procedure is applied in the form of model examples for various transport path.

scholarly journals European Union and Central Asia: new trends of cooperation in current circumstances

2020 ◽  
pp. 80-88
Author(s):  
Assima AUBAKIR ◽  
Tuleutay SULEIMENOV
Keyword(s):  
European Union ◽  
Central Asia ◽  
Point Of View ◽  
The European Union ◽  
Asian Countries ◽  
Central Asian ◽  
New Strategy ◽  
Long Time ◽  
Central Asian Countries

Determination of clear contours of European policy for Central Asia, which could satisfy the interests of both the European Union and the countries of the region, took quite a long time, and is still at the stage of forming common approaches to the implementation of mutually beneficial cooperation. The first program documents of the European Union in relation to Central Asia, called strategies, were to a greater extent only action plans aimed at maintaining its political and economic presence in the region. Meanwhile, the Central Asian countries are always interested in pragmatic interaction with the European Union on equal basis. In 2019, the European Union adopted a new Strategy for Central Asia, which replaced the previous 2007 document. According to European politicians, it marks a new stage in relations between the two regions with improved approaches to building interaction between them. The purpose of the article is to analyze new trends in relations between Central Asia and the European Union from the point of view of both participants of this process and the evolution of the relevant EU policy documents.

scholarly journals Smokes: Part I.—A study of their behaviour and a method of determining the number of particles they contain

1923 ◽  
Vol 102 (718) ◽  
pp. 600-615 ◽  
Keyword(s):  
Protective Action ◽  
Colloidal Suspensions ◽  
Point Of View ◽  
Solid Particles ◽  
Electronic Charge ◽  
Colloidal Systems ◽  
Liquid Systems ◽  
The Stability ◽  
The Many ◽  
Liquid States

Theoretically, at least, systems of solid particles of ultra-microscopic size suspended in a gaseous medium, should show many resemblances to those analogous systems in which the dispersion medium is a liquid. It might be expected that the well-known characteristics of colloidal matter, such as coagulation, peptisation, protective action, gel formation, etc., would have their counterpart in the simpler gaseous systems. Should this prove to be the case much information should accrue from a study of these aerosols in which many complicating factors are absent. Now although the movement of individual particles (not necessarily of ultra-microscopic size), suspended in gases, has been investigated very carefully, and the study has led to experimental and theoretical results of the greatest importance, for instance, the measurement of the unit electronic charge (de Broglie (1), Ehrenhaft (2), Millikan (3)), little attention has been paid to the question of the stability of gaseous systems and the changes they undergo, and no attempt has been made to compare the properties of solid colloidal suspensions in the gaseous and liquid states. From this point of view, dusts, fumes, smokes, and clouds are colloidal systems possessing varying degrees of stability, dispersion, and concentration, which sometimes flocculate or precipitate rapidly, sometimes remain highly disperse for long periods of time, and correspond to the many types of liquid systems which vary from coarse suspensions to fine-textured sols.

General Information Models of Intelligent Building Control Systems: Scientific Problem and Hypothesis

2013 ◽  
Vol 838-841 ◽  
pp. 2969-2972 ◽  
Author(s):  
Andrey Volkov
Keyword(s):  
Control Systems ◽  
Intelligent Systems ◽  
General Information ◽  
Point Of View ◽  
Intelligent Building ◽  
Building Control ◽  
Information Models ◽  
Key Concepts ◽  
The Stability

In the paper the problem of the general information simulation of the building control intelligent systems from the point of view of abstract cybernetics is examined. There are represented some resonings about the state and the prospects for practice and scientific studies in the field of constructing Building Intelligence. There are examined the questions and the resonings, connected with the determination of the key concepts of the construction Building Intelligence: control of object (building), the stability of object (building), the homeostat of object (building).

Electric-Field Effects in Dilute Suspensions of Carbon Nanotubes Dispersed in Nematic Liquid Crystals

2010 ◽  
Vol 428-429 ◽  
pp. 173-181 ◽  
Author(s):  
Muklesur Rahman ◽  
Wei Lee
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Crystal ◽  
Carbon Nanotube ◽  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Colloidal Particles ◽  
Liquid Crystal Display ◽  
New Physics ◽  
Colloidal System ◽  
Colloidal Systems

Colloids composed of liquid-crystal hydrosols exhibit a rich set of interesting phenomena. The coupling between liquid-crystalline media and colloidal particles plays an essential role leading to an abundant source of new physics. In the last few years, peculiar behaviors of carbon-nanotube-doped calamitic liquid crystals have attracted considerable attention. This paper provides a brief introduction to this alluring subject for its on-going research development in this laboratory. First presented are our current understandings of the nematic colloidal system comprising carbon nanotubes and of their possible orientation and dynamics under the application of an external field. Various electro-optical and electrical properties of a liquid-crystal display rectified by the nanoscale carbonaceous guest are then addressed to a larger extent. Dielectric relaxation obtained from a nematic impregnated with carbon nanotubes is also discussed. With historical significance for the dawn of the liquid-crystal–carbon-nanotube research, several important findings of enhanced nonlinear optical properties in typical nematic mesomaterials consisting of suspended nanotubes are delineated. With the new colloidal systems of elongated nanoscale solids dispersed in anisotropic fluids in the mesophase, many new intriguing phenomena are awaiting theoretical and experimental explorations. Collaborations are called to draw attention of interested theoretical physicists, in particular.

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