Evaluation of surface forces and structure formation in water-organic dispersed systems of aluminum oxide

2012 ◽  
Vol 38 (5) ◽  
pp. 449-454 ◽  
Author(s):  
P. V. Krivoshapkin ◽  
E. F. Krivoshapkina ◽  
B. N. Dudkin
Author(s):  
В.Г. Ермолинский ◽  
О.П. Ковалева

Анализ результатов многочисленных исследований показывает, что регулирование свойств волокнистых полуфабрикатов, а также стабильность качества бумаги и картона возможны при условии учёта специфики процессов структурообразования в дисперсных системах, дисперсионной средой в которых является вода или её растворы на каждом этапе в многоступенчатых системах переработки целлюлозосодержащих материалов. В результате исключения изтеоретических основ технологии и практики целлюлозно-бумажного производства понятия об индивидуальности природных волокон целлюлозы, предназначенной для производства бумаги, все исследования физико-химических свойств целлюлозы производились на образцах целлюлозы, предназначенной для дальнейшей химической переработки. При этом представления о гидрофильности волокон гидратцеллюлозы были перенесены и на волокна природной целлюлозы. В связи с этим отрицалась мозаичность поверхности растительных волокон и, следовательно, исключалась возможность реализации гидрофобных взаимодействий в системе «целлюлоза-вода». Характер и степень изменения параметров взаимодействия волокон с образованием фазовых связок в структуре волокон и между волокнами в листе бумаги рассматривает физико-химическая механика дисперсных систем, а выявленные закономерности учитываются в методах золь-гель технологии модифицирования поверхности волокон целлюлозы. Обобщение научно-технической информации на основе единого подхода к проблеме структурообразования в системе «целлюлоза-вода», базирующегося на представлениях физико-химической механики дисперсных систем и физико-химии полимеров, показало, что данные вопросы требуют тщательного и углубленного изучения с целью регулирования и достижения требуемых свойств целлюлозосодержащих материалов. Analysis of the results of numerous studies shows that the regulation of the properties and stability of the quality of paper and cardboard is possible subject to the specifics of the processes of structure formation in dispersed systems, the dispersion medium in which is water or its solutions, at each stage in multi-stage systems for processing cellulose-containing materials. As a result of excluding the concept of the individuality of natural cellulose fibers intended for paper production from the theoretical foundations of pulp and paper production technology and practice, all studies of the physical and chemical properties of cellulose were performed on samples of cellulose intended for further chemical processing. At the same time, ideas about the hydrophilicity of hydrate cellulose fibers were transferred to natural cellulose fibers. In this regard, the mosaic surface of plant fibers was denied and, consequently, the possibility of hydrophobic interactions in the «cellulose-water» system was excluded. The nature and degree of changes in the parameters of the interaction of fibers with the formation of phase bonds in the structure of fibers andbetween fibers in a sheet of paper is considered only by physical and chemical mechanics, and the revealed regularities are taken into account in the methods of Sol-gel technology for modifying the surface of cellulose fibers. Generalization of scientific and technical information based on a unified approach to the problem of structure formation in the "cellulose-water" system, based on the concepts of physical and chemical mechanics of dispersed systems and physical chemistry of polymers, showed that these issues require careful and in-depth study in order to regulate and achieve the required properties of cellulose-containing materials.


2018 ◽  
Vol 8 (4) ◽  
pp. 44-49
Author(s):  
Anatoly A. ABRAMENKO ◽  
Vitaly V. VOLKOV ◽  
(SOLOVYEVA) Ekaterina A. BRITVINA

Currently one of the tasks of materials science is to fi nd ways to reduce the cost of building materials. Studies have shown that the initial strength of the starting components does not aff ect the properties of the material. The article presents a study of the physicochemical processes occurring on the surface of dispersed components, the infl uence of the thickness of water fi lms on the strength of the fi nal material. The interdependence between the area of the endo-eff ects of thermograms and the strength of the materials obtained is considered. A model of interaction in dispersed systems is proposed, which allows one to infl uence the structure formation of composite materials in a targeted manner. Research is aimed at studying the patt erns of physicochemical processes on the surface of fi ne particles, the understanding of which allows us to predict, and subsequently set the properties of the materials obtained.


2010 ◽  
Vol 67 (7-8) ◽  
pp. 224-228
Author(s):  
I. A. Zhenzhurist ◽  
V. M. Zaripova ◽  
L. F. Mubarakshina ◽  
V. G. Khozin

Author(s):  
S. D. Boruk ◽  
M. F. Kravchenko ◽  
O. L. Romanovska

In the paper the requirements to the physicochemical properties of the potential substitutes of the used food additives are considered. Cocoa is one of the products that is constantly looking for its potential substitutes. Studies have shown that when added to aquatic systems, cocoa is divided into two components: substances that pass into the volume of the system and are evenly distributed in it due to the passage of extraction processes, and resistant to the external influence of particles that swell and become nodes of the spatial structural network. Potential substitutes for cocoa in confectionery should not only preserve the relevant organoleptic properties of the final product, but also reproduce the behavior of cocoa in semi-finished products. We have shown that the separation of cocoa into soluble and insoluble component occurs in the ratio of 3: 1. The obtained results allow us to predict that in such systems the soluble component exerts a greater influence on their rheological characteristics. It has been found that the introduction of cocoa flour and its ingredients leads to a gradual increase in the viscosity of the dough. This is due to the processes of structure formation in the dispersed systems due to the leaching of substances from cocoa. It should be noted that cocoa powder works most effectively, the water-soluble component is less effective and finally the insoluble component has little effect on the viscosity of the dough samples. This indicates the decisive role of the intensity of interparticle interaction in the processes of structure formation in such systems. Substances that are contained in a water-soluble component capable of forming bridging bonds contribute to the formation of structure in the system. Purely mechanical impurities (insoluble component) have virtually no effect on the rheological characteristics of the system. It was found that the total effect of cocoa components on rheological characteristics is less than the effect of cocoa powder as a complex additive. This indicates that particles of the dispersed phase of a water-insoluble cocoa component are more likely to form a structural framework with molecules of a water-soluble component of cocoa. Therefore, the chemical affinity of soluble and insoluble components plays an important role in the structuring of dispersed systems based on wheat flour.


Author(s):  
В.Г. Ермолинский ◽  
О.П. Ковалева

В статье рассмотрены различные подходы к пониманию природы связей в целлюлозно-волокнистых системах. Анализ результатов многочисленных исследований показывает, что при изготовлении высокотехнологичных целлюлозно-бумажных изделий необходимо учитывать специфику процессов структурообразования в дисперсных системах, дисперсионной средой в которых является вода или её растворы, на каждом этапе в многоступенчатых системах химической переработки растительного сырья. В статье освещаются особенности диалектики развития прикладной науки (отрицание отрицания) и её влияние на решение проблем отечественной научной школы текстильной и целлюлозно-бумажной промышленности. Выделение физикохимии растворов высокомолекулярных соединений из коллоидной химии в отдельную науку явилось причиной создания теоретических основ технологии искусственных волокон и целлюлозно-бумажного производства. Игнорирование научных положений о структурообразовании дисперсных систем с точки зрения фазового взаимодействия их компонентов и релаксационного состояния является причиной сдерживания прогресса в совершенствовании технологических процессов целлюлозно-бумажного производства. Разработанные теоретические основы получения дисперсных структур с заданными механическими свойствами не были доведены до создания моделей технологических процессов, необходимых для изготовления отечественного технологического оборудования. Таким образом, исключение представлений коллоидной химии и её раздела – физико-химической механики из повседневной практики целлюлозно- бумажного производства препятствуют целенаправленному решению проблем при получении высокотехнологичных материалов. The article deals with different approaches to understanding the nature of bonds in cellulose-fibrous systems. Analysis of the results of numerous studies shows that in the manufacture of high-tech pulp and paper products it is necessary to take into account the specifics of the processes of structure formation in dispersed systems, the dispersion medium in which is water or its solutions, at each stage in multi-stage systems of chemical processing of vegetable raw materials. The article highlights the features of dialectics of applied science (denial of negation) and its impact on solving the problems of the domestic scientific school of textile and pulp and paper industry. The separation of physical chemistry of solutions of high-molecular compounds from colloidal chemistry into a separate science was the reason for the creation of the theoretical foundations of the technology of artificial fibers and pulp and paper production. Ignoring the scientific provisions on the structure formation of dispersed systems from the point of view of the phase interaction of their components and the relaxation state is the reason for holding back progress in improving the technological processes of pulp and paper production. The developed theoretical basis for obtaining dispersed structures with specified mechanical properties were not brought to the creation of models of technological processes necessary for the manufacture of domestic technological equipment. Thus, the exclusion of colloidal chemistry, and its section – physical and chemical mechanics, from the daily practice of pulp and paper production prevents the purposeful solution of problems in the production of high-tech materials.


2020 ◽  
Vol 864 ◽  
pp. 158-163
Author(s):  
Kateryna Pushkarova ◽  
Andrii Plugin ◽  
Maryna Sukhanevych

The article presents the studies of the processes of structure formation in the system "cement-plasticizer - crude carbon nanotubes", established the relationship with the parameters of the structure, physical-mechanical and operational properties of composite materials from the standpoint of physicochemical mechanics of dispersed systems and shows the influence of processes on the physical-mechanical properties of cement composites.


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