scholarly journals Effect of Film Forming Agent on Particle Coalescence in Polymer Emulsion Films.

2002 ◽  
pp. 47-52
Author(s):  
Tooru SUGAWARA ◽  
Hitoshi HOSOKAWA ◽  
Takeaki IIDA
Keyword(s):  
Polymer Emulsion ◽  
Film Forming ◽  
Particle Coalescence ◽  
Emulsion Films

Effect of Ca2+ Ions on the Film Formation of an Anionic Styrene/n-Butylacrylate Latexpolymer in Cement Pore Solution

2013 ◽  
Vol 687 ◽  
pp. 322-328 ◽  
Author(s):  
Thomas Pavlitschek ◽  
Markus Gretz ◽  
Johann Plank
Keyword(s):  
Pore Solution ◽  
Film Formation ◽  
Water Film ◽  
Particle Packing ◽  
Secondary Phases ◽  
Particle Deformation ◽  
Film Forming ◽  
Forming Temperature ◽  
Particle Coalescence ◽  
Forming Behaviour

Several methods were employed to study the time dependent film formation of a self synthesized anionic latex dispersion in water and cement pore solution. First, a model carboxylated styrene/n-butyl acrylate latex dispersion possessing a minimum film forming temperature (MFFT) of 18 °C and a glass transition temperature (Tg) of 30 °C was synthesized via emulsion polymerization. Next, its film forming behaviour was studied at 40 °C, using an ESEM instrument. The analysis revealed that upon removal of water, film formation occurs as a result of particle packing, particle deformation and finally particle coalescence. Film formation is significantly hindered in synthetic cement pore solution. This effect can be ascribed to adsorption of Ca2+ ions onto the surface of the anionic latex particles and to interfacial secondary phases. This layer of adsorbed Ca2+ ions hinders interdiffusion of the macromolecules and subsequent film formation of the latex polymer.

Thermoresponsive nanogels with film-forming ability

2018 ◽  
Vol 9 (8) ◽  
pp. 1004-1011 ◽  
Author(s):  
Ana S. Sonzogni ◽  
Mario C. G. Passeggi ◽  
Stefanie Wedepohl ◽  
Marcelo Calderón ◽  
Luis M. Gugliotta ◽  
...  
Keyword(s):  
One Pot ◽  
Film Forming ◽  
Particle Coalescence

A one pot semibatch method was proposed for synthesizing poly(N-vinylcaprolactam)-based nanogels with particle coalescence ability.

Assessment of coverage degree during particulate material encapsulation in fluidized bed

1970 ◽  
Author(s):  
Aleksandr G. Lipin ◽  
Vladimir O. Nebukin ◽  
Andrey A. Lipin
Keyword(s):  
Mathematical Model ◽  
Fluidized Bed ◽  
Protective Coating ◽  
Total Surface Area ◽  
Particulate Material ◽  
Polymer Emulsion ◽  
Thin Polymer ◽  
Film Forming ◽  
Uncoated Surface ◽  
Encapsulation Process

By encapsulating granular materials, it is possible to eliminate caking, to provide a delayed release of the active substance. In this work the encapsulation is carried out by spraying the polymer emulsion onto the particles of the fluidized bed by means of pneumatic nozzles. Drops of the polymer emulsion, having faced with the particles are spread on their surface, forming a liquid film. Solvent removing by drying causes solidification of the film. The quality of the encapsulation process was evaluated by the degree of coverage, which is equal to the fraction of the total surface area of the particles coated with a protective coating. When thin polymer shells are applied, it is very important to determine the process parameters that ensure the continuity of the protective coating. A mathematical model, which allows to predict the particles coverage degree in the fluidized bed apparatus, is given. It is assumed that the growth rate of the degree of coverage is proportional to the fraction of the uncoated surface and the consumption of the film-forming material. To identify the parameters of the developed mathematical model and verify of its adequacy, a physical experiment was exercised on a laboratory scale installation. During the experiment, samples of particles were taken from the apparatus at intervals of one minute to determine their degree of coverage. The method for determining the degree of coverage is based on a comparative analysis of the dissolution curves of the initial and processed pellets. Graphic dependencies characterizing the evolution of coverage degree of granules in time at different flow rates of the film-forming substance are given. The comparison of the calculated and experimental data, which showed their good agreement, was performed. Thus, it is shown that the proposed mathematical model of the formation of a protective coating on particles in the apparatus of the fluidized bed allows to predict reliably the degree of coverage of particles and to choose the rational parameters of the encapsulation process.

Clean Electron Microscope Substrate Films Used for Micrometeorite Collection and Study

1967 ◽  
Vol 25 ◽  
pp. 366-367
Author(s):  
D. M. Davies ◽  
R. Kemner ◽  
E. F. Fullam
Keyword(s):  
Thin Film ◽  
Electron Microscope ◽  
High Altitude ◽  
Amyl Acetate ◽  
Temperature Variations ◽  
Film Forming ◽  
Film Specimen ◽  
Particulate Contaminants

All serious electron microscopists at one time or another have been concerned with the cleanliness and freedom from artifacts of thin film specimen support substrates. This is particularly important where there are relatively few particles of a sample to be found for study, as in the case of micrometeorite collections. For the deposition of such celestial garbage through the use of balloons, rockets, and aircraft, the thin film substrates must have not only all the attributes necessary for use in the electron microscope, but also be able to withstand rather wide temperature variations at high altitude, vibration and shock inherent in the collection vehicle's operation and occasionally an unscheduled violent landing.Nitrocellulose has been selected as a film forming material that meets these requirements yet lends itself to a relatively simple clean-up procedure to remove particulate contaminants. A 1% nitrocellulose solution is prepared by dissolving “Parlodion” in redistilled amyl acetate from which all moisture has been removed.

A Freeze Shadow Technique for the Preparation of Soft Paint Latexes for Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 314-315
Author(s):  
Earl R. Walter ◽  
Glen H. Bryant
Keyword(s):  
Sample Preparation ◽  
High Vacuum ◽  
Vacuum System ◽  
Latex Particles ◽  
New Methods ◽  
Diffusion Pump ◽  
Film Forming ◽  
Routine Basis ◽  
Distribution Studies ◽  
Preparation Techniques

With the development of soft, film forming latexes for use in paints and other coatings applications, it became desirable to develop new methods of sample preparation for latex particle size distribution studies with the electron microscope. Conventional latex sample preparation techniques were inadequate due to the pronounced tendency of these new soft latex particles to distort, flatten and fuse on the substrate when they dried. In order to avoid these complications and obtain electron micrographs of undistorted latex particles of soft resins, a freeze-dry, cold shadowing technique was developed. The method has now been used in our laboratory on a routine basis for several years.The cold shadowing is done in a specially constructed vacuum system, having a conventional mechanical fore pump and oil diffusion pump supplying vacuum. The system incorporates bellows type high vacuum valves to permit a prepump cycle and opening of the shadowing chamber without shutting down the oil diffusion pump. A baffeled sorption trap isolates the shadowing chamber from the pumps.

Modern devices for treatment of the surgeon’s hands and the surgical field (literature review)

2020 ◽  
pp. 41-50
Author(s):  
Artem Mikhailovich Morozov ◽  
◽  
Alexey Nikolaevich Sergeev ◽  
Gennady Alexandrovich Dubatolov ◽  
Nikolay Alexandrovich Sergeev ◽  
...  
Keyword(s):  
Cost Effective ◽  
Surgical Infection ◽  
Operating Field ◽  
Functional Additives ◽  
Literary Sources ◽  
Film Forming ◽  
Key Points ◽  
Surgical Field ◽  
Ammonium Compounds ◽  
Active Substances

The aim – analyze modern Russian and foreign literary sources in order to determine modern means for treating the hands of the surgeon and the operating field. Results. One of the key points in the prevention of surgical infection is the treatment of the surgeon’s hands and the operating field with effective skin antiseptics in order to destroy pathogenic and opportunistic microorganisms that colonize intact skin. In modern practice, skin antiseptics are predominantly used containing alcohols as active substances, in particular ethyl, propyl and isopropyl, halogenated substances such as iodine and iodophores, guanidines, which include chlorhexidine digluconate, as well as quaternary ammonium compounds. Moreover, the most widespread are combined preparations containing several active substances and functional additives, which makes it possible to neutralize the negative properties of various active substances. Also, an interesting and promising direction is the use of polymer operating films or film-forming antiseptics. Currently, research is being actively carried out aimed at finding and developing modern highly effective antiseptic agents and their rational combinations that meet the necessary requirements, are optimal in their properties, cost-effective and comfortable to use.

Effect of plant film-forming anti-transpirant on transpiration efficiency of winter wheat flag-leaf

2012 ◽  
Vol 19 (5) ◽  
pp. 1091-1095
Author(s):  
Chang-Hai SHI ◽  
Shao-Hua KONG ◽  
Hong-Mei ZHAI ◽  
Jing YANG ◽  
Dong-Xiao LI ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Flag Leaf ◽  
Transpiration Efficiency ◽  
Film Forming

In the stability of paints and varnishes for protective and decorative wood finish

2016 ◽  
Author(s):  
Ю.И. Цой
Keyword(s):  
Organic Solvents ◽  
Evaluation Criteria ◽  
Ternary Systems ◽  
Solubility Parameters ◽  
Formaldehyde Resin ◽  
Film Forming ◽  
The Difference ◽  
Molecular Forces ◽  
The Stability ◽  
Thermodynamic Interaction

Задача получения однородного состава ЛКМ сводится к правильному выбору пленкообразователей и соответствующих растворителей и, в случае необходимости, разбавителей и добавок. На основе положений теории растворимости была проведена оценка совместимости компонентов и стабильности таких систем. Критериями оценки были приняты параметры растворимости и термодинамического взаимодействия. Исследовали совместимость алкидных лаков с аминоформальдегидными смолами в бутаноле, и результаты этих исследований представлены в треугольной фазовой диаграмме. Для оценки совместимости смол по результатам расчета параметров термодинамического взаимодействия были построены спинодали для тройных систем. Как показывает анализ результатов проведенных исследований, даже при большой разности ?? = |?12 – ?13| = 0,2 наблюдается небольшая область несовместимости. С уменьшением разности ?? область несовместимости сужается. При ?23 > ?с область несовместимости расширяется как для ? = 0,2, так и для ?? = 0,1 и ?? = 0. Таким образом, для таких систем на совместимость компонентов, в первую очередь, влияет их взаимодействие между собой – чем оно больше, тем лучше они совместимы. Проведенные исследования показали, что парциальные параметры растворимости, учитывающие природу когезионных сил, более объективно характеризуют растворимость пленкообразующих смол в органических растворителях, чем их общий параметр растворимости. Растворимость пленкообразующих алкидных и этерифицированных аминоформальдегидных смол в органических растворителях обусловлена термодинамическим взаимодействием молекулярных сил различной природы. Стабильность смеси алкидной и этерифицированной аминоформальдегидной смолы в бутаноле обусловлена в большей степени термодинамическим взаимодействием молекулярных сил; при этом степень бутанолизации меламиноформальдегидной смолы оказывает наибольшее влияние на стабильность cистемы. Проведенные исследования по стабильности лакокрасочных смесей из различных пленкообразующих смол на основе рассмотренных критериев оценки могут быть использованы для совершенствования технологии защитно-декоративной отделки древесины. The problem of obtaining a homogeneous composition of the coatings is reduced to the proper selection of film-forming agents, and diluent and, if appropriate, diluents and additives. On the basis of the theory of solubility, we have carried out the assessment of the compatibility of the components and stability of such systems. The evaluation criteria were adopted the parameters of the solubility and thermodynamic interaction. Researched the compatibility with alkyd varnishes aminoformaldehyde resin in butanol, and the results of these studies are presented in the triangular phase diagram. To evaluate the compatibility of the resins according to the results of calculation of thermodynamic parameters of interaction were built spinodal for ternary systems. As the analysis of the results of the studies, even when the difference ??|?12 – ?13| = 0,2 there is a small area of incompatibility. With the decrease of the difference ? ? region incompatibility narrows. When ?23> ?с region incompatibility extends to ?? = 0,2, and for ?? = 0.1 and ?? = 0. Thus, for such systems, compatibility of components, primarily, affects their interaction with each other – the further away it is, the better they are compatible. Studies have shown that the partial solubility parameters, which take into account the nature of cohesive forces, more objectively characterize the solubility of film-forming resins in organic solvents than their total solubility parameter. The solubility and film-forming aminoformaldehyde esterified alkyd resins in organic solvents due to thermodynamic interaction of molecular forces of different nature. Тhe stability of the mixture and aminoformaldehyde esterified alkyd resin in butanol is generated largely by thermodynamic forces of molecular interaction; the degree of butanolate melamine-formaldehyde resin has the greatest effect on the stability of the system. Conducted research on the stability of the paint mixtures of various film-forming resins on the basis of the evaluation criteria can be used to improve the technology of protective and decorative wood finish.

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