Moisture permeability, diffusion and sorption in organic film-forming materials

2007 ◽  
Vol 1 (4) ◽  
pp. 141-158 ◽  
Author(s):  
A. Morris Thomas
2012 ◽  
Vol 7 (4) ◽  
Author(s):  
Norikazu Sugaya

This new surface treatment is simple and easy as well as low in cost. The processes can even be performed by hand. Pharmaceutical raw materials used for the surface treatment, such as hydrochloric acid and nitric acid used in a mixed acid washing process and vegetable oil used in an organic film forming process, are easily obtained in many countries.


Author(s):  
I.A. Bazhenov ◽  
T.E. Abramova ◽  
N.S. Mineeva ◽  
M.E. Solovyov ◽  
A.N. Danilova ◽  
...  

The process of film-forming of polyfunctional oligobutadienes of cationic type of different microstructure from organic-film-forming systems in the presence of acid-type hardeners was studied. The method of computer modeling indicates on the impact of cross-linking agents on the type of cross-linking and the flexibility of the polymer chains determining the physical and performance properties of the materials. A scientific approach to the creation of special purpose compositions with an improved combination of properties was proposed.


Author(s):  
Sergii Guzii ◽  
Ihar Bazhelka ◽  
Anastasiya Kanavalava

The biostability of organic film-formers of paints and varnishes intended for staining wood to the action of the fungus Aspergillus niger was studied. It was found that in Sabouraud's environment on days 7, 14 and 21 from the beginning of infection, the epoxy hardener is characterized by the minimum level of damage, respectively, 1, 1.6 and 2.4 points; alkyd film former has 2 points, and in subsequent time intervals 3.7 points; epoxy resin on day 7 is characterized by a lesion level of 1.7 points, on the following days of exposure – 4 points; pentaphthalic film former, respectively, 2.7, 3.7 and 4 points. According to the degree of resistance in the Sabouraud environment, organic film-formers of wood paints can be ranked as follows: epoxy (hardener)>alkyd>epoxy resin>pentaphthalic>organosilicon. It is shown that in the environment of Czapek on 7, 14 and 21 days from the beginning of infection, the minimum level of damage is characterized by an epoxy hardener, respectively, 2, 2.3 and 3 points; pentaphthalic film former, respectively, 2 and 3 points; alkyd film former, respectively, 2.4, 3.7 and 4 points; epoxy resin on day 7 is characterized by a lesion level of 3 points, on the following days of exposure – 4 points. According to the degree of resistance in the environment of Czapek, organic film-forming agents for wood paints can be ranked as follows: epoxy (hardener)>pentaphthalic>alkyd>epoxy resin>organosilicon. Organosilicon film-formers were most intensively affected by the fungus both 7 days after exposure and at a later time, reaching the maximum values of the lesions – 4 points. During the test period, no zones of mycelium growth inhibition were observed in the studied organic bases


Author(s):  
D. M. Davies ◽  
R. Kemner ◽  
E. F. Fullam

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.


Author(s):  
John C. Russ ◽  
Nicholas C. Barbi

The rapid growth of interest in attaching energy-dispersive x-ray analysis systems to transmission electron microscopes has centered largely on microanalysis of biological specimens. These are frequently either embedded in plastic or supported by an organic film, which is of great importance as regards stability under the beam since it provides thermal and electrical conductivity from the specimen to the grid.Unfortunately, the supporting medium also produces continuum x-radiation or Bremsstrahlung, which is added to the x-ray spectrum from the sample. It is not difficult to separate the characteristic peaks from the elements in the specimen from the total continuum background, but sometimes it is also necessary to separate the continuum due to the sample from that due to the support. For instance, it is possible to compute relative elemental concentrations in the sample, without standards, based on the relative net characteristic elemental intensities without regard to background; but to calculate absolute concentration, it is necessary to use the background signal itself as a measure of the total excited specimen mass.


Author(s):  
Earl R. Walter ◽  
Glen H. Bryant

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.


2020 ◽  
pp. 41-50
Author(s):  
Artem Mikhailovich Morozov ◽  
◽  
Alexey Nikolaevich Sergeev ◽  
Gennady Alexandrovich Dubatolov ◽  
Nikolay Alexandrovich Sergeev ◽  
...  

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.


2012 ◽  
Vol 19 (5) ◽  
pp. 1091-1095
Author(s):  
Chang-Hai SHI ◽  
Shao-Hua KONG ◽  
Hong-Mei ZHAI ◽  
Jing YANG ◽  
Dong-Xiao LI ◽  
...  

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