Atmospheric pressure plasma-chemical reactor for the modification of polymeric roll materials

Greetings to you, dear reader! Today I would like to talk about one of the applications of low-temperature atmospheric pressure plasma. The Internet is now a lot of information about how to get high voltage capable of penetrating a discharge of sufficient power. Many lovers get beautiful discharges such as arc streamers, crowns, etc. from Tesla coils, horizontal transformers of televisions and microwave ovens.



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In addition to beauty, gas discharge plasma can be widely used in various industries as a tool for modification, activation, and purification. One of the traditional areas of application is light industry, where low-pressure or atmospheric pressure plasma is used to process polymer films in order to prepare it for painting, varnishing, gluing products and the like. Those. in essence, the purpose of plasma exposure here is an increase in the surface energy of the material. Giving the surface specific properties, for example, forming the maximum amount of a certain type of double bonds in the absence of another type of bonds is a non-trivial task due to the high chemical activity of a non-equilibrium gas-discharge plasma.





Recently, the field of application of polymeric materials has expanded significantly. In addition to the traditional, relatively primitive use as packaging, electrical insulation, textile materials, they, in particular polymers, are used in the manufacture of exchange membranes, fibers. A large number of medical polymers have appeared - a number of specific requirements are imposed on them, which can often be met only by grafting various drugs onto the surface, for which the surface must be uniformly and uniformly activated. Those. an idea emerged that was voiced in the previous paragraph - imparting specific properties to the surface.

In view of the fact that the interests, including scientific ones, are associated with low-temperature plasma, a number of works were read in which the possibility of using so-called plasma-solution systems for the modification of polymeric materials was shown. The simplest system is a metal and liquid electrodes, between which a gas discharge burns, and the modified material is in solution. In such a system, plasma activity can be combined with the directionality and selectivity of the processes occurring in the solution under its influence.

Thus, plasma-solution systems can be a promising direction for the development and improvement of methods for selectively imparting certain properties to polymeric materials. For this, the following installation was invented:

The installation is a cell with a solution through which a polymer film passes, pulled by an electromechanical drive.

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The surface of the solution in the cell is scanned by the discharge in reverse translational motion with stops for pulling the film. Thus, we have a two-axis CNC machine.

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The prototype was made of drives of two toy machines, a piece of organic glass and several semiconductor devices. Since, in my opinion, I have already reviewed the text, I’ll give videos for clarity:



Then they replaced the scanning system with a CD-ROM drive in order to get rid of the IR sensors, and also replaced the film pulling system with a mechanism for running paper through the printer. Since the drives based on stepper motors, we had to slightly change the electrical part ...



The electrical part consists of a board with an AVR ATmega8 microcontroller and two drivers L293d and l298N.

In the process of working from the discharge, the solution in the cell was heated and it was necessary to additionally manufacture a larger cell. For the exchange of fluids between them, two vaz car washer pumps were used.



Further work has become more complicated due to the lack of controls, as every time the microcontroller is pretty tired of reflashing the microcontroller. As a result, almost the entire installation was reworked: they placed everything in a separate building, replaced the MK with megu16, added an LCD and a few buttons - the remote turned out to control speeds and distances:



At this, the installation was left alone, many experiments were carried out, optimal operating modes were identified, for different solutions and the power invested in the discharge. All rollers use plain distilled water as a working solution. Experiments were carried out with different solutions, so far I cannot say anything about the results for objective reasons. A patent was obtained for the installation.

For this resource, I am writing an article for the first time, and I haven’t figured out everything especially with the design. For content, write in the comments.

Thanks for attention!

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