The influence of the unipolar corona discharge on surface energy of modified cardboard

2019 ◽  
Author(s):  
S. I. Basyrova ◽  
M. F. Galikhanov ◽  
I. F. Shaymukhametova ◽  
S. A. Bogdanova
Keyword(s):  
Surface Energy ◽  
Corona Discharge ◽  
Unipolar Corona Discharge

An approach for unipolar corona discharge in N2/O2 gas mixture by considering townsend conditions

2011 ◽  
Vol 69 (4) ◽  
pp. 284-290 ◽  
Author(s):  
Hafiz Z. Alisoy ◽  
Ali Yesil ◽  
Murat Koseoglu ◽  
Ibrahim Unal
Keyword(s):  
Corona Discharge ◽  
Gas Mixture ◽  
Unipolar Corona Discharge

scholarly journals “Electrical wind” in CO2–laser mixtures at superatmospheric pressures

2021 ◽  
Vol 2064 (1) ◽  
pp. 012026
Author(s):  
B A Kozlov ◽  
D S Makhanko
Keyword(s):  
Carbon Dioxide ◽  
Chemical Composition ◽  
Corona Discharge ◽  
Flow Velocity ◽  
Wind Velocity ◽  
Discharge Current ◽  
Gas Flow ◽  
Molecular Nitrogen ◽  
Unipolar Corona Discharge ◽  
Gas Flow Velocity

Abstract This article presents the results of “electrical wind” investigations in CO2–laser mixtures at superatmospheric (1–12 atm) pressures. It is established that for a fixed value of the unipolar corona discharge current, the gas flow velocity does not depend on the pressure, but is determined by the chemical composition of the working mixture. The maximum values of the “electrical wind” velocity are achieved in carbon dioxide and molecular nitrogen and their values are 3.2 and 2.9 ms−1. In typical laser mixtures CO2:N2:He = 1:1:1 – 1:1:3 the velocity of the “electrical wind ” are in the range from 2.5 to 1.5 ms−.

Separation of oil emulsion using polyacrylonitrile membranes, modified by corona discharge

2020 ◽  
pp. 30-37
Author(s):  
I. G. Shaikhiev ◽  
◽  
V. O. Dryakhlov ◽  
M. F. Galikhanov ◽  
D. D. Fazullin ◽  
...  
Keyword(s):  
Corona Discharge ◽  
Treatment Time ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Water Emulsion ◽  
Oil Emulsion ◽  
Force Microscopy ◽  
Atomic Force ◽  
Unipolar Corona Discharge ◽  
Pes Membrane

It is investigated the influence of the parameters of the unipolar corona discharge (the treatment time, voltage) on the performance and selectivity of separation of model emulsions “oil in water” based on the oil in the Devonian deposits Tomatocage field (Republic of Tatarstan) using polyacrylonitrile membranes with a molecular weight cut-off of 60 kDa particles. Determined COD values of the original emulsions and filtrates. The values of the processing time (30 seconds) and voltage of the corona (5 kV) membranes, which achieved the best performance and selectivity of the separation process of oil-water emulsion. Sitting drop methods, x-ray diffraction and atomic force microscopy showed changes of the surface structure and internal structure of treated membrane. In particular, there was decrease in the wetting angle from 45.1 to 43.3 and an increase in the degree of crystallinity from 0.15 to 0.18, which is due to the flow on the surface of PES membrane processes of etching and oxidation resulting from exposure to a unipolar corona discharge ozone, which is also confirmed by images of the surface of the filter elements and the histograms of the topography, based on which it showed a decrease in height and number of protrusions from 42 nm and 7500 to 10 nm and 2500.

Characteristics of a unipolar corona discharge in active media of high-pressure atomic Ar, Kr, and Xe lasers

1997 ◽  
Vol 27 (6) ◽  
pp. 505-508 ◽  
Author(s):  
Aleksandr K Shuaibov ◽  
Igor' V Shevera ◽  
Arkadii I Dashchenko
Keyword(s):  
High Pressure ◽  
Corona Discharge ◽  
Active Media ◽  
Unipolar Corona Discharge

Hydrophobicity recovery of corona-modified superhydrophobic surfaces produced by the electrospinning of poly(methyl methacrylate)-graft-poly(dimethylsiloxane) hybrid copolymers

2009 ◽  
Vol 81 (3) ◽  
pp. 495-511 ◽  
Author(s):  
Morne Swart ◽  
Peter E. Mallon
Keyword(s):  
Surface Energy ◽  
Methyl Methacrylate ◽  
Corona Discharge ◽  
Surface Segregation ◽  
Electrospinning Process ◽  
Superhydrophobic Surfaces ◽  
Copolymer Composition ◽  
Fiber Morphology ◽  
Free Radical Copolymerization ◽  
Poly Methyl Methacrylate

Superhydrophobicity is dependent on both the surface energy and the texture of the surface. These factors are discussed in terms of a series of electrospun poly(methyl methacrylate)-graft-poly(dimethylsiloxane) (PMMA-g-PDMS) copolymers with different poly(dimethylsiloxane) (PDMS) content. These copolymers are synthesized via conventional free radical copolymerization of methyl methacrylate (MMA) and monomethacryloxypropyl-terminated PDMS macromonomers. It is shown how these copolymers can be electrospun to produce copolymer fibers with diameters in the 100-1000 nm range. The effect of the copolymer composition (and hence the surface energy) and the electrospinning tip-to-collector distance (TCD) on the fiber morphology is discussed. The surfaces produced by the electrospinning process show superhydrophobic properties where the preferential surface segregation of the PDMS component is combined with the roughness of the fiber surface. The surface energy of the fibers is varied by variation of the PDMS content in the copolymers as well as by post-spinning modification with corona discharge. The hydrophobicity of the surfaces shows a greater dependence on the PDMS content than on the average fiber diameter. After exposure of these fiber surfaces to corona discharge, the initial superhydrophobic surfaces become easily wettable despite the fact that much of the surface roughness is maintained after exposure. The samples show the phenomena of hydrophobocity recovery after corona exposure. The rate and extent of this recovery depends on the PDMS content and the corona exposure time. Despite the recovery, scanning electron microscopy (SEM), swelling measurements, and confocal Raman spectroscopy show that permanent surface changes have taken place. The surfaces do not recover to their original superhydrophobic state.

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