Surface modification of melamine formaldehyde resin particles in a stratified glow discharge in neon

Abstract

The paper presents the description of the change in size and structure with time of the surface of polymer particles of melamine formaldehyde injected as a dust component of a complex plasma formed in a stratified glow discharge in neon. The experiment was carried out in a specialized discharge chamber, equipped with a device for collecting particles from a dust trap. The analysis of the size and surface structure was carried out by scanning electron microscopy, which gives the original and the resulting surface views of the plasma‐processed particles. These profiles show the variation in surface roughness distribution under the action of the plasma. The time dependence of the particle diameter on plasma exposure was tracked. Data show that 25 min of exposure results in the dust particles losing a substantial part of their volume, which is accompanied by a decrease of the diameter by half. Our results coincide with previous data for smaller particles in similar plasma conditions.The particles used in this work are larger but still are able to levitate in a dust trap, and corresponding processes of size degradation and surface modification are extremely intense.

Particle charge in PK-4 dc discharge from ground-based and microgravity experiments

“…In addition, the data of experiments performed on ISS confirm previous observations from parabolic flights, [3] that microparticles in ground-based experiments move faster than under microgravity conditions. The difference is more pronounced for the lower pressure range (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). The theoretical curves are in agreement with this tendency.…”

“…Another possible reason for the deviation between the theory and experimental measurements could be the changing of the microparticle mass and shape during the exposure in the plasma discharge as it has been reported in several works. [26][27][28][29][30] Since in our case the time of the microparticles levitation in the discharge corresponds to a minute timescale, we do not expect this effect to be very important.…”

Self-organization of Coulomb balls in glow DC discharge in neon at cryogenic temperature

“…The vertical light stripes along the edges of the images and blurred glare are the result of background illumination of scattered laser radiation. The appearance of fuzzy areas in figure 3(b) is possibly caused by the background scattering of laser radiation on the finely dispersed phase formed by sputtering the surface of some melamine formaldehyde particles in the discharge [42,43,45]. The effect of background illumination appeared in all images after several tens of minutes of operation of the experimental setup.…”

Dust-Acoustic Nonlinear Waves in a Nanoparticle Fraction of Ultracold (2K) Multicomponent Dusty Plasma

“…This hypothesis was confirmed during an additional experiment carried out at room temperature, which revealed an intense glow near the cone outlet. It is well known that polymer surfaces are easily sputtered in strata of the DC glow discharge [ 47 , 48 ]. Therefore, we can expect rather an efficient sputtering of the cone material because it contains acrylic polymer [ 24 ].…”