A low-pressure plasma surface treatment of polymeric powders was carried out in a circulating fluidized bed (CFB) reactor (10 mm-I.D. × 800 mm-high) with CF4 glow discharge. The effects of solid circulation rate, treatment time and radio frequency (rf) power of plasma on fluorination of high-density polyethylene (HDPE) powders have been determined. X-ray photoelectron spectroscopy (XPS) and the...

the aisi 316 l stainless steel (ss) specimens were exposed to passivation surface through two different processes including; holding in 40-vol% hno3 at temperature of 60 ºc for 30 min and 15-vol%h2so4 at ambient temperature for 1 hour. the corrosion behavior of specimens was evaluated in physiological solutions by electrochemical in vitro tests through linear and tafel polarization tests. cycli...

Cold atmospheric pressure plasma jets (APPJs) are able to generate chemically reactive species desired for material processing and biomedical applications. A great amount of attention has been devoted to characterizing these APPJ sources and expanding their applications. Less is known on the interaction mechanisms between cold atmospheric pressure plasma and material surfaces. Since both plasma...

BACKGROUND Dust accumulation on surfaces of critical instruments has been a major concern during lunar and Mars missions. Operation of instruments such as solar panels, chromatic calibration targets, as well as Extra Vehicular Activity (EVA) suits has been severely compromised in the past as a result of dust accumulation and adhesion. Wind storms with wind speeds of up to 70 mph have not been e...

A novel plasma treatment method/plasma source called cupping-assisted plasma treatment/ source for skin disinfection is introduced. The idea combines ancient Chinese ‘cupping’ technology with plasma sources to generate active plasma inside an isolated, pressurecontrolled chamber attached to the skin. Advantages of lower pressure include reducing the threshold voltage for plasma ignition and imp...

We report a simple method for fabrication of one-dimensional, two-dimensional and nested hierarchical wrinkling patterns on polymeric surfaces using plasma treatment. The morphology of wrinkle patterns, specifically the wavelength and amplitude of each wrinkle generation, is controlled by the treatment time and stretching release after each treatment step. By systematically varying these two ke...

the technique used to control the airflow is based on the electro-hydrodynamic actuator which is also called plasma actuator. this actuator ensures the airflow control thanks to the electric wind created by the electrical corona discharge. this ionic wind is developed at the profile surface tangential to the initial free airflow so that it has a significant effect on the boundary layer flow. th...