Imaging gas and plasma interactions in the surface-chemical modification of polymers using micro-plasma jets

This paper reports on the correlation between gas flow and plasma behaviour in the outflow of a micro-atmospheric pressure plasma jet operating in helium using both 2D optical imaging and Schlieren photography. Schlieren photography shows that the helium outflow changes from laminar to turbulent con...

Full description

Saved in:
Bibliographic Details
Published in:Journal of physics. D, Applied physics Applied physics, 2011-04, Vol.44 (15), p.155206
Main Authors: Oh, Jun-Seok, Olabanji, Olumuyiwa T, Hale, Craig, Mariani, Raffaello, Kontis, Konstantinos, Bradley, James W
Format: Article
Language:English
Subjects:
Exact sciences and technology
Fundamental areas of phenomenology (including applications)
Instruments, apparatus, components and techniques common to several branches of physics and astronomy
Optical elements, devices, and systems
Optics
Photography, photographic instruments and techniques
xerography
Physics
Physics of gases, plasmas and electric discharges
Physics of plasmas and electric discharges
Plasma turbulence
Schlieren devices
Waves, oscillations, and instabilities in plasmas and intense beams
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This paper reports on the correlation between gas flow and plasma behaviour in the outflow of a micro-atmospheric pressure plasma jet operating in helium using both 2D optical imaging and Schlieren photography. Schlieren photography shows that the helium outflow changes from laminar to turbulent conditions after distances between 20 and 50 mm from the nozzle. Above a flow rate of 1.4 slm, the length of the laminar region decreases with increasing flow rate. However, by contrast the visible plasma plume increases in length with increasing flow rate until its extension just exceeds that of the laminar region. At this point, the plasma becomes turbulent and its length decreases. Exposing polystyrene (PS) samples to the plasma jet significantly alters the water contact angle in a defined area, with the hydrophobic PS surface becoming more hydrophilic. This modification occurs both with and without direct contact of the visible glow on the surface. The radius of the treated area is much larger than the width of the visible jet but much smaller than the area of the turbulence on the surface. The treated area reduces with increasing nozzle–substrate distance.
ISSN:0022-3727
1361-6463
DOI:10.1088/0022-3727/44/15/155206