Surface Treatment of Polymeric Fine Powders by CF4 Plasma in a Circulating Fluidized Bed Reactor

Abstract

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 CF 4 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 contact angle measurements were made to characterize the surfaces of powders. Solid holdup in the CFB plasma reactor mainly governs the stability of plasma glow and the surface property of the powders. Surface of HDPE powders is fluorinated into CHF-CH 2 , CHF-CHF and CF 2 groups. The extent of fluorination increases up to 54% with the treatment time and rf power. The atomic percent of surface fluorine content increases with the composite parameters [(W/FM)t] and [(W/FM)t]/m down to 2,500 GJ•s/kg-gas and 19.8 GJ•s/kg-solid, respectively, thereafter it remains constant.

Influence of increased velocity on the statistical discharge characteristics of He and air barrier discharges

“…However, it appears rather inappropriate for particulate materials, i.e. powders with characteristic particle sizes from 1 to 100 µm [13][14][15][16]. In the confined space of a typical BD gap [4,17], direct plasma interaction enhances powder agglomeration, and thus promotes equipment clogging.…”

High-efficiency plasma surface modification of graphite-encapsulated magnetic nanoparticles using a pulsed particle explosion technique

“…Recently, the plasma processing of magnetic materials has drawn much attention with regard to nanoparticle surface treatment for medical uses, such as drug delivery systems or magnetic resonance imaging systems. There have been several plasma reactor systems already developed for particle treatment, such as the bell jar reactor, 12,13) downstream reactor, 14) rotary drum reactor, 15) plasma fluidized bed reactor, [16][17][18] circulating bed reactor, 19,20) plasma batch reactor, 21) plasma downer reactor, 22) and plasma reactor with a mechanical vibrator such as an electromagnet 12) or a stirrer. 13) The purpose of these plasma systems is to interface particles with plasma species.…”

Investigation of the Performance of Barrel Atmospheric Plasma Source for the Deposition of Fluorocarbon Coating onto Silicone Polymer Particles

“…These treatments can be used for example, to change the chemical composition, increase the surface energy, modify the crystallinity, morphology, and surface topography, or remove contaminants and weak boundary layers [2,3]. One area of interest is in decreasing the surface energy of polymers by creating Teflon-like surfaces which exhibit non-wetting behavior, low permeability and good thermal stability [4]. Polymers are however often processed as granules, for examples with applications in the additive manufacturing and biotechnology (Cell support) [5,6].…”