The Degradation of Cellulose by Radio Frequency Plasma

Abstract

This paper describes the results of using oxygen (O2) plasma to treat both greige and scoured cotton yarns to cause significant degradation of cellulose. This study is an effort to reduce hazardous caustic chemicals commonly used to make the cellulose molecule more accessible for uses in such applications as biofuels. Through high power density, 0.46 W/cm2, and the study of varying exposure times, we find longer durations of 30 min to 90 min result in significant cellulose structure degradation. Due to waxes and contaminants found on greige yarns, scoured yarn degradation occurs at shorter exposure times than greige yarns, however, both experience tearing and pitting with longer exposures. This study provides evidence that significant degradation of cellulosic yarns can be achieved through high power density O2 plasma exposure.

Effect of Microwave Plasma Pre-Treatment on Cotton Cellulose Dissolution

“…This is likely attributed to the etching effect of highly energized plasma particles. Similar physical degradation was reported in several studies when fibers were exposed to oxygen plasma as well as DC air plasma and di-electric barrier discharge plasma (DBD) [ 49 , 52 , 53 , 54 ]. The presence of surface cracks and defects in plasma-pretreated cotton fibers could improve cellulose dissolution as they can facilitate solvent diffusion and accessibility to the internal well-organized structures of cellulose.…”

“…Plasma pretreatment of cotton fibers for 20 and 40 min decreased the MW of cellulose by 36% (2.5 × 10 5 Da) and 60% (1.5 × 10 5 Da), respectively. Shepherd et al reported a similar effect of oxygen plasma treatment on the MW of cellulose [ 52 ]. The authors found that the initial level of polymer degradation was largely dependent on the level of impurities, such as wax substances, located on the sample surface.…”

“…This supports the breakage of the pyranosidic bond between O(ring)-C1. Other studies also reported pyranosidic cleavage of cellulose chains forming -C=O group due to the exposure of cellulose to oxygen plasma [ 42 , 52 , 56 ]. In addition, the products of oxidation reactions might increase the intensity of -C=O group as well.…”

Surface functionalization of greige cotton knitted fabric through plasma and cationization for dyeing with reactive and acid dyes

“…A slight reduction of washing fastness for plasma treated fabrics was also reported by other authors (Akbarpour et al 2013;Feng et al 2020). Some research observed a physical degradation of the fabric after plasma treatment, such as microcracks pitting and splitting of the ber (Shepherd and Frey 2018;Feng et al 2020). These degraded bers were probably removed from the fabric during the washing and rubbing fastness tests.…”

“…The surface etching by atmospheric plasma partially destroyed the hydrophobic layer and the hydrophilicity is dependent on the power and time of the plasma treatment (Carneiro et al 2001;Karahan and Özdoğan 2008). Shepherd and Frey (2018) treated scoured and greige cotton yarns with long plasma exposure times (15-90 min). Scoured cotton had severe physical damage, even at the lowest exposure time (15 min), while greige yarns had less degradation.…”