ELECTROKINETIC AND SORPTION PROPERTIES OF PLASMA TREATED JUTE FABRICS

Abstract

Jute fibers are characterized by a complex layered structure with the presence of a hydrophobic surface outer layer consisting of a mixture of waxes and fats. This outer layer is responsible for fibers' low sorption properties. In this work, raw jute fabric was subjected to atmospheric pressure dielectric barrier discharge (DBD) under different conditions (150 Hz and 15.2 kV, vs. 300 Hz and 12.6 kV, air as working gas, constant time of 120 s) to remove the mentioned hydrophobic layer. Changes in the surface chemistry of DBD modified jute fabrics were monitored by ATR-FTIR spectroscopy and measurement of the electrokinetic properties, while the fabric sorption properties were evaluated by measuring the wetting time and capillarity. Special attention was given to the aging effect investigated up to fourteen days after plasma treatment. The obtained results reveal that the measurement of the electrokinetic properties could be used to follow changes in the surface chemistry of DBD treated jute fabrics due to the post-plasma reactions (Fig. 1) and confirm the significance of aging effects in natural cellulose fibers’ functionalization using plasma. Although the changes in the fabric surface chemistry were more pronounced for fabric treated with a higher DBD frequency DBD, a lower frequency DBD treatment resulted in better sorption properties. Both DBD treatments and aging decreased wetting time from 145.9±6.0 s for raw jute fabric down to 1.2±0.1 s for a lower frequency DBD treated fabric after 7 days of aging. Independently on the applied DBD treatment conditions, the jute fabrics' capillarity was significantly improved; i.e., their capillary height increased from 87 mm for the raw jute fabrics up to 138 mm and 120 mm for a lower and higher frequency DBD treated fabrics, respectively.