Modification of Cotton by Radiofrequency Plasma of Ammonia

Abstract

Cotton printcloth was treated with low-temperature, low-pressure ammonia plasma created by passing ammonia gas through a radiofrequency (rf) electric field of 13.56 MHz. Fabrics were exposed to the plasma for 3600 s. Pressure was maintained at 150 μm Hg and rf power at 40 W. Samples located between the electrodes lost additional weight over that caused by removal of moisture under reduced pressure. Material that was insoluble in cupriethylenediamine was formed in the cotton fibers. Cross sections of these fibers resembled those of conventionally crosslinked cotton cellulose in that they resisted layering. Electron spectroscopy for chemical analysis (ESCA) and multiple internal-reflectance spectroscopy (MIR) showed addition of nitrogen and suggested an amide structure. Free radical sites that produced chemiluminescence were formed. Comparison of ESR spectra with those obtained previously with rf plasmas led to the conclusion that glucoside bonds were broken to form activated carbonyls. The irradiated fabric exhibited a modest increase in conditioned wrinkle recovery with no change in wet recovery.