Modification of one side of mulberry silk fabric by monochromatic VUV excimer lamp

One side of mulberry silk fabric surface was irradiated with monochromatic VUV excimer lamp (172 nm). Change in surface morphology due to one side (I) and two side (II) irradiation was analyzed using high resolution scanning electron microscope (SEM) and atomic force microscope (AFM). The irradiated samples were further characterized through measurement of wetting time, vertical and horizontal wicking. Surface nanopores of 100 nm × 10 nm were formed on the irradiated side, however, on back side change in morphology was not observed. Upon one side irradiation the wettability and wickability improved significantly. One side irradiated silk surface (I) showed average wetting time of 14.7 s and 7.2 s while the two side irradiated silk surface (II) showed a wetting time of 9.3 s and 3.1 s for irradiation period of 1 min and 5 min, respectively. Beyond 5 min of irradiation the wettability of both the surfaces stabilized. Mechanism responsible for wetting behaviour of one side irradiated sample has been proposed. The influence of lamp geometry on irradiation effect was found to be noticeable for irradiation timings <5 min.