In this study, we fixed silk sericin in fabrics as a finishing product. First of all, we have extracted sericin from silkworm cocoons in order to obtain the optimum yield of sericin that is not denatured. For this reason, we have searched the optimum parameters for a favorite sericin extraction. Then, the sericin extracted was fixed onto wool and cotton fabrics in an aim to modify some of their properties. The tests of treated fabrics showed that sericin has an affinity for wool, whereas it does not have it for cotton. This affinity for wool fiber was obtained in defined conditions with about 48% exhaustion rate for a sericin concentration of 2.5% (w/w). Compared to different sericin concentrations (0%, 2.5%, 5%, 10% and 20%), a 5% of sericin (w/w) improved the wool samples touch until a score of 4 points, as well as the water’s absorption with a profit of 70.75%. The samples also showed an improved antibacterial activity.

Durable and highly hydrophilic polyester fabric was produced by cross-linking Sericin on air-atmospheric plasma treated polyester fabric. Surface change properties were characterized by wettability measurements (water contact angle-WCA and % capillarity), Atomic Force Microscopy and zeta potential measurements. Chemical analyses using TBO dye were carried out to estimate surface functional groups after plasma treatment and Sericin cross-linking. Positive zeta potential values at low pH values, as well as AFM images confirm grafting of Sericin. With Sericin cross-linked onto both cleaned PET and plasma-treated PET, WCA reached that of PET subjected to plasma treatment alone, that is WCA between 40° and 46° compared to 81° for the hydrophobic untreated polyester fabric. However, plasma-treated polyester is readily subjected to aging, while cross-linked Sericin on plasma-treated PET yields a more durable hydrophilic finish with a high capillarity, 85% compared to 39% for Sericin on the untreated PET, and 3% for the untreated PET fabric. Plasma treatment creates chain-scissions at the polymer surface leading to the appearance of polar groups which promote the cross-linking of greater amount of Sericin.

Plasma treatment is known as a new technology applied on textile surface allowing the modification of their chemical properties. In our study, we have activated a cotton fabric surface with air atmospheric plasma. The wettabilty measurements, in terms of water contact angle and capillarity, reveal the hydrophobic behavior of cotton surface after plasma treatment under the studied conditions. The water contact angle increases from 60 degrees for the untreated sample to 128 degrees after 1 week from plasma activation. The capillarity of the plasma-treated surface reaches 42% instead of 72% for the untreated one. The chemical, morphological and physical modifications of cotton surface were also investigated before and after plasma activation.