Crosslinking of Sericin on air atmospheric plasma treated polyester fabric

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 degrees and 46 degrees compared to 81 degrees 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.