Multifunctional surface modification of silk fabric via graphene oxide repeatedly coating and chemical reduction method

Multifunctional silk fabrics with electrical conductive, anti-ultraviolet and water repellent were successfully prepared by surface modification with graphene oxide (GO). The yellow-brown GO deposited on the surface of silk fabric was converted into graphitic black reduced graphene (RGO) by sodium hydrosulfite. The surface properties of silk fabrics were changed by repeatedly RGO coating process, which have been proved by SEM and XPS. The SEM results showed that the RGO sheets were successive form a continuously thin film on the surface of silk fabrics, and the deposition of GO or RGO also can be proved by XPS. The electrical conductivity was tested by electrical surface resistance value of the silk fabric, the surface resistance decreased with increasing of RGO surface modification times, and a low surface resistance value reached to 3.241 K ohm cm(-1) after 9 times of modification, indicating the silk obtained excellent conductivity. The UPF value of one time GO modification silk fabric (silk-1RGO) was enhanced significantly to 24.45 in comparison to 10.40 of original silk. The contact angle of RGO coating silk samples was all above of 120. The durability of RGO coated silk fabrics was tested by laundering. The electrical surface resistance of silk-4RGO (65.74 K ohm cm(-1)), silk-6RGO (15.541K ohm cm(-1)) and silk-8RGO (3.86 K ohm cm(-1)) fabrics was up to 86.82, 22.30 and 6.57 K ohm cm(-1) after 10 times of standard washing, respectively. The UPF value, contact angle and color differences of RGO modified silk fabric slightly changed before and after 10 times of standard washing. Therefore, the washing fastness of electric conduction, anti-ultraviolet and water repellent multifunctional silk fabrics was excellent. (C) 2017 Elsevier B.V. All rights reserved.