Application of surface wettability modified polypropylene nonwoven in Janus composite fibrous mats for the function of directional water transport

Textiles with the function of directional water (sweat) transport play a pivotal role in regulating human thermal and wet comfort. Polypropylene nonwoven (PPNW) fabric has an excellent moisture (sweat) conduction due to its inert water absorption, which makes moisture be difficult to adhere on the PP fiber surface. Nevertheless, excessive hydrophobicity also affects the comfort of clothing materials, and thus it is significant to improve wettability of PP fiber used in the field of textile. In this study, it was reported a kind of composite fibrous mats with the function of directional water transport. The polymerization of acrylic acid (AAc) was grafted on the surface of plasma-treated PPNW (TPPNW) as the inner layer (TPPNW-AAc), which was able to improve the wettability of the PPNW surface. Polyacrylonitrile containing alumina nano-particles (PAN-Al2O3) layer was deposited on the surface of TPPNW-AAc by electrospinning technology as the outer layer. The wettability difference between the inner and outer layers of the material was utilized to induce the push-pull effect to transport water from the TPPNW-AAc layer to the PAN-Al2O3 layer. The surface wettability of the TPPNW-AAc layer and the performance of the directional water transport of composite fibrous mats were characterized systematically. Experimental results demonstrated that the composite fibrous mats showed the excellent accumulative one-way transport index (AOTI, 870%), remarkable overall moisture management capacity (OMMC, 0.8) when the contact angle of the TPPNW-AAc surface can be reduced from 119 degrees to 30 degrees, and decent wearability performance.