Moisture wicking textiles with directional water transport

The use of textile-based clothing is predominant globally owing to its flexibility, cost and effectiveness especially during hot and humid conditions. Due to the rapid climatic changes and global warming, demand for quick drying performance-based clothes has significantly increased. This has attracted significant attention of many researchers. Among the available commercial materials for personal moisture wicking, textiles composed of profiled fibers is the commonly used moisture wicking technology. It employs capillarity force to get rid of sweat from the body. Unfortunately, textile exhibit a bidirectional water transport system thus during the transfer of the moisture, both the inner and outer side of the textiles will get wet hence clinging to the body which may lead to more discomfort.

To this note, the challenge is to develop a directional water transport system. The porous materials can be classified as either wettability gradient or Janus wettability which signify a gradual change in wettability and abrupt change in wettability across the porous materials respectively. However, they experience several limitations including difficulties in preventing the transport of water in the reverse direction and balancing the flow of water in the forward direction. Therefore, researchers have been looking for alternatives and have identified the combination of the two strategies as a promising solution to balance the water transport capacity and prevent penetration in the reverse direction. Consequently, multilayered electrospun fibrous membranes have the potential of achieving progressive wettability in conjunction with the two strategies.

In a recent research paper published in Small, Donghua University scientists: Professor Bin Ding, Professor Xianfeng Wang, Professor Jianyong Yu and Dr. Dongyang Miao developed a functional moisture wicking textile with directional water transport capability. It was based on trilayered fibrous membrane fabricated through electrospinning method followed by alkali treatment. They used hydrolyzed polyacrylonitrile-SiO2 fibrous membrane as the outer layer and polyurethane as the inner layer. Furthermore, a transfer layer was introduced to achieve progressive wettability by guiding water penetration from the inner layer to the outer layer while blocking penetration in the reverse direction. They purposed to develop more comfortable and efficient wicking textiles for hot and humid conditions.

The author observed a high directional water transport capacity for the resulting trilayered fibrous membrane. For instance, a directional transport index of 1021% and a reverse breakthrough pressure of 16.1 cm H2O was obtained. This was greater than those obtained for bilayered fibrous membrane.

The study by Donghua University researchers successfully proposed a directional water transport mechanism for functional textiles. This was attributed to the additional transfer layer which resulted in the progressive water flow from the inner layer to the outer layer while preventing the reverse flow. Additionally, the successful synthesis of such fascinating materials paves the way to understand the directional water transport mechanism which would be valuable for the design of functional textiles for personal drying applications, such as workwear and advanced sportswear.