Donghua University: Inspired By The Transpiration Of Plants, The Functional Textiles With Moisture Absorption And Cooling Are Developed

With the continuous improvement of living standards, people have higher and higher requirements for the comfort and functionality of clothing. People in the process of exercise will produce a lot of heat, if can not be discharged in time, it will produce sticky and other discomfort. The heat dissipation of human body is mainly in the form of sweat evaporation and heat conduction inside and outside the fabric. Therefore, the demand for textiles with hygroscopic, sweat-wicking and cooling functions is increasing year by year.

However, the rapid evaporation of sweat depends on the interconnected capillary pores, and the efficient internal and external heat conduction requires a compact structure, and there is a conflict between the optimal balance of the two. At present, the development of comfort functional textile fabrics usually focuses on the moisture absorption and moisture transfer, but ignores the heat dissipation performance. Therefore, it is of great significance to develop textiles with moisture absorption and cooling function.

After millions of years of natural evolution, plants have an optimized way of water transmission and heat emission transpiration. Through the multi-level bifurcation network of vascular tissue and leaf vein system, plants can obtain the required nutrients and water and exchange heat with the outside world.

Through comparison, it can be found that the working principles of plant transpiration and moisture absorption and cooling textiles are similar. Plants absorb water from the ground and transport through vascular and leaf vein systems to promote nutrient transfer and water evaporation, and avoid high temperature damage; moisture absorbing and cool textiles absorb sweat from the skin surface, and quickly transfer and evaporate through the capillary pores between fibers, bringing dry and cool microclimate to the human body. Therefore, the fiber membrane with multi-level interconnection network structure can be the optimal design direction of multifunctional moisture absorption and cooling textiles.

Recently, dingbin research group of Donghua University has successfully prepared moisture absorbing and cool textiles with multi-level interconnected mesh structure based on biomimetic plant transpiration. The fabric is made of polyurethane / boron nitride Nanoflake (PU / bnns) high thermal conductivity oriented fiber, and the multi-stage bifurcated inter fiber interworking channels are used to realize the anti gravity single moisture transmission and efficient heat dissipation performance.

The results show that the unidirectional moisture permeability index of the prepared fabric is 1072%, and the water evaporation rate is 0.36g/h. The thermal infrared camera can directly see that the bionic PU / bnns fiber film has better heat dissipation performance than the traditional fabric under dry / wet conditions.

In addition, on the basis of optimizing the performance, the moisture conduction and heat dissipation mechanism based on the multi-stage interconnected mesh structure is proposed, which provides a theoretical basis for the in-depth understanding of the heat and moisture transport in the multi-stage interconnected channels of fiber materials, and provides a reference for the design and development of multifunctional moisture absorption and cool textiles.