The Magic Two Dimensional Preferential Spreading Phenomenon Provides New Ideas For Functional Fabric Development.

When the liquid is in

When the surface is diffused, the absorption and absorption of liquid also occur at the same time. This phenomenon restricts the practical application of materials to a large extent.

Therefore, how to make liquid rapid spreading and reducing osmosis is a huge challenge.

Xuan paper is a traditional Chinese classical painting and calligraphy paper, produced in Anhui province of China. The preparation process needs 140 steps, and the preparation cycle lasts for two years. Up to now, it has been over 1500 years ago.

Because of its unique ink wettability, Xuan paper has been widely loved by Chinese calligraphy and painting and has been used for thousands of years.

The researchers studied the two dimensional preferential spreading of Xuan paper. They found that water would spread horizontally on Xuan paper, but rarely penetrated the back of the paper.

After testing, it was found that 150 L of water could spread on the surface of Xuan paper without any penetration.

Two dimensional preferential spreading of liquid on Xuan paper

The main chemical constituents of Xuan paper are

They have good hydrophilicity and high surface energy.

Unlike other papers, Xuan paper is made up of long fibers, which are interwoven in the drying process of the pulp rather than arranged in disorder.

Therefore, the long fibers in Xuan paper should be arranged in layers, even though there is no definite interlayer boundary.

When water is in contact with Xuan paper, the first water will be absorbed into the micron hole, and the spreading process will suddenly accelerate. Then, the uninfiltrated nanofiber hole begins to absorb the liquid, causing the liquid spreading to accelerate again.

With the excessive accumulation of liquid in the superstructure, the liquid gradually approached the lower fiber, and then formed a liquid bridge between the upper and lower layers of Xuan paper fibers.

Once the liquid bridge is formed, the liquid will expand rapidly on the surface of the next layer of fiber, consume a lot of liquid, and the liquid bridge will gradually weaken or even break.

Therefore, the lateral spread of liquid on the surface of Xuan paper is dominant and longitudinal penetration is blocked.

Two dimensional preferential spreading mechanism

The unique spreading properties of Xuan paper are mainly attributed to its unique layered micro / nano pore composite structure and chemical composition.

Inspired by Chinese Xuan paper, a cellulose acetate membrane similar to Xuan paper structure was prepared by electrospinning method. After hydrolysis, the cellulose paper with similar microstructure and chemical composition on the surface of Xuan paper was obtained.

The experimental results show that the nanoscale cellulose paper can achieve rapid spreading of 175 L water without penetration, and has better spreading performance than Xuan paper.

The relevant articles are published online on Advanced Functional Materials. This work can provide inspiration for designing the application of anisotropic wetting fabrics by studying and simulating the phenomenon of two-dimensional preferential spreading of Xuan paper, for example, research and development of new anti penetration clothing.

And so on.