What are the uses of nanocellulose?

When people mention the word "nano", they usually think of some high-tech technologies or products. Nanocellulose is a linear material with a very small diameter, which is at the nanometer level, but its length is very poor, so it is called nanofiber. Nanofibers are widely used, especially in the chemical and pharmaceutical industries. Nanocellulose plays an important role and has many of the following uses.

Nanocellulose Application:

Nanofibers have a wide range of uses. For example, when nanofibers are implanted into the surface of fabrics, they can form a stable gas film to create an amphiphilic interface fabric that is waterproof, oil-proof, and anti-fouling. Advanced protective clothing made of nanofibers has a porous fabric with a membrane, which not only allows air to pass through and is breathable, but also can block wind and filter fine particles, has barrier properties to aerosols, and can protect against biological and chemical weapons and toxic substances. In addition, nanofibers can also be used for purification and filtration of chemical and pharmaceutical products.

manufacture

The manufacturing of nanofibers can be roughly divided into three categories.

1. Molecular technology preparation method: the preparation of single-tube or multi-tube carbon nanotube bundles is reported more frequently. There are three main preparation methods: arc discharge method, laser ablation method and fixed bed catalytic cracking method. The first two methods are difficult to separate and purify because of the coexistence of various forms of carbon products. The arc discharge method places a graphite rod in a container filled with hydrogen and uses a high-voltage arc discharge to deposit carbon nanotubes at the cathode. The fixed-bed catalytic cracking method prepares carbon nanotubes from natural gas. The gas is blown into a boiling state over an activated catalyst on a distribution plate, and carbon nanotubes grow on the surface of the catalyst. This method has the advantages of simple process, low cost, easy control of the scale of carbon nanotubes, large length and high yield, but the catalyst in this method can only be expanded in the form of a thin film.

2. Spinning preparation method This method can be divided into polymer jet electrostatic stretching spinning method, island-type multi-component spinning method and single-screw mixing spinning method. Fibers with a thickness of 0.001 dtex (about 10 nm) can be produced by the single-screw mixing method.

3. Biological preparation method: This method uses bacteria to cultivate finer cellulose. The nano-scale cellulose synthesized by American scientists from Acetobacter xylinum does not contain lignin, has high crystallinity, high degree of polymerization, good molecular orientation, and excellent mechanical properties.