Method for dispersing nanocellulose in water

Dispersing nanocellulose in water usually takes several steps to ensure uniform dispersion and avoid agglomeration. Here are the common methods of dispersion:

1. Mechanical stirring

Steps: Add the nanocellulose powder directly to the water and stir with a high-speed stirrer. The stirring time and speed need to be adjusted according to the properties of the nanocellulose.

Advantages: Simple and easy to use, suitable for small-scale preparation.

Limitations: For nanocellulose with high concentrations or severe agglomeration, the effect may not be ideal.

2. Ultrasonic dispersion

Steps: Use ultrasonic wave to break the agglomerates of nanocellulose and disperse them in water. Usually, probe ultrasonic instruments are used, and the processing lasts for several minutes to more than ten minutes.

Advantages: It can effectively disperse nanocellulose to obtain a uniform and stable dispersion.

Limitations: Ultrasonic treatment may cause partial damage to the nanocellulose structure, so the ultrasonic time and power need to be controlled.

3. Add dispersant

Steps: Add an appropriate amount of dispersant (such as surfactant, polymer, etc.) to the water, then add nanocellulose, stir or disperse it ultrasonically.

Advantages: Dispersants can significantly reduce the agglomeration tendency of nanocellulose, improve the dispersion effect and the stability of the dispersion liquid.

Limitations: The right dispersant needs to be selected to avoid adverse effects on subsequent applications or material properties.

4. pH adjustment

Steps: Adjust the pH value of the aqueous solution to make it close to the isoelectric point of the nanocellulose, reduce electrostatic attraction, and help the nanocellulose to disperse better.

Advantages: pH adjustment is a gentle method suitable for application scenarios that are sensitive to chemical composition.

Limitations: The pH value needs to be accurately controlled, otherwise the structural stability of the nanocellulose may be affected.

5. High pressure homogeneity

Step: The mixture of nanocellulose and water is processed through a high-pressure homogenizer, and the nanocellulose is dispersed evenly by high pressure.

Advantages: It can handle high viscosity and high concentration nanocellulose dispersion, and the effect is long-lasting.

Limitations: The equipment is expensive and complex to operate, suitable for industrial production.

6. Freezing-thawing cycle

Steps: Freeze the nanocellulose suspension and then thaw. Repeat several times to promote the dispersion of cellulose.

Advantages: Helps further refine the fibers and helps improve dispersion stability.

Limitations: Long time, suitable for small-scale dispersion under laboratory conditions.

By the above method, can be effectively nanocellulose dispersed in water to obtain a uniform nanocellulose dispersion liquid. The choice of different methods should be determined based on the specific application requirements, the properties of nanocellulose and the production scale.