Preparation method of magnetic cellulose aerogel

Abstract

The invention discloses a preparation method of magnetic cellulose aerogel. The method comprises the following steps: firstly carrying out pretreatment on fiber material, then carrying out modification treatment on the fiber material, and then carrying out partial dissolution on the fiber after modification treatment to prepare an aerogel cross-linking agent solution; preparing a magnetic materialraw solution; adding alkali and the magnetic material raw solution into a cellulose solution, and generating magnetic particles in the magnetic material solution; dispersing and adhering the magneticparticles to the surface of the fiber, carrying out evaporation and concentration on the solution, taking out remaining cellulose solution, adding a cross-linking agent solution under stirring and heating effects, heating until the temperature is 60 to 100 DEG C, carrying out preliminary gelation on the solution 2 to 6 hours later, and carrying out vacuum drying and freeze drying to obtain the magnetic aerogel. The magnetic composite aerogel obtained in the invention has the characteristics of low density, porosity, elasticity and the like, and due to the introduction of inorganic particles,the compressive strength of the material is improved, and the material has the characteristic of superparamagnetism.

Description

technical field [0001] The invention relates to the field of preparation technology of nanoporous materials, in particular to a method for preparing magnetic cellulose airgel by using natural polymer cellulose material as the main raw material. Background technique [0002] Gel is a new type of porous material, which is a special gel that replaces the liquid in the gel with gas without changing the network structure or volume of the gel itself. This material has a nanoscale porous structure and high porosity, which can be as high as 98%. The porous network structure of airgel makes it have unique properties, such as high porosity, high specific surface area, low light refractive index, low sound velocity, low thermal conductivity, low dielectric constant, etc. There are also various materials for preparing airgel. In terms of natural cellulose materials, they include nanocellulose, regenerated cellulose, and bacterial cellulose. The scope of application is quite wide, and ...

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Problems solved by technology

This method is a physical process. Due to the inherent properties of the magnetic particles, agglomeration is very easy to occur. The magnetic particles will be subjected to great resistance during the filling process, resulting in blockage of the pores, which limits the effective dispersion of the particles, resulting in the formation of Composite particles aggregate and distribute unevenly, resulting in inhomogeneous airgel magnetic properties

Moreover, the number of cavities between fibers is limited, and the magnetic particles cannot be effectively adsorbed on the cellulose, resulting in the loss of a large amount of magnetic particles. Although it can be improved by adding retention aids, it will greatly reduce the mechanical properties of the material, such as tensile strength. Strength and compressive strength, the resulting material after filling is weaker than the unfilled material

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