Amino silane modified nanocellulose aerogel preparation method

Abstract

The invention relates to an amino silane modified nanocellulose aerogel preparation method. The method includes: 1) making nanocellulose suspension liquid into semi-transparent colloid; 2) extruding the nanocellulose colloid to form spherical or short rod-like hydrogel; 3) turning the formed nanocellulose hydrogel into alcogel; 4) making nanocellulose aerogel; 5) allowing adsorption of gaseous organic amine on the surface of the nanocellulose aerogel; 6) performing vacuum recovery of residual organic amino catalysts; 7) allowing chemical reaction of gaseous amino silane and the nanocellulose aerogel; 8) performing vacuum recovery of unreacted amino silane and 9) making corresponding amino silane modified nanocellulose aerogel. The method has advantages that 1) solvent recovery and separation in a liquid-phase modification process can be avoided, and an amination modification process is simplified; 2) an original microcosmic three-dimensional network structure of nanocellulose aerogel is kept, and modification grafting density and uniformity are improved; 3) process simplicity, high efficiency and low cost are realized.

Description

technical field [0001] The invention relates to a method for modifying nano-cellulose airgel with aminosilane, and belongs to the technical field of wood fiber composite materials. Background technique [0002] Nanocellulose is a cellulose-like substance with a one-dimensional or multi-dimensional dimension at the nanometer level (1-100nm), and is a natural polymer. It has the characteristics of cellulose renewability, good biocompatibility, and biodegradability. At the same time, it also has the characteristics of large specific surface area, superior mechanical properties and optical properties. Airgel is a material with a high permeability three-dimensional network structure, which has the characteristics of extremely high porosity, high specific surface area, extremely low density, and low thermal conductivity. At present, aerogels have potential applications in biomedical carriers, photoelectric sensors, catalytic technology, adsorption technology, and energy storage. ...

AI Technical Summary

Problems solved by technology

[0005] At present, the amino group functional modification of nanocellulose airgel is mainly carried out in the liquid phase (including aqueous phase and organic phase). During the functional modification, the distribution of aminosilane molecules on the surface of nanocellulose is difficult to control. After the denaturation, the thickness inhomogeneity of the "coating" of aminosilane molecules on the surface of nanocellulose is serious; at the same time, the self-polymerization phenomenon between aminosilanes is serious, and self-polymerization will lead to partial pore closure in nanocellulose aerogels Or blockage, reducing the porosity and specific surface area of ​​the original airgel, and the graft density is low, generally only 3-6mmolN / g

In addition, during liquid phase modification, there are complex solvent recovery and separation processes. Therefore, it is necessary to develop a new process method to overcome the above problems encountered in the liquid phase modification process