A preparation method of silica airgel ink for 3D direct writing printing

Abstract

The invention discloses a silica airgel ink for 3D direct writing printing and a preparation method thereof. The ink is mainly composed of 5-18wt% nano-silica powder, 15-80wt% silica sol, 0-3wt% Polyvinyl alcohol, composed of 0-50wt% polyalcohol solvent and 0-67wt% water; its preparation process is: first prepare defoaming polyvinyl alcohol solution, then mix silica sol, polyvinyl alcohol solution, polyalcohol solvent and remove Ionized water is used to prepare a glue solution that can be used for gel curing, and finally the glue solution that can be used for gel curing is mixed with nano-silica powder, and the silica airgel ink that can be used for 3D direct writing printing is obtained through degassing; through this The silica airgel ink prepared by the method has good viscoelasticity, low room temperature volatility and printability, which will be beneficial to the additive manufacturing of silica airgel.

Description

technical field [0001] The invention relates to the technical field of additive manufacturing of silicon oxide aerogel, in particular to a preparation method of silicon oxide aerogel ink for 3D direct writing printing. [0002] technical background [0003] The mesoporous silica aerogel prepared by the traditional sol-gel process has significant advantages such as low density, high porosity, high specific surface area, low dielectric constant and low thermal conductivity, and is currently the most widely studied and used. A type of aerogel. Among them, the low thermal conductivity of silica aerogel is particularly noticeable, and its excellent thermal insulation performance makes it show great economic value in the fields of industrial thermal insulation and civil thermal insulation, thus making the market of aerogel thermal insulation materials more attractive. The scale of possession is also expanding. [0004] However, the problem of brittleness is still the key to restr...

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Problems solved by technology

However, this method needs to add more organic substances to the ink, which is not suitable for the preparation of inorganic materials; Chinese patent CN110423515A discloses a magnesia ceramic ink for 3D direct writing molding and its preparation method. In this invention, 57-70wt% The solid content of ceramic powder magnesium oxide can make the printing ink exhibit good pseudoplasticity, but the solid content of the ink is too high, which is not conducive to the preparation of low-density, high-porosity airgel materials; [Nature, 2020, 584.7821 :387-392] reported a method for additive manufacturing of silica airgel, which uses micron-sized silica airgel powder as the main thickener, and controls the airgel powder in amyl alcohol-water solvent The ratio in the system prepares airgel ink with good pseudoplasticity. Although this method can realize the printing of silica airgel ink at room temperature, it needs to add a large amount of organic polyetheramine to realize the ink’s uniformity during the ink preparation process. Homogeneous phase stability, which makes the removal of organics complicated and difficult by media replacement during subsequent solvent replacement and supercritical drying

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