US 11,958,209 B2 · Delignified wood materials, and methods for fabricating and use thereof

Abstract

A delignified wood material is formed by removing substantially all of the lignin from natural wood. The resulting delignified wood retains cellulose-based lumina of the natural wood, with nanofibers of the cellulose microfibrils being substantially aligned along a common direction. The unique microstructure and composition of the delignified wood can provide advantageous thermal insulation and mechanical properties, among other advantages described herein. The thermal and mechanical properties of the delignified wood material can be tailored by pressing or densifying the delignified wood, with increased densification yielding improved strength and thermal conductivity. The chemical composition of the delignified wood also offers unique optical properties that enable passive cooling under solar illumination.

Claims20

Dependent claims

A structure comprising:

a first piece of natural wood that has been chemically treated to remove lignin from the natural wood and to increase a porosity as compared to the natural wood before chemical treatment, and subsequently dried by freeze drying or critical point drying so as to substantially preserve a structure of cellulose-based lumina of the natural wood with the increased porosity,
wherein inner volumes of the cellulose-based lumina remain open or unobstructed in a cross-sectional view,
at least 90% of the lignin in the natural wood has been removed by the chemical treatment,
the first piece has been chemically treated to be hydrophobic or is provided with a hydrophobic coating,
the first piece is substantially white in color, and
the first piece exhibits a reflectivity of at least 90% in a wavelength range of 400-700 nm.

3 more elements

A method comprising:

removing at least 90% of lignin from a piece of natural wood while substantially retaining cellulose-based lumina of the natural wood, thereby producing a piece of delignified wood with increased porosity as compared to the natural wood before chemical treatment;
after the removing, drying the piece of delignified wood by freeze drying or critical point drying to preserve a structure of cellulose-based lumina of the natural wood with increased porosity and such that the cellulose-based lumina remain open or unobstructed in a cross-sectional view;
and
after the drying, chemically-treating the piece of delignified wood to be hydrophobic or providing the piece of delignified wood with a hydrophobic coating,
wherein after the drying, the piece of delignified wood is substantially white in color and exhibits a reflectivity of at least 90% in a wavelength range of 400-700 nm.

2 more elements

Dependencies are inferred from the claim text.

Delignified wood materials, and methods for fabricating and use thereof

Life of this patent

Delignified wood materials, and methods for fabricating and use thereof

Life of this patent

Abstract

Claims20