Treating cellulosic materials and methods of making treated cellulosic materials

1 . A method comprising:

permeating a first additive into cellulosic material, the first additive being in a vapor phase and configured to react with one or more functional groups of the cellulosic material;

adsorbing the first additive into one or more capillaries of the cellulosic material; and

permeating a second additive into the cellulosic material, the second additive being in a vapor phase and configured to seal one or more of the capillaries by adsorbing onto one or more of the functional groups;

wherein the first additive is configured to modify at least one property of the cellulosic material.

2 . The method of claim 1 , wherein:

permeating the first additive comprises atomic layer deposition (ALD) of the first additive into the cellulosic material; and

the ALD comprises from 1 to 50 deposition cycles.

3 . The method of claim 1 , wherein:

one or more of the functional groups comprises a nucleophile; and

the first additive is configured to react with the nucleophile.

4 . The method of claim 1 , wherein:

the cellulosic material is selected from the group consisting of wood lumber, engineered wood product, natural wood products, plastic lumber, engineered composites, plywood, sawdust board, particle board, sawdust, wood chips, wood strands, hardwood, and softwood; and

one property of the cellulosic material is selected from the group consisting of hydrophobicity, thermal conductivity, thermal diffusivity, fungo-toxicity, toxicity, wettability, tensile strength, biodegradability, bio-toxicity, corrosiveness, and swelling.

5 . The method of claim 1 , wherein the first additive comprises a metal oxide.

6 . The method of claim 1 , wherein permeating the first additive and permeating the second additive comprises ALD of the first additive and the second additive into the cellulosic material, respectively.

7 . The method of claim 6 , wherein the ALD comprises from 1 to 50 deposition cycles.

8 . The method of claim 1 , wherein:

one or more of the functional groups comprises a nucleophile; and

at least one of the first additive or the second additive is configured to react with the nucleophile.

9 . The method of claim 1 , wherein:

the first additive comprises a metal oxide; and

the second additive comprises a polymer.

10 . The method of claim 1 , wherein the first additive is configured to make the cellulosic material hydrophobic and anti-fungal.

11 . The method of claim 1 , wherein:

the cellulosic material further has reactive surface sites;

permeating the first additive comprises ALD of the first additive into the cellulosic material; and

the first additive comprises a precursor that chemically binds to the reactive surface sites.

12 . The method of claim 11 , wherein:

permeating the first additive comprises a single cycle ALD process of exposing the cellulosic material to a gas phase of the precursor being a metal-containing precursor; and

the second additive is an oxidant to provide an atomic-scale inorganic surface coating of less than 5 nm to the cellulosic material.

13 . The method of claim 11 further comprising introducing a co-reactant to the cellulosic material to either oxidize or reduce the precursor and re-activate the reactive surface sites.

14 . The method of claim 13 , wherein the ALD occurs after the introducing.

15 . The method of claim 11 , wherein each ALD deposits about 1 Å of the precursor.

16 . Vapor phase processing for modifying external and internal surface porosities of cellulosic material comprising:

permeating a first additive into the cellulosic material, the first additive being in a vapor phase and configured to react with one or more functional groups of the cellulosic material;

adsorbing the first additive into one or more capillaries of the cellulosic material; and

permeating a second additive into the cellulosic material, the second additive being in a vapor phase and configured to seal one or more of the capillaries by adsorbing onto one or more of the functional groups;

wherein:

permeating the first additive comprises a single cycle atomic layer deposition (ALD) process of exposing the cellulosic material to a gas phase metal-containing precursor;

the second additive is an oxidant;

the steps of permeating, adsorbing and permeating form a coating of less than 5 nm; and

the coating is configured to provide the cellulosic material with hydrophobicity, water repellency, and anti-fungal properties.

17 . The vapor phase processing of claim 16 , wherein the exposing enables penetration of the coating within a depth of the cellulosic material.

18 . A method of modifying one or more properties of a cellulosic material having one or more capillaries and one or more functional groups comprising:

permeating a first additive into cellulosic material, the first additive being in a vapor phase and configured to react with one or more of the functional groups;

adsorbing the first additive into one or more of the capillaries; and

permeating a second additive into the cellulosic material, the second additive being in a vapor phase and configured to seal one or more of the capillaries by adsorbing into one or more of the functional groups.

19 . The method of claim 18 , wherein at least one of:

the first additive comprises a metal oxide;

the second additive comprises a polymer;

permeating the first additive and permeating the second additive comprises atomic layer deposition (ALD) of the first additive and the second additive into the cellulosic material, respectively; or

one or more of the functional groups comprises a nucleophile and at least one of the first additive or the second additive is configured to react with the nucleophile.