Treating cellulosic materials and methods of making treated cellulosic materials

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.

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.