Articles of manufacture comprising nanocellulose elements
The present invention provides formulations comprising a suspension of nanocellulose (NC) elements and a drying/dispersal additive selected from the group consisting of temperature-responsive polymers, small molecule additives in volatile systems, and blocking agents and methods of preparing such formulations, and further provides NC-containing materials, composite materials and useful articles of manufacture made therefrom.
1. A liquid formulation having a barrier property, comprising:
a suspension of nanocellulose (NC) elements in a liquid medium, wherein the NC elements comprise at least one of cellulose nanofibers and cellulose microfibers,
a drying/dispersal additive, wherein the drying/dispersal additive is a lower critical solution temperature (LCST polymer), and
a barrier-producing material having selected from the group consisting of an oil and grease resistant (OGR) property, a water resistant (WVR) property and a combination of both a water resistant (WVR) property, wherein the barrier-producing material comprises cellulose acetate;
and wherein the cellulose nanofibers have a diameter between about 4 nm and about 20 nm and the cellulose microfibers have a diameter between about 20 nm and about 100 nm.
2. The liquid formulation of claim 1 , wherein the NC elements comprise of cellulose nanofibers.
3. The liquid formulation of claim 1 , wherein the drying/dispersal additive is methyl cellulose.
4. The liquid formulation of claim 1 , wherein the barrier property is a combination of the WVR property and an oil and grease resistant (OGR) property.
5. The liquid formulation of claim 1 , wherein the barrier-producing material is a mixture of methyl cellulose and the cellulose acetate.
6. The liquid formulation of claim 1 , wherein the LCST polymer is selected from the group consisting of methyl cellulose, hydroxylethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, ethylhydroxyethyl cellulose, polyvinylcaprolactam, poly(methyl vinyl ether), poly(N-isopropylacrylamide), poly(N,N-diethylacrylamide), poly(ethylene oxide) and poly(propylene oxide) block copolymer, and elastin poly(pentapeptide).
7. The liquid formulation of claim 6 , wherein the LCST polymer is hydroxypropylmethyl cellulose.
8. A method of producing a redispersible, dried NC-containing material, wherein the dried NC-containing material has a barrier property a barrier property including and has the nanocellulose elements embedded within the material, the method comprising:
drying the liquid formulation of claim 1 to form the redispersible, dried NC-containing material,
wherein the redispersibility of the dried NC-containing material is greater than that of a dried control material prepared by drying a control suspension of nanocellulose elements in the liquid medium, wherein the control suspension lacks the drying/dispersal additive.
9. A method of redispersing nanocellulose elements, comprising:
adding a redispersing fluid to the dried NC-containing material of claim 8 , thereby redispersing the nanocellulose elements.