Bacterial cellulose suspensions
AssigneeCellugy Aps
InventorsIsabel Alvarez-Martos, Deby Fapyane, Alixander Perzon
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Abstract
The invention presented herein relates to bacterial cellulose (BC) suspensions, and methods of production and uses of the same. In particular, the invention relates to BC suspensions suitable for coating applications.
Claims66
A bacterial cellulose (BC) suspension comprising 1.6 to 2.3% (w/v) BC solids, said suspension comprising BC fiber clusters having a size between 10 nm and 1500 μm, said suspension having a viscosity between 1 and 500 Pa·s at a shear stress of 1/s.
The BC suspension according to any one of the preceding claims, wherein the sizes of the BC fiber clusters varies between 0.5 and 1500 μm, such as between 0.5 and 1300 μm, such as between 1 and 200 μm, such as between 5 and 1400 μm, such as between 5 and 1350 μm, such as between 5 and 1300 μm, such as between 50 and 1400 μm, such as between 50 and 1350 μm, such as between 75 and 1300 μm, such as between 75 and 1300 μm, such as between 70 and 1250 μm, such as between 5 and 1240 μm.
The BC suspension according to any one of the preceding claims, wherein the median size of the BC fiber clusters varies between 50 and 100 μm, such as between 50 and 75 μm, such as between 75 and 100 μm.
The BC suspension according to any one of the preceding claims, comprising BC suspended in a protic solvent, such as water.
The BC suspension according to any one of the preceding claims, further comprising an additional component, such as glycerol, polyvinyl alcohol (PVOH), pectin, casein, starch, modified and/or unmodified silicon oxide, and/or titanium oxide.
The BC suspension according to any one of the preceding claims, wherein at least some of the accessible chemical groups of the BC are functionalized, such as 1 to 80%, such as 5 to 80%, such as 10 to 80%, such as 20 to 80%, such as 30 to 80%, such as 40 to 80%, such as 50 to 80%, such as 60 to 80%;
- such as 70 to 80%, preferably wherein the accessible chemical groups are accessible hydroxyl groups.
The BC suspension according to any one of the preceding claims, wherein at least some of the accessible hydroxyl groups of the BC are substituted with nitro groups, optionally, wherein 1 to 80% of the accessible hydroxyl groups are substituted with nitro groups, such as 5 to 80%, such as 10 to 80%, such as 20 to 80%, such as 30 to 80%, such as 40 to 80%, such as 50 to 80%, such as 60 to 80%, such as 70 to 80%.
The BC suspension according to any one of the preceding claims, wherein at least some of the accessible hydroxyl groups of the BC are acetylated, optionally, wherein 1 to 80% of the accessible hydroxyl groups are acetylated, such as 5 to 80%, such as 10 to 80%, such as 20 to 80%, such as 30 to 80%, such as 40 to 80%, such as 50 to 80%, such as 60 to 80%, such as 70 to 80%.
The BC suspension according to any one of the preceding claims, which when applied to coat a paper of a grammage of 60 g/m2 at a dry coating thickness of 40 μm results in a water vapor transmission rate (WVTR) range of 50-200 g/m2/day at 50% relative humidity, such as 75-175 g/m2/day at 50% relative humidity, such as 85-160 g/m2/day at 50% relative humidity, such as 90-155 g/m2/day at 50% relative humidity, such as 90.8-154.6 g/m2/day at 50% relative humidity.
The BC suspension according to any one of the preceding claims, which when applied to coat a paper of a grammage of 60 g/m2 at a dry coating thickness of 40 μm results in an oxygen transfer rate (OTR) range of 2.5-40 ml/m2/day/atm, such as 5-35 ml/m2/day/atm, such as 7.5-30 ml/m2/day/atm, such as 10-26 ml/m2/day/atm, such as 11.2-24.2 ml/m2/day/atm.
A method for producing a bacterial cellulose (BC) suspension comprising the steps of:
- a) Incubating at least one cellulose producing bacteria in a culture medium, and optionally, at least one other microorganism which does not produce cellulose, thereby obtaining BC in said culture medium;
- b) Recovering said BC;
- c) Optionally, contacting said BC with a functionalization agent, wherein said functionalization agent is selected from nitric acid and acetic anhydride, thereby functionalizing said BC;
- d) Converting the recovered BC of step b) and/or the functionalized BC of step c) into a BC suspension comprising 1.6 to 2.3% (w/v) BC solids, said BC suspension comprising BC fiber clusters having a size between 10 nm and 1500 μm, and/or said BC suspension having a viscosity between 1 and 500 Pa·s at a shear stress of 1/s.
Use of the BC suspension as defined in any one of the preceding claims for coating a material, such as the surface of a material.
Dependencies are inferred from the claim text.