The disclosure provides a very simple and convenient method for producing a porous material of a water-soluble polymer. The herein disclosed method for producing a porous material of a water-soluble polymer includes a step of preparing a solution in which a water-soluble polymer is dissolved in a mixed solvent of water mixed with a solvent having a boiling point higher than that of water, and a step of evaporating and thereby removing the mixed solvent from the solution. The solubility of the water-soluble polymer in the solvent having a boiling point higher than that of water is lower than the solubility of the water-soluble polymer in water. Voids are formed, in the step of evaporating and thereby removing the mixed solvent, by the solvent having a boiling point higher than that of water.

This cellulose powder has: an average degree of polymerization of 100 to 350; a weight average particle size of over 30 m, but less than 250 m; an apparent specific volume of 2 to less than 15 cm.sup.3/g; and an organic carbon content from residual impurities, which is defined by the total organic carbon content (%) during 1% NaOH extraction to the total organic carbon content (%) during pure water extraction, of over 0.07 to 0.3%.

A carrier for ligand immobilization obtained by shrinking polysaccharide porous beads not less than 10% by a shrinkage rate defined by the following formula, and crosslinking the polysaccharide porous beads: Shrinkage rate (%)=(1V.sub.2/V.sub.1)100 (wherein, V.sub.1 indicates the gel volume of polysaccharide porous beads before shrinkage, and V.sub.2 indicates the gel volume of polysaccharide porous beads after shrinkage).

A carrier for ligand immobilization obtained by shrinking polysaccharide porous beads not less than 10% by a shrinkage rate defined by the following formula, and crosslinking the polysaccharide porous beads: Shrinkage rate (%)=(1V.sub.2/V.sub.1)100 (wherein, V.sub.1 indicates the gel volume of polysaccharide porous beads before shrinkage, and V.sub.2 indicates the gel volume of polysaccharide porous beads after shrinkage).

There is provided a package material comprising an oxygen barrier polymer film, wherein the film comprises a polymer obtainable by a process comprising the steps of: a) oxidizing cellulose fibers to ultimately obtain cross-linked cellulose; and b) homogenizing the product of step a) to obtain fibrils in a width range of 1 nm to 150 nm. A corresponding use is also provided.

A polymer-nanocellulose-lignin composite as disclosed comprises a polymer, nanocellulose, and lignin, wherein lignin forms a hydrophobic interface between the polymer and the nanocellulose. In some variations, a process is disclosed for producing a polymer-nanocellulose-lignin composite material, comprising: fractionating lignocellulosic biomass in the presence of an acid, a solvent for lignin, and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin, wherein lignin deposits onto fiber surfaces or into fiber pores; mechanically treating the cellulose-rich solids to form a hydrophobic nanocellulose material comprising cellulose fibrils and/or cellulose crystals; hydrolyzing the hemicellulose to generate fermentable hemicellulosic sugars; fermenting the fermentable hemicellulosic sugars to generate a monomer or monomer precursor; polymerizing the monomer to produce a polymer; and combining the polymer with the lignin-coated nanocellulose to generate a polymer-nanocellulose-lignin composite material for use in a wide variety of products.

There is provided a use of a material comprising fibers as an oxygen barrier, wherein the fibers comprise native cellulose and dialcohol cellulose. There is also provided a material comprising fibers and having a density of at least 1200 kg/m.sup.3, wherein the fibers comprise native cellulose and dialcohol cellulose and the oxygen permeability of the material according to ASTM D3985 is below 30 ml.Math.?m/(m.sup.2.Math.kPa.Math.24 h) at 23? C. and 80% relative humidity.

The present disclosure provides a core-shell nanocomposite material comprising an intrinsically conductive polymer (ICP) and surface-modified cellulose nanocrystals (CNCs) as well as synthesis for preparing same and its use thereof in various applications.

It is an object of the present invention to provide an ultrafine cellulose fiber-containing material having favorable re-dispersibility, which can exhibit excellent thickening properties after it has been re-dispersed, even after long-term storage. The present invention relates to a cellulose fiber-containing material comprising cellulose fibers having a fiber width of 1000 nm or less and a di- or more-valent metal component, wherein the content of the cellulose fibers is 5% by mass or more with respect to the total mass of the cellulose fiber-containing material, the content of the metal component is 0.5% by mass or less with respect to the total mass of the cellulose fiber-containing material, and when the cellulose fiber-containing material is processed into a slurry having a solid concentration of 0.5% by mass, the pH of the slurry is 4 or more.

A dispersion of a cellulose nanofiber (CNF) and a cellulose nanocrystal (CNC) that maintains a physical property even after drying and redispersing and has a long pot life is provided. A composite of the CNF and the CNC having a higher rupture strength and a higher oxygen gas barrier property is also provided. The dispersion contains a CNF having a sulfate ester group and a CNC having a sulfate ester group. The composite contains the CNF having a sulfate ester group and the CNC having a sulfate ester group.