The United States of America As Represented by the Secretary of

Cellulose Sciences International, Inc.

Emory University

Other

Rajai H Atalla

Craig L Hill

Ira A Weinstock

Steven L Edwards

Akira Isogai

Richard S Reiner

Rowan S Atalla

A method is provided for the post-treatment of nanoporous celluloses with an eye to scale up to plant operation wherein recycling and recovery of reagents is crucial in the efficient and cost effective operation of a full-scale plant. The instant method includes diminishing the alkali (e.g., sodium hydroxide) concentration of the treatment solution by converting it to a salt (e.g., a sodium salt).

Alternative post treatment for stabilizing highly disordered celluloses

Disclosed are methods and systems for treating cellulose to make it more accessible for enzymatic or chemical modification. The invention includes treating cellulose with an alkali in an alcohol/water co-solvent system. The treatment decrystallizes or deaggregates the cellulosic material. The methods and systems increase the efficiency of enzymatic or chemical modifications of cellulose for use as biofuels or cellulose derivatives.

Nano-deaggregated cellulose

Fibrous cellulosic products incorporating both conventional cellulosic fibers and laterally expanded cellulose fibers exhibit exceptional porosity, bulk, absorbency and resiliency properties. Typical products include absorbent tissue products, absorbent fluff products and flat papers. The laterally expanded cellulose fibers exhibit: (i) a broadened X-Ray diffraction peak for the most prominent reflection having a width at half-height, (W), of at least about 3.0&#xb0; 2&#x398;, (ii) broad overlapping maxima in their Raman spectrum between 285 and 500 cm, the height of the two tallest of said maxima in said spectrum between 285 and 500 cmbeing between 35 and 50% of the height of the peak near 1098 cmand (iii) a blue stain when treated with Graff C-stain, the stain exhibiting less red than the stains exhibited with bleached hardwood kraft fibers and bleached softwood kraft fibers.

Tissue products incorporating nanoporous cellulose fiber

Highly disordered cellulose

A method for delignifying wood pulp and fiber is disclosed. The method comprises the steps of obtaining a wood pulp and exposing the wood pulp to a polyoxometalate of the formula �V.sub.l Mo.sub.m W.sub.n Nb.sub.o Ta.sub.p (TM).sub.q X.sub.r O.sub.s !.sup.x- where l is 0-18, m is 0-40, n is 0-40, o is 0-10, p is 0-10, q is 0-9, r is 0-6, TM is a d-electron-containing transition metal ion, and X is a heteroatom, which is a p or d block element, where l+m+n+o+p.gtoreq.4, l+m+q&gt;0 and s is sufficiently large that x&gt;0. The exposure is under conditions wherein the polyoxometalate is reduced. In a preferable form of the invention, the method additionally comprises the step of reoxidizing the polyoxometalate.

Oxidative delignification of wood or wood pulp by transition

A method for delignifying wood pulp and fiber is disclosed. The method comprises the steps of obtaining a wood pulp and exposing the wood pulp to a polyoxometalate of the formula [V.sub.l Mo.sub.m W.sub.n Nb.sub.o Ta.sub.p (TM).sub.q X.sub.r O.sub.s ].sup.x- where l is 0-18, m is . 0-40, n is 0-40, o is 0-10, p is 0-10, q is 0-9, r is 0-6, TM is a d-electron-containing transition metal ion, and X is a heteroatom, which is a p or d block element, where l+m+n+o+p.gtoreq.4, l+m+q&gt;0 and s is sufficiently large that x&gt;0. The exposure is under conditions wherein the polyoxometalate is reduced. In a preferable form of the invention, the method additionally comprises the step of reoxidizing the polyoxometalate.

A method for oxidative degradation of lignin and polysaccharide fragments dissolved during polyoxometalate delignification or bleaching of wood pulp, wood fiber or pulp obtained from a non-woody plant. The method comprises the steps of obtaining a spent polyoxometalate bleaching solution containing a polyoxometalate of the formula [V.sub.l Mo.sub.m W.sub.n Nb.sub.o Ta.sub.p (TM).sub.q X.sub.r O.sub.s ].sup.x- where 1 is 0-18, m is 0-40, n is 0-40, o is 0-10, p is 0-10, q is 0-9, r is 0-6, TM is a d-electron-containing transition metal ion, and X is a heteroatom which is p or d block element, provided that l+m+n+o+p.gtoreq.4, l+m+q&gt;0 and s is sufficiently large that x&gt;0, and heating the solution in the presence of an oxidant under conditions wherein the dissolved organic compounds are oxidatively degraded to volatile organic compounds and water.

Oxidation of lignin and polysaccharides mediated by polyoxometalate

The present invention provides a cellulose solution prepared by dissolving a cellulose which has not previously been subject to explosive disruption at atmospheric pressures in an aqueous alkali solution which can be shaped into a fiber, film or other article or applied to the surface or treatment of other materials by coating, dipping, or other suitable methods.

Growing community of inventors

Verona, WI, United States of America

Rajai H Atalla