This invention relates a compostable lid for sealing a beverage capsule or a beverage pad wherein the lid comprises a natural-fiber based support obtainable by: (i) providing a first fibrous base sheet comprising natural fiber material sensitive to a gelatinizing agent; (ii) treating the first base sheet with a gelatinizing agent to give a treated first fibrous base sheet comprising gelatinized material; (iii) providing a second fibrous base sheet; (iv) contacting the treated first fibrous base sheet and the second base sheet with each other; (v) causing at least partial migration of the gelatinized material from the treated first fibrous base sheet into the second fibrous base sheet to give a multilayer product; and (vi) neutralizing and/or washing the product thus obtained and then drying it.

Methods for the preparation of carbon fiber from polyolefin fiber precursor, wherein the polyolefin fiber precursor is partially sulfonated and then carbonized to produce carbon fiber. Methods for producing hollow carbon fibers, wherein the hollow core is circular- or complex-shaped, are also described. Methods for producing carbon fibers possessing a circular- or complex-shaped outer surface, which may be solid or hollow, are also described.

Methods for the preparation of carbon fiber from polyolefin fiber precursor, wherein the polyolefin fiber precursor is partially sulfonated and then carbonized to produce carbon fiber. Methods for producing hollow carbon fibers, wherein the hollow core is circular- or complex-shaped, are also described. Methods for producing carbon fibers possessing a circular- or complex-shaped outer surface, which may be solid or hollow, are also described.

The present invention relates to a parchmentized fibrous support containing parchmentizable synthetic fibers parchmentized with sulfuric acid, the process for making such a support and the use thereof.

The present invention relates to a parchmentized fibrous support containing parchmentizable synthetic fibers parchmentized with sulfuric acid, the process for making such a support and the use thereof.

A sulfonated polymer fiber screen and a method for fabricating the same is disclosed. For example, a composition may include a plurality of sulfonated polymer fibers. The sulfonated polymer fibers may include polyether ether ketone (PEEK) fibers or polyaryl ether ketone (PAEK) fibers that are contacted with an acid bath that includes a sulfur containing group.

A separator medium for electrochemical cells that contains at least one nonwoven sheet of polymeric fibers. The nonwoven sheet has a surface area of about 0.5 to about 1.5 m.sup.2/g and has a maximum pore size that is equal to or more than 2.5 times the mean flow pore size and more than 11 times the minimum pore size. The sheet may be sulfonated to a level of 0.67% and demonstrates superior tensile properties after sulfonation and relative to previously known separators.

A separator medium for electrochemical cells that contains at least one nonwoven sheet of polymeric fibers. The nonwoven sheet has a surface area of about 0.5 to about 1.5 m.sup.2/g and has a maximum pore size that is equal to or more than 2.5 times the mean flow pore size and more than 11 times the minimum pore size. The sheet may be sulfonated to a level of 0.67% and demonstrates superior tensile properties after sulfonation and relative to previously known separators.

Method for the preparation of a non-woven mat or paper made of carbon fibers, the method comprising carbonizing a non-woven mat or paper preform (precursor) comprised of a plurality of bonded sulfonated polyolefin fibers to produce said non-woven mat or paper made of carbon fibers. The preforms and resulting non-woven mat or paper made of carbon fiber, as well as articles and devices containing them, and methods for their use, are also described.

Method for the preparation of a non-woven mat or paper made of carbon fibers, the method comprising carbonizing a non-woven mat or paper preform (precursor) comprised of a plurality of bonded sulfonated polyolefin fibers to produce said non-woven mat or paper made of carbon fibers. The preforms and resulting non-woven mat or paper made of carbon fiber, as well as articles and devices containing them, and methods for their use, are also described.