Reversible swelling and collapsing the latent pores of natural fiber welded biopolymer by way of solvent treatment to regenerate mesoporous or nonporous biopolymeric structures

Abstract

A method of reversible swelling and collapsing of the latent pores of natural fiber welded biopolymer by way of sequential solvent treatment to i) regenerate mesoporous biopolymeric structures, comprising the steps of providing a nonporous natural fiber welded biopolymer composite, submerging the nonporous composite in polar solvent, exchanging submersion solvents, typically starting from a solvent of polar identity and ending with a solvent of nonpolar identity, then removing the solvent; and ii) regenerate nonporous biopolymeric structures, comprising the steps of providing a mesoporous natural fiber welded biopolymer composite, submerging the mesoporous composite in polar solvent, then removing the solvent. A mesoporous biopolymeric structure wherein the NFW nonporous composite expresses a BET surface area change of <5 m2 g−1 to >40 m2 g−1. A nonporous biopolymeric structure wherein the NFW mesoporous composite expresses a BET surface area change of >40 m2 g−1 to <5 m2 g−1.

What we claim is: 
     
         1 . A method of reversible swelling and collapsing of the latent pores of natural fiber welded biopolymer by way of sequential solvent treatment to regenerate mesoporous biopolymeric structures from nonporous or low porosity fiber welded materials, comprising the steps of:
 providing a nonporous or low porosity natural fiber welded biocomposite;   submerging the nonporous or low porosity natural fiber welded biocomposite in a polar solvent having a dielectric constant ≥20; and   forming a mesoporous biopolymer composite.   
     
     
         2 . The method of reversible swelling and collapsing of the latent pores of natural fiber welded biopolymer by way of sequential solvent treatment to regenerate mesoporous biopolymeric structures from nonporous or low porosity fiber welded materials of  claim 1  further comprising the step of:
 exchanging the polar solvent starting from a solvent of polar identity and ending with a solvent of nonpolar identity having a dielectric constant <5. 
 
     
     
         3 . The method of reversible swelling and collapsing of the latent pores of natural fiber welded biopolymer by way of sequential solvent treatment to regenerate mesoporous biopolymeric structures of  claim 2  further comprising the step of:
 removing the nonpolar solvent from the mesoporous biopolymer composite. 
 
     
     
         4 . The method of reversible swelling and collapsing of the latent pores of natural fiber welded biopolymer by way of sequential solvent treatment to regenerate mesoporous biopolymeric structures of  claim 3  wherein
 the nonporous or low porosity natural fiber welded biocomposite expresses a Brunauer-Emmett-Teller (BET) surface area of <5 m 2  g −1  prior to the step of submerging the nonporous or low porosity natural fiber welded biocomposite in polar solvent and expresses a BET surface area of >40 m 2  g −1  after the step of removing the nonpolar solvent from the mesoporous biopolymer composite. 
 
     
     
         5 . A method of reversible swelling and collapsing of the latent pores of natural fiber welded biopolymer by way of polar solvent treatment to regenerate nonporous biopolymeric structures from a higher surface area fiber welded material, comprising the steps of:
 providing a natural fiber welded mesoporous composite;   submerging the mesoporous composite in a polar solvent;   forming a nonporous biopolymer composite; and   removing the polar solvent from the nonporous biopolymer composite.   
     
     
         6 . The method of reversible swelling and collapsing of the latent pores of natural fiber welded biopolymer by way of polar solvent treatment to regenerate nonporous biopolymeric structures of  claim 5  wherein
 the natural fiber welded mesoporous composite expresses a BET surface area of >40 m 2  g −1  prior to the step of submerging the mesoporous composite in polar solvent and expresses a BET surface area of <5 m 2  g −1  after the step of removing the polar solvent from the nonporous biopolymer composite. 
 
     
     
         7 . A mesoporous biopolymeric structure made from the steps of:
 providing a natural fiber welded nonporous composite;   submerging the natural fiber welded nonporous composite in a polar solvent;   forming a mesoporous biopolymeric structure; and   exchanging the solvent, starting from a solvent of polar identity and ending with a solvent of nonpolar identity.   
     
     
         8 . The mesoporous biopolymeric structure of  claim 7  further comprising the step of:
 removing the nonpolar solvent from the mesoporous biopolymeric structure. 
 
     
     
         9 . The mesoporous biopolymeric structure of  claim 8  wherein
 the natural fiber welded nonporous composite expresses a BET surface area of <5 m 2  g −1  prior to the step of submerging the natural fiber welded nanoporous composite in polar solvent and expresses a BET surface area of >40 m 2  g −1  after the step of removing the solvent from the mesoporous biopolymeric structure. 
 
     
     
         10 . A nonporous biopolymeric structure made from the steps of:
 providing a natural fiber welded mesoporous composite;   submerging the natural fiber welded mesoporous composite in a polar solvent;   forming a nonporous biopolymeric structure; and   removing the polar solvent from the nonporous biopolymeric structure.   
     
     
         11 . The nonporous biopolymeric structure of  claim 10  wherein
 the natural fiber welded mesoporous composite expresses a BET surface area of >40 m 2  g −1  prior to the step of submerging the natural fiber welded mesoporous composite in polar solvent and expresses a BET surface area of <5 m 2  g −1  after the step of removing the polar solvent from the nonporous biopolymeric composite.