Nanofiber structure constituted of polyhydroxyalkanoic acid, and non-woven fabric

Abstract

The biodegradability of a nanofiber film (a nanofiber structure) produced in example 1 by microorganisms or the like when the nanofiber film is allowed to leave in soil is examined. FIG. 4(a) shows a photograph of the nanofiber film immediately after the nanofiber film is placed in soil. FIG. 4(b) shows a photograph of the nanofiber film (a) that is allowed to leave as it for 12 days. As is obvious from the comparison between these photographs, a polyhydroxyalkanoic acid nanofiber film can be degraded in soil remarkably rapidly. Therefore, PHA can be produced from a plant-derived resource occurring in nature, can be degraded by microorganisms in soil to return to nature, and can be used as a resource material which can overcome the disadvantages of the conventional PP non-woven fabrics (e.g., the generation of CO2 upon incineration) and which can be used permanently, thereby enabling the production of a novel non-woven fabric.

1 . A nanofiber structure formed of polyhydroxyalkanoic acid. 
     
     
         2 . The nanofiber structure according to  claim 1 , wherein the polyhydroxyalkanoic acid includes polyhydroxybutylate as a main component. 
     
     
         3 . The nanofiber structure according to  claim 1 , wherein the nanofiber structure has a fiber diameter of 1 μm or less. 
     
     
         4 . The nanofiber structure according to  claim 1 , wherein the nanofiber structure is degraded by microorganisms in soil in a natural environment. 
     
     
         5 . The nanofiber structure according to  claim 1 , wherein the nanofiber structure has a porosity of 50% or more. 
     
     
         6 . The nanofiber structure according to  claim 1 , wherein the nanofiber structure has water repellency, and a contact angle of pure water to a surface of the nanofiber structure is 100° or more. 
     
     
         7 . The nanofiber structure according to  claim 1 , wherein the nanofiber structure has oil absorbency. 
     
     
         8 . The nanofiber structure according to  claim 1 , wherein the nanofiber structure has organic solvent absorbency. 
     
     
         9 . The nanofiber structure according to  claim 1 , wherein the surface of the nanofiber structure has hydrophilicity by surface modification by a plasma treatment, a corona discharge, electron beam irradiation, or laser irradiation, or the like. 
     
     
         10 . The nanofiber structure according to  claim 1 , further comprising an adsorbent material. 
     
     
         11 . The nanofiber structure according to  claim 1 , wherein the nanofiber structure is partially fused to have a film shape.