Fecha de publicación: 15/08/2024 Fuente: WIPO "circular economy" The present invention relates to a method of obtaining keratin protein isolate from a keratin source, the method comprising: (a) preparing a first mixture comprising keratin source, chaotropic solvent, and a first reducing agent; (b) precipitating keratin protein from the first mixture; (c) preparing a second mixture comprising the keratin protein and a second reducing agent; and (d) precipitating keratin protein isolate from the second mixture. The present invention also relates to a method of obtaining keratin amyloid fibrils, the method comprising: (i) obtaining keratin protein isolate; (ii) preparing a third mixture comprising keratin protein isolate, acid solution, and a third reducing agent; and (iii) subjecting the third mixture to heat treatment to obtain keratin amyloid fibrils. The present invention also relates to a method of fabricating a membrane for an electrochemical cell or a proton conductive cell.