Bioinspired Processing of Keratin into Upcycled Fibers through pH-Induced Coacervation

Jianwu Sun, Guillermo Monreal Santiago*, Feng Yan, Wen Zhou, Petra Rudolf, Giuseppe Portale, Marleen Kamperman*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Keratin is an important byproduct of the animal industry, but almost all of it ends up in landfills due to a lack of efficient recycling methods. To make better use of keratin-based natural resources, the current extraction and processing strategies need to be improved or replaced by more sustainable and cost-effective processes. Here, we developed a simple and environmentally benign method to process extracted keratin, using HCl to induce the formation of a coacervate, a separate aqueous phase with a very high protein concentration. Remarkably, this pH-induced coacervation did not result in the denaturation of keratin, and we could even observe an increase in the amount of ordered secondary structures. The low-pH coacervates could be extruded and wet-spun into high-performance keratin fibers, without requiring heating or any organic solvents. The secondary structure of keratin was largely conserved in these regenerated fibers, which exhibited excellent mechanical performance. The process developed in this study represents a simple and environmentally friendly strategy to upcycle waste keratin into high-performance materials.

Original languageEnglish
Pages (from-to)1985-1994
Number of pages10
JournalACS Sustainable Chemistry and Engineering
Issue number5
Publication statusPublished - 6-Feb-2023


  • coacervate
  • fibers
  • keratin
  • processing
  • regenerated
  • upcycling
  • wet spinning

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