Ionic-liquid-processed keratin-based biocomposite films with cellulose and chitin for sustainable dye removal

abstract

Poultry is a widely consumed meat worldwide; however, its industrial processing generates a significant amount of feather waste. Since the major component of chicken feathers is keratin (90 wt%), this study focused on using acetate-based ionic liquids (ILs) to fully dissolve chicken feathers and recover keratin, using a sustainable and cost-effective approach, ultimately allowing waste valorisation. The recovered keratin was processed into films, either pure or blended with cellulose and alpha-chitin, aiming to develop a structural polymer biocomposite with improved mechanical properties. Experimental parameters were evaluated using different blend ratios, altering the pH, and adding glycerol as a plasticiser. Physico-chemical analysis revealed that all films exhibited hydrophilic behaviour and are stable up to 160 degrees C. Furthermore, the tensile strength of the keratin-based films significantly increased by adding chitin (achieving up to 66 MPa). Considering the growing significance of biopolymer-based films in wastewater treatment applications, the keratin-based films were evaluated as adsorbents for dye removal. Reactive Blue 4 (RB4) was used as a model dye, and the adsorption kinetics and isotherms were investigated. Between the studied films, the maximum adsorption capacity (55.7 mg g-1) was obtained for the keratin film, emphasising the potential of this biomaterial in wastewater treatment. Abundant biopolymers derived from wastes were used to prepare bio-based films, resulting in notable enhancements in their properties and promising potential as effective adsorbent materials.

keywords

WOOL KERATIN; MICROCRYSTALLINE CELLULOSE; DISSOLUTION; DEGRADATION; ADSORPTION; GLYCEROL; FEATHERS; BONDS

subject category

Chemistry; Science & Technology - Other Topics; Engineering

authors

Polesca, C; Passos, H; Nakasu, PYS; Coutinho, JAP; Freire, MG; Hallett, JP

Groups

G4 - Renewable Materials and Circular Economy
G5 - Biomimetic, Biological and Living Materials

Projects

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)

acknowledgements

This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020), UIDP/50011/2020 (DOI 10.54499/UIDP/50011/2020) & LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020), financed by national funds through the FCT/MCTES (PIDDAC). C. Polesca acknowledges FCT - Fundac & atilde;o para a Ciencia e a Tecnologia for the PhD grant with the reference UI/BD/151282/2021 (DOI 10.54499/UI/BD/151282/2021). This work was supported by national funds through FCT/MCTES (PIDDAC): LSRE-LCM, UIDB/50020/2020 (DOI: 10.54499/UIDB/50020/2020) and UIDP/50020/2020 (DOI: 10.54499/UIDP/50020/2020); and ALiCE, LA/P/0045/2020 (DOI: 10.54499/LA/P/0045/2020). J. H. and P. Y. S. N. were supported by the UKRI Supergen Bioenergy Impact Hub.