Abstrakti
Cross-linked and decolorized lignin nanoparticles (LNPs) were prepared enzymatically and chemically from softwood Kraft lignin. Colloidal lignin particles (CLPs, ca. 200 nm) in a non-malodorous aqueous dispersion could be dried and redispersed in tetrahydrofuran (THF) or in water retaining their stability i.e. spherical shape and size. Two fungal laccases, Trametes hirsuta (ThL) and Melanocarpus albomyces (MaL) were used in the cross-linking reactions. Reactivity of ThL and MaL on Lignoboost™ lignin and LNPs was confirmed by high performance size exclusion chromatography (HPSEC) and oxygen consumption measurements with simultaneous detection of red-brown color due to the formation of quinones. Zeta potential measurements verified oxidation of LNPs via formation of surface-oriented carboxylic acid groups. Dynamic light scattering (DLS) revealed minor changes in the particle size distributions of LNPs after laccase catalyzed radicalization, indicating preferably covalent intraparticular cross-linking over polymerization. Changes in the surface morphology of laccase treated LNPs were imaged by atomic force (AFM) and transmission emission (TEM) microscopy. Furthermore, decolorization of LNPs without degradation was obtained using ultrasonication with H2O2 in alkaline reaction conditions. The research results have high impact for the utilization of Kraft lignin as nanosized colloidal particles in advanced bionanomaterial applications in medicine, foods and cosmetics including different sectors from chemical industry.
| Alkuperäiskieli | englanti |
|---|---|
| Lehti | Enzyme and microbial technology |
| Vuosikerta | 111 |
| Sivut | 48-56 |
| Sivumäärä | 9 |
| ISSN | 0141-0229 |
| DOI - pysyväislinkit | |
| Tila | Julkaistu - huhtik. 2018 |
| OKM-julkaisutyyppi | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä, vertaisarvioitu |
Lisätietoja
Funding Information:This work was supported by the national institutes as Aalto University and VTT Technical Research Centre of Finland Ltd (Forest meets chemistry −program); TEKES The Finnish Funding Agency for Innovation (COLIAD-project); the Academy of Finland (grant numbers 276696 , 278279 , 263504 , 267497 , 2736459 ); the Academy of Finland’s Centers of Excellence Programme (grant number 272361 ). In addition, Dr. Martina Andberg (VTT Technical Research Centre of Finland Ltd., Espoo Finland) is acknowledged for providing the laccases for the study. Päivi Matikainen and Outi Liehunen (VTT Technical Research Centre of Finland Ltd., Espoo, Finland), Marja Kärkkäinen, Rita Hatakka and MSc. student Yan Zhenxing (Aalto University, Espoo, Finland) are thanked for the laboratory assistance. Appendix A
Publisher Copyright:
© 2018 The Author(s)