Bicomponent films of cellulose and lignin and their biodegradation

Transcription

1 LIGNOCELLVALUE-ADDED MATERIALS AND FUNCTIONAL STRUCTURES FROM LIGNOCELLULOSICS Bicomponent films of cellulose and lignin and their biodegradation Steering group meeting Ingrid Hoeger Outline Background and motivation Film development and characterization Enzymatic treatment of bicomponent films Conclusions 1

2 Background and motivation Thin films Simplified systems Surface Interactions Fundamental information Background and motivation Polymer blends Macroscopically homogeneous mixtures of two or more polymers. Can exhibit miscibility, partial miscibility or phase separation. IUPAC Compendium of Chemical Terminology 2nd Edition (1997) Lloyd M. Robeson, Polymer Blends, Hanser 2

3 Background: Lignin inhibitor effect Summary Irreversible adsorption of enzymes onto lignin Inhibition effect of lignin The degree of interaction varies with enzyme type Type of lignin: large inhibition effect Bicomponent films: development and characterization 3

4 TMSC: Trimethylsilyl cellulose Cellulose/Lignin thin films: manufacture Dissolve TMSC in chloroform, 10 g/l Dissolve LAc in chloroform, 10g/l Blend TMSC / LAc (conc. of the major component fixed at 5 g/l ) Spin coating on silicon wafers at 2000 rpm for 1.5 min. LAc : Acetylated lignin De-silylation of TMSC:* Hydrochloric acid atmosphere in a desiccator, under vacuum below 80 mbar for 2 min De-acetylation:** Ammonium hydroxide atmosphere at room T for 1 day followed by washing with water. *M. Schaub, et al. Adv. Mater., 1993, 5, 919. E. Kontturi, et al, Polymer, 2003, 44, ** Shimamoto S, and Gray D. Cellulose (1999) 6, Characterization of the thin films AFM Morphology and surface roughness Hydrophobicity / hydrophilicity Contact Angle XPS Deacetylation and component distribution 4

5 Thin films of pure cellulose and lignin TMSC Cellulose De-silylation Acetylated lignin Lignin De-acetylation % atom (XPS): deacetylation lignin films Film O 1s C 1s N 1s Si 2p C-C C-O C=O COO Acetylated Lignin Deacetylated Lignin Film O/C Acetylated Lignin 0.33 Deacetylated Lignin

6 Bicomponent films (AFM) TMSC TMSC-LAc 10:1 TMSC-LAc 5:1 TMSC-LAc 1:1 5 µm x 5 µm scan size Blend ratio 1:1 De-acetylation De-silylation TMSC-LAc TMSC-Lignin Cellulose-LAc Cellulose-Lignin De-silylation De-acetylation 5 µm x 5 µm scan size 6

7 Blend ratio 1:1 TMSC-Lignin Cellulose-Lignin TMSC-LAc Cellulose-LAc Cellulose-Lignin 1 µm x 1 µm scan size Cellulose Bicomponent films (AFM) Cellulose-Lignin 10:1 Cellulose-Lignin 5:1 Cellulose-Lignin 1:1 5 µm x 5 µm scan size 7

8 Contact angle ( ) Contact angles of bicomponent thin films TMSC/LAc TMSC/Lignin Cellulose/Lignin TMCS/LAc TMSC/Lignin Cellulose/Lignin 10/1 5/1 1/1 1/5 Blend ratio with respect to cellulose 91 TMSC 49 Cellulose 65º Acetylated lignin 58 Lignin Enzymatic hydrolysis of bicomponent thin films 8

9 Adsorption Hydrolysis Enzyme composition Enzyme Composition in weight (%) FPU (UI/ml) CMC (IU/ml) Avicel (IU/ml) Xylanase (µmol*ml -1 min -1 ) Mixture 1 Cellulase Mixture 2 Cellulase Xylanase < Xylanase b-glucosidase Cellulolytic activity on neat cellulose and lignin films 5% enzyme solution, ph 5 (acetate buffer), 40 C Enzyme injection Rinse with acetate buffer ß-glucosidase Xylanase Hydrolysis of Cellulose films Adsorption on lignin films 9

10 Enzymatic treatment Cellulolytic activity on bicomponent cellulose/lignin films Cellulose cel:lig 10:1 cel:lig 5:1 cel:lig 1:1 Lignin Bicomponent films after enzymatic treatment (AFM) Cellulose cel:lig 10:1 cel:lig 5:1 cel:lig 1:1 5 µm x 5 µm scan size 10

11 Correlation graph: C-C vs O/C (XPS) Conclusions Thin bicomponent films of cellulose/lignin where successfully developed Inhibition of enzymatic activity (b/c lignin) was observed in bicomponent films 11

12 Acknowledgments Prof. Orlando Rojas, Dr. Ilari Filpponen, Dr. Monika Österberg and Prof. Janne Laine LignoCell (Aalto) and Hoffman Fellowship (NC State) for funding support. Members of the Colloids Interfaces Group, NCSU Members of the Forest Products Surface Chemistry, Aalto Rita Hatakka, Dr. Leena-Sisko Johansson and Dr. Anna-Stiina Jääskeläinen, Aalto University Raquel Martin, INIA Dr. Armindo Gaspar, Novozymes North America, NC, USA Dr. Ewellyn Capanema, Lignol Innovations Ltd., Canada 12