Enhanced Morphological Characterization of Cellulose Nano/Microfibers through Image Skeleton Analysis
Jose Luis Sanchez-Salvador,
Cristina Campano,
Patricio Lopez-Exposito,
Quim Tarrés,
Pere Mutjé,
Marc Delgado-Aguilar,
M. Concepcion Monte,
Angeles Blanco
Affiliations
Jose Luis Sanchez-Salvador
Department of Chemical Engineering and Materials, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avenida Complutense, 28040 Madrid, Spain
Cristina Campano
Department of Chemical Engineering and Materials, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avenida Complutense, 28040 Madrid, Spain
Patricio Lopez-Exposito
Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganés, Spain
Quim Tarrés
Group LEPAMAP, Department of Chemical Engineering, University of Girona, C/M. Aurèlia Campmany 61, 17071 Girona, Spain
Pere Mutjé
Group LEPAMAP, Department of Chemical Engineering, University of Girona, C/M. Aurèlia Campmany 61, 17071 Girona, Spain
Marc Delgado-Aguilar
Group LEPAMAP, Department of Chemical Engineering, University of Girona, C/M. Aurèlia Campmany 61, 17071 Girona, Spain
M. Concepcion Monte
Department of Chemical Engineering and Materials, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avenida Complutense, 28040 Madrid, Spain
Angeles Blanco
Department of Chemical Engineering and Materials, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avenida Complutense, 28040 Madrid, Spain
The present paper proposes a novel approach for the morphological characterization of cellulose nano and microfibers suspensions (CMF/CNFs) based on the analysis of eroded CMF/CNF microscopy images. This approach offers a detailed morphological characterization and quantification of the micro and nanofibers networks present in the product, which allows the mode of fibrillation associated to the different CMF/CNF extraction conditions to be discerned. This information is needed to control CMF/CNF quality during industrial production. Five cellulose raw materials, from wood and non-wood sources, were subjected to mechanical, enzymatic, and (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (TEMPO)-mediated oxidative pre-treatments followed by different homogenization sequences to obtain products of different morphologies. Skeleton analysis of microscopy images provided in-depth morphological information of CMF/CNFs that, complemented with aspect ratio information, estimated from gel point data, allowed the quantification of: (i) fibers peeling after mechanical pretreatment; (ii) fibers shortening induced by enzymes, and (iii) CMF/CNF entanglement from TEMPO-mediated oxidation. Being mostly based on optical microscopy and image analysis, the present method is easy to implement at industrial scale as a tool to monitor and control CMF/CNF quality and homogeneity.
