Optical and mechanical properties of nanofibrillated cellulose: Toward a robust platform for next-generation green technologies.
Nanofibrillated cellulose, a polymer that can be obtained from one of the most abundant biopolymers in nature, is being increasingly explored due to its outstanding properties for packaging and device applications. Still, open challenges in engineering its intrinsic properties remain to address. To elucidate the optical and mechanical stability of nanofibrillated cellulose as a standalone platform, herein we report on three main findings: (i) for the first time an experimental determination of the optical bandgap of nanofibrillated cellulose, important for future modeling purposes, based on the onset of the optical bandgap of the nanofibrillated cellulose film at Eg≈275 nm (4.5 eV), obtained using absorption and cathodoluminescence measurements. In addition, comparing this result with ab-initio calculations of the electronic structure the exciton binding energy is estimated to be Eex≈800 meV; (ii) hydrostatic pressure experiments revealed that nanofibrillated cellulose is structurally stable at least up to 1.2 GPa; and (iii) surface elastic properties with repeatability better than 5% were observed under moisture cycles with changes of the Young modulus as large as 65%. The results obtained show the precise determination of significant properties as elastic properties and interactions that are compared with similar works and, moreover, demonstrate that nanofibrillated cellulose properties can be reversibly controlled, supporting the extended potential of nanofibrillated cellulose as a robust platform for green-technology applications.
ICN2 Catalan Institute of Nanoscience and Nanotechnology, Campus UAB, Bellaterra, Barcelona 08193, Spain. Electronic address: claudia.simao@icn.cat.
Claudia D
CD
Simão
ICN2 Catalan Institute of Nanoscience and Nanotechnology, Campus UAB, Bellaterra, Barcelona 08193, Spain.
Juan S
JS
Reparaz
ICN2 Catalan Institute of Nanoscience and Nanotechnology, Campus UAB, Bellaterra, Barcelona 08193, Spain.
Markus R
MR
Wagner
ICN2 Catalan Institute of Nanoscience and Nanotechnology, Campus UAB, Bellaterra, Barcelona 08193, Spain.
Bartlomiej
B
Graczykowski
ICN2 Catalan Institute of Nanoscience and Nanotechnology, Campus UAB, Bellaterra, Barcelona 08193, Spain.
Martin
M
Kreuzer
ICN2 Catalan Institute of Nanoscience and Nanotechnology, Campus UAB, Bellaterra, Barcelona 08193, Spain; Unit of Computer-Aided Molecular "Biosilico" Discovery and Bioinformatic Research (CAMD-BIR Unit), Faculty of Chemistry-Pharmacy, Universidad Central "Marta Abreu" de Las Villas, Santa Clara 54830, Villa Clara, Cuba.
Yasser B
YB
Ruiz-Blanco
ICN2 Catalan Institute of Nanoscience and Nanotechnology, Campus UAB, Bellaterra, Barcelona 08193, Spain.
Yamila
Y
García
VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Espoo, Finland.
Jani-Markus
JM
Malho
Institut de Ciencia de Materials de Barcelona, ICMAB-CSIC, Barcelona, Spain; Catalan Institute of Research and Advanced Studies (ICREA), Barcelona 08010, Spain.
Alejandro R
AR
Goñi
VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Espoo, Finland.
Jouni
J
Ahopelto
ICN2 Catalan Institute of Nanoscience and Nanotechnology, Campus UAB, Bellaterra, Barcelona 08193, Spain; Catalan Institute of Research and Advanced Studies (ICREA), Barcelona 08010, Spain.
Clivia M
CM
Sotomayor Torres
D029662:Betula / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry* / Q000648:ultrastructure*; D055119:Elastic Modulus; D055772:Green Chemistry Technology / Q000379:methods; D049449:Luminescence; D008422:Materials Testing; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure*; D011312:Pressure; D013499:Surface Properties
D002482:Cellulose
High pressure Raman; Moisture stability; Nanofibrillated cellulose; Optical bandgap; Quantitative nanomechanical force microscopy