TY - JOUR
T1 - Tailoring strength of nanocellulose foams by electrostatic complexation
AU - Mariano, Marcos
AU - Souza, Sivoney F.
AU - Borges, Antônio C.
AU - do Nascimento, Diego M.
AU - Bernardes, Juliana S.
N1 - Funding Information:
The authors are thankful for the funding from the São Paulo Research Foundation (FAPESP, grant 16/04514-7 ), the Brazilian Federal Agency for Support and Evaluation of Graduate Education within the Ministry of Education of Brazil (CAPES, by S.F.S Scholarship), the National Council for Scientific and Technological (CNPq, by D.M.N. Scholarship), and the Brazilian ́Synchrotron Light Laboratory, LNLS , for SAXS beamtime and for its staff support. Also, the authors thank Mateus B. Cardoso and Caio G. Otoni for valuable discussions about this topic.
Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2021/3/15
Y1 - 2021/3/15
N2 - Supramolecular assembly of biobased components in water is a promising strategy to construct advanced materials. Herein, electrostatic complexation was used to prepare wet-resilient foams with improved mechanical property. Small-angle X-ray scattering and cryo-transmission electron microscopy experiments showed that suspensions with oppositely charged cellulose nanofibers are a mixture of clusters and networks of entangled fibers. The balance between these structures governs the colloidal stability and the rheological behavior of CNFs in water. Foams prepared from suspensions exhibited maximum compressive modulus at the mass composition of 1:1 (ca 0.12 MPa), suggesting that meaningful attractive interactions happen at this point and act as stiffening structure in the material. Besides the electrostatic attraction, hydrogen bonds and hydrophobic contacts may also occur within the clustering, improving the water stability of cationic foams. These results may provide a basis for the development of robust all- cellulose materials prepared in water, with nontoxic chemicals.
AB - Supramolecular assembly of biobased components in water is a promising strategy to construct advanced materials. Herein, electrostatic complexation was used to prepare wet-resilient foams with improved mechanical property. Small-angle X-ray scattering and cryo-transmission electron microscopy experiments showed that suspensions with oppositely charged cellulose nanofibers are a mixture of clusters and networks of entangled fibers. The balance between these structures governs the colloidal stability and the rheological behavior of CNFs in water. Foams prepared from suspensions exhibited maximum compressive modulus at the mass composition of 1:1 (ca 0.12 MPa), suggesting that meaningful attractive interactions happen at this point and act as stiffening structure in the material. Besides the electrostatic attraction, hydrogen bonds and hydrophobic contacts may also occur within the clustering, improving the water stability of cationic foams. These results may provide a basis for the development of robust all- cellulose materials prepared in water, with nontoxic chemicals.
KW - Anionic cellulose nanofibers
KW - Cationic cellulose nanofibers
KW - Electrostatic complexation
KW - Foams
UR - http://dx.doi.org/10.1016/j.carbpol.2020.117547
U2 - 10.1016/j.carbpol.2020.117547
DO - 10.1016/j.carbpol.2020.117547
M3 - Article
C2 - 33483055
AN - SCOPUS:85098569717
SN - 0144-8617
VL - 256
JO - Carbohydrate Polymers
JF - Carbohydrate Polymers
M1 - 117547
ER -