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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Interfacial properties of cellulose nanoparticles obtained from acid and enzymatic hydrolysis of cellulose

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Author(s):
Domingues, Amanda A. ; Pereira, Fabiano V. ; Sierakowski, Maria Rita ; Rojas, Orlando J. ; Petri, Denise F. S.
Total Authors: 5
Document type: Journal article
Source: Cellulose; v. 23, n. 4, p. 2421-2437, AUG 2016.
Web of Science Citations: 7
Abstract

Rod-shaped cellulose nanocrystals obtained by acid hydrolysis of eucalyptus fibers (CNCa) presented high aspect ratio (estimated length and width of 180 and 5 nm, respectively) and zeta potential of -(17 +/- 1) mV at pH 6. This typical morphology of cellulose nanocrystals was in contrast to nanoparticles obtained upon enzymatic hydrolysis of bacterial cellulose (CNCe), which were asymmetric and irregular due to surface-bound cellulases and presented a distinctive surface roughness. Interestingly, CNCe also displayed axial grooves, to yield a C-shape cross section that has not been reported before. The effect of the characteristic shape and surface chemistry of CNCa and of grooved CNCe was studied at oil/water interfaces and solid surfaces. Emulsions (20 % v/v oil) prepared with the CNCa were more stable than those prepared with CNCe, owing to their characteristic shape and surface chemistry. Hydrophilic (silica surfaces cationized by pre-adsorbed polycation) and hydrophobic (polystyrene films) solid surfaces were used as substrates for the adsorption of CNCe and CNCa for each type of surface. The ellipsometric data and AFM images indicated larger affinity of CNCe than CNCa for the hydrophobic surface. On the other hand, CNCa formed homogeneous monolayer on hydrophilic surfaces, whereas CNCe formed discontinuous films. Sequential adsorption behavior of CNCa on CNCe layers (or vice versa) suggested that the interaction between them is controlled by the orientation of enzymes bound to CNCe. (AU)

FAPESP's process: 10/51219-4 - Interactions between macromolecules and surfaces
Grantee:Denise Freitas Siqueira Petri
Support Opportunities: Regular Research Grants
FAPESP's process: 13/03480-3 - Stability of oil in water emulsions by cellulose nanocrystals, polycations and ultrasound
Grantee:Amanda Araujo Domingues
Support Opportunities: Scholarships in Brazil - Scientific Initiation