Authors: Amanda A Domingues Fabiano V Pereira Maria Rita Sierakowski Orlando J Rojas Denise F S Petri
Publish Date: 2016/05/23
Volume: 23, Issue: 4, Pages: 2421-2437
Abstract
Rodshaped 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 surfacebound cellulases and presented a distinctive surface roughness Interestingly CNCe also displayed axial grooves to yield a Cshape 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 preadsorbed 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 CNCeThe authors thank the Brazilian Funding agencies FAPESP Grant 2010/512194 and 2013/034803 CNPq Grants 305178/20130 306245/20140 and 448497/20140 FINEP Grant 0113039600 and Rede Nanobiotec CAPESOJR is grateful for partial funding support by the Academy of Finland through its Centers of Excellence Program 2014–2019 under project “Molecular Engineering of Biosynthetic Hybrid Materials Research” HYBER Dr TiinaE Nypelö is acknowledged for helpful discussions
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