Understanding heat driven gelation of anionic cellulose nanofibrils: Combining saturation transfer difference (STD) NMR, small angle X-ray scattering (SAXS) and rheology

Filler size effect in an attractive fibrillated network: a structural and rheological perspective

“…Since the lower threshold for the data fitting was q min = 0.06 À1 , using values of L ) 2p q min kept the fitting unchanged. The model yielded values of R min = 1.1 AE 0.1 nm, R maj = 4.7 AE 0.1 nm and b Kuhn = 21.4 AE 0.1 nm, in good agreement with previous SAXS measurements 9,19,27 and imaging analysis of OCNF. 9 Upon SiNp addition, the SANS patterns had a similar trend to that of the pure OCNF gel, indicating that, in the probed q range, neither of these fillers strongly alters the structure of the fibrillated network.…”

“…2a) contains information regarding the shape of the fibrils in the high-q and intermediate-q region, which probe the radius and the larger dimensions of the fibril, respectively. 9,19,27 The upturn in the low-q region has been instead associated with the attractive interfibrillar interactions as described by Schmitt et al 9 The data were fitted, in the q region where interfibrillar interactions are not detectable (high-q and intermediate-q range), to a model of non-interacting flexible cylinders with an elliptical cross-section from which the minor radius (R min ), major radius (R maj ) and the Kuhn length (b Kuhn ) were obtained, where b Kuhn is indicative of the OCNF mesh size. 9 The data fitting was carried out using a fixed and arbitrary contour length (L) of 500 nm as the average length was not accessible in the probed q range, as indicated by the lack of a plateau in the low-q region.…”

“…An OCNF dispersion was prepared as previously described, 19 using a TEMPO/NaOCl/NaBr oxidation method. 20 A 2 wt% OCNF stock was redispersed from freeze-dried OCNF in ultrapure deionised (DI) water (18.2 MO cm) and stirred overnight, followed by a mild sonication process (Ultrasonic Processor FB-505, Fisher, 200 W cm À2 , equipped with a 1 cm probe, using a series of 1 s on/1 s off in pulse mode for a net time of 120 s at 30% amplitude on ca.…”

Technologies and Formulation Design of Polysaccharide-Based Hydrogels for Drug Delivery

“…Temperature-induced gelation as well as gel properties are highly depending upon polysaccharide typology. In fact, different mechanisms are discussed in the literature, e.g., for agar [74][75][76], κ-carrageenan [76,77], starch [78,79], cellulose [80][81][82] and chitosan [83].…”

Charge-driven interfacial gelation of cellulose nanofibrils across the water/oil interface

“…Over the last decade rod-like cellulose nanoparticles (CNP), such as cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC), have received much attention due to the combined biocompatibility and tuneable self-assembly of these particles, which allows the production of eco-friendly materials with tailored properties. 1 The relationship between CNP assembly and bulk properties has been widely explored, through the combination of surface modification and tuning of environmental conditions (e.g., pH, 2 ionic strength, 3,4 presence of surfactants, 5,6 and heat 7 ). Stable CNP dispersions have been successfully produced by introducing charged moieties onto cellulose nanoparticle surfaces.…”