Salt-induced thermal gelation of xyloglucan in aqueous media.

The influence of NaSO as a kosmotropic salt on the thermogelation of xyloglucan (XG) solutions was measured by rheology. The gelation occurred at lower temperatures and shorter times when the salt concentration was increased above 0.5 mol.

Influence of mechanical pretreatment to isolate cellulose nanocrystals by sulfuric acid hydrolysis.

The mechanical pretreatments intensities on characteristics of cellulose nanocrystals (CNC) prior to acid hydrolysis was evaluated. The cellulose was submitted to mechanical pretreatment as: magnetic stirring (CNC), blending (CNC) or grinding by 20 (CNC) and 40 (CNC) passages in a super mass colloid mill. Then, all samples were submitted to HSO hydrolysis and the CNC were evaluated by total mass yield (TMY%), rheological behavior, size distribution for width/length (WD), crystallinity index (CI%), OSO substitution degree (SD) and zeta potential (ζ).

Xyloglucan gelation induced by enzymatic degalactosylation; kinetics and the effect of the molar mass.

Gelation kinetics of aqueous solutions of xyloglucan (XG) extracted from H. courbaril seeds were investigated, in-situ, during enzymatic removal of galactose units by oscillatory shear rheological measurements, at different XG and enzyme (β-galactosidase) concentrations. Increasing the enzyme concentration (C) led to an increase of the gelation rate.

Bacterial cellulose in biomedical applications: A review.

Bacterial cellulose (BC) derived materials represents major advances to the current regenerative and diagnostic medicine. BC is a highly pure, biocompatible and versatile material that can be utilized in several applications - individually or in the combination with different components (e.g.

TEMPO-mediated oxidation on galactomannan: Gal/Man ratio and chain flexibility dependence.

Guar (GG) and locust bean (LBG) galactomannans (GMs) oxidation at C-6 was performed with catalyst TEMPO, in which the reaction progress was monitored by consume of NaOH solution. The products were characterized by spectroscopic analysis, infrared, and (1)H-nuclear magnetic resonance, confirming the presence of aldehydes groups as intermediate of reaction to carboxylic acid. From high performance anion exchange chromatography with pulsed amperometric detection Man/Gal molar ratio was determined and demonstrated a preference to oxidize Man during the reaction on both GMs, following a first order kinetics of oxidation.