scholarly journals Stable, metastable and unstable cellulose solutions

2017 ◽  
Vol 4 (8) ◽  
pp. 170487 ◽  
Author(s):  
Marta Gubitosi ◽  
Pegah Nosrati ◽  
Mona Koder Hamid ◽  
Stefan Kuczera ◽  
Manja A. Behrens ◽  
...  
Keyword(s):  
Microcrystalline Cellulose ◽  
Small Angle ◽  
Supersaturated Solution ◽  
Cellulose Ii ◽  
Cellulose I ◽  
Tetrabutylammonium Hydroxide ◽  
X Ray ◽  
Stable Regime ◽  
X Ray Scattering ◽  
A Minor

We have characterized the dissolution state of microcrystalline cellulose (MCC) in aqueous tetrabutylammonium hydroxide, TBAH(aq), at different concentrations of TBAH, by means of turbidity and small-angle X-ray scattering. The solubility of cellulose increases with increasing TBAH concentration, which is consistent with solubilization driven by neutralization. When comparing the two polymorphs, the solubility of cellulose I is higher than that of cellulose II. This has the consequence that the dissolution of MCC (cellulose I) may create a supersaturated solution with respect to cellulose II. As for the dissolution state of cellulose, we identify three different regimes. (i) In the stable regime, corresponding to concentrations below the solubility of cellulose II, cellulose is molecularly dissolved and the solutions are thermodynamically stable. (ii) In the metastable regime, corresponding to lower supersaturations with respect to cellulose II, a minor aggregation of cellulose occurs and the solutions are kinetically stable. (iii) In the unstable regime, corresponding to larger supersaturations, there is macroscopic precipitation of cellulose II from solution. Finally, we also discuss strong alkali solvents in general and compare TBAH(aq) with the classical NaOH(aq) solvent.

On the dissolution state of cellulose in aqueous tetrabutylammonium hydroxide solutions

RSC Advances ◽  
2016 ◽  
Vol 6 (36) ◽  
pp. 30199-30204 ◽  
Author(s):  
M. A. Behrens ◽  
J. A. Holdaway ◽  
P. Nosrati ◽  
U. Olsson
Keyword(s):  
Microcrystalline Cellulose ◽  
Small Angle ◽  
Tetrabutylammonium Hydroxide ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

We have characterized the dissolution state of microcrystalline cellulose (MCC) in aqueous 40 wt% tetrabutylammonium hydroxide (TBAH) using a combination of light and small angle X-ray scattering, up to 0.1 g cm−3.

Insight into the nanostructure of anisotropic cellulose aerogels upon compression

Soft Matter ◽  
2019 ◽  
Vol 15 (41) ◽  
pp. 8372-8380 ◽  
Author(s):  
Harald Rennhofer ◽  
Sven F. Plappert ◽  
Helga C. Lichtenegger ◽  
Sigrid Bernstorff ◽  
Michael Fitzka ◽  
...  
Keyword(s):  
Small Angle ◽  
Compressive Strain ◽  
Cellulose Ii ◽  
Stress Strain ◽  
X Ray ◽  
X Ray Scattering ◽  
Insight Into ◽  
Ray Scattering

In this article we report on the nanostructural changes of a cellulose II aerogel network during compressive strain of up to 80%, which are investigated by in situ small angle X-ray scattering and linked to the corresponding stress–strain curves.

scholarly journals Structure of nickel nanoparticles in a microcrystalline cellulose matrix studied using anomalous small-angle X-ray scattering

2007 ◽  
Vol 40 (s1) ◽  
pp. s489-s494 ◽  
Author(s):  
Kari Pirkkalainen ◽  
Ulla Vainio ◽  
Kaisa Kisko ◽  
Tiiu Elbra ◽  
Tomas Kohout ◽  
...  
Keyword(s):  
Microcrystalline Cellulose ◽  
Small Angle ◽  
Nickel Nanoparticles ◽  
X Ray ◽  
X Ray Scattering ◽  
Cellulose Matrix ◽  
Ray Scattering

A Revised O2 Reduction Model in Li-O2 Batteries as Revealed by in Situ Small Angle X-Ray Scattering

2019 ◽  
Author(s):  
Christian Prehal ◽  
Aleksej Samojlov ◽  
Manfred Nachtnebel ◽  
Manfred Kriechbaum ◽  
Heinz Amenitsch ◽  
...  
Keyword(s):  
Small Angle ◽  
Wide Angle ◽  
Reduction Mechanism ◽  
Reduction Model ◽  
X Ray ◽  
X Ray Scattering ◽  
O2 Reduction ◽  
Ray Scattering

<b>Here we use in situ small and wide angle X-ray scattering to elucidate unexpected mechanistic insights of the O2 reduction mechanism in Li-O2 batteries.<br></b>

In situ Time-Resolved Small-Angle X-ray Scattering Reveals the Formation Kinetics of Polyelectrolyte Complex Micelles

2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell
Keyword(s):  
Small Angle ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Polyelectrolyte Complex ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Kinetics Of ◽  
Ray Scattering

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.

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