Journal ArticleDOI
Cellulose polymorphy, crystallite size, and the Segal Crystallinity Index
TLDR
In this paper, the X-ray diffraction-based Segal Crystallinity Index (CI) was calculated for simulated different sizes of crystallites for cellulose Iβ and II.Abstract:
The X-ray diffraction-based Segal Crystallinity Index (CI) was calculated for simulated different sizes of crystallites for cellulose Iβ and II. The Mercury software was used, and different crystallite sizes were based on different input peak widths at half of the maximum peak intensity (pwhm). The two cellulose polymorphs, Iβ and II, gave different CIs despite having the same pwhm values and perfect periodicity. The higher CIs for cellulose II were attributed to a greater distance between the major peaks that are closest to the recommended 2-θ value for assessing the amorphous content. That results in less peak overlap at the recommended 2-θ value. Patterns calculated with simulated preferred orientation had somewhat higher CIs for cellulose Iβ, whereas there was very little effect on the CIs for cellulose II.read more
Citations
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Journal ArticleDOI
Idealized powder diffraction patterns for cellulose polymorphs
TL;DR: In this paper, powder diffraction patterns from cellulose Iα, Iβ, II, IIII, and IIIII were calculated based on the published atomic coordinates and unit cell dimensions contained in modified "crystal information files" that are supplied in the Supplementary Information.
Journal ArticleDOI
Current characterization methods for cellulose nanomaterials
E. Johan Foster,Robert J. Moon,Umesh P. Agarwal,Michael J. Bortner,Julien Bras,Sandra Camarero-Espinosa,Kathleen J. Chan,Martin J. D. Clift,Emily D. Cranston,Stephen J. Eichhorn,Douglas M. Fox,Wadood Y. Hamad,Laurent Heux,Bruno Jean,Matthew Korey,Kimberly J. Ong,Michael S. Reid,Scott Renneckar,Rose Roberts,Jo Anne Shatkin,John Simonsen,Kelly L. Stinson-Bagby,Nandula D. Wanasekara,Jeffrey P. Youngblood +23 more
TL;DR: This review establishes detailed best practices, methods and techniques for characterizing CNM particle morphology, surface chemistry, surface charge, purity, crystallinity, rheological properties, mechanical properties, and toxicity for two distinct forms of CNMs: cellulose nanocrystals and cellulose Nanofibrils.
Journal ArticleDOI
Nanocellulose as a natural source for groundbreaking applications in materials science: Today’s state
Dieter Klemm,Emily D. Cranston,Dagmar Fischer,Miguel Gama,Stephanie A. Kedzior,Dana Kralisch,Friederike Kramer,Tetsuo Kondo,Tom Lindström,Sandor Nietzsche,Katrin Petzold-Welcke,Falk Rauchfuß +11 more
TL;DR: Nanocelluloses are natural materials with at least one dimension in the nano-scale as discussed by the authors, which combine important cellulose properties with the features of nanomaterials and open new horizons for materials science and its applications.
Journal ArticleDOI
A critical review of analytical methods in pretreatment of lignocelluloses: Composition, imaging, and crystallinity.
TL;DR: A critical review of the first three categories of lignocelluloses pretreatment methods as well as their constraints in various applications is presented.
Journal ArticleDOI
Segal crystallinity index revisited by the simulation of X-ray diffraction patterns of cotton cellulose Iβ and cellulose II.
TL;DR: The Segal method estimates the amorphous fraction of cellulose Iβ materials simply based on intensity in an X-ray diffraction pattern and was extended to cellulose II using 16° 2θ intensity, which resulted in relatively good agreement with the simulation for mercerized cotton.
References
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Journal ArticleDOI
Mercury CSD 2.0 – new features for the visualization and investigation of crystal structures
Clare F. Macrae,Ian J. Bruno,James A. Chisholm,Paul R. Edgington,Patrick McCabe,Elna Pidcock,Lucia Rodriguez-Monge,Robin Taylor,Jacco van de Streek,Peter A. Wood +9 more
TL;DR: Mercury as discussed by the authors is a crystal structure visualization tool that allows highly customizable searching of structural databases for intermolecular interaction motifs and packing patterns, as well as the ability to perform packing similarity calculations between structures containing the same compound.
Journal ArticleDOI
An Empirical Method for Estimating the Degree of Crystallinity of Native Cellulose Using the X-Ray Diffractometer
TL;DR: In this paper, an empirical method for determining the crystallinity of native cellulose was studied with an x-ray diffractometer using the focusing and transmission techniques, and the influence of fluctuations in the primary radiation and in counting and recording processes have been determined.
Journal ArticleDOI
Scherrer after sixty years: a survey and some new results in the determination of crystallite size
J. I. Langford,A. J. C. Wilson +1 more
TL;DR: In this article, the Scherrer constants of simple regular shapes have been determined for all low-angle reflections (h2 + k2 + l2 ≤ 100) for four measures of breadth.
Journal ArticleDOI
Crystal Structure and Hydrogen-Bonding System in Cellulose Iβ from Synchrotron X-ray and Neutron Fiber Diffraction
TL;DR: In this article, the crystal and molecular structure of cellulose Iβ were determined using synchrotron and neutron diffraction data recorded from oriented fibrous samples prepared by aligning cellulose microcrystals from tunicin.
Journal ArticleDOI
Cellulose crystallinity index: measurement techniques and their impact on interpreting cellulase performance
TL;DR: Four different techniques incorporating X-ray diffraction and solid-state 13C nuclear magnetic resonance (NMR) were compared using eight different cellulose preparations and it was found that the simplest method, which is also the most widely used, and which involves measurement of just two heights in the X- Ray diffractogram, produced significantly higher crystallinity values than did the other methods.