scholarly journals Slowing down of dynamics and orientational order preceding crystallization in hard-sphere systems

2020 ◽  
Vol 6 (43) ◽  
pp. eabc5916
Author(s):  
Felix Lehmkühler ◽  
Birgit Hankiewicz ◽  
Martin A. Schroer ◽  
Leonard Müller ◽  
Beatrice Ruta ◽  
...  
Keyword(s):  
Hard Sphere ◽  
Soft Matter ◽  
Volume Fraction ◽  
Orientational Order ◽  
Strong Increase ◽  
Quasi Equilibrium ◽  
Slowing Down ◽  
X Ray Scattering ◽  
Matter System ◽  
Scattering Study

Despite intensive studies in the past decades, the local structure of disordered matter remains widely unknown. We show the results of a coherent x-ray scattering study revealing higher-order correlations in dense colloidal hard-sphere systems in the vicinity of their crystallization and glass transition. With increasing volume fraction, we observe a strong increase in correlations at both medium-range and next-neighbor distances in the supercooled state, both invisible to conventional scattering techniques. Next-neighbor correlations are indicative of ordered precursor clusters preceding crystallization. Furthermore, the increase in such correlations is accompanied by a marked slowing down of the dynamics, proving experimentally a direct relation between orientational order and sample dynamics in a soft matter system. In contrast, correlations continuously increase for nonequilibrated, glassy samples, suggesting that orientational order is reached before the sample slows down to reach (quasi-)equilibrium.

An improved small-angle X-ray scattering analysis of δ′ precipitation in an Al–Li alloy for growth kinetic studies

1999 ◽  
Vol 32 (3) ◽  
pp. 426-435 ◽  
Author(s):  
Cheng-Si Tsao ◽  
Tsang-Lang Lin
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Hard Sphere ◽  
Volume Fraction ◽  
The Other ◽  
Improved Method ◽  
Saxs Data ◽  
X Ray ◽  
X Ray Scattering ◽  
Two Parameters

An improved method for small-angle X-ray scattering (SAXS) data analysis is developed to reconstruct the free-form particle size distribution of δ′ precipitation in an Al–Li alloy. This improved method consists of four iterative steps; the interparticle interference is also included. The indirect transform method (ITM) plus a hard-sphere (HS) model which considers the depleted zones are used in the analysis of δ′ precipitation in an Al–Li alloy. Two parameters, namely the hard-sphere volume fraction, ηHS, and the ratio of hard-sphere radius to the particle radius,RHS/R, which determine the structure factor of the interparticle effect, are iteratively calculated using the monodisperse assumption and Gaussian size distribution. These two parameters are finally used in reconstructing the particle size distribution by the ITM + HS method. This method is tested by analysing simulated SAXS data and shows a better agreement than found in similar studies. This improved method is applied to analyse a set of experimental SAXS intensities from δ′ (Al3Li particles) precipitation in an Al–9.7 at.% Li alloy. The monodisperse results are compared with the polydisperse ITM + HS results. The current ITM + HS method fits the SAXS data better than the other methods. The variations of average radii with aging time were found to follow the kinetic power law. The SAXS results are used to investigate the theoretical kinetic model of the volume-fraction effect on late-stage coarsening (Ostwald ripening). By comparing both experimentally obtained asymptotic size distributions of δ′ particles as well as coarsening rate constants with those predicted by the various kinetic models, the modified Lifshitz–Slyozov–Wagner (MLSW) theory is found to be in better agreement with the experimental results than the other theories.

A thermoporometry and small-angle x-ray scattering study of wet silica sonogels as the pore volume fraction is varied

2007 ◽  
Vol 20 (2) ◽  
pp. 025225 ◽  
Author(s):  
D R Vollet ◽  
J P Scalari ◽  
D A Donatti ◽  
A Ibañez Ruiz
Keyword(s):  
Small Angle ◽  
Pore Volume ◽  
Volume Fraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Pore Volume Fraction ◽  
Scattering Study ◽  
Ray Scattering

A new method for evaluating the size of plate-like precipitates by small-angle scattering

2012 ◽  
Vol 45 (6) ◽  
pp. 1208-1218 ◽  
Author(s):  
Frédéric De Geuser ◽  
Françoise Bley ◽  
Alexis Deschamps
Keyword(s):  
Small Angle ◽  
Volume Fraction ◽  
Small Angle Scattering ◽  
Number Density ◽  
X Ray ◽  
X Ray Scattering ◽  
Angle Scattering ◽  
Ewald Sphere ◽  
Scattering Study

A methodology is presented for extracting the thickness and length of plate-like precipitates from streaking that appears in the small-angle scattering pattern of moderately textured polycrystalline samples. This methodology builds upon existing work on single crystals but is extended to polycrystals through a modeling of the streaking misalignment distribution. It is also shown that it is essential to take into account the Ewald sphere curvature. The protocol is applied to anin situsmall-angle X-ray scattering study of the transition between θ′ andT1in an Al–Li–Cu system, where the contributions of both phases are well separated, and the size, volume fraction and number density are monitored.

scholarly journals Diffusing wave microrheology of highly scattering concentrated monodisperse emulsions

2019 ◽  
Vol 116 (16) ◽  
pp. 7766-7771 ◽  
Author(s):  
Ha Seong Kim ◽  
Nesrin Şenbil ◽  
Chi Zhang ◽  
Frank Scheffold ◽  
Thomas G. Mason
Keyword(s):  
Soft Matter ◽  
Volume Fraction ◽  
Low Frequency ◽  
Mean Free Path ◽  
Quantitative Agreement ◽  
Einstein Relation ◽  
Quasi Equilibrium ◽  
Shear Moduli ◽  
Wide Range ◽  
Collective Scattering

Motivated by improvements in diffusing wave spectroscopy (DWS) for nonergodic, highly optically scattering soft matter and by cursory treatment of collective scattering effects in prior DWS microrheology experiments, we investigate the low-frequency plateau elastic shear moduli Gp′ of concentrated, monodisperse, disordered oil-in-water emulsions as droplets jam. In such experiments, the droplets play dual roles both as optical probes and as the jammed objects that impart shear elasticity. Here, we demonstrate that collective scattering significantly affects DWS mean-square displacements (MSDs) in dense colloidal emulsions. By measuring and analyzing the scattering mean free path as a function of droplet volume fraction φ, we obtain a φ-dependent average structure factor. We use this to correct DWS MSDs by up to a factor of 4 and then calculate Gp′ predicted by the generalized Stokes–Einstein relation. We show that DWS-microrheological Gp′(φ) agrees well with mechanically measured Gp′(φ) over about three orders of magnitude when droplets are jammed but only weakly deformed. Moreover, both of these measurements are consistent with predictions of an entropic–electrostatic–interfacial (EEI) model, based on quasi-equilibrium free-energy minimization of disordered, screened-charge–stabilized, deformable droplets, which accurately describes prior mechanical measurements of Gp′(φ) made on similar disordered monodisperse emulsions over a wide range of droplet radii and φ. This very good quantitative agreement between DWS microrheology, mechanical rheometry, and the EEI model provides a comprehensive and self-consistent view of weakly jammed emulsions. Extensions of this approach may improve DWS microrheology on other systems of dense, jammed colloids that are highly scattering.

Stability and Orientational Order of Gold Nanorods in Nematic Suspensions: A Small Angle X-ray Scattering Study

2015 ◽  
Vol 610 (1) ◽  
pp. 44-50 ◽  
Author(s):  
M. R. Thomas ◽  
J. E. Hallett ◽  
S. Klein ◽  
S. Mann ◽  
A. W. Perriman ◽  
...  
Keyword(s):  
Gold Nanorods ◽  
Small Angle ◽  
Orientational Order ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering

Orientational order in gravity dispersed clay colloids: A synchrotron x-ray scattering study of Na fluorohectorite suspensions

2001 ◽  
Vol 64 (6) ◽  
Author(s):  
E. DiMasi ◽  
J. O. Fossum ◽  
T. Gog ◽  
C. Venkataraman
Keyword(s):  
Orientational Order ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering

Orientational Order of Colloidal Disk-Shaped Particles under Shear-Flow Conditions: a Rheological−Small-Angle X-ray Scattering Study

2010 ◽  
Vol 114 (49) ◽  
pp. 16347-16355 ◽  
Author(s):  
Isabelle Bihannic ◽  
Christophe Baravian ◽  
Jérôme F. L. Duval ◽  
Erwan Paineau ◽  
Florian Meneau ◽  
...  
Keyword(s):  
Shear Flow ◽  
Small Angle ◽  
Orientational Order ◽  
Flow Conditions ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering

An X-ray Scattering Study of Laterally Modulated Structures: Investigation of Coherence and Resolution Effects with a Grating

1996 ◽  
Vol 6 (8) ◽  
pp. 1085-1094 ◽  
Author(s):  
A. Gibaud ◽  
J. Wang ◽  
M. Tolan ◽  
G. Vignaud ◽  
S. K. Sinha
Keyword(s):  
X Ray ◽  
X Ray Scattering ◽  
Modulated Structures ◽  
Scattering Study ◽  
Ray Scattering

A Small-Angle X-ray Scattering Study of α-helical Bundle-Forming Peptide–Polymer Conjugates in Solution: Chain Conformations

2013 ◽  
Vol 46 (4) ◽  
pp. 1625-1632 ◽  
Author(s):  
Reidar Lund ◽  
Jessica Shu ◽  
Ting Xu
Keyword(s):  
Small Angle ◽  
X Ray ◽  
Helical Bundle ◽  
Polymer Conjugates ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Chain Conformations ◽  
Ray Scattering

Evolution of Pore Ordering during Anodizing of Aluminum Single Crystals: In Situ Small-Angle X-ray Scattering Study

2021 ◽  
Author(s):  
Ilya V. Roslyakov ◽  
Andrei P. Chumakov ◽  
Andrei A. Eliseev ◽  
Alexey P. Leontiev ◽  
Oleg V. Konovalov ◽  
...  
Keyword(s):  
Single Crystals ◽  
Small Angle ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering
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