scholarly journals Studies of structure and dynamics of solid polymers by elastic and inelastic neutron scattering

1978 ◽  
Vol 50 (11-12) ◽  
pp. 1319-1341 ◽  
Author(s):  
E. W. Fischer
Keyword(s):  
Neutron Scattering ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Solid Polymers ◽  
Structure And Dynamics

Ti-Zr-Ni Quasicrystals: Structure and Hydrogen Storage

1995 ◽  
Vol 400 ◽  
Author(s):  
R. M. Stroud ◽  
A. M. Viano ◽  
E. H. Majzoub ◽  
P. C. Gibbons ◽  
K. F. Kelton
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Transition Metal ◽  
Hydrogen Storage ◽  
Neutron Scattering ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
X Ray ◽  
Structure And Dynamics ◽  
Icosahedral Phases

AbstractTitanium-based icosahedral phases constitute the second largest class of quasicrystals. In contrast with other Ti-based icosahedral phases (i-phases), Ti-Zr-Ni i-phases are well ordered and their formation is inhibited by the presence of Si and O, elements that stabilize the Ti-3d transition metal quasicrystals. We present x-ray and DSC data that suggest that Ti-Zr-Ni i-phases form a different class of titanium-based quasicrystals that are closely related to the MgZn2 Laves phase. The DSC data also suggest that the i-phase may be stable in these alloys. The ability of Ti-Zr-Ni i-phases to absorb up to 62 atomic % of hydrogen is presented and discussed. This opens new avenues of investigation of the structure and dynamics of quasiperiodic phases using elastic and inelastic neutron scattering and nuclear magnetic resonance and may point to potential uses for quasicrystals in hydrogen storage applications.

scholarly journals Concentration dependence of vibrational properties of bioprotectant/water mixtures by inelastic neutron scattering

2006 ◽  
Vol 4 (12) ◽  
pp. 167-173 ◽  
Author(s):  
S Magazù ◽  
F Migliardo ◽  
A.J Ramirez-Cuesta
Keyword(s):  
Neutron Scattering ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Biological Molecules ◽  
Chemical Mechanisms ◽  
Structure And Dynamics ◽  
Biophysical Processes ◽  
Bending Modes ◽  
Physical And Chemical ◽  
Vibrational Features

Neutron scattering has been demonstrated to be a powerful tool for characterizing the structure and dynamics of biological molecules and for investigating the physical and chemical mechanisms of biophysical processes. The aim of the present work is to investigate by inelastic neutron scattering (INS) the vibrational behaviour of a class of bioprotectant systems, such as homologous disaccharides, trehalose, maltose and sucrose, in water mixtures. INS measurements have been performed on trehalose/H 2 O, maltose/H 2 O and sucrose/H 2 O mixtures at very low temperature as a function of concentration by using the thermal original spectrometer with cylindrical analyzers (TOSCA) spectrometer at the ISIS Facility (DRAL, UK). The findings allow the analyses of the vibrational features of the INS spectra in order to study the effect of disaccharides on the H 2 O hydrogen-bonded tetrahedral network. The obtained neutron scattering findings point out that disaccharides, and in particular trehalose, have a destructuring effect on the water tetrahedral network, as emphasized by the analysis of the librational modes region from 50 to 130 meV energy transfer. On the other hand, the analysis of the bending modes region (130–225  meV) shows a locally ordered structure in the disaccharide/H 2 O mixtures. Finally, the observed experimental evidences are linked to the different bioprotective effectiveness of disaccharides as a function of concentration.

scholarly journals Understanding the Structure and Dynamics of Nanocellulose-Based Composites with Neutral and Ionic Poly(methacrylate) Derivatives Using Inelastic Neutron Scattering and DFT Calculations

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1689
Author(s):  
Carla Vilela ◽  
Carmen S. R. Freire ◽  
Catarina Araújo ◽  
Svemir Rudić ◽  
Armando J. D. Silvestre ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Density Functional ◽  
Inelastic Neutron Scattering ◽  
Density Functional Theory Calculations ◽  
Inelastic Neutron ◽  
Spectral Lines ◽  
Model Systems ◽  
Functional Theory ◽  
Bacterial Nanocellulose ◽  
Structure And Dynamics

Bacterial nanocellulose (BC)-based composites containing poly(2-hydroxyethyl methacrylate) (PHEMA), poly(methacroylcholine chloride) (PMACC) or poly(methacroylcholine hydroxide) (PMACH) were characterized by inelastic neutron scattering (INS) spectroscopy, combined with DFT (density functional theory) calculations of model systems. A reasonable match between calculated and experimental spectral lines and their intensities was used to support the vibrational assignment of the observed bands and to validate the possible structures. The differences between the spectra of the nanocomposites and the pure precursors indicate that interactions between the components are stronger for the ionic poly(methacrylate) derivatives than for the neutral counterpart. Displaced anions interact differently with cellulose chains, due to the different ability to compete with the O–H···O hydrogen bonds in cellulose. Hence, the INS is an adequate technique to delve deeper into the structure and dynamics of nanocellulose-based composites, confirming that they are true nanocomposite materials instead of simple mixtures of totally independent domains.

Neutron Scattering in Structural Biology and Biomolecular Materials

MRS Bulletin ◽  
1999 ◽  
Vol 24 (12) ◽  
pp. 40-47 ◽  
Author(s):  
J. Kent Blasie ◽  
Peter Timmins
Keyword(s):  
Neutron Scattering ◽  
Inelastic Neutron Scattering ◽  
Biological Systems ◽  
Inelastic Neutron ◽  
Hydrogen Atoms ◽  
Length Scales ◽  
Elastic Neutron ◽  
Neutron Sources ◽  
Structure And Dynamics ◽  
Scattering Technique

The substantial power of both elastic and inelastic neutron-scattering techniques for the investigation of the structure and dynamics of biological systems and related biomolecular-based materials—as with soft matter in the previous article by Lindner and Wignall—arises primarily from the essentially isomorphous nature of the substitution of deuterium for selected hydrogen atoms in these systems, coupled with the exquisite sensitivity of neutron scattering to this isotopic substitution. Since these systems are comprised of large macromolecules and supramolecular assemblies thereof, their essential structures and dynamics extend from the atomic scale up to very large length scales of the Order of 101–104 Å. Hence neutron sources and neutron-scattering spectrometers optimized for longer wavelength (or “cold”) thermal neutrons are necessary in order to most effectively address the structure and dynamics at the longer length scales inherent to these Systems.The large majority of previous neutron-scattering experiments on biological systems have been performed with reactor neutron sources. Some of the more significant of these are briefly summarized in the following sections. They may be categorized in terms of the nature of the intermolecular order, both orientational and positional, within the System of interest and either the elastic neutron-scattering technique employed to investigate their time-averaged structures or the inelastic neutron-scattering technique employed to investigate their dynamics.

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