scholarly journals Dynamics of Water and Other Molecular Liquids Confined Within Voids and on Surface of Lignin Aggregates in Aging Bio Crude Oils

2021 ◽  
Vol 9 ◽  
Author(s):  
Massimo Bonini ◽  
Emiliano Fratini ◽  
Antonio Faraone
Keyword(s):  
Neutron Scattering ◽  
Renewable Energy Sources ◽  
Quantitative Information ◽  
Translational Diffusion ◽  
Crude Oils ◽  
Time Range ◽  
Molecular Liquids ◽  
Elastic Neutron ◽  
Structure And Dynamics ◽  
Elastic Neutron Scattering

Neutron scattering methods were employed to study the microscopic structure and dynamics of Bio Crude Oils (BCOs) and their lignin fractions. The structure of the carbonaceous aggregates was investigated using Small Angle Neutron Scattering to reveal a fractal hierarchy as well as a growth of the aggregates as the aging of the BCO proceeds. Elastic Neutron Scattering measurements indicate that BCO liquid phase, comprised of water and other hydrogenated molecular liquids, is in a state of extreme confinement. Quasi-Elastic Neutron Scattering yields information on the molecular motions, indicating that long range translational diffusion is suppressed and only localized dynamics take place on the tens of picosecond time range. The obtained results provide quantitative information on the molecular activity, as aging proceed, in these reactive materials of relevance as potential renewable energy sources.

scholarly journals Effects of water on the stochastic motions of propane confined in MCM-41-S pores

2019 ◽  
Vol 21 (45) ◽  
pp. 25035-25046 ◽  
Author(s):  
Siddharth Gautam ◽  
Tran Thi Bao Le ◽  
Gernot Rother ◽  
Niina Jalarvo ◽  
Tingting Liu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Neutron Scattering ◽  
Molecular Dynamics Simulations ◽  
Elastic Neutron ◽  
Structure And Dynamics ◽  
Cylindrical Pores ◽  
Elastic Neutron Scattering ◽  
Dynamics Simulations ◽  
Mcm 41

Quasi-elastic neutron scattering (QENS) and molecular dynamics simulations (MDS) reveal the effects of water on the structure and dynamics of propane confined in 1.5 nm wide cylindrical pores of MCM-41-S.

scholarly journals Methanol dynamics in H-ZSM-5 with Si/Al ratio of 25: a quasi-elastic neutron scattering (QENS) study

2021 ◽  
Author(s):  
Santhosh K. Matam ◽  
C. Richard A. Catlow ◽  
Ian P. Silverwood ◽  
Alexander J. O’Malley
Keyword(s):  
Neutron Scattering ◽  
Rotational Diffusion ◽  
Jump Diffusion ◽  
Translational Diffusion ◽  
Elastic Neutron ◽  
Measurement Temperature ◽  
Diffusion Dynamics ◽  
Mobile Fraction ◽  
Jump Diffusion Model ◽  
Elastic Neutron Scattering

AbstractMethanol dynamics in zeolite H-ZSM-5 (Si/Al of 25) with a methanol loading of ~ 30 molecules per unit cell has been studied at 298, 323, 348 and 373 K by incoherent quasi-elastic neutron scattering (QENS). The elastic incoherent structure factor (EISF) reveals that the majority of methanol is immobile, in the range between 70 and 80%, depending on the measurement temperature. At 298 K, ≈ 20% methanol is mobile on the instrumental timescale, exhibiting isotropic rotational dynamics with a rotational diffusion coefficient (DR) of 4.75 × 1010 s−1. Upon increasing the measurement temperature from 298 to 323 K, the nature of the methanol dynamics changes from rotational to translational diffusion dynamics. Similar translational diffusion rates are measured at 348 and 373 K, though with a larger mobile fraction as temperature increases. The translational diffusion is characterised as jump diffusion confined to a sphere with a radius close to that of a ZSM-5 channel. The diffusion coefficients may be calculated using either the Volino–Dianoux (VD) model of diffusion confined to a sphere, or the Chudley–Elliot (CE) jump diffusion model. The VD model gives rise to a self-diffusion co-efficient (Ds) of methanol in the range of 7.8–8.4 × 10–10 m2 s−1. The CE model gives a Ds of around 1.2 (± 0.1) × 10–9 m2 s−1 with a jump distance of 2.8 (either + 0.15 or − 0.1) Å and a residence time (τ) of ~ 10.8 (either + 0.1 or − 0.2) ps. A correlation between the present and earlier studies that report methanol dynamics in H-ZSM-5 with Si/Al of 36 is made, suggesting that with increasing Si/Al ratio, the mobile fraction of methanol increases while DR decreases.

Membranes studied using neutron scattering and NMR

1995 ◽  
Vol 73 (11-12) ◽  
pp. 687-696 ◽  
Author(s):  
Myer Bloom ◽  
Thomas M. Bayerl
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Neutron Scattering ◽  
Spectral Characteristics ◽  
Nmr Relaxation ◽  
Elastic Neutron ◽  
Fluid Membranes ◽  
Dynamical Properties ◽  
Elastic Neutron Scattering ◽  
Complementary Techniques

After reviewing some of the basic measurements that characterize the study of physical properties of matter using neutron scattering and nuclear magnetic resonance (NMR), connections between information obtained in current research on fluid membranes using these two complementary techniques are explored in two major chapters. In the first, the type of information on the structure of fluid membranes obtained from coherent elastic neutron scattering is compared with that from NMR spectral characteristics. Then, the type of information obtained on dynamical properties from NMR relaxation (T1 and T2) measurements is compared with that from quasi-elastic neutron scattering. Examples of such connections are given with an emphasis on relationships between the time and distance scales intrinsic to neutron scattering and NMR.

A quasi-elastic neutron scattering (QNS) study

1987 ◽  
Vol 55 (2) ◽  
pp. 183-201 ◽  
Author(s):  
W. Petry ◽  
G. Vogl ◽  
A. Heidemann ◽  
K.-H. Steinmetz
Keyword(s):  
Neutron Scattering ◽  
Elastic Neutron ◽  
Elastic Neutron Scattering
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