Proton and Deuteron Double Resonance Studies of Structural Differences Between Amorphous Si and Ge Films

1993 ◽  
Vol 297 ◽  
Author(s):  
P.H. Chan ◽  
P.A. Fedders ◽  
R.E. Norberg ◽  
W. Paul ◽  
D. Pang ◽  
...  
Keyword(s):  
Pulse Sequence ◽  
Double Resonance ◽  
Resonance Method ◽  
Micro Structure ◽  
High Quality ◽  
Structural Differences ◽  
Amorphous Si

Proton and deuteron double resonance methods have been used to study the structure of high quality plasma-deposited a-Si:H,D and a-Ge:H,D films. The micro-structure of the a-Si is dominated by nanovoids with dimension <3 Å while the a-Ge shows many larger microvoids. We have observed new proton HD multiple echoes in the films by using a three pulse sequence double resonance method. The new echoes imply that HD molecules in a-Ge principally are located in large microvoids, which is not the case in high quality a-Si.

scholarly journals Use of Solid-State NMR Spectroscopy for the Characterization of Molecular Structure and Dynamics in Solid Polymer and Hybrid Electrolytes

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1207
Author(s):  
Gabrielle Foran ◽  
Nina Verdier ◽  
David Lepage ◽  
Cédric Malveau ◽  
Nicolas Dupré ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Pulse Sequence ◽  
Dynamic Properties ◽  
Double Resonance ◽  
Solid Polymer ◽  
Pulse Field ◽  
Solid State Nmr Spectroscopy

Solid-state NMR spectroscopy is an established experimental technique which is used for the characterization of structural and dynamic properties of materials in their native state. Many types of solid-state NMR experiments have been used to characterize both lithium-based and sodium-based solid polymer and polymer–ceramic hybrid electrolyte materials. This review describes several solid-state NMR experiments that are commonly employed in the analysis of these systems: pulse field gradient NMR, electrophoretic NMR, variable temperature T1 relaxation, T2 relaxation and linewidth analysis, exchange spectroscopy, cross polarization, Rotational Echo Double Resonance, and isotope enrichment. In this review, each technique is introduced with a short description of the pulse sequence, and examples of experiments that have been performed in real solid-state polymer and/or hybrid electrolyte systems are provided. The results and conclusions of these experiments are discussed to inform readers of the strengths and weaknesses of each technique when applied to polymer and hybrid electrolyte systems. It is anticipated that this review may be used to aid in the selection of solid-state NMR experiments for the analysis of these systems.

scholarly journals Double Resonance Method for Determination of Gel Point

2019 ◽  
pp. 160-165
Author(s):  
Ivan S. Kozhevnikov ◽  
Lyubov K. Altunina ◽  
Andrey V. Bogoslovsky ◽  
Lyubov A. Stasyeva
Keyword(s):  
Double Resonance ◽  
Resonance Method ◽  
Gel Point ◽  
Cellulose Ether ◽  
Different Diameters

The application of double resonance method for determining the dynamics of fluidity changes of thermotropic gel-forming compositions based on cellulose ether is considered. To determine the gel point, a modified version of the ‘Rheokinetika’ viscometer including two identical sensors and measuring cells of different diameters

Laser-rf double-resonance study of SiO+

1995 ◽  
Vol 73 (1-2) ◽  
pp. 101-105 ◽  
Author(s):  
T. J. Scholl ◽  
R. Cameron ◽  
S. D. Rosner ◽  
R. A. Holt
Keyword(s):  
Fine Structure ◽  
Ground State ◽  
Molecular Model ◽  
Double Resonance ◽  
Rotational Quantum Number ◽  
Resonance Method ◽  
Rotational Transition ◽  
Quantum Numbers ◽  
Data Yield ◽  
Π State

We used the laser-rf double resonance method to measure 15 fine structure intervals for rotational quantum numbers ranging from N = 5 to 79 of the ν = 0 level of the X2Σ+ state of SiO+. We present a molecular model, including perturbations from the A2Π state, which explains the observed strong variation of fine structure as a function of rotational quantum number. These data yield greatly improved predictions of the microwave spectrum of the ground state of SiO+. In particular we predicted the ground state rotational transition (N = 2, J = 5/2) → (N = 1, J = 3/2) to be 86 063(1) MHz, confirming that this transition is not the source of the radio line known as U86.2 at 86 243.45(40) MHz.

Pulsed electron–electron double resonance: beyond nanometre distance measurements on biomacromolecules

2011 ◽  
Vol 434 (3) ◽  
pp. 353-363 ◽  
Author(s):  
Gunnar W. Reginsson ◽  
Olav Schiemann
Keyword(s):  
Protein Complexes ◽  
Double Resonance ◽  
Resonance Method ◽  
Spin Labels ◽  
Coupling Mechanism ◽  
Distance Measurements ◽  
Paramagnetic Resonance ◽  
Distance Distributions ◽  
Nitroxide Spin Labels ◽  
Amino Acid Radicals

PELDOR (or DEER; pulsed electron–electron double resonance) is an EPR (electron paramagnetic resonance) method that measures via the dipolar electron–electron coupling distances in the nanometre range, currently 1.5–8 nm, with high precision and reliability. Depending on the quality of the data, the error can be as small as 0.1 nm. Beyond mere mean distances, PELDOR yields distance distributions, which provide access to conformational distributions and dynamics. It can also be used to count the number of monomers in a complex and allows determination of the orientations of spin centres with respect to each other. If, in addition to the dipolar through-space coupling, a through-bond exchange coupling mechanism contributes to the overall coupling both mechanisms can be separated and quantified. Over the last 10 years PELDOR has emerged as a powerful new biophysical method without size restriction to the biomolecule to be studied, and has been applied to a large variety of nucleic acids as well as proteins and protein complexes in solution or within membranes. Small nitroxide spin labels, paramagnetic metal ions, amino acid radicals or intrinsic clusters and cofactor radicals have been used as spin centres.

The Microstructure of Nanocarrier System and its Application in Cosmetics

Nano LIFE ◽  
2020 ◽  
Vol 10 (04) ◽  
pp. 2040012 ◽  
Author(s):  
Liang Gan ◽  
Jianjun Deng ◽  
Liuyun Hu ◽  
Wangwang Lu ◽  
Dingyuan Cui ◽  
...  
Keyword(s):  
Pharmacological Activity ◽  
Targeted Delivery ◽  
Nanostructured Lipid Carriers ◽  
Living Standard ◽  
Intracellular Uptake ◽  
Sustained Delivery ◽  
Micro Structure ◽  
Active Components ◽  
High Quality ◽  
Active Molecule

With the improvement of living standard, consumers have higher requirements on functions of cosmetics. Nanocarrier systems can offer remarkable features and have potential in targeted-oriented active molecule delivery. In order to improve the functions of cosmetics, nanocarrier system has been widely used in cosmetics. Nanoemulsions, liposomes and nanostructured lipid carriers (NLCs) have attracted considerable attention as three main nanocarrier systems for cosmetics and personal care products. They have a lot of advantages such as improving stability, improving tissue macrophages distribution, increasing solubility, bioavailability, protection of actives from toxicity, enhancing pharmacological activity and intracellular uptake, targeted delivery and sustained delivery. In this paper, the definition, classification and micro-structure of these three carriers were reviewed. The applications of nanoemulsions, liposomes and NLCs in cosmetics were discussed. The beneficial aspects of nanoemulsions, liposomes and NLCs in cosmetics are very broad. They have very promising future for the delivery of cosmetic active components/ingredients and for the production of high-quality cosmetics.

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