2 edition of Nuclear spin relaxation and morphology of solid polyolefins. found in the catalog.
Nuclear spin relaxation and morphology of solid polyolefins.
Race R. Yeung
Thesis (Ph.D.), School of Chemical Sciences, University of East Anglia, 1985.
The Spin Hamiltonian Revisited • Life is easier if: Examples: 2) interaction with dipole ﬁeld of other nuclei 3) spin-spin coupling • In general, is the sum of different terms representing different physical interactions. € H ˆ € H ˆ =H ˆ 1 + H ˆ 2 + H ˆ 3 +! 1) interaction of spin with € . Conclusions. Both the peaks’ assignments for T 2 distributions of FAMEs and the model for their liquid crystal-like morphology in the liquid phase were confirmed. The study of morphological structures within liquids and their response to temperature changes by 1 H LF-NMR has a high value in the field of biodiesel and other research and applied disciplines in numerous physicochemical- and.
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Nuclear spin relaxation and morphology of solid polyolefins Author: Yeung, R. ISNI: Awarding Body: University of East Anglia Current Institution: University of East Anglia Date of Award: Availability of Full Text: Full text unavailable from EThOS.
Spin Temperature and Nuclear Spin Relaxation in Matter: Basic Principles and Applications (The International Series of Monographs on Physics) [Wolf, Dieter] on *FREE* shipping on qualifying offers.
Spin Temperature and Nuclear Spin Relaxation in Matter: Basic Principles and Applications (The International Series of Monographs on Physics). Nuclear magnetic resonance (NMR) is widely used across many fields because of the rich data it produces, and some of the most valuable data come from the study of nuclear spin relaxation Nuclear spin relaxation and morphology of solid polyolefins.
book solution. While described to varying degrees in all major NMR books, spin relaxation is often perceived as a difficult, if not obscure, topic, and an accessibleCited by: understanding precision polyolefins by solid state nuclear magnetic resonance spectroscopy and x-ray scattering.
yuying wei. a dissertation presented to the graduate school of the university of florida in partial fulfillment of the requirements for the degree of doctor of philosophy. university of florida. Nuclear spin relaxation has been developed as a standard method for studying molecular motions in liquids, solids, polymers, and—to a lesser extent—gases, staring with the pioneering work of Bloembergen, Purcell, and Pound [ 1 ].Cited by: Nuclear magnetic resonance (NMR) is widely used across many fields of science because of the rich data it produces, and some of the most valuable data come from studies of nuclear spin relaxation in solution.
The first edition of this book, published more than a decade ago, provided an accessible and cohesive treatment of the field. The main features of nuclear spin relaxation in paramagnetic systems in solution have been described in the late fifties and early sixties by Solomon, Bloembergen and Morgan (1–4).
Briefly, two spins (I = nuclear spin, S = electron spin) in a paramagnetic complex are allowed to interact through hyperfine interaction (dipolar, DD, and scalar, SC). High-density polyethylene was studied by solid state 1 H NMR spectral fitting, relaxation, and spin diffusion methods.
The results are compared with measurements made by Raman spectroscopy, solid state 13 C NMR, density, and DSC methods. A modified Goldman−Shen solid state 1 H NMR technique was used to estimate the thicknesses of microscopic domains of the polyethylene.
High-density polyethylene was studied by solid state 1H NMR spectral fitting, relaxation, and spin diffusion methods. The results are compared with measurements made by Raman spectroscopy, solid state 13C NMR, density, and DSC methods.
A modified Goldman−Shen solid state 1H NMR technique was used to estimate the thicknesses of microscopic domains of the polyethylene. Abstract. Nuclear spin relaxation of methane in solid xenon has been studied by infrared spectroscopy.
From the analysis of the temporal changes of the rovibrational peaks, the rates of the nuclear spin relaxation of I = 2 ← 1 correlated to the rotational relaxation of J = 0 ← 1 were obtained at temperatures of – K. On the basis of the temperature dependence of the relaxation rate. The pore size distribution (PSD) and pore connectivity (PC) within porous polymer particles are probed by combining NMR cryoporometry and NMR relaxometry (spin−spin relaxation).
With water as a probe molecule, the constant K in the so-called Gibbs−Thompson equation and the surface relaxivity (ρ2) were determined to be K = ( ± 50) KÅ and ρ2 = ( ± ) × ms-1, respectively. The relative concentrations and carbon spin–lattice relaxation constants (T 1,C) of the amorphous, intermediate, and crystalline phases of unaged crosslinked polyolefin cable insulation (ultimate elongation, e=%), 60 Co γ-irradiated (e=22%), and irradiated+annealed (e=%) samples were determined by chemometric analyses of directly polarized solid-state 13 C NMR spectra.
High-density polyethylene was studied by solid state 1H NMR spectral fitting, relaxation, and spin diffusion methods. The results are compared with measurements made by Raman spectroscopy, solid. The NMR spin‐spin relaxation (T 2) spectra of high‐density polyethylene (PE) has been investigated over a wide range of temperatures, both in the solid and molten us work in these laboratories has shown that the T 2 relaxation spectrum of molten polyethylene differs from that of other polymers studied in that (a) it cannot be decomposed into two relaxation spectra (T 2S and T.
High-resolution solid-state 13C nuclear magnetic resonance spectra and 13C spin–lattice relaxation times T1(13C) are used to characterize the structure of a polymer blend prepared from poly.
The curve-fitting for the observed FIDs gives the individual spin–spin relaxation characteristics in different phases: crystalline, amorphous and interfacial.
4–9 Such a resolution into several components has been long attempted on a broad-line spectrum of solid PE. 10–13 These results will reflect the sample morphologies. 1 H Nuclear magnetic resonance (NMR) relaxometry was exploited to investigate the dynamics of solid proteins. The relaxation experiments were performed at 37 °C over a broad frequency range, from approximately 10 kHz to 40 MHz.
Two relaxation contributions to the overall 1 H spin–lattice relaxation were revealed; they were associated with 1 H– 1 H and 1 H– 14 N magnetic dipole–dipole. FID and T 2 relaxation decay, which were measured using SPE and HEPS respectively, were combined in a single file. The T 2 decay is shown at short (a, c) and long decay time (b, d).
The solid line represents the result of a least-square adjustment of the decay. The dotted lines show the separate relaxation components. Understanding Precision Polyolefins by Solid State Nuclear Magnetic Resonance Spectroscopy and X-Ray Scattering admet, dynamics, morphology, nmr, polyethylene, precision, xrd 15 TgX Glass transition temperature cT Degree of crystallinity 1T Spin lattice relaxation time 2SUPER S eparation of undistorted powder patterns by effortless.
Dear Colleagues, Since their early days, Nuclear Magnetic Resonance (NMR) and Polymer Science have had a strong and enduring liaison. Many times, the discovery of a new class of polymers required the development of new NMR techniques or the set-up of new interpretative paradigms, as in the case of the precise determination of the polymer tacticity.
PHYSICAL REVIEW B VOLUME 7, NUMBER 7 APRIL Nuclear-Spin Relaxation in the Rotating Frame in Solid Da~ F. Weinhaus, H. Meyer, and S. Myers~ Department of Physics, Duke University, Durham, ¹rth Carolina Z A. Harris Department of Physics, University of Pennsylvania, Philadelphia, Pennsylvania (Received 28 September ) The decay of the nuclear magnetization along a spin.
The deuteron spin–lattice relaxation time T 1 and spin–spin relaxation time T 2 have been studied in CD 4 and CD 3 H between 55 °K and °K. T 1 was found to increase very slowly with temperature over the entire temperature range for CD 4 with no measurable change being observable at the melting point.
Since the deuteron spin relaxation is produced by intramolecular quadrupolar. Nuclear magnetic resonance (NMR) is widely used across many fields because of the rich data it produces, and some of the most valuable data come from the study of nuclear spin relaxation in solution.
While described to varying degrees in all major NMR books, spin relaxation is often perceived as a difficult, if not obscure, topic, and an Reviews: 1. The material was put in a heated press at °C for 10 min and thereafter was cooled to room temperature.
The flat sheet samples were used for solid-state 13 C NMR analyses. Solid-state 13 C nuclear magnetic resonance. Solid-state carbon NMR techniques were performed on a Varian VXR spectrometer at room temperature.
Proton spin-lattice relaxation and proton spin-lattice relaxation in the rotating frame were observed in the solid polycarbonate of 1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethylene from to K. Solid-state nuclear magnetic resonance (NMR) has long emerged as a valuable technique for characterizing the molecular structure, conformation, and dynamics of polymer chains in various polymer systems.
The principles of the solid-state 13C NMR cross-polarization experiment are described along with corresponding relaxation measurements. The ensuing recent applications of. A method for the simultaneous measurement of NMR spin-lattice and spin-spin relaxation times in compartmentalized systems.
Journal of Magnetic Resonance ()99 (1), 13C n.m.r. spin-lattice relaxation times have been determined for carbons in a number of solid alkanes and in two linear polyethylenes. 13C spin-lattice relaxation times, T1s, for the internal. Get this from a library. Nuclear spin relaxation in liquids: theory, experiments, and applications.
[Jozef Kowalewski; Lena Mäler] -- "Nuclear magnetic resonance (NMR) is widely used because of the rich data it produces, and some of the most valuable data come from the study of nuclear spin relaxation in solution.
This book. Solid-state 1H NMR spin diffusion experiments are useful tools for the elucidation of domain sizes of heterogeneous polymers. For quantitative determination of domain sizes, however, reliable values of the spin diffusion coefficients are required. In this paper, spin diffusion coefficients are calibrated for mobile polymers through the transverse relaxation rate T of 1H magnetization.
Spin‐spin (T 2) relaxation is a time constant which describes the signal decay in the transverse (x,y) plane and is routinely utilized in conventional in‐vivo medical 1 H MRI to generate image contrast.
18 The T 2 relaxation mechanism, in solids, is attributed to numerous factors such as dipole‐dipole coupling, anisotropies, quadrupole. Solid-state NMR allows to characterize the molecular structure and the organization of the macromolecules in the bulk.
Special techniques offer to study dynamic aspects over a large range of characteristic rates. Solid-state NMR allows to characterize morphology properties, e.g. chain alignment in oriented polymers . The deuteron and proton spin‐lattice and spin‐spin relaxation times T 1 and T 2 of adsorbed water in commercial portland cement and tricalcium silicate pastes were studied as functions of the hardening time at room temperature.
The time dependence of the water self‐diffusion coefficient of tricalcium silicate pastes was also followed. Kenji Masuda, Masayuki Adachi, Asako Hirai, Hiroyuki Yamamoto, Hironori Kaji, Fumitaka Horii, Solid-state 13C and 1H spin diffusion NMR analyses of the microfibril structure for bacterial cellulose, Solid State Nuclear Magnetic Resonance, /S(03), 23, 4, (), ().
Get this from a library. Nuclear spin relaxation in liquids: theory, experiments, and applications. [Jozef Kowalewski; Lena Mäler] -- With coverage ranging from basic to rigorous theory & simple to sophisticated experimental methods, this book goes into more detail than most texts on nuclear spin relaxation in solution.
Topics. Introduction. A typical NMR experiment consists of a sample of nuclei of spin ℐ placed in a strong, uniform magnetic field B ⃑ 0 (the magnetic field is taken to be along the laboratory z-axis; B z = B 0, B x = B y = 0 and ℐ is the nuclear spin quantum number) until the sample reaches thermal equilibrium.
In an external field, the magnetic moment μ ⇀ = γ I ^ ⇀ of each spin. M.E.A. Cudby's 72 research works with 1, citations and 4, reads, including: The condensation of resorcinol with benzil. We report proton Zeeman relaxation rates in solid 1,4-di-isopropylbenzene (DIB) and in 1,3,5-tri-isopropylbenzene (TIB) at Larmor frequencies of and 53 MHz.
The temperature ranged from to K for DIB and from 85 to K for TIB. In DIB the free induction decay contains both a liquid-like and a solid. Abstract. The main advantage of NMR in the characterization of polymers is the unique molecular structural information which can be obtained.
For instance, the relative configurational distribution (tacticity) and regioirregularities (defects) in homopolymers of polypropylene (PP) can be mapped out and represent a unique microfingerprint of the polymer.
New insights into the thermal behaviour of organic ionic plastic crystals: magnetic resonance imaging of polycrystalline morphology alterations induced by solid–solid phase transitions K.
Romanenko, J. Pringle, L. O'Dell and M. Forsyth, Phys. Chem. Chem. Phys.,17. : Nuclear Spin Relaxation in Liquids: Theory, Experiments, and Applications, Second Edition (): Kowalewski, Jozef, Maler, Lena: Books.and Relaxation Studies of Solid Biopolymers).1–3 The origin of the nuclear spin relaxation is due to the ﬂuctuations of the molecules about their average structures.4 Within the broad context of molecular spectroscopy, the Hamiltonian operator H (t) describes how the system evolves with time.
It depends on both spatial and spin coordinates.Reports measurements of the electrical conductivity and 19 F nuclear magnetic resonance (NMR) relaxation times T 1, T 2, T 1 rho and T 1D in BaF 2 single crystals over a temperature range KK. The dominant process responsible for the 19 F spin relaxation is self-diffusion.
The magnitude and temperature dependence of the relaxation times.