Analysis of 2H NMR spectra of water molecules on the surface of nano-silica material MCM-41: Deconvolution of the signal into a Lorentzian and a powder pattern line shapes

2012 ◽  
Vol 407 (1) ◽  
pp. 179-183 ◽  
Author(s):  
J. Hassan
Keyword(s):  
Nmr Spectra ◽  
Powder Pattern ◽  
Water Molecules ◽  
2H Nmr ◽  
Nano Silica ◽  
Line Shapes ◽  
Silica Material ◽  
Pattern Line ◽  
Mcm 41

scholarly journals Study of Structural Phase Transitions in [Mg(H2O)6][SiF6] by Means of Single Crystal 2H NMR

2002 ◽  
Vol 57 (6-7) ◽  
pp. 408-412 ◽  
Author(s):  
Takahiro Iijima ◽  
Motohiro Mizuno ◽  
Masahiko Suhara ◽  
Kazunaka Endo
Keyword(s):  
Phase Transition ◽  
Single Crystal ◽  
Nmr Spectra ◽  
Structural Phase ◽  
Water Molecules ◽  
2H Nmr ◽  
Structural Phase Transitions ◽  
H Nmr ◽  
Rotational Modulation ◽  
Infinite Temperature

The temperature and angular dependences of 2H NMR spectra were measured for single crystal of [Mg(H2O)6][SiF6]. At 283 K, (e2Qq/h,η) of 2H, averaged by fast 180° flip of water molecules, were obtained as (128 kHz, 0.72), (123 kHz, 0.82) and (106 kHz, 0.80), corresponding to three unequal water molecules in [Mg(H2O)6]2+. At 338 K, (e2Qq/h,η) averaged further by the fast reorientation of [Mg(H2O)6]2+ around the 3 axis was obtained as (57 kHz, 0.01). In phase II, the jumping rate for the reorientation ( ) and the amplitude of the rotational modulation (Δ ) of [Mg(H2O)6]2+ about the C3 axis were obtained from the simulation of 2H NMR spectra. The jumping rate at infinite temperature and the activation energy were estimated from the temperature dependence of k as k0 = 9 1017 s-1 and a = 78 kJmol-1, respectively. The II-III phase transition was found to be related with the freeze of this motion

scholarly journals Measurements of 1H and 2H NMR Spectra for Water Molecules Sorbed into Polymers.

1996 ◽  
Vol 53 (5) ◽  
pp. 308-310 ◽  
Author(s):  
Hiroshi KUSANAGI ◽  
Kenji MATSUMURA
Keyword(s):  
Nmr Spectra ◽  
Water Molecules ◽  
2H Nmr

13C NMR-spektroskopische Untersuchungen an Äthylaluminiumverbindungen / 13C NMR Spectroscopic Investigations of Ethylaluminium Compounds

1976 ◽  
Vol 31 (6) ◽  
pp. 730-736 ◽  
Author(s):  
R. Rottler ◽  
C. G. Kreiter ◽  
G. Fink
Keyword(s):  
Temperature Dependence ◽  
Exchange Reaction ◽  
13C Nmr ◽  
Line Shape ◽  
Nmr Spectra ◽  
Exchange Process ◽  
Kcal Mole ◽  
Line Shapes ◽  
Calculated Line ◽  
C Nmr

The 13C NMR spectra of the ethylaluminium compounds [Al(C2H5)xCl3_x]2 x = 1, 1,5, 2 and 3 are presented and factors governing the temperature dependence of the line shape are discussed. The exchange reaction of terminal ethyl groups for chlorine ligands and ethyl ligands, resp., in ethylaluminium-sesquichloride was investigated by fitting the calculated line shapes to the observed spectra.The energy of activation of this exchange process was determined as to be 12,3 ‡ 1,5 kcal/mole. The synthesis of 13C2-[Al(C2H5)Cl2]2 is described.

scholarly journals Method for Introducing Zeolites and MCM-41 into Polypropylene Melt-Blown Nonwovens

2019 ◽  
Vol 19 (4) ◽  
pp. 312-323
Author(s):  
Agnieszka Brochocka ◽  
Aleksandra Zagawa ◽  
Rafał Panek ◽  
Jarosław Madej ◽  
Wojciech Franus
Keyword(s):  
Functional Materials ◽  
Polymer Fibers ◽  
Protective Equipment ◽  
Silica Material ◽  
Paraffin Oil ◽  
Different Types ◽  
Oil Mist ◽  
European Standards ◽  
Polypropylene Melt ◽  
Mcm 41

Abstract In this work, a method for introducing zeolites and mesoporous siliceous materials into the melt-blown process for the production of polypropylene nonwovens was developed and the functional materials obtained were tested. Both types of additives were introduced in the melt-blown technology using a device placed in the duct of the die assembly. Nine types of polypropylene melt-blown nonwovens were made with different types of zeolites (clinoptilolite, Na-X, Na-A, Na-P1, sodalite, Na-P1 with hexadecyl trimethylammonium bromide (HDTMA), ZeoEco 20, and BioZeo R.01) or mesoporous silica material (Mobil Composition of Matter No. 41, abbreviated as MCM-41). The nonwovens were studied in terms of protective and functional parameters: sodium chloride and paraffin oil mist aerosol penetration, airflow resistance, and sorption capacity for toluene, ammonia, acetone, and cyclohexane, in accordance with the requirements of the European standards concerning respiratory protective equipment. The tests showed that zeolites and MCM-41 can be successfully incorporated within the structure of elementary polymer fibers using an environmentally friendly “dry” melt-blown technology with nonwovens modified so as to impart multiple functionalities in one integrated technological process. The developed method of introducing the studied materials to polypropylene melt-blown nonwovens led to the production of new multipurpose materials with good protective and functional properties. The best polypropylene nonwovens were produced with the addition of 250 g/m2 of MCM-41 or Na-P1 zeolite modified with HDTMA.

Deuterium Quadrupolar Parameters from 1H and 2H NMR Spectra for Pyridine-d5, Benzonitrile-d5 and Chlorobenzene-d5 Using Liquid Crystal Solvents

1986 ◽  
Vol 41 (1-2) ◽  
pp. 431-435 ◽  
Author(s):  
R. Ambrosetti ◽  
D. Catalano ◽  
C. Forte ◽  
C. A. Veracini
Keyword(s):  
Liquid Crystal ◽  
Nmr Spectra ◽  
Order Parameters ◽  
Dipolar Couplings ◽  
Coupling Constants ◽  
2H Nmr ◽  
H Nmr ◽  
Quadrupolar Coupling ◽  
Asymmetry Parameters ◽  
Quadrupolar Splittings

T he quadrupolar coupling constants (DQCC) and the asymmetry parameters (η) for the ortho, meta and para deuterons in pyridine-d5, benzonitrile-d5 and chlorobenzene-d5 were determined by NMR spectroscopy in oriented phases. The 1H and 2H NMR spectra were recorded in the following solutions in liquid crystal solvents: pyridine + pyridine-d5 in PCH , in ZLI 1167 and in EBBA; benzonitrile + benzonitrile-d5 and chlorobenzene + chlorobenzene-d5 in the same solvents.The order parameters of the non-deuterated solutes in the various solutions were calculated using the dipolar couplings of the proton spectra and the rα structures taken from the literature. The same order parameters were assumed to describe also the orientation of the deuterated solute in the corresponding solutions.Each 2H spectrum yielded three quadrupolar splittings for the three different deuterated positions in the labelled solute. The splittings from the three different solutions of the same solute, together with the order parameters and the rα structure, were used to determine DQCC and η of the ortho, meta and para deuterons (Pyridine-d5: DQCCortho= 183(1) kHz, ηortho = 0.030(5), DQCCmeta = 185(1) kHz, ηmeta = 0.030(10), DQCCpara = 188(6) kHz, ηpara = 0.01(5). Benzonitrile-d5: DQCCortho = 171(12) kHz, ηortho = 0.07(3), DQCCmeta = 175(12) kHz, ηmeta = 0.05(3), DQCCpara = 176(4) kHz, ηpara = 0.10(7). Chlorobenzene-d5: DQCCortho = 180(2) kHz, ηortho = 0.06(1), DQCCmeta = 174(2) kHz, ηmeta = 0.09(3), DQCCpara= 182(4) kHz, ηPara = 0.06(4)). The results are discussed, as well as the limits and possibilities of the method used.

14N Quadrupole Interactions in Nitrogen-Containing Ceramics. Effects on 29Si NMR Line Shapes and Structural Implications

1992 ◽  
Vol 47 (1-2) ◽  
pp. 39-44 ◽  
Author(s):  
Alejandro Olivieri
Keyword(s):  
Solid State ◽  
Nmr Spectra ◽  
Dipolar Coupling ◽  
Coupling Constants ◽  
Simple Equation ◽  
29Si Nmr ◽  
Experimental Conditions ◽  
Line Shapes ◽  
Quadrupole Interactions ◽  
Quadrupole Coupling

AbstractSimulations of solid-state 29Si NMR spectra in nitrogen-containing silicon ceramics and glasses are described. The range of SiNxO4-x tetrahedra is covered, with emphasis on the experimental conditions needed to observe the effect of the incompletely averaged 29Si, 14N dipolar coupling. A simple equation is discussed concerning its use in the interpretation of these 29Si spectra, including the computation of 14N quadrupole coupling constants with its absolute sign.

Multiaxial Reorientationsof ND+4 Ions Studied by 2H-NMR Spectroscopy

1991 ◽  
Vol 46 (10) ◽  
pp. 829-840 ◽  
Author(s):  
Z. T. Lalowicz ◽  
S. F. Sagnowski
Keyword(s):  
Nmr Spectroscopy ◽  
Density Matrix ◽  
Nmr Spectra ◽  
Activation Energies ◽  
Matrix Formalism ◽  
2H Nmr ◽  
Jump Frequency ◽  
H Nmr ◽  
2H Nmr Spectroscopy ◽  
Density Matrix Formalism

AbstractThe density matrix formalism is used to simulate motional averaging in the 2H-NMR spectra of reorienting ND+4 ions. The development of the spectra under increasing jump frequency about a single C3 or C2 axis is followed. Next we assume a hierarchy of axes in terms of activation energies sufficient to reach extreme narrowing conditions for some axes before activating jumps about a next one. Primary reorientations about the fastest C3 or C2 symmetry axes define the shape of spectra, the width of which is then stepwise reduced by fast reorientations about the subsequent axes in a postulated sequence of statistically uncorrelated jumps.

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