Characterization of wet aggregate stability of soils by H-NMR relaxometry

2014 ◽  
Vol 53 (9) ◽  
pp. 694-703 ◽  
Author(s):  
C. Buchmann ◽  
M. Meyer ◽  
G. E. Schaumann
Author(s):  
Sinem Akkaya ◽  
Baris Ozel ◽  
Mecit Halil Oztop ◽  
Derya Kocak Yanik ◽  
Fahrettin Gogus

2019 ◽  
Vol 17 (3) ◽  
pp. 541-554
Author(s):  
Neeranuth Intakaew ◽  
Puracheth Rithchumpon ◽  
Chanatkran Prommin ◽  
Saranphong Yimklan ◽  
Nawee Kungwan ◽  
...  

New chiral derivatizing agents and the effect of aromatic rings were investigated for absolute configuration of chiral alcohols via1H-NMR.


e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 491-499
Author(s):  
Fukai Yang ◽  
Hao Yu ◽  
Yuyuan Deng ◽  
Xinyu Xu

Abstract In this article, five kinds of soybean oil-based polyols (polyol-E, polyol-P, polyol-I, polyol-B, and polyol-M) were prepared by ring-opening the epoxy groups in epoxidized soybean oil (ESO) with ethyl alcohol, 1-pentanol, isoamyl alcohol, p-tert-butylphenol, and 4-methoxyphenol in the presence of tetrafluoroboric acid as the catalyst. The SOPs were characterized by FTIR, 1H NMR, GPC, viscosity, and hydroxyl numbers. Compared with ESO, the retention time of SOPs is shortened, indicating that the molecular weight of SOPs is increased. The structure of different monomers can significantly affect the hydroxyl numbers of SOPs. Due to the large steric hindrance of isoamyl alcohol, p-hydroxyanisole, and p-tert-butylphenol, SOPs prepared by these three monomers often undergo further dehydration to ether reactions, which consumes the hydroxyl of polyols, thus forming dimers and multimers; therefore, the hydroxyl numbers are much lower than polyol-E and polyol-P. The viscosity of polyol-E and polyol-P is much lower than that of polyol-I, polyol-B, and polyol-M. A longer distance between the molecules and the smaller intermolecular force makes the SOPs dehydrate to ether again. This generates dimer or polymers and makes the viscosity of these SOPs larger, and the molecular weight greatly increases.


2021 ◽  
Vol 75 (2-3) ◽  
pp. 119-131
Author(s):  
Albert A. Smith ◽  
Nicolas Bolik-Coulon ◽  
Matthias Ernst ◽  
Beat H. Meier ◽  
Fabien Ferrage

AbstractThe dynamics of molecules in solution is usually quantified by the determination of timescale-specific amplitudes of motions. High-resolution nuclear magnetic resonance (NMR) relaxometry experiments—where the sample is transferred to low fields for longitudinal (T1) relaxation, and back to high field for detection with residue-specific resolution—seeks to increase the ability to distinguish the contributions from motion on timescales slower than a few nanoseconds. However, tumbling of a molecule in solution masks some of these motions. Therefore, we investigate to what extent relaxometry improves timescale resolution, using the “detector” analysis of dynamics. Here, we demonstrate improvements in the characterization of internal dynamics of methyl-bearing side chains by carbon-13 relaxometry in the small protein ubiquitin. We show that relaxometry data leads to better information about nanosecond motions as compared to high-field relaxation data only. Our calculations show that gains from relaxometry are greater with increasing correlation time of rotational diffusion.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Evelyn Carolina Martínez Ceballos ◽  
Ricardo Vera Graziano ◽  
Gonzalo Martínez Barrera ◽  
Oscar Olea Mejía

Poly(dichlorophosphazene) was prepared by melt ring-opening polymerization of the hexachlorocyclotriphosphazene. Poly[bis(2-hydroxyethyl-methacrylate)-phosphazene] and poly[(2-hydroxyethyl-methacrylate)-graft-poly(lactic-acid)-phosphazene] were obtained by nucleophilic condensation reactions at different concentrations of the substituents. The properties of the synthesized copolymers were assessed by FTIR,1H-NMR and31P-NMR, thermal analysis (DSC-TGA), and electron microscopy (SEM). The copolymers have a block structure and show twoTg's below room temperature. They are stable up to a temperature of 100°C. The type of the substituents attached to the PZ backbone determines the morphology of the polymers.


e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Saeed Zahmatkesh ◽  
Abdol Reza Hajipour

AbstractPyromellitic dianhydride (1) was reacted with L-leucine (2) to result in [N,N'-(pyromellitoyl)-bis-L-leucine diacid] (3). This compound (3) was converted to N,N'-(pyromellitoyl)-bis-L-leucine diacid chloride (4) by reaction with thionyl chloride. The microwave-assisted polycondensation of this diacid chloride (4) with polyethyleneglycol-diol (PEG-200) and/or three synthetic bisphenols furnish a series of new PEIs and Co-PEIs in a laboratory microwave oven (Milestone). The resulting polymers and copolymers have inherent viscosities in the range of 0.31- 0.53 dl g-1. These polymers are optically active, thermally stable and soluble in polar aprotic solvents such as DMF, DMSO, NMP, DMAc and sulfuric acid. All of the above polymers were fully characterized by IR spectroscopy, 1H NMR spectroscopy, elemental analyses, specific rotation and thermal analyses. Some structural characterizations and physical properties of these optically active PEIs and Co-PEIs are reported.


2002 ◽  
Vol 06 (02) ◽  
pp. 114-121 ◽  
Author(s):  
L. A. Tomachynski ◽  
V. Ya. Chernii ◽  
S. V. Volkov

The reaction of PcMCl 2 ( M = Zr , Hf ) with β-diketones is reported. 1 H NMR and elemental analysis suggest the substitution of two Cl atoms for two β-diketone fragments takes place as a result of this reaction and the complexes PcM(β-dik)2 are formed. All obtained complexes are stable and highly soluble in most organic solvents. The data from 1 H and 19 F NMR, and UV-vis spectroscopy suggest the coordination of two β-diketone ligands in a cis geometry about the central atom of the macrocycle. It was shown bis(β-diketonato)zirconium(IV) and hafnium(IV) phthalocyanines containing β-diketones with donor or acceptor groups or with bulky substituents can be obtained.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Amal Amin ◽  
Moshera Samy

Different polyesteramides hyperbranched polymers (HPEA1-6)/montomorillonite clay (MMT) nanocomposites were prepared with three different loading contents of clay (4, 10, and 15 wt%). The obtained nanocomposites were characterized via XRD, thermal analyses, and TEM. Generally, intercalation behavior was observed. The hyperbranched polyesteramides (HPEA1-6) were originally prepared by the bulky reaction between maleic anhydride (MAn), succinic anhydride (ScAn), and phthalic anhydride (PhAn) with either diethanolamine (DEA) or diisopropanolamine (DiPA). The resulting hyperbranched polyesteramides (HPEA1-6) were characterized by GPC, IR,1H-NMR, TGA, and DSC.


2018 ◽  
Vol 22 (09n10) ◽  
pp. 814-820
Author(s):  
Yingying Jia ◽  
Ling Xu ◽  
Bangshao Yin ◽  
Mingbo Zhou ◽  
Jianxin Song

Beginning with 5,10,15-triarylporphyrin-nickel complex, five meso-to-meso directly linked porphyrin-diazaporphyrin triads were successfully prepared for the first time through a series of reactions including formylation via Vilsmeier–Haack reaction, condensation with pyrrole, bromination with [Formula: see text]-Bromosuccinimide (NBS), oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), metal-templated cyclization of dibromodipyrrin-metal complexes with NaN[Formula: see text] and demetalization. All these triads were comprehensively characterized by [Formula: see text]H NMR, high-resolution mass spectrometry and UV-vis absorption. In addition, the structure of compound 6Ni was unambiguously determined by X-ray diffraction analysis, which showed that the two dihedral angles are both 86.65 (4)[Formula: see text] between each mean plane of porphyrin and that of central diazaporphyrin The UV-vis absorption spectra disclosed that the longest wavelengths of Soret bands and Q bands for these triads were observed at 429 and 642 nm, respectively. In contrast to diazaporphyrin-porphyrin dyads, diazaporphyrin dimers and diazaporphyrin monomers reported previously the molar extinction coefficients, particularly for triad 8Ni are much higher.


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