Cellulose nanofiber (MFC) reinforced starch-based foams, prepared by the freezing/freeze-drying route, are very interesting porous materials due to strong MFC reinforcement of cell wall itself. However, in order fully realize potential these nanocomposite biofoams, both composition and structure must be controlled. The effect starch–MFC–water suspension composition, together with preparation temperature (−27, −78, −196 °C) on foam is investigated. NMR-analysis bound water content, DSC...

Abstract Cellulose nanofibril (CNF) materials are candidates for the sustainable development of high mechanical performance nanomaterials. Due to inherent hydrophilicity and limited functionality range, most applications require chemical modification CNF. However, targeted transformations directly on CNF cumbersome due propensity aggregate in non-aqueous solvents at concentrations, complicating choice suitable reagents requiring tedious separations final product. This work addresses this...

In the context of chemical recycling mixed plastics and paper, multitemperature step pyrolysis has shown good potential for separation oxygenated products from hydrocarbons. Here, we report results an investigation first at low temperature, which involves dehydrochlorination polyvinyl chloride (PVC) cellulose, main component paper. Calcium oxide (CaO), selected its adsorption ability catalytic activity on biooil deoxygenation, was used upgrading downstream pyrolysis. Additionally, studied...

Green chemical modification of cellulose presents a unique challenge, especially from the vantage point sustainable development that is favored by use wood fibers, heterogeneous conditions, and reactants solvents biobased relevance. However, conditions imply supramolecular assembly whose composition build-up depend on initial source pretreatments. Also, understanding reaction outcomes accompanied inherently challenging characterization. The key question how we should design our systems to...

The molecular self-diffusion coefficients in nematic and smectic-A thermotropic liquid crystals are measured using stimulated-echo-type 2H 1H pulse-field-gradient spin-echo nuclear magnetic resonance (PGSE NMR) combined with multiple-pulse dipolar decoupling slice selection. temperature dependence of the principal components diffusion tensor phase follows a simple Arrhenius relationship except region nematic-isotropic transition where it reflects, merely, decrease orientational order....

Abstract Application of rapid sample rotation and radiofrequency irradiation in magic angle spinning (MAS) NMR lipid bilayers can significantly increase the temperature. In this work, we studied extent heating during acquisition 1 H‐decoupled 13 C MAS spectra hydrated dimyristoylphosphatidylcholine (DMPC) L α phase. First, describe a simple procedure for determining temperature by observing shift H water signal. The method is then used to identify assess various factors that contribute...

This paper presents a theoretical, numerical, and experimental study of new class separated local field (SLF) techniques. These techniques are based on the heteronuclear isotropic mixing leading to spin exchange via (HIMSELF). It is shown that highly efficient robust SLF experiments can be designed double channel windowless homonuclear decoupling sequences. Compared rotating frame Hartmann-Hahn cross polarization, approach less susceptible frequency offset chemical shift interaction applied...

Magnetically aligned bicelles are increasingly being used as model membranes in solution- and solid-state NMR studies of the structure, dynamics, topology, interaction membrane-associated peptides proteins. These commonly utilize PISEMA pulse sequence to measure dipolar coupling chemical shift, two key parameters subsequent structural analysis. In present study, we demonstrate that other rotating-frame sequences not suitable for measurement long-range heteronuclear couplings, they provide...

Abstract The interaction between moisture and the macromolecular wood tissue is of critical importance to properties. In this context, magnetic resonance imaging (MRI) very promising as method could deliver molecular information on submillimeter scale (i.e., along concentration gradients) about both free adsorbed water cell wall polymers. present study, it demonstrated for first time that containing heavy ( 2 H O) can be studied by MRI based separated images due MRI) polymers 1 MRI). Data...

Abstract The methodology of NMR experiments intended to measure anisotropic diffusion is reviewed. Experiments this kind preferably require oriented samples and/or orientation‐dependent spin coupling magnetic field gradients in different directions. One strategy systems with broad lines employs line narrowing techniques, thereby allowing for efficient gradient encoding/decoding. Depending on the nuclei, couplings and samples, preferred methods vary from decoupling through echo techniques...

Bicelles are increasingly being used as membrane mimicking systems in NMR experiments to investigate the structure of proteins. In this study, we demonstrate effectiveness a 2D solid-state approach that can be measure structural constraints, such heteronuclear dipolar couplings between 1H, 13C, and 31P nuclei, bicelles without need for isotopic enrichment. This method does not require high radio frequency power unlike presently rotating-frame separated-local-field (SLF) techniques, PISEMA....

Recently (Dvinskikh et al., J. Magn. Reson., 2003, 164, 165 and Dvinskikh 2004, 168, 194), some of us introduced two efficient solid-state NMR techniques for the determination heteronuclear dipolar couplings under magic-angle spinning (MAS). These two-dimensional (2D) recoupling methods have been applied previously to simple amino acids, columnar systems with high positional orientational order. In this work, we show that 2D MAS sequences produce unparalleled 1H–13C resolution in unoriented...

The diffusion of ions in an ionic liquid crystal exhibiting a bicontinuous cubic liquid-crystalline phase has been investigated by NMR spectroscopy order to examine the behaviour ordered nanostructure.

Molecular reorientation in the two amorphous phases of triphenyl phosphite, namely supercooled liquid (phase aI) and newly discovered second phase aII), was investigated by dielectric relaxation two-dimensional (2D) nuclear magnetic resonance spectroscopy (NMR) time frequency domain. Whereas aI exhibits relaxational features typical liquids, molecular motion aII is characterized an extremely broad loss a pronounced nonexponential reorientational correlation function. Using Gaussian...

The orientation-dependent molecular diffusion in the nematic liquid crystal 4-pentyl-4′-cyanobiphenyl is measured to high accuracy. applied nuclear magnetic resonance method combines multiple-pulse homonuclear dipolar decoupling with pulsed-field-gradient stimulated echo and slice selection. obtained temperature dependencies of principal coefficients are not described by a simple Arrhenius relationship but reflect decrease orientational order close nematic-to-isotropic phase transition....

This paper presents a theoretical, numerical, and experimental study of phase- frequency-switched Lee-Goldburg cross-polarization (FSLG-CP) under magic-angle spinning conditions. It is shown that well-defined amplitude modulation one the two radio-frequency (rf) fields in FSLG-CP sequence results highly efficient heteronuclear dipolar recoupling. The recoupled interaction gamma-encoded and, ideal conditions, effective spin Hamiltonian equivalent to continuous-wave CP. In practice, however,...

The conformational response of dimyristoylphosphatidylcholine bilayers in the liquid crystalline phase to hydration is investigated by a novel magic-angle spinning cross-polarization NMR technique.

Propeller propellant: The largest nitrogen oxide to date, trinitramide (TNA), has been prepared following extensive quantum chemical studies in which its kinetic stability and several physical properties were estimated. TNA was detected using IR NMR spectroscopy. compound is highly energetic shows promise for cryogenic propulsion as a reagent high-energy-density material research. Detailed facts of importance specialist readers are published "Supporting Information". Such documents...