Presented here is an effective approach to desmearing slit ultra-small-angle neutron scattering (USANS) data, based on complementary small-angle neutron scattering (SANS) measurements, leading to a seamless merging of these data sets. The study focuses on the methodological aspects of desmearing USANS data, which can then be presented in the conventional manner of SANS, enabling a broader pool of data analysis methods. The key innovation lies in the use of smeared SANS data for extrapolating slit USANS, offering a self-consistent integrand function for desmearing with Lake's iterative method.
View Article and Find Full Text PDFIn this study, various techniques, such as energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman spectroscopy, and spectrophotometry, were used to analyze the properties of nanometric CdS particles synthesized with varying precursor concentrations. EDX analysis revealed the nonstoichiometric composition manifested by an increase in the Cd/S ratio from 1.02 up to 1.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
October 2022
Commercially available and administered to the patients ethosuximide is a racemic mixture of two enantiomers, each of them exist in different conformations. The presence of the species mentioned are proven by the title experimental methods aided by DFT model calculations. Results of the latter are matched against spectroscopic data by the clustering window analysis.
View Article and Find Full Text PDFThis article shows the full characteristics (, the phase situation as well as the relaxation and vibrational dynamics) of the ()-4'-(1-methyloctyloxycarbonyl)biphenyl-4-yl 4-[5-(2,2,3,3,4,4,4-heptafluorobutoxy)pentyl-1-oxy]-benzoate chiral liquid crystal. Besides two enantiotropic chiral smectic phases (SmC* and ), the compound under study also forms the hexatic smectic phase and two crystal phases (Cr1 and Cr2). The XRD patterns imply a similar structure of both crystal phases.
View Article and Find Full Text PDFThe phase transitions, crystallization kinetics and molecular dynamics of ()-4'-(1-methylheptylcarbonyl)biphenyl-4-yl 4-[5-(2,2,3,3,4,4,4-heptafluorobutoxy)pent-1-oxy] benzoate (3F5HPhH6) are investigated by differential scanning calorimetry, polarizing optical microscopy and broadband dielectric spectroscopy. The vitrification of the antiferroelectric hexatic phase is observed for cooling rates ≥5 K min and the fragility index determined from dielectric data is ≈ 90. Two regimes of non-isothermal cold crystallization are distinguished using the Kissinger and Augis-Bennett methods in the heating rate ranges of 1-5 K min (larger activation energy) and 8-20 K min (lower activation energy).
View Article and Find Full Text PDFThe impact of high pressure on molecular dynamics and the crystallization process in the smectic phase with antiferroelectric properties of partially fluorinated liquid crystal (S)-4'-(1-methyloctyloxycarbonyl)biphenyl-4-yl-4-[7-(2,2,3,3,4,4,4-heptafluorobutoxy)heptyl-1-oxy]-benzoate (3F7HPhH7) was studied by broadband dielectric spectroscopy (BDS). By analyzing dielectric spectra measured under isobaric and isothermal conditions, the changes of the activation volume vs. temperature and the activation enthalpy vs.
View Article and Find Full Text PDFThe relaxation dynamics in the thermodynamic states of the glass-forming antiferroelectric liquid crystal (S)-4'-(1-methyloctyloxycarbonyl) biphenyl-4-yl 4-[7-(2,2,3,3,4,4,4-heptafluorobutoxy) heptyl-1-oxy]-benzoate (3F7HPhH7) was studied by broadband dielectric spectroscopy (BDS). Two glass transitions were found at T = 259 K and T = 239 K, which were associated with the freezing of anti-phase motions and reorientation around the long molecular axis in the antiferroelectric SmC* phase, respectively. The low temperature α2-relaxation process shows a Vogel-Fulcher-Tammann (VFT)-type temperature dependence of its structural relaxation time τ(T).
View Article and Find Full Text PDFInspired by the unusual shapes of the titration curve observed for many surfactants and mixed colloidal systems, we decided to extend the analysis to isothermal titration calorimetric curves (ITC) by paying special attention to potential structural changes in micellar aggregates. In this paper, we used isothermal titration calorimetry in conjunction with Scanning Transmission Electron Microscopy (STEM), Small-Angle Neutron Scattering (SANS) and X-ray Scattering (SAXS) methods support by Monte Carlo and semiempirical quantum chemistry simulations to confirm if the isothermal calorimetric curve shape can reflect micelle transition phenomena. For that purpose, we analysed, from the thermodynamic point of view, a group of cationic gemini surfactants, alkanediyl-α,ω-bis(dimethylalkylammonium) bromides.
View Article and Find Full Text PDFIn hunting for safe and cost-effective materials for post-Li-ion energy storage, the design and synthesis of high-performance solid electrolytes (SEs) for all-solid-state batteries are bottlenecks. Many issues associated with chemical stability during processing and storage and use of the SEs in ambient conditions need to be addressed. Now, the effect of water as well as oxyhdryl group ( OH) on NaBi O Cl are investigated by evaluating ionic conductivity.
View Article and Find Full Text PDFGiven the extensive efforts focused on protecting the environment, eco-friendly cathode materials are a prerequisite for the development of Na-ion battery technology. Such materials should contain abundant and inexpensive elements. In the paper, we present NASICON-NaFeMn(PO) ( = 0, 0.
View Article and Find Full Text PDFPolymorphism and molecular dynamics of ethosuximide with molecules of left- and right-handed chirality have been studied in detail using dielectric spectroscopy. Density functional theory calculations of molecular conformations and dimer formation were performed to aid the interpretation of measurements. Moving window correlation analysis of the imaginary part of dielectric permittivity spectra allowed us to complete the monotropic system of phases found by the differential scanning calorimetry method.
View Article and Find Full Text PDFHerein, the correlation between electronic structure, transport and electrochemical properties of layered LiNiCoMnO cathode material is revealed. Comprehensive experimental studies of physicochemical properties of LiNiCoMnO cathode material (XRD, electrical conductivity, thermoelectric power) are supported by electronic structure calculations performed using the Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA) to account for the chemical disorder. It is found that even small O defects (∼1%) could significantly modify electronic density of states DOS characteristics via the formation of extra broad peaks inside the former band gap leading to its substantial narrowing.
View Article and Find Full Text PDFLiFePO₄ is considered to be one of the most promising cathode materials for lithium ion batteries for electric vehicle (EV) application. However, there are still a number of unsolved issues regarding the influence of Li and Fe-site substitution on the physicochemical properties of LiFePO₄. This is a review-type article, presenting results of our group, related to the possibility of the chemical modification of phosphoolivine by introduction of cation dopants in Li and Fe sublattices.
View Article and Find Full Text PDFMolecular rotational dynamics in p,p'-di-n-heptyl-azoxybenzene was studied by means of quasielastic neutron scattering (QENS) and 13C cross-polarization magic-angle-spinning (CPMAS) NMR. Fast reorientation of the hydrogen nuclei was observed by QENS in the two liquid crystalline (LC) phases nematic and smectic A, as well as in the crystalline phase. The latter could not be restricted to the -CH3 rotations alone, and a clear indication was found of some other reorientation motions persisting in the crystal.
View Article and Find Full Text PDFAmong the many alterations of cancer cells is the expression of different surface oligosaccharides. In this work, oligosaccharide expression in living cells (cancer and reference ones) was studied with atomic force microscopy by using lectins as probes. The unbinding force obtained for the same lectin type (concanavalin A or Sambucus nigra) suggested slightly dissimilar structures of binding sites of the same ligand type.
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