Nanoparticles of spinel ferrites with a composition of Co0.9Cu0.1Fe2O4 (AM NPs) were effectively synthesized via a hydrothermal route. The structure of ferrite nanoparticles was characterized with X-ray diffraction, which showed a single cubic spinel phase. Energy-dispersive X-ray (EDX) spectroscopy and field emission-scanning electron microscopy (FE-SEM) were employed to analyse elemental composition and surface morphology, respectively. Moreover, the effects of the Co0.9Cu0.1Fe2O4 on the morphology of [PLA = polylactic acid] nanocomposites were examined through polarized light optical microscopy (POM) and X-ray diffraction (XRD). The thermal behaviours for tested samples were studied through [DSC = differential scanning calorimetry] and [TGA = thermal gravimetric analysis]. A great number of minor PLA spherulites were detected using POM in the presence of the Co0.9Cu0.1Fe2O4 ceramic magnetic nanoparticles (AM), increasing with AM nanoparticle contents. X-ray diffraction (XRD) analysis showed that the presence of nanoparticles led to an increase in the intensity of diffraction peaks. The DSC findings implied that the crystallization behaviours for the efficient PLA as well as its nanocomposites were affected by the addition of AM nanoparticles. They act as efficient nucleating agents because they shift the temperature of crystallization to a lower value. The Avrami models were used to analyse kinetics data. The experimental data were well described using the Avrami method for all samples tested. The addition of AM to the PLA matrix resulted in a decrease in the crystallization half-time t1/2 values, indicating a faster crystallization rate. TGA data showed that the occurrence of AM nanoparticles decreased the thermal stability of PLA.

As emerging water pollutants, oxytetracycline (OTC) and its derivatives are detrimental to humans, organisms, and aquatic ecosystems. Oxytetracycline hydrochloride (OTCH) was effectively absorbed from water by silica (SiO 2 ) and metakaolinite (MK). In this study, we employed a unique metric known as BAGI to evaluate the suggested analytical method's suitability effectively. Blue applicability grade index (BAGI) complements green assessment tools such as the Green analytical procedure index (GAPI), Complex green analytical procedure index ComplexGAPI, Analytical GREEnness (AGREE), Analytical greenness for sample preparation (AGREEprep), and Analytical eco-scale (ESA). The BAGI metric focuses on the practical aspects of white analytical chemistry, especially those related to "blue. " The optimal parameters for adsorbing OTCH were determined by a study (pH, OTCH concentration at the beginning of the reaction, sorbent dose, and reaction duration). This study of sorbent properties was conducted via X-ray diffraction (XRD) and Fourier -transform infrared spectroscopy (FTIR). The highest levels of OTCH adsorption were seen at pH 5 -6 for MK and at pH 7 for SiO 2 . The most desirable clay minerals are those with smaller quantities. The Langmuir model accurately characterizes the results, showing a strong correlation between OTCH sorption onto MK with a maximum capacity of 165.04 mg/g and a moderate correlation for SiO 2 with a maximum capacity of 25.3 mg/g. Therefore, these findings regarding the effectiveness of adsorption and the analysis of properties offer supplementary insights into the potential use of clay minerals as cost-effective and eco-friendly sorbents for treating wastewater.

Purpose: In this work, we mix two simple nematic liquid crystals (NLCs) and investigated the binaryNLCs mixtures of 7CB/PCH5 of different mixing ratios. Methodology: The pure liquid crystals 7CB and PCH5 and binary mixtures of them of high temperature stability were thermally analyzed by differential scanning calorimetry. The mixture 7CB/PCH5:30/70 wt% has the highest thermal stability with a nematic-isotropic (N-I) transition temperature at 50oC. The electrooptic properties of 7CB, PCH5, and the mixture 7CB/PCH5:30/70 wt% at room temperature were also investigated using an amplitude modulated electric signal (1 kHz - 100 Hz) by increasing diving peak voltage from 0 V to 10 V. The threshold volage is relatively reduced for the binary mixture in comparison to that value for PCH5. In comparison to the pure LCs, the mixture 7CB/PCH5:30/70 wt% has the fastest response times of values 2.36 ms total time response, 0.41 ms rise time, and 1.95 ms fall time. It has also the highest contrast ratio. Moreover, it has a maximum measured transmission that is higher than those for PCH5 and 7CB by about 17 % and 8%, respectively, at a field strength of 2V/mm. Findings: The obtained results indicate that the electrooptic properties of PCH5 was improved when mixed with a proper ratio of 7CB, of lower cost, more stablity , and higher potential for photonic applications. Unique Contriburibution to Theory, Practice and Policy: This expermental study shows that simply by mixing two relatively low cost NLCs materials, one of high thermal stability and low electro-optic properties with other one of low thermal stability and better electro-optic properties; this would improve the stability, response, and transmition of the binary mixture. If the a suitable driving method is applied, without doping with other orgnic or inorganic matrial.

In the present work, we used the ex situ casting technique to synthesize a nanocomposite (NC) of polyvinyl alcohol (PVA) and nanosize palladium (Pd). The Pd has a particle size in the range from 2 to 22 nm with 10 nm on average. Samples from the synthesized NC have been irradiated with different fluences ranging from 2 to 20 J/cm(2) from GaAs infrared pulsed laser (5-watt power, 904 nm wavelength, 200 ns pulse duration, 1200 Hz frequency and 0.28 cm(2) spot area). Nonisothermal crystallization kinetics of the synthesized NC was investigated using differential scanning calorimetry (DSC) with different cooling rates. The Jeziorny and Mo approaches were applied to describe the nonisothermal analysis. Several nonisothermal kinetic parameters, such as the crystallization peak temperature (T-c ), the enthalpy of crystallization (Delta H-c ), the degree of crystallinity (X-c ), the crystallization halftime (t (1/2)), the Avrami exponent (n) and the activation of crystallization (E-a ) were evaluated and interpreted as a function of laser fluences. The results indicated that the incorporation Pd nanoparticles into the PVA matrix accelerate the crystallization process, while the laser radiation causes chain crosslinking that reduces the crystallinity.

New three-ring ester/azomethine homologues series, (E)-4-((4-hydroxybenzylidene)amino)phenyl 4-(alkoxy)benzoate In, were prepared and their properties were investigated experimentally and theoretically. FT-IR, NMR, and elemental analyses were used to confirm the chemical structures of the synthesized compounds. The mesomorphic activities of the planned homologues were evaluated using differential scanning calorimetry (DSC) and polarized optical microscopy. All of the homologous examined were found to have non-mesomorphic properties. Theoretical calculations using the density functional theory (DFT) were used to validate the experimental data and determine the most stable conformation of the synthesized compounds. All calculated conformers’ thermal properties, dipole moments, and polarizability were discussed. The results show that the terminal alkoxy chain length affects the thermal parameters of the conformers. The correlations between these parameters’ values and the conformer type were demonstrated. The base component was expected to be in two conformers according to the orientation of the N atom of imine-linkage. DFT calculations revealed the more probable of the two possible conformers, and the incorporation of the alkoxy terminal chain in one position affect its geometrical and mesomerphic characteristics.

Two groups of laterally substituted non-mesomorphic and liquid crystalline materials bearing monoazo group were prepared and investigated via experimental and theoretical techniques. The molecular structures of the designed dyes were evaluated by FT-IR and NMR spectroscopic analyses. Mesomorphic examinations for all synthesized dyes were investigated by polarized optical microscopy (POM) and differential scanning calorimetry (DSC). Results revealed that, the thermal and optical properties of investigated compounds are mainly dependent on their molecular geometry. The optimized geometries of the azo derivatives and their electronic absorption of the dyes were carried out using the B3LYP/6-311G level of the DFT method. The azo dyes were measured for their dyeing performance on polyester fabrics. The dyed fabrics have excellent fastness properties with a color strength of 1.49–3.43 and an exhaustion rate of 82–64%. The chemical descriptor parameters of disperse azo dyes in gas phase were calculated and correlated with dyeing parameters.

New four-ring ester/azomethine/ester liquid crystal series, 4-alkoxybenzoyloxy 4’-phenylazomethine phenyloxy 4”-alkoxybenzoate In, were prepared, and their thermal stability and mesomorphic activity were investigated. The two wing carboxylic units were used aiming to achieve new mesomorphic properties for the prepared materials. The two ester linkages and the two terminal alkoxy chains were incorporated to modify the molecular structure. The chemical structures of the synthesised compounds were confirmed via FT-IR, NMR and elemental analysis. Differential scanning calorimetry (DSC) and polarising optical microscopy were applied to determine the mesomorphic features of the designed homologues. All of the studied homologous were shown to exhibit superior thermal stability and enormous mesomorphic temperature ranges. Moreover, enantiotropic smectic A and nematic phases were shown to cover all of the homologues. The influence of inclusion the di-ester moieties on the mesophase behaviour was investigated through a comparison with the previously investigated three-ring series bearing only one ester linkage. Two binary phase diagrams were constructed and addressed in terms of the smectic and nematic temperature ranges.

New mesomorphic homologue series of laterally fluorinated azo/esters, 2-fluoro-4-((4-alkoxy)phenyl)diazenyl)phenyl 4-(alkoxy)benzoate (I-n/m), were synthesized and investigated their behaviour via experimental and computational tools. The prepared series bearing eight derivatives that differ from each other by the terminally attached alkoxy chain groups at their ends. Elemental analyses, FT-IR and NMR spectroscopy were carried out to elucidate their molecular structures. Mesophase and optical examinations of the synthesized homologues are conducted using differential scanning calorimetry (DSC) and polarised optical microscopy (POM). Mesomorphic characterisations revealed that all the laterally F substituted derivatives are monomorphic exhibiting nematic (N) mesophase with enantiotropic properties, except the longest terminal chain member possesses N phase monotropically. The comparative studies between the present group, I-6/m, and the laterally-neat series revealed that the type and stability of the produced phase are dependent upon the influenced molecular dipole moment of the mesogenic core which is mainly dependent on the insertion of the lateral F atom. Computational approaches were carried by DFT calculations and the optimised structures of present investigated series have been deduced. DFT results revealed that, the incorporation of lateral F atom has essential effects on the stability of possible geometries as well as their thermal and physical parameters.

New supramolecular complexes, based on H-bonding interactions between 4-(pyridin-4-yl) azo-(2-chlorophenyl) 4-alkoxybenzoates (Bn) and 4-[(4-(n-hexyloxy)phenylimino)methyl]benzoic acid (A6), were prepared and their thermal and mesomorphic properties investigated via differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FT-IR) in order to confirm their H-bonding interactions. The mesophase behavior of each mixture was examined by DSC and polarized optical microscopy (POM). According to the findings of the study, in all of the designed mixtures, the introduction of laterally polar chlorine atom to the supramolecular complexes produces polymorphic compounds possessing smectic A, smectic C and nematic mesophases, in addition, all products have low melting transitions. Thermal stabilities of the associated phases depend on the position and orientation of the lateral polar Cl− atom as well as the length of terminal flexible alkoxy chain. Comparisons were made between the present lateral Cl− complexes and previously investigated laterally-neat complexes in order to investigate the impact of the addition, nature and orientation of polar substituent on the mesomorphic behavior. The investigations revealed that, the polarity and mesomeric nature of inserted lateral substituent into the base component play an essential role in affecting their mesomorphic properties. Furthermore, for current complexes, induced polymorphic phases have been found by introducing the chlorine atom.

Three binary systems were prepared by mixing of two different mesogenic derivatives, homologues, the first is azo/ester, namely 4-alkoxyphenylazo-4′-phenyl-4″-alkoxybenzoates (IIn+m) and the second is Schiff base/ester, namely 4-(arylideneamino)phenyl-4″-alkoxy benzoates (In+m). The two corresponding analogues from both series in the binary mixtures investigated are of the same terminal alkoxy chain length. Mesomorphic properties were investigated by differential scanning calorimetry (DSC) and phases identified by polarized optical microscope (POM). Photophysical studies were investigated by UV spectroscopy connected to a hot stage. Results were discussed based on constructed binary phase diagrams. All mixtures were found to exhibit eutectic compositions, with linear or slightly linear nematic and smectic A stability/composition dependences. Geometrical parameters were predicted applying density functional theory (DFT) calculations. Twist angle (θ), aspect ratio, dipole moment and the polarizability of the individual compounds were discussed and correlated with the experimental results to illustrate the enhanced the mesophase stability and the mesophase range of the mixture at the eutectic composition compared with those of their individual components.

New four isomeric chair architectures of 1:1 H-bonded supramolecular complexes were prepared through intermolecular interactions between 4-(2-(pyridin-4-yl)diazenyl-(2-(or 3-)chlorophenyl) 4-alkoxybenzoates and 4-n-alkoxybenzoic acids. The H-bond formation of all complexes was confirmed by differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FTIR). Mesomorphic characterization was carried by DSC and polarized optical microscopy (POM). It was found that all prepared laterally chloro-substituted supramolecular complexes were nematogenic, and exhibited nematic phase and low melting temperature. The thermal stability of the nematic mesophase observed depends upon the location and spatial orientation of the lateral Cl− atom in as well as the length of terminal chains. Theoretical calculations were carried out within the paradigm of the density functional theory (DFT) in order to establish the molecular conformation for the formed complexes and estimate their thermal parameters. The results of the computational calculations revealed that the H-bonded complexes were in a chair form molecular geometry. Additionally, out of the acquired data, it was possible to designate the influence of the position and orientation of the lateral group as well as the alkoxy chain length on the stability of the nematic phase.

ABSTRACT New series of the Schiff base/esters, 4-((2′-or 3′-fluorophenylimino)methyl)phenyl-4″-alkoxy benzoates were prepared and their mesophase behaviour investigated. The type of the mesophase and its transition temperature were determined by differential scanning calorimetry (DSC) and polarised optical microscopy (POM). The optimised structures of Schiff base/ester and their azo/ester groups have been deduced theoretically by density functional theory (DFT). Each group of homologues differs from the other by the position of the fluorine atom on the terminal benzene ring, in addition to laterally neat homologues. Comparative studies revealed that the position and orientation of the lateral fluorine atom as well as the type of the linking core not only affects the melting temperature but also the mesophase stability. DFT results showed that the type and stability of the mesophase could be illustrated in the terms of calculated dipole moment, polarisability, thermal energy and molecular electrostatic potential. Graphical abstract

The novel coronavirus, COVID-19, caused by SARS-CoV-2, is a global health pandemic that started in December 2019. The effective drug target among coronaviruses is the main protease M-pro, because of its essential role in processing the polyproteins that are translated from the viral RNA. In this study, the bioactivity of some selected heterocyclic drugs named Favipiravir (1), Amodiaquine (2), 2 '-Fluoro-2 '-deoxycytidine (3), and Ribavirin (4) was evaluated as inhibitors and nucleotide analogues for COVID-19 using computational modeling strategies. The density functional theory (DFT) calculations were performed to estimate the thermal parameters, dipole moment, polarizability, and molecular electrostatic potential of the present drugs; additionally, Mulliken atomic charges of the drugs as well as the chemical reactivity descriptors were investigated. The nominated drugs were docked on SARS-CoV-2 main protease (PDB: 6LU7) to evaluate the binding affinity of these drugs. Besides, the computations data of DFT the docking simulation studies was predicted that the Amodiaquine (2) has the least binding energy (-7.77 Kcal/mol) and might serve as a good inhibitor to SARS-CoV-2 comparable with the approved medicines, hydroxychloroquine, and remdesivir which have binding affinity -6.06 and -4.96 Kcal/mol, respectively. The high binding affinity of 2 was attributed to the presence of three hydrogen bonds along with different hydrophobic interactions between the drug and the critical amino acids residues of the receptor. Finally, the estimated molecular electrostatic potential results by DFT were used to illustrate the molecular docking findings. The DFT calculations showed that drug 2 has the highest of lying HOMO, electrophilicity index, basicity, and dipole moment. All these parameters could share with different extent to significantly affect the binding affinity of these drugs with the active protein sites.

New geometrical architectures of chair- and V-shaped supramolecular liquid crystalline complexes were molded through 1:1 intermolecular hydrogen bonding interactions between 4-(4-(hexyloxy)phenylazo)methyl)phenyl nicotinate and 4-alkoxybenzoic acids. The length of terminal alkoxy acid chains varied, n = 6 to 16 carbons. The mesomorphic behaviour of these complexes was examined through differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). Fourier-transform infrared spectroscopy (FT-IR) was carried out to confirm the presence of Fermi bands that appeared for the hydrogen bonding formation. Enantiotropic nematic phases were observed and covered all lengths of alkoxy chains. The geometrical structures of the prepared supramolecular complexes geometries were estimated by Density functional theory (DFT) calculations. The supramolecular complexes I/An are projected to exhibit a nonlinear geometry with V-shaped and chair-shaped geometry. The chair-shaped conformers of I/An were found to be more stable than V-shaped isomeric complexes. Moreover, the effect of the change of the mesogenic core on the mesophase thermal stability (TC) has been investigated by a comparative study of the present azo supramolecular H-bonding LCs (SMHBCs) I/An and our previously reported their Schiff base analogue complexes, II/An. The findings of the DFT illustrated the high impact of CH=N as a mesogenic core on the mesomorphic behavior in terms of the competitive lateral and terminal intermolecular interactions as well as the molecular electrostatic potential (MEP).

Nonlinear architecture liquid crystalline materials of supramolecular 1:1 H-bonded complexes (I/II and I/III) were prepared through a self-assembly intermolecular interaction between azopyridine (I) and 4-n-alkoxybenzoic acid (II) as well as 4-n-alkoxyphenylazo benzoic acid (III). The H-bond formation of the prepared supramolecular hydrogen bonded (SMHB) complexes was confirmed by Fourier-transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). Optical and mesomorphic behaviors of the prepared complexes were studied by polarized optical microscopy (POM) as well as DSC. Theoretical calculations were performed by the density functional theory (DFT) and used to predict the molecular geometries of the synthesized complexes, and the results were used to explain the experimental mesomorphic and optical properties in terms of their estimated thermal parameters. Ordinary and extraordinary refractive indices as well as birefringence at different temperatures were investigated for each sample using an Abbe refractometer and modified spectrophotometer techniques. Microscopic and macroscopic order parameters were calculated for individual compounds and their supramolecular complexes.

New analogues series of two rings Schiff base comprising different terminal polar substituents changed between N(CH3)2, CH3O, H, Cl, F, CN and NO2 were prepared using conventional heating and a ball-milling method. An alkoxy chain substituent contributes one end of their molecular structure. Mesomorphic and optical properties as well as their thermal stability were investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). FT-IR, 1H NMR, 13C NMR, and elemental analysis were carried out to elucidate and confirm the molecular structures of the synthesized compounds. The mesophase type and stability of the prepared compounds are rationalized based on the varying Van der Waal volume and polarizability of the terminal groups as well as the intermolecular interactions. After compiling all resulting experimental data and discussing it in the performance of Hammett and Density functional theoretical estimated parameters, it found that the molecular structure and the dipole moment as well as the polarizability of the prepared compounds are highly affected by the electronic nature of the terminal substituent X rather than its volume. Moreover, the mesophase type and its stability were explained in the term of the DFT data and Hammett as well as Van der Waal's volume of the terminal substituents.

The effects of bacterial poly(hydroxyoctanoate) (PHO) and talc on the nonisothermal cold crystallization behaviours of poly(lactic acid) (PLA) were analysed with differential scanning calorimetry (DSC), and the thermal stability of the samples was observed with thermal gravimetric analysis (TGA). The modified Avrami's model was used to describe the nonisothermal cold crystallization kinetics of neat PLA and its blends. The activation energies E for nonisothermal cold crystallization were calculated by the isoconversional method of Kissinger-Akahira-Sunose (KAS). The DSC results showed that the PLA/PHO blends were immiscible in the whole studied range, and as the PHO and talc content increased, the crystallization rate of PLA accelerated, and the crystallinity of PLA in the PLA samples increased. The values of the Avrami exponent indicated that the nonisothermal cold crystallization of the neat PLA and its blends exhibited heterogeneous, three-dimensional spherulitic growth. The E values were strongly dependent on PHO and talc. The TGA results showed that the presence of PHO and talc slightly influenced the thermal stability of PLA.

Four new series of laterally methyl-substituted hydrogen-bonded supramolecular complexes were prepared. The prepared complexes were thermally investigated by differential scanning calorimetry (DSC) and phases identified by polarized light microscopy (PLM). Supramolecular hydrogen-bonded complexes formed from a 1:1 mixture of any two derivatives, bearing different alkoxy chains, of 4-alkoxyphenylazobenzoic acid and 4-(2-(pyridin-4-yl)diazenyl-(2-(or 3-)methylphenyl) 4-alkoxybenzoate. The investigated 1:1 mixture made by introducing a lateral methyl group by different spatial orientation angles into pyridine-based components. All new complexes were confirmed by Fourier-transform infrared spectroscopy (FTIR) and computational calculations used to study their stabilities. It is found that the prepared complexes are dimorphic, exhibiting smectic C and enhanced nematic phases. A comparison was made between the new series and previously investigated simpler complexes, revealed that the incorporation of the phenylazo group elongate the mesogenic part and hence broad nematic phases were obtained with high stability.

Three new groups of azobenzene liquid crystals named,4-[2-(4-substituted phenyl)diazenyl]phenyl hexdecanoate, 4-[2-(4-substituted phenyl)diazenyl]phenyl octadeca-9-enoate, and 4-[2-(4-substituted phenyl)diazenyl]phenyl octadeca-9,12-dienoate were prepared from naturally occurring fatty acids (palmitic, oleic and linoleic acids). All groups were investigated for their mesophase formation and thermal stability of pure compounds and their binary mixtures by differential scanning calorimetry (DSC), polarised light microscopy (PLM) and thermogravemetric analyses (TGA). Each group contains two compounds that differ from each other by the polar substituent X (CH3O and Cl) with different number (n) of carbons in the fatty alkyl chains. Molecular structures of the prepared compounds were confirmed via FT-IR, H-1 NMR, C-13 NMR and elemental analysis. Mesomorphic and thermal properties were investigated. Smectic A phase is the mesophase observed in all of the compounds prepared and their binary mixtures with low melting temperatures. Moreover, DFT calculations were discussed for the prepared compounds. The results revealed that the alkyl chain of the carboxylate part does not significantly affect on the energy difference of the FMOs as well as the thermodynamic parameters. However, the high electronegative Cl substituent has significant effect on the energy difference of the FMOs and decreases the dipole moments of the prepared compounds. [GRAPHICS] .