Publications

To improve the properties of bio-oil, a new method was proposed that does not involve introduction of any energy medium. An ether-soluble fraction (ES), a dichloromethane soluble fraction (DCMS), and a dichloromethane insoluble fraction (DCMIS) of bio-oil were obtained using ether and dichloromethane as extraction solvents. The same amount of each fraction (10 g) was blended into bio-oil with a certain quantity of 100 g. The three samples were then placed in sealed vials and heated for 12, 60, and 180 h at both 60 C and 80 C in an oil bath. Based on the aging properties of the three fractions, blended bio-oil was prepared using ES and DCMS in certain volume ratio. The total yield of the three fractions combined was around 90 wt%; the weight loss was thought to be due to the volatilization of low molecular weight matter and water during the process of solvent evaporation using a rotary evaporator. The aging test results indicated that the DCMIS fraction had the poorest properties compared with ES and DCMS such as acid number, water content and viscosity. In order to get the best properties of blended bio-oil, the optimal volume ratio of ES/DCMS was 1/2 according to the aging test.

A series of scarce amino-substituted cyclopentafullerenes instead of the expected N-alkyl-2,5-disubstituted fulleropyrrolidines were synthesized in moderate to excellent yields via the simple one-step reaction of [60]fullerene with cheap and easily available β-substituted propionaldehydes and secondary amines in the absence/presence of magnesium perchlorate. The in situ generation of allylic amines from β-substituted propionaldehydes and secondary amines played a crucial role in the successful preparation of amino-substituted cyclopentafullerenes without additional carbons. With the addition of magnesium perchlorate, secondary amines containing ethyl group(s) could produce novel amino-substituted cyclopentafullerenes with two additional carbons. All the obtained cyclopentafullerenes displayed high stereoselectivity with cis isomers as the exclusive or major products. Plausible reaction mechanisms are proposed to elucidate the above-mentioned reaction process.

The nanoindentation technique is being widely utilized to measure the mechanical properties of small single crystals of molecular materials. However, all the experiments reported hitherto were performed under quasi-static conditions and at relatively low loading rates. “Will the plastic response change if the tests are performed at high strain rates?” is a question we address in this communication. For this, we have examined the strain rate sensitivity of nanoindentation responses on the major faces of four different molecular crystals: L-alanine, saccharin, p-nitroaniline, and sulfathiazole. Experimental results indicate that the measured hardness values are loading rate insensitive. The possible reasons for this insensitivity and implications for applications in pharmaceutical manufacturing are discussed.

A new typical phenothiazine compound functionalized with thienyl-indandione derivative (PTZTID) was synthesized and characterized using spectral analysis (ultraviolet-visible (UV-vis) light, infrared (IR), ¹ H nuclear magnetic resonance (NMR) and ¹³ C NMR tools). The UV-vis absorption spectra of the PTZTID solution in 1,4-dioxane showed two absorption bands attributed to localized aromatic π-π* transitions of conjugated aromatic moieties and intramolecular charge transfer with the characteristics of a π-π* transition. The fluorescence spectra exhibited a maximum emission wavelength at 580 nm. The effect of concentration on photophysical properties took the form of a minor hypsochromic shift, which was attributed to some extent to the occurrence of H-type aggregation of the PTZTID derivative. Binary solvent effects on the spectroscopic behaviour of PTZTID were measured at different H₂ O/1,4-dioxane ratios. Similarly, when increasing the water content, a hypsochromic shift was observed that resulted from H-type aggregation. Furthermore, geometry and electronic configurations of PTZTID were studied at density functional theory /B3LYP level and indicated that the compound had a nonplanar (butterfly structure).

In this approach, zinc oxide (ZnO) is a multipurpose substance with remarkable characteristics such as high sensitivity, a large specific area, non-toxicity, excellent compatibility, and a high isoelectric point, which make it attractive for discussion with some limitations. It is the most favorable possible option for the collection of nanostructures in terms of structure and their characteristics. The development of numerous ZnO nanostructure-based electrochemical sensors and biosensors used in health diagnosis, pharmaceutical evaluation, food hygiene, and contamination of the environment monitoring is described, as well as the production of ZnO nanostructures. Nanostructured ZnO has good chemical and temperature durability as an n-type semiconducting material, making it useful in a wide range of uses, from luminous materials to supercapacitors, batteries, solar cells, photocatalysis, biosensors, medicinal devices, and more. When compared to the bulk materials, the nanosized materials have both a higher rate of disintegration and a higher solubility. Furthermore, ZnO nanoparticles are regarded as top contenders for electrochemical sensors due to their strong electrochemical behaviors and electron transmission characteristics. The impact of many factors, including selectivity, sensitivity, detection limit, strength, and structures, arrangements, and their respective functioning processes, has been investigated. This study concentrated a substantial amount of its attention on the recent advancements that have been made in ZnO-based nanoparticles, composites, and modified materials for use in the application areas of energy storage and conversion devices as well as biological applications. Supercapacitors, Li-ion batteries, dye-sensitized solar cells, photocatalysis, biosensors, medicinal, and biological systems have been studied. ZnO-based materials are constantly analyzed for their advantages in energy and life science applications.

In the title compound, C(16)H(14)ClN(3)O(3)S, the thia-zine ring adopts a sofa (half-chair) conformation, with an r.m.s. deviation from the mean plane of 0.23 Å. The S atom and S-bonded C atom exhibit the maximum deviations from the thia-zine mean plane [-0.3976 (12) and 0.3179 (14) Å, respectively]. The conformations around the double bonds in the R(2)C=N-N=CHR unit are Z and E. An intra-molecular O-H⋯N hydrogen bond with the hy-droxy group as donor generates an S(6) ring motif. In the crystal, pairs of weak C-H⋯O inter-actions connect the mol-ecules, forming inversion dimers.

Herein, the cloud-point (CP) measurements of a nonionic surface-active agent named Tween 80 [poly(oxyethylene) (20) sorbitanmonooleate; Tw 80] were carried out in this study in the absence and attendance of an amikacin sulfate (AS) drug/(AS+ inorganic electrolyte (NaCl, NaNO3 and Na2SO4)). AS drug has been utilized to treat or prevent a wide range of bacterial infections. The measured values of CP in the aqueous phase for Tw 80 were observed in decreasing fashion with an increase in the concentration of surfactant. The obtained values of CP for Tw 80 solution were also noticed to decrease with increasing drug concentration. The determined CP values for (surfactant + drug) mixture were observed to decrease for the electrolytes’ participation with respect to their nonparticipation, and the presence of electrolytes (sodium salts) in declining CP measurement was recorded and followed the order NaCl > NaNO3 > Na2SO4. The ΔGc0 values are found to be positive that denotes the character of clouding is nonspontaneous. The ΔHc0 and ΔSc0 calculations were shown to be negative for the system studied except for the (Tw 80 + H2O) phase. The negative values of ΔHc0 and ΔSc0 decreased with the increment of electrolyte concentration. The thermodynamic parameters of transfer for the studied system were also evaluated and are illustrated in detail.