Ethanolic NaOH Research Articles

Chemical and Green Synthesis, Characterization, Electrical and Antimicrobial Activity of ZrO2 Nanoparticles

ZrO2 nanoparticles were successfully synthesized using a chemical and green synthesis method. Their structural, morphological, optical, anti microbial and electrochemical properties were characterized. The green and chemical synthesis of ZrO2 was achieved by using the ethanolic extract and NaOH as reagents. XRD analysis confirmed the ZrO2 nanoparticles' tetragonal crystal phase. The surface morphological properties under the phases of nucleation, growth and aggregation as well as elementary composition were confirmed by SEM and EDS. The Fourier Transform Infra Red (FTIR) analysis was used to investigate into the functional groups that were present in the molecules of the synthesized nanomaterials. The presence of zirconium oxide nanoparticles with an optical band gap value between 4.73 and 5.48 eV was confirmed by the absorption spectra at 226-232 nm Antimicrobial studies showed that ZrO2 nanoparticles had bactericidal activity at a dose of 10 g/mL against Proteus vulgaris, Eschericia coli, Pseudomonas aeruginosa, Enterococcus faecalis and Staphylococcus aureus. The overall results of this study showed that ZrO2 NPs with excellent bioremediation and antibacterial characteristics were formed. The electrochemical behavior of both ZrO2 nano particles was examined using cyclic voltammetry studies were observed. The maximum enhanced specific capacitance value at a 10 mV/s scan rate.

Anticancer activity, DFT calculation, ADMET study and molecular docking of synthetic Chalcone (2E)-1-(4-Aminophenyl)-3-(3,4,5-trimethoxyphenyl)-2- propen-1-one in breast cancer cell line (MCF-7)

The (2E)-1-(4-Aminophenyl)-3-(3,4,5-trimethoxyphenyl)-2-propen-1-one was prepared by the reaction between 4-aminoacetophenone and 3,4,5, trimethoxy benzaldehyde in ethanolic NaOH. Then in vitro anticancer activity was evaluated against the MCF-7 breast cell line. The molecular properties like bond length, bond angle, molecular electrostatic potential surface (MEPs), Mullikan charge, HOMO-LUMO, and NBO analysis data obtained by DFT/B3LYP method using 6- 31+G(d,p) basis set to get electronic states and molecular parameters of the title molecule. Because of their advantageous pharmacokinetic properties, the synthesized compound was shown to have moderate anticancer activity and could advance to a higher level of the drug development process. Molecular docking studies were utilized to foresee the binding interactions of the title compound with the EGFR tyrosine kinase domain (PDB ID: 1M17). In silico ADME study is also performed to predict the pharmacokinetic profile which expressed good oral drug-like behavior.

The mineral phase evolution characteristics and hydration activity enhancement mechanism of steel slag under NaOH alkaline excitation

During the slow cooling process of steel slag, crystals of the inert ore phase (C2F) and active ore phase (C2S, C3S) grow dependently, and the irregular interlacement and coating between ore phases strongly affect the hydration activity of the active ore phase in steel slag. Therefore, in this article, a typical alkaline activator, NaOH, was selected, the solvent type and concentration were optimized, and the etching behavior and mechanism of action of the NaOH alkaline activator on the surface of steel slag particles were clarified by analyzing the mineral phase composition, microstructure, particle size distribution, and pore structure evolution characteristics under alkaline excitation. In addition, the water hydration products, microstructure, exothermic hydration and thermogravimetric data before and after the excitation of steel slag were characterized, revealing the mechanism of enhancing the hydration activity of steel slag under alkaline NaOH stimulation. The results showed that both NaOH aqueous solution and ethanol solution could effectively increase the mass fraction of active mineral phases in steel slag; among them, the 0.08 mol/L NaOH ethanol solution had the best chemical activation effect on the steel slag. Compared with that of the raw steel slag, the total mass fraction of the active mineral phases (C2S and C3S) increased from 37.3 wt% to 45.6 wt%, and the mass fraction of the inert mineral phase C2F decreased from 38.3 wt% to 19.1 wt%. The consumption of active mineral phases in steel slag is reduced by the water in the activator. The alkaline activator erodes the dense inert mineral phase C2F on the surface of the steel slag particles, resulting in etching pits that expose the active silicate mineral phase and provide additional hydration sites. The cumulative heat release from the steel slag after alkaline excitation was 116.27 J/g at 72 h, which was 66.88 J/g higher than that of the raw steel slag. These conditions significantly improved the early hydration performance of the steel slag and promoted the formation of amorphous cementitious products (CH, C-S-H and AFt) in the steel slag system, which subsequently filled the capillary pores of the steel slag and formed a denser microstructure.

Sodium Glyceroxide: An Efficient Homogeneous Alkaline Catalyst for Biodiesel Synthesis

Biodiesel is obtained from the alcoholysis of triglycerides and has been used as a renewable alternative to diesel. Though the methanolysis of triglycerides in the presence of MeONa catalyst has been widely used, searching for alternatives that may improve the competitiveness of the production chain is still a challenge. The aim of this work was to evaluate sodium glyceroxide as a catalyst in the methanolysis of soy oil. Sodium glyceroxide was obtained from glycerol and NaOH in ethanol, and characterized by thermogravimetric analysis (TGA), X-ray powder diffraction (XRD) and, Fourier transform infrared (FTIR) spectroscopy. The transesterification reaction was optimized after two sets of experiments based on the Doehlert matrix experimental design. In the first one, the influence of the molar ratio of methanol/triglyceride, and the amount of catalyst (m/m with respect to the triglyceride) were studied. In the second set, the temperature, and the reaction time were studied. The best conditions were found as 12:1 molar ratio, 2% of catalyst, 50 ºC, and 60 min. The conditions were applied in the transesterification of canola and sunflower oils, and tallow. All the biodiesels were obtained with an ester content superior to 98%, free from methanol and triglycerides. Specific mass, viscosity, and pour point were determined and met the international specifications.

Synthesis, crystal structure and Hirshfeld analysis of trans-bis-{(2E)-N-phenyl-2-[(2E)-3-phenyl-2-propen-1-yl-idene]hydrazinecarbo-thio-amidato-κ2N1,S}palladium(II).

The reaction of (2E)-N-phenyl-2-[(2E)-3-phenyl-2-propen-1-yl-idene]hydra-zine-carbo-thio-amide (common name: cinnamaldehyde-4-phenyl-thio-semi-carbazone) deprotonated with NaOH in ethanol with an ethano-lic suspension of PdII chloride in a 2:1 molar ratio yielded the title compound, [Pd(C16H14N3S)2]. The anionic ligands act as metal chelators, κ2 N 1 S-donors, forming five-membered rings with a trans-configuration. The PdII ion is fourfold coordinated in a slightly distorted square-planar geometry. For each ligand, one H⋯S and one H⋯N intra-molecular inter-actions are observed, with S(5) and S(6) graph-set motifs. Concerning the H⋯S inter-actions, the coordination sphere resembles a hydrogen-bonded macrocyclic environment-type. In the crystal, the complexes are linked via pairs of H⋯S inter-actions, with graph-set motif R 2 2(8), and building a mono-periodic hydrogen-bonded ribbon along [001]. The Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are: H⋯H (45.3%), H⋯C/C⋯H (28.0%), H⋯S/S⋯H (8.0%) and H⋯N/N⋯H (7.4%).

Enzymatic esterification/transesterification of rice bran acid oil for subsequent γ-oryzanol recovery

This study recovered γ-oryzanol from rice bran acid oil (RBAO), following an initial enzymatic esterification/transesterification to selectively convert its glyceride impurities into fatty acid ethyl esters (FAEEs) or biodiesel. γ-oryzanol was then deprotonated and separated from the biodiesel into the resulting aqueous phase via acid-base extraction. Herein, we determine the effects of varying reaction conditions, i.e., ethanol:RBAO molar ratio, temperature, reaction time, enzyme loading, and agitation speed, on the degrees of glyceride removal, γ-oryzanol loss, free fatty acid (FFA) remaining, and biodiesel content. Up to 100% glyceride removal was achieved with a relatively high biodiesel yield (84%) and γ-oryzanol loss as low as 26% under our most suitable reaction conditions (5:1 ethanol:RBAO molar ratio, 40 °C, 24 h reaction time, 10%wt enzyme loading, 200 rpm agitation). Furthermore, of the remaining oryzanol, up to 94% was recovered by the acid-base extraction with 2-4 M ethanolic NaOH solution. Our results suggest that a combination of enzymatic esterification/transesterification with subsequent acid-base extraction offers an efficient alternative approach to the simultaneous production of biodiesel and γ-oryzanol recovery from low-cost RBAO. Based on our analysis of techno-economic and environmental sustainability, integration of the present method into a rice bran oil refinery would make the process profitable, with the minimum use of toxic chemicals and energy.

SYNTHESIS AND ANTIBACTERIAL ACTIVITY OF N-(4-METHOXYPHENYL)ACETAMIDE AND N-PHENYLACETAMIDE DERIVATIVES

Particular attention in the cultivation of industrial and agricultural crops is paid to the fight against pathogenic fungi, which not only lead to significant yield losses, but they are also dangerous to humans. The aim of this work is the synthesis of biologically active compounds in the series of aromatic dithiocarbamic acids based on N-(4-methoxyphenyl)acetamide and N-phenylacetamide and the study of their antifungal and antibacterial activities. Results and discussion. Biologically active aromatic sodium dithiocarbamates were synthesized by the reaction of amines (N-(4-methoxyphenyl)acetamide and N-phenylacetamide) with carbon disulfide in the presence of NaOH in ethanol at a temperature of 25°C in 78 and 85% yields. Thioanhydrides were synthesized by the acylation of sodium acetyl(4-methoxyphenyl)carbamodithioate and sodium acetyl(phenyl)carbamodithioate with acid chlorides (benzoic, 3,4-dimethoxybenzoic, 2-bromobenzoic, and 4-nitrobenzoic) in chloroform at a temperature of 25°C. The corresponding derivatives of aromatic thioanhydrides of dithiocarbamic acids were obtained in 49-88% yields. The structure of the synthesized compounds was established on the basis of elemental analysis data, IR spectra, 1Н and 13С NMR spectroscopy. Antifungal and bactericidal properties of the synthesized compounds were studied against phytopathogenic fungi and Fusarium oxysporum and Pectobacterium carotovorum bacteria. Conclusion. According to the test results, it was revealed that sodium acetyl(4-methoxyphenyl)carbamodithioate at a concentration of 0.4% has a high fungicidal activity and completely inhibits the growth of the Fusarium oxysporum phytopathogen. The maximum zone of inhibition (18 mm) of Pectobacterium carotovorum bacteria was at a concentration of 0.4%.

Converting textile waste into value-added chemicals: An integrated bio-refinery process

The rate of textile waste generation worldwide has increased dramatically due to a rise in clothing consumption and production. Here, conversion of cotton-based, colored cotton-based, and blended cotton-polyethylene terephthalate (PET) textile waste materials into value-added chemicals (bioethanol, sorbitol, lactic acid, terephthalic acid (TPA), and ethylene glycol (EG)) via enzymatic hydrolysis and fermentation was investigated. In order to enhance the efficiency of enzymatic saccharification, effective pretreatment methods for each type of textile waste were developed, respectively. A high glucose yield of 99.1% was obtained from white cotton-based textile waste after NaOH pretreatment. Furthermore, the digestibility of the cellulose in colored cotton-based textile wastes was increased 1.38–1.75 times because of the removal of dye materials by HPAC-NaOH pretreatment. The blended cotton−PET samples showed good hydrolysis efficiency following PET removal via NaOH–ethanol pretreatment, with a glucose yield of 92.49%. The sugar content produced via enzymatic hydrolysis was then converted into key platform chemicals (bioethanol, sorbitol, and lactic acid) via fermentation or hydrogenation. The maximum ethanol yield was achieved with the white T-shirt sample (537 mL/kg substrate), which was 3.2, 2.1, and 2.6 times higher than those obtained with rice straw, pine wood, and oak wood, respectively. Glucose was selectively converted into sorbitol and LA at a yield of 70% and 83.67%, respectively. TPA and EG were produced from blended cotton−PET via NaOH–ethanol pretreatment. The integrated biorefinery process proposed here demonstrates significant potential for valorization of textile waste.

Valorization of waste Fe-rich sludge as erdite/KFeS2 rods under atmosphere condition and evaluation of their mutual transformation.

Pilot scale production of one-dimensional (FeS2)nn- rods was performed by using an automatic 20L vessel at 80°C under atmosphere condition with the resource utilization of Fe-rich sludge. The sludge was simulated at lab-scale with chemical pure of ferric trichloride. After the sludge treatment, the corresponding rods were not formed at room temperature. But by heating at 80°C, erdite rod was well-crystallized after 0.5h by only adding Na halite, and KFeS2 rod was crystallized weakly after 2h and highly at 10h with the addition of K halite. After 48h heating, the rods grow radially to 300nm for erdite, but to 5μm for KFeS2. However, at room temperature, erdite rod was converted to high crystallized KFeS2 in KOH water or ethanol solution, whilst the conversion of KFeS2 rod to erdite also occurred in NaOH water solution, but terminated in NaOH ethanol solution, without any morphology change. It is also noted that with the presence of both Na and K halite, the rod was an intermediate of erdite to KFeS2 with 1μm length after heating at 100°C but converted to 10-μm-length KFeS2 crystal at the temperature of > 120°C. The thermodynamic results confirmed that during the rod polymerization, the Fe(OH)3HS- formation was the sole rate-limiting step and showed a positive Gibbs value of 6.45kJ/mol at room temperature and negative values at the temperature of > 48°C. In summary, this method not only enabled the vaporization of waste Fe-rich sludge as value-added rods without generating any secondary waste but also showed a new route for the in situ conversion of erdite/KFeS2 rods at room temperature.

Microwave Irradiated Eco-friendly Synthesis of Pyrimidine Derivatives as Potential Antitubercular Agents

The microwave irradiation method is applied for the efficient synthesis of pyrimidine derivatives. The synthetic protocol involves Knoevenagel condensation followed by Michael addition reaction and cyclization of equimolar quantities of aromatic aldehydes, ethyl cyanoacetate and guanidine in the presence of ethanolic NaOH solution to produce corresponding pyrimidine derivatives. The reaction mixture was allowed to reflux under microwave radiation at power level-2 for 7-12 min. The microwave heating technique offers a cleaner reaction with a shorter reaction time and improved product yield as compared to conventional synthesis. The newly synthesized compounds were characterized by their FT-IR, 1H NMR and LC-MS spectral data. All the synthesized pyrimidine derivatives were evaluated in vitro for their antitubercular activity in vitro by using the luciferase reporter phage (LRP) assay method. The antimycobacterial activity was determined in terms of the percent reduction in the relative light unit (RLU). The test compounds exhibited promising antitubercular activity against Mycobacterium tuberculosis H37Rv and clinical isolates, S, H, R and E resistant M. tuberculosis in comparison with the standard drug (isoniazid).

DESIGN AND SYNTHESIS OF NOVEL TRIAZOLYL/OXADIAZOLYL/ THIADIAZOLYL-CARBAZOLES AS POTENT ANTICONVULSANT AGENTS

Compound-1, was synthesized by the reaction of carbazole with chloroacetyl chloride in dry acetone. Compound 1 on reaction with hydrazine hydrate yielded compound 2, which on reaction with various substituted phenyl isothiocyanates in absolute alcohol yielded compounds 3-8 i.e.2-(carbazolylacetyl)- N-(substituted phenyl)-hydrazine carbothioamides. Compounds 3-8, on reaction with aqueous NaOH, ethanolic NaOH and conc. H2 SO4 afforded triazoles (9-14), oxadiazoles (15-20) and thiadiazoles (21-26), respectively. The structures of these compounds were established on the basis of analytical and spectral data. Twenty four newly synthesized compounds were evaluated for their anticonvulsant activity and acute toxicity.

Kinetic Analysis of Cellulose Acetate/Cellulose II Hybrid Fiber Formation by Alkaline Hydrolysis

Cellulose acetate (CA) can be converted to cellulose II through a deacetylation process using ethanolic NaOH solution. Infrared spectroscopy was used to observe the degree of acetylation by comparing the absorption intensities of C═O and C–O stretches. Attenuated total reflection-Fourier transform infrared (ATR-FTIR) analysis, which only measures a few microns into the fiber diameter, was compared with FTIR, which measures the whole fiber cross-section. Steady deacetylation of the whole fiber over 180 min was observed with FTIR to eventual complete deacetylation. In comparison, ATR-FTIR shows deacetylation occurring more rapidly to complete deacetylation after 90 min, indicating rapid deacetylation of the CA fiber periphery. Data were fitted to a pseudo-second order kinetic model, with high correlation (R² > 0.99), and it was observed that the deacetylation rate (k₂) observed with ATR-FTIR (−0.634 min⁻¹) was twice as rapid as the deacetylation rate observed with FTIR (−0.315 min⁻¹). IR observations were in agreement with the analysis of fiber cross-sections by confocal microscopy, where it was observed that changes in fiber morphology occurred with treatment time and progressive hydrolysis of cellulose acetate to cellulose II. A differential fiber chemical composition was created within the CA fiber cross-section; after 5 min, the outer regions of the fiber cross-section are hydrolyzed to cellulose II and this hydrolysis increases heterogeneously with time to complete hydrolysis after 180 min and conversion to cellulose II. These results indicate the potential to produce fibers with a differential periphery/core structure, which can be accurately designed according to the relative degrees of cellulose II/CA required for specific applications by varying the treatment time in application of this model.

Efficacy of four cleaning solutions for the decontamination of selected cytotoxic drugs on the different surfaces of an automated compounding system

The automated aseptic preparation of ready-to-administer antineoplastic drug solutions with robotic systems reduces the risk of occupational exposure. However, the surfaces in the preparation area of the robot are to be cleaned by wiping with an appropriate cleaning solution. The aim of the study was to evaluate the cleaning efficacy of four cleaning solutions on four surface materials installed in the APOTECAchemo robot. Predefined amounts of cisplatin (Cis), 5-fluorouracil (5-FU), and cyclophosphamide (CP) were intentionally spread on test plates made of stainless steel, aluminium, polyoxymethylene, and polycarbonate just as installed in the robotic system APOTECAchemo. After drying, the plates were cleaned with 0.2% ethanolic NaOH, 0.23% isopropanolic sodium dodecylsulfate (SDS-2P), 0.5% sodium hypochlorite (NaOCl), and 0.1% benzalkonium chloride (BZK) solutions following a standardized wiping protocol. Residual contamination was recovered with wipe tests, Pt was quantified by voltammetry, and 5-FU and CP was quantified by gas chromatography-tandem mass spectrometry (GC-MSMS). The mean residual contamination after cleaning and the cleaning efficacy (CE) rates were calculated and aggregated on different levels. The CE rates varied between 81.5% and 100% and lay in the majority of cases above 90%. The lowest CE rates were registered for Pt contamination. Especially on aluminium surfaces the residual contamination was high. The overall CE rates of the three different drugs and four different surface types amounted to 98.3% for NaOCl, 97.9% for SDS-2P, 96.9% for ethanolic NaOH, and 96.5% for BZK. The tested cleaning solutions proved to be higher than 90% in most cases, but none of them was able to eliminate 100% of the intentional surface contamination of three antineoplastic drugs on the test plates. The cleaning efficacy varied according to the different surface types and antineoplastic drug. Results could be used in the daily clinical practice to develop and implement effective cleaning procedures.

Synthesis on aggregation of colloidal solutions of ICG-active silica nanoparticles and their application in in‐vivo fluorescence imaging

This study reports two findings. The first is a method for preparing a colloidal solution of silica (SiO2) nanoparticles activated with fluorescent dye or fluorescent dye-active SiO2 nanoparticles. Preparation of a colloid solution of spherical SiO2 nanoparticles with an average size of 109.4 ± 8.6 nm was performed using the sol-gel method at 35 °C using 0.2 M tetraethylorthosilicate, 25 M H2O, and 0.01 M NaOH in ethanol. Two kinds of cationic chemicals (poly-diallyldimethylammonium chloride (PDADMAC) and (3-aminopropyl) triethoxysilane (APES) were examined for surface-modification or surface-cationization of the SiO2 nanoparticles (SiO2/PDADMAC and SiO2/APES). To activate the SiO2 nanoparticles with fluorescent dye, indocyanine green (ICG) molecules were fixed on the surface-modified SiO2 nanoparticles by mixing ICG dissolved in albumin aqueous solution and the surface-modified SiO2 nanoparticle colloid solution (SiO2/PDADMAC/ICG and SiO2/APES/ICG) through electrostatic aggregation. The second finding is the verification of the fluorescence ability of the ICG-active SiO2 nanoparticle colloid solutions. Both the ICG-active SiO2 nanoparticle colloid solutions exerted fluorescence even at high ICG concentrations. Mouse tissues could be imaged by injecting the ICG-immobilized SiO2 nanoparticle colloid solution into the tail vein of the mouse and measuring the emitted fluorescence intensity. Pulmonary embolism was avoided in the SiO2/APES/ICG particle colloid solution-injected group, in which the particles reached the tissues more efficiently than in the SiO2/PDADMAC/ICG nanoparticles-injected group.

Gelation Modification of Alginate Nonwoven Fabrics

Calcium alginate nonwoven fabrics were gelation-modified by two-stage with aqueous HCl solution and then ethanolic NaOH solution. The structure and crystallinity properties of the samples were characterized by FT-IR, SEM, and XRD. The preparation conditions and modification mechanism were investigated. The results indicated that the crystal structure of calcium alginate fibers was destroyed; the crystallinity and calcium ion content decreased after HCl treatment. This resulted from the formation of ester bonds among the hydrolytic molecules after NaOH treatment. The best gel performance was obtained at the HCl concentration of 0.05-0.1 wt% with the NaOH concentration in ethanol of 2–4 mol/l. The liquid absorption of nonwoven alginate fabrics increased by 145 %. The water capability increased by 2673 % after modification, while the thickness, mass per unit area, permeability, and tensile strength of nonwoven alginate fabrics changed little.

Morphological Study of Chitosan/Poly (Vinyl Alcohol) Nanofibers Prepared by Electrospinning, Collected on Reticulated Vitreous Carbon.

In this work, chitosan (CS)/poly (vinyl alcohol) (PVA) nanofibers were prepared by using the electrospinning method. Different CS concentrations (0.5, 1, 2, and 3 wt %), maintaining the PVA concentration at 8 wt %, were tested. Likewise, the studied electrospinning experimental parameters were: syringe/collector distance, solution flow and voltage. Subsequently, the electrospun fibers were collected on a reticulated vitreous carbon (RVC) support for 0.25, 0.5, 1, 1.5, and 2 h. The morphology and diameter of the CS/PVA nanofibers were characterized by scanning electron microscopy (SEM), finding diameters in the order of 132 and 212 nm; the best results (uniform fibers) were obtained from the solution with 2 wt % of chitosan and a voltage, distance, and flow rate of 16 kV, 20 cm, and 0.13 mL/h, respectively. Afterwards, a treatment with an ethanolic NaOH solution was performed, observing a change in the fiber morphology and a diameter decrease (117 ± 9 nm).

Triboelectric Nanogenerator Based on Human Hair

Triboelectric nanogenerators (TENGs) can be incorporated into modern electronic devices requiring sustainable, renewable, and reliable microscale energy sources. We report the first use of human hair, which is known to be a highly triboelectric material, for the fabrication of biobased TENGs. Ethanolic NaOH was used to dissolve hair, and two simple fabrication techniques, bar- and spin-coating methods, were used to prepare hair-based films on electrode substrates. The dissolved hair paste has somewhat different chemical composition from original hair, but the hair-based film has almost the same level as the untreated human hair in the triboelectric series. The spin-coated film is thinner and has more even surface compared with the bar-coated one, and exhibits better performance in triboelectric generation. The TENG using a spin-coated hair film produced the maximum peak-to-peak voltage of 103 V and the power density of 60 mW m–2 across a 1.2 MΩ resistor; using the TENG device, an array of LEDs was in situ...

Cellulose Acetate Derived Free-Standing Electrospun Carbon Nanofibrous Mat As an Anode Material for Rechargeable Lithium-Ion Battery

Introduction Electrospun polymer derived carbon nanofibers have received attention in recent years as an anode material for energy storage devices due to their enhanced surface area, single step synthesis and shorter diffusion length.[1] Due to these enhanced surface properties, carbon nanofibers showed promising performance even at high C-rate applications.[2] More often, carbon derived from Polyacrylonitrile and its composites are explored as anode material for energy storage devices due to high carbon yield.[1,3,4] However, some other polymeric carbon precursors like polypyrrole, polyvinyl alcohol, and more recently, SU-8 negative photoresist were also explored as an electrode material for a rechargeable Lithium-ion battery. Use of SU-8 facilitates fabrication of three-dimensional electrodes as it can be patterned using photolithography, but it is an expensive source for carbon. The present study is the first report, where cellulose acetate derived carbon fibers have been used as an anode for lithium-ion battery. Cellulose acetate is an inexpensive polymeric carbon precursor. Moreover, our group has recently developed template-assisted electrospinning technique to produce patterned three-dimensional cellulose acetate nanofibrous structures [5] which can be explored further for higher surface area and enhanced performance. Experimental Cellulose acetate polymer (Mw: 29,000 g/mol; Sigma Aldrich, India) was mixed with a binary solvent (acetone and dimethylamide) and the 16 wt.% solution was electrospun to form the nanofibers. As-prepared electrospun cellulose acetate nanofibers mat was regenerated to cellulose nanofabric by deacetylation in 0.05 M NaOH in ethanol, as direct carbonization of cellulose acetate fibers results in melting. After deacetylation cellulose fiber mat was stabilized at 240 °C prior to carbonization at 900 °C in inert atmosphere. Cellulose acetate derived carbon nanofabric was then directly used as a free-standing electrode without any further modification. Electrochemical performance of mat was investigated using Swagelok cell, where lithium metal was used as counter electrode. Results and discussions: Surface morphology of the electrospun fibers was investigated with scanning electron microscope (Figure 1(a)) and deacetylation of cellulose acetate fibers was confirmed by Raman spectroscopy (Figure 1 (b)). A band near 1095 cm -1 can be clearly observed only for regenerated cellulose fiber in figure 1 (b) which corresponds to C-O ring stretching mode, and confirms the conversion of cellulose acetate nanofibers to cellulose nanofibers. Electrochemical performance of cellulose acetate derived carbon fibers was studied at 37.2 mA/g current density. Figure 1(c) shows the cyclic performance of cellulose acetate derived carbon fibers for 100 cycles of charge/discharge. The reversible capacity of these carbon nanofibers was observed to be similar to polyacrylonitrile derived carbon fibers. [3,4] Specific reversible capacity after 100 cycles was found to be ~290 mAh/g. Initial lower columbic efficiency can be attributed to faradic reactions and SEI formation, which is characteristic of carbon materials. Due to the enhanced surface area of free standing carbon fiber mat and entangled three-dimensional porous structure, initial fade was significant. This may be attributed to irreversible surface adsorption of lithium ion. However, after initial 10 cycles, more than 90% of columbic efficiency was retained. Electrochemical performance at higher current densities and detailed structural analysis will be presented in conference presentation.

Ru-Catalyzed Estragole Isomerization under Homogeneous and Ionic Liquid Biphasic Conditions.

The isomerization of estragole to trans-anethole is an important reaction and is industrially performed using an excess of NaOH or KOH in ethanol at high temperatures with very low selectivity. Simple Ru-based transition-metal complexes, under homogeneous, ionic liquid (IL)-supported (biphasic) and “solventless” conditions, can be used for this reaction. The selectivity of this reaction is more sensitive to the solvent/support used than the ligands associated with the metal catalyst. Thus, under the optimized reaction conditions, 100% conversion can be achieved in the estragole isomerization, using as little as 4 × 10–3 mol % (40 ppm) of [RuHCl(CO)(PPh3)3] in toluene, reflecting a total turnover number (TON) of 25 000 and turnover frequencies (TOFs) of up to 500 min–1 at 80 °C. Using a dimeric Ru precursor, [RuCl(μ-Cl)(η3:η3-C10H16)]2, in ethanol associated with P(OEt)3, a TON of 10 000 and a TOF of 125 min–1 are obtained with 100% conversion and 99% selectivity. These two Ru catalytic systems can be transposed to biphasic IL systems by using ionic-tagged P-ligands such as 1-(3-(diphenylphosphanyl)propyl)-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide immobilized in 1-(3-hydroxypropyl)-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl) imide with up to 99% selectivity and almost complete estragole conversion. However, the reaction is much slower than that performed under solventless or homogeneous conditions. The use of ionic-tagged ligands significantly reduces the Ru leaching to the organic phase, compared to that in reactions performed under homogeneous conditions, where the catalytic system loses catalytic performance after the second recycling. Detailed kinetic investigations of the reaction catalyzed by [RuHCl(CO)(PPh3)3] indicate that a simplified kinetic model (a monomolecular reversible first-order reaction) is adequate for fitting the homogeneous reaction at 80 °C and under biphasic conditions. However, the kinetics of the reaction are better described if all of the elementary steps are taken into consideration, especially at 40 °C.

Synthesis, structural characterization, electrochemical studies and DFT calculations on nickel(II) complexes of N-picolinoyl-N′-benzothioylhydrazide and 5-(pyridine-4-yl)-2H-1,2,4-triazole-3-thione

Two Ni(II) complexes, [Ni(pbth)2] and [Ni(ptt)2(en)2] {Hpbth = N-picolinoyl-N′-benzothioylhydrazide, Hptt = 5-(pyridine-4-yl)-2H-1,2,4-triazole-3-thione} have been synthesized and characterized by physico-chemical and spectroscopic methods. [Ni(pbth)2] contains a pair of N-picolinoyl-N′-benzothioylhydrazide ligands coordinated via their thione sulfur, pyridyl nitrogen and hydrazinic nitrogen atoms, forming two C2N2Ni and two CSN2Ni five-membered chelate rings. The intermediate compound 1-isonicotinoyl-3-thiosemicarbazide is converted to 5-(pyridine-4-yl)-2H-1,2,4-triazole-3-thione in the presence of ethanolic NaOH, giving the complex [Ni(ptt)2(en)2] in which the ptt ligands coordinate through their triazole ring nitrogen atoms, while four more nitrogens from two ethylenediamine ligands complete the octahedral structure. The crystal structures of the complexes involve various types of intermolecular extended hydrogen bonds, forming supramolecular frameworks. Cyclic voltammetry studies of both complexes show quasi-reversible redox behavior. Density Functional Theory electronic structure calculations corroborate our experimental findings.