Amount Of ZnCl2 Research Articles

Solid-liquid phase equilibria in the ternary systems H2O+ZnCl2+NaCl at temperatures of 298, 313 and 333 K

In this study, an economic separation method is suggested with the use of phase equilibria in order to ensure the recycling of ZnCl2, the industrial waste amount of which is very high, and to prevent it from an environmental pollutant. Sodium chloride?zinc chloride?water systems were examined by the isothermal method at temperatures of 298, 313 and 333 K. The analyses of the liquid and solid phases were used to determine the composition of the solid phase using the Schreinemaker?s graphic method. The solid?liquid phase equilibrium and viscosity data belonging to all the ternary systems were identified and the solubility and viscosity changes with temperature were compared. The viscosity values were inversely proportional to the temperature as the amount of ZnCl2 in the solution increased. NaCl, 2NaCl ZnCl2 nH2O (n: 2, 0), ZnCl2 salts were observed at 298, 313 and 333 K in the solid phases that are in equilibrium with the liquid phase at the invariant point.

Statistical Study of Nonthermal Plasma-Assisted ZnO Coating of Cotton Fabric through Ultrasonic-Assisted Green Synthesis for Improved Self-Cleaning and Antimicrobial Properties.

Nonthermal plasma processing is a dry, environment-friendly and chemical-free method of improving the wettability, adhesion, self-cleaning and dying quality of fabrics without affecting their bulk properties. This study presents a green synthesis and coating method for the immobilization of nanoparticles of ZnO on the nonthermal plasma functionalized cotton fabric. The self-cleaning activity of ZnO-coated cotton was then optimized statistically. The ultraviolet protection and antimicrobial activity of the optimized and a control sample were also elaborated in this study. Psidium guajava Linn (guava) plant extract and zinc chloride were used in the ultrasonic biosynthesis of ZnO nanoparticles and concurrent immobilization over plasma functionalized cotton. Sodium hydroxide was used as a reaction accelerator. Statistical complete composite design (CCD) based on the amount of ZnCl2, NaOH and plasma exposure time was used to optimize the role of input parameters on the self-cleaning ability of the coated cotton. Methylene blue in water was used as a sample pollutant in the self-cleaning study. The ZnO-coated cotton showed notably high self-cleaning activity of 94% and a UV protection factor of 69.87. The antimicrobial activity against E. Coli and S. Aureus bacteria was also appreciably high compared to the control.

Preparing an adsorbent from the unused solid waste of Rosewater extraction for high efficient removal of Crystal Violet

The unused waste of Rosewater extraction has been used in this study for the synthesis of an adsorbent. The activation of the unused waste of Rosewater extraction was performed by ZnCl2 and the electric furnace. The effects of temperature and the amount of ZnCl2 on Crystal Violet (CV) removal were studied. The highest dye removal was obtained by 30 wt% ZnCl2 for one hour and heating at 600 °C. The synthesized adsorbent was characterized by scanning electron microscopy, X-ray diffraction technique, X-ray fluorescence spectrometer, and Fourier transform infrared spectroscopy and N2 adsorption/desorption isotherm. The studies showed the percentage of ZnO is high in the prepared adsorbent. The analyses showed the adsorbent has a higher volume of wide micropores and a small volume of mesopores with BET surface area 432.51 m2 g−1. The effects of temperature (25–40 °C), adsorbent dosage (0.5–2 g L−1), pH (2–11), time (0–320 min), and dye concentration (3–10 mg L−1) on adsorbent's ability for dye adsorption were studied. The fractal-like integrated kinetic model and Freundlich isotherm were the best kinetic and isotherm equations for CV adsorption on the synthesized adsorbent. These results show that the surface of the adsorbent is heterogeneous. The thermodynamic study showed that adsorption is spontaneous, and it is chemisorption. The adsorption performance of CV on the prepared adsorbent was compared with the commercial activated carbon. Comparing the adsorption capacities of the synthesized adsorbent (168.8 mg g−1), commercial activated carbon (108.22 mg g−1), and some other adsorbents for CV removal proved, it is a high efficient adsorbent. The importance of this study is providing a condition for the preparation of a low-cost and high efficient adsorbent from the unused waste of Rosewater extraction for water purification.

Testing the carbonization condition for high surface area preparation of activated carbon following type IV green alga Ulva lactuca

Activated carbon with high specific surface area has been produced from green alga Ulva lactuca by using zinc chloride (ZnCl2) solution as an activating agent under carbonization temperature ranged from 500 to 900 °C. The effects of carbonization temperatures, holding time, and amount of ZnCl2 followed by soaking in hydrochloric acid on the specific surface area, pore morphology, and mass yield of the prepared activated carbon were investigated. In this work, the activated carbon with high specific surface area was achieved using 1:2 (ZiCl2: Ulva lactuca) impregnation agent, 700 °C as activation temperature, 30 min as holding time, and soaking with 3.0 M hydrochloric acid as the optimum conditions. This condition produced an activated carbon with specific surface area (SBET) and micropore surface area (Smi) of 1486.3 and 1582.04 m2/g, respectively, with mean pore diameter (DP) of 2.39 nm. The results showed that the chemical activation by ZnCl2 is a useful technique for obtaining activated carbon from Ulva lactuca with desired pore size distributions and morphology at moderate activation temperatures.

Preparation of porous carbon nanofibers with remarkable microwave absorption performance through electrospinning

In this research, 1D porous carbon nanofibers (PCFs) were prepared by electrospinning and annealing process. The PCFs with excellent microwave absorption (MA) performance were prepared by a simple one-route method by mixing with different amount of ZnCl2 in the precursors. During the process of annealing, ZnCl2 can promote the formation of porous structures and ZnO or Zn complexes by gasifying at high temperature. The porous structures can enhance the multiple reflections and the ZnO or Zn complexes can enhance the dielectric loss. The obtained PCFs were characterized by SEM, TEM, XRD, Raman and XPS. The PCFs with 5 wt% ZnCl2 exhibit excellent microwave absorption properties with a minimum reflection loss (RLmin) of −51 dB at 9.1 GHz and the effective band under −10 dB ranges from 8 to 11 GHz with a width of 3 mm. It is believed that this method would be a facile approach for preparing porous carbon fibers as lightweight microwave absorption materials.

Synthesis of 5-Methyl-1,2,4-triazolo[1,5-a]pyrimidin-7(4H)-one in Supercritical Carbon Dioxide

5-Methyl-1,2,4-triazolo[1,5-a]pyrimidin-7(4H)-one, an intermediate product in the synthesis of the antiviral drug Triazid®, was obtained for the first time by condensation of 3H-1,2,4-triazol-5-amine with ethyl acetoacetate in the presence of a catalytic amount of ZnCl2 in supercritical carbon dioxide (200 bar) under solvent-free conditions. Depending on the temperature and reaction time, the conversion was 90%.

ZnCl2‐Catalyzed Aza‐Diels–Alder Reaction for the Synthesis of 1H‐Pyrazolo[3,4‐b]pyridine‐4,5‐dicarboxylate Derivatives

A new ZnCl2‐catalyzed aza‐Diels–Alder reaction was developed for the preparation of pyrazolo[3,4‐b]pyridine‐4,5‐dicarboxylates through the reaction of pyrazoylimines with acetylenedicarboxylic acid diethyl ester (diethyl but‐2‐ynedioate). Based on optimization studies and economic factors, the best amount of ZnCl2 was established to be 20 mol‐% relative to the azadiene. On the other hand, N,N‐diisopropylamidinyl N‐pyrazoyl imine was found to be the best azadiene substrate.

Amidolysis of Oxirane: Effect of Protein Type, Oils, and ZnCl2 on the Rheological Properties of Cross-Linked Protein and Oxirane

Amidolysis of oxirane group of epoxidized sesame, sunflower, and cottonseed oils was achieved by reaction with primary amide of millet and gluten proteins. Gluten is a coproduct of wheat starch industry and available commercially. Millet is a major part of the staple food of the semiarid region of the tropics. Gluten is a mixture of glutenins and gliadins rich in glutamine residues; however, millet is rich in glutamine and leucine. We have taken advantage of the available primary amide of glutamine for cross-linking with the oxirane of sunflower, sesame, and cottonseed oils under controlled conditions to give a resin of amidohydroxy of gluten and millet proteins. Cross-linking gave a resin with a wide range of textural properties. The texture of the resin was dependent on the source of the oxirane, the amide group, and the amount of the catalyst (ZnCl2). The thermal properties, textural, solubility, and rheological properties were determined as well as the reaction time. The data showed direct relationships between the ZnCl2, nature of oil, and protein type and the properties of the final resin. Consistently, the results pointed to similarity among the outcome of the reactions between sesame and sunflower oils. Depending on the amount of ZnCl2, the texture of the resin can range from viscose to rubbery. The reaction time was influenced by oxirane source, protein type, and catalyst and ranged from 30 min to 4 hr.

Solid-state chiral resolution mediated by stoichiometry: crystallizing etiracetam with ZnCl2.

Chiral resolution of racemic etiracetam was achieved via co-crystallization with ZnCl2. Depending on the amount of ZnCl2 either a stable racemic compound or a stable conglomerate can be obtained. Excess ZnCl2 triggers the quantitative conversion of the racemate into the conglomerate solid; this unprecedented behaviour was investigated through a racetam/ZnCl2/solvent phase diagram.

One-stage synthesis of condensed pyrimidines by reaction of substituted 3-(pyrimidin-5-yl)propanoic acids with ortho-diamines: Extension of limits

By condensation of 2-aryl-substituted pyrimidin-5-ylpropanoic acids with 1,2-ethanediamine and 1,2-benzenediamine in polyphosphoric acid new derivatives of heterocyclic systems were synthesized: imidazo- and benzo[4',5']imidazo[1',2':1,6]pyrido[2,3-d]pyrimidines. Unlike that the reaction of substituted 2-mercaptopyrimidin-5-ylpropanoic acid with 1,2-benzenediamine in polyphosphoric acid in the presence of equimolar amount of ZnCl2 proceeds by a tandem mechanism with the formation of 4-methyl-5,6-dihydrobenzo[4',5']imidazo[1',2':1,6]pyrido[2,3-d]pyrimidine-2-thiol and the corresponding disulfide.

Preparation of Zn(BH4)2 and diborane and hydrogen release properties of Zn(BH4)2+xMgH2 (x=1, 5, 10, and 15)

Zn(BH4)2 was prepared by milling ZnCl2 and NaBH4 in a planetary ball mill under Ar atmosphere, and Zn(BH4)2+xMgH2 (x=1, 5, 10, and 15) samples were prepared. Diborane (B2H6) and hydrogen release characteristics of the Zn(BH4)2 and Zn(BH4)2+xMgH2 samples were studied. The samples synthesized by milling ZnCl2 and NaBH4 contained Zn(BH4)2 and NaCl, together with small amounts of ZnCl2 and NaBH4. We designated these samples as Zn(BH4)2(+NaCl). The weight loss up to 400 °C of the Zn(BH4)2(+NaCl) sample synthesized by milling 4 h was 11.2 wt%. FT-IR analysis showed that Zn(BH4)2 was formed in the Zn(BH4)2(+NaCl) samples. MgH2 was also milled in a planetary ball mill, and mixed with the Zn(BH4)2(+NaCl) synthesized by milling for 4 h in a mortar and pestle. The weight loss up to 400 °C of Zn(BH4)2(+NaCl)+MgH2 was 8.2 wt%, corresponding to the weight % of diborane and hydrogen released from the Zn(BH4)2(+NaCl)+MgH2 sample, with respect to the sample weight. DTA results of Zn(BH4)2(+NaCl)+xMgH2 showed that the decomposition peak of Zn(BH4)2 was at about 61 °C, and that of MgH2 was at about 370-389 °C.

Hydrogen storage of Mg–Zn mixed metal borohydrides

On the basis of DFT results on the ideal amount of Zn required to dissolute into the α-phase of Mg(BH4)2 (space group P6122) and experimental results recently presented in the literature, mixtures of α-Mg(BH4)2 and ZnCl2 have been prepared by ball-milling, reactive milling and cryo-milling in Mg:Zn starting ratios of 1:0.33, 1:0.2 and 1:0.1. Samples have been characterized with different experimental techniques (PXD, TGA, TPD with RGA and desorption kinetics in a Sieverts apparatus). All the as-milled samples exhibited a H2 release beginning approximately at 125°C, indicating a significant decrease in the decomposition temperature compared to pure Mg(BH4)2. With the exception of the Mg(BH4)2−0.33ZnCl2 sample ball-milled under 1bar Ar for 3h that showed a small B2H6 release around 120°C, all samples are free of B2H6 emissions. Results from desorption kinetics at 195°C suggest a strong relation between the amount of ZnCl2 in the starting mixture and the weight loss.

Zinc incorporation capacity of whey protein nanoparticles prepared with desolvation with ethanol

Whey protein isolate (WPI) nanoparticles were prepared using ethanol desolvation, and their capacity to incorporate ZnCl2 was analysed. Desolvation was carried out at pH 9 and the volume of added ethanol was 0–3 times the volume of protein solution. The desolvated solutions were dispersed in acidified water (pH 3) immediately after desolvation. The size of the WPI nanoparticles increased with the volume ratio of ethanol:water used, as well as with the amount of ZnCl2. The nanoparticles showed high incorporation efficiencies, and remained stable after 30days of storage at 22°C. The amount of zinc incorporated in the WPI particle suspensions was within the range of daily zinc requirements for healthy adults.

Synthesis of Diphenyl Carbonate from Carbon Dioxide, Phenol, and Carbon Tetrachloride Catalysed by ZnCl2 Using Trifluoromethanesulfonic Acid as Functional Co-Catalyst

Diphenyl carbonate (DPC) was synthesised from carbon dioxide, phenol, and carbon tetrachloride catalysed by the Lewis acid ZnCl2 with the addition of co-catalyst. It was found that common bases are not effective co-catalysts for the production of DPC, and only slight enhancement in the catalytic activity of ZnCl2 was observed in the presence of inorganic additives such as inorganic carbonates and quaternary ammonium salts. Although poor conversion of phenol and yield of DPC were obtained using ZnCl2 or trifluoromethanesulfonic acid (CF3SO3H) as the sole catalyst, the catalytic activity of ZnCl2 was significantly improved by the addition of a catalytic amount of CF3SO3H. CF3SO3H has been proven to be an effective co-catalyst. The conversion of phenol and the yield of DPC were dependent on the amount of ZnCl2 and CF3SO3H, the reaction temperature, and the pressure of CO2. A possible reaction mechanism for the synthesis of DPC catalysed by the co-catalytic system including ZnCl2 and CF3SO3H was also proposed.

ChemInform Abstract: ZnCl2‐Catalyzed Hydrodefluorination of gem‐Difluoromethylene Derivatives with Lithium Aluminum Hydride.

AbstractA novel system for the process is developed.

Studies on the Optimisation of the Preparation Method and the Characterisation of Zinc Butyl Xanthate

Zinc butyl xanthate (Zn(bxt)2) was prepared using both AR-grade and commercial-grade n-butyl alcohol (n-BuOH), potassium hydroxide (KOH), carbon disulphide (CS2), and zinc chloride (ZnCl2). The effect of the order of mixing of the reactants on the reaction time and the yield of Zn(bxt)2 was studied. The effect of the amount of ZnCl2 used for precipitation on the yield of Zn(bxt)2 was also investigated. The irritating smell of Zn(bxt)2 could be reduced considerably by using commercial-grade reagents. The yield of Zn(bxt)2 could be increased and the reaction time reduced. The maximum yield was obtained when 1 mol% ZnCl2 was used. The Zn(bxt)2 obtained was characterised by means of Fourier transform IR spectroscopy (FTIR), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and proton magnetic resonance (1H NMR) spectroscopy.

Efficient Method of Synthesis of N,N′-Disubstituted Ureas/Thioureas by a Zinc Chloride Catalyzed Thermal Reaction

Symmetrically N,N′-disubstituted ureas/thioureas were synthesized by heating amines or phenyl hydrazine and urea/thiourea on a preheated hot plate at 80–85°C under solvent-free conditions in the presence of a catalytic amount of ZnCl2 as a catalyst. The protocol has the advantages of not using toxic phosgene and other hazardous substrates or organic solvents. Increased reaction rate, good yield, and a simple workup procedure are involved.

Influence of catalyst on the yields and properties of products from biomass liquefaction in subcritical water

In recent years, increasing attention has been focused on the liquefaction of biomass in subcritical water by researchers. The authors try to obtain bio-oil of high quality and high yields using straw as starting material. This process was affected by many factors such as different conditions of pressure, heating rate, reaction time and addition of catalyst. In this paper, the effects of the dosage and kinds of catalysts, respectively, on the yield and Higher Heating Value (HHV) of the bio-oil were investigated and the influence of the mixture of different catalysts was also studied. The effect of catalyst on liquefaction of straw was studied using a high pressure batch autoclave under the subcritical water (T = 573 K, P = 18 MPa, t = 5 min) and the bio-oil obtained was observed and analysed. It was found that addition of appropriate amount of ZnCl2 could increase the yield of the bio-oil to as high as 32.90%, and addition of appropriate amount of Na2S could obviously improve the HHV of the bio-oil to the maximum of 34,056 kJ/kg. When the two catalysts of ZnCl2 and Na2S were added in a certain proportion at the same time, both the yield and the HHV of the bio oil could reach their maximum of 33.85% and 34,428 kJ/kg, and the residue of the reaction reached its minimum. GC-MS technology was also adopted to make qualitative and quantitative analyses on bio-oil as to further confirm the bio-oil's components. The main components of the bio-oil were ketones, phenol substances and their derivatives.

Improvement of the Asymmetric Induction from Lactic Acid Derivatives Enhanced by ZnCl2

Lactic acid methyl ester, lactic acid ethyl ester, and (2S)‐ethyl‐2‐methoxy propanate were used as solvents for acetophenone reduction by boron hydrides. Moderate enantiomeric excess up to 60% was obtained in the presence of stoichiometric amounts of ZnCl2. There is evidence for an intermediate between the solvents, the Lewis acid and the ketone, as the prerequisite for chirality transfer. The importance of the Lewis acid is to strengthen interaction between solvent and educt compared to the hydroxy group.

Comparison of different Lewis acids supported on natural phosphate as new catalysts for chemoselective dithioacetalization of carbonyl compounds under solvent-free conditions

Various carbonyl compounds can be efficiently converted to their corresponding dithioacetals in the presence of catalytic amounts of ZnCl2, NiCl2 or CuCl2 supported on natural phosphate. The best catalytic activities were observed with the zinc catalysts. In addition, by employing these catalysts, highly chemoselective dithioacetalization of carbonyl compounds has been achieved.