Journal of Applied Research in Chemistry
Year:2020 | Volume:14 | Issue:1|Papers Count:13

In this study, the synthesis of Metal-organic frameworks UiO-66-NH2 and HKUST-1 were performed using the solvothermal method. Then, Acetaminophen, Amoxicillin, and Ibuprofen were loaded in UiO-66-NH2 and Ergotamine, Acetaminophen were loaded in HKUST-1 as pharmaceutical models. Subsequently, the performances of these two compounds were evaluated as carrier of these four drugs. Also, the crystalline structures of these nanoparticles were characterized by substrate spectroscopy, X-ray diffraction, and. thermogravimetric analysis. Finally, UV-vis spectroscopy was used to measure the release of the drugs. The results showed that ibuprofen, acetaminophen, and amoxicillin were loaded in UiO-66-NH2 at 1. 2, 0. 7 and 0. 5 mg, respectively, and their release rates during two days were 25, 28 and 43 %, respectively. Also, ergotamine and acetaminophen loaded in HKUST-1 were observed to be 1. 07 and 0. 98 mg, respectively, and their release rates were 35 and 43%, respectively.

The application of rechargeable lithium-air batteries in devices with capability of energy storage has been taken into consideration extensively. There are many methods to increase the performances of these batteries, such as using an appropriate catalyst and electrolyte. In the present research, Ppy/Co/Fe nanocatalyst was synthesized by using chemical precipitation and it was characterized using FT-IR, Raman, SEM, and XRD. The results indicated that the nanocatalyst with particle sizes of 35 nm has been synthesized successfully. To evaluate the effect of nanocatalyst, the battery was constructed and the experiments revealed that its power is very greater compared to the battery without nanocatalyst. Also, the battery containing nanocatalyst has more energy storage. The results of cyclic voltammetry indicated that due to the presence of PPy/Co/Fe nanocatalyst, the reversibility of cathode is increased significantly in comparison to the battery without nanocatalyst. The carbon black in the structure of nanocatalyst leads to increase the capacity of the battery because it improved the catalytic behavior of nanocatalyst. In was found that, in a usual cycle of charge/discharge process, the discharge process takes place longer time which is indication of long lifetime of the battery.

In this study, chemically modified MCM-41 mesoporous structure was used as adsorbent for removal of Rhodamine B and Yellow 13. In the step stage, chemical modification carried out using N-(2-aminoethyl(-3-aminopropyltrimethoxysilane and in the next stage with pyridine carbaldehyde. Therefore, surface of MCM-41 mesoporous has amino-and pyridine-groups that its performance as adsorbent has been increased. Removal proficiency was studied with parameters such as sorbent mass, pH, contact time, and temperature. Sorbent mass in 1-8 mg, pH in 2-10, contact time in 10-120 min, temperature in 25-65 º C variable. The results showed that as sorbent mass in 1-6 mg, contact time in 10-90 min, and temperature in 25-65 º C increased, removal of dyes increased in 60-100% in values. Optimal conditions were determined as sorbent mass in 5 mg, contact time in 90 min, temperature in 55 and 65 ° C, and pH value in 5 and 8 for Rhodamine B and Yellow 13, respectively. After determination of optimal conditions, its application was investigated on removal of Rhodamine B and Yellow 13 from pharmacy and textile wastes, respectively. The maximum removal values of Rhodamine B and Yellow 13 in wastes using modified MCM-41 were 97. 15 and 95. 55%, respectively.

In this research, for the first time zeolite 13X, as an environmentally benign sorbent, was used in the removal of calcium cations by flame photometer method. In order to improve the performance of the absorbent, different modifiers were used. Row and modified sorbents were characterized by Fourier transform infrared )FT-IR), X ray Diffraction )XRD), field emission scanning electron microscopy )FESEM) equipped with an energy dispersive X-ray spectroscopy )EDS(, Elemental mapping, and Brunauer– Emmett– Teller )BET( analysis. The result of different sorbents indicated that, zeolite 13X modified with NaOH )1M) and EDTA )0. 2 M), showed the best performance in the removal of calcium as high as 89. 74%. Moreover, the central composite design )CCD) defined under response surface methodology, was applied to investigate the combined influences of adsorption parameters consist of pH, contact time, concentrations of Calcium in solution, and amount of adsorbent. Investigation of experimental results using ANOVA analysis revealed that concentrations and amount of adsorbent were more effective variables than all of other parameters to calcium removal from aqueous solution. Also, adsorption behavior of Calcium was evaluated by the Langmuir and Freundlich isotherm models. For the adsorption of calcium, Langmuir adsorption model was the best model with R2 equal to 0. 9998. Hence, according to the results and high efficiency of sorbents for the removal of calcium, use of this technique and process is recommended for calcium removal from hard water.

In this study, electro-polymerization of zincon was performed on the graphite using cyclic voltammetry. According to the cyclic voltammetry results, the process began with the phenolic hydrogen oxidation, continued with the amine hydrogen oxidation, and ended with the release of carbon dioxide at higher potentials. Evaluation of the performance of the electrode before and after electro-polymerization indicates an increase in the surface area up to twice. The scanning electron microscopy images confirm the polymer formation on the surface of graphite. To optimize the electro-polymerization conditions, the parameters of number of cycles, scan rate, and monomer concentration optimized. The optimum valuses for number of cycles, scanning rate, and monomer concentration are 10, 25 mV / s and 0. 2 mmol / l, respectively.

Chlorinated hydrocarbons are one of the side-products of the petrochemical industry. With respect to the environmental problems caused by industrial wastes, a method of reducing damage to the environment is the use of these wastes as a fuel for the incinerator furnace. The main objective of this study was laboratory optimization of the chlorinated hydrocarbon waste incineration performance in the petrochemical industry to reduce and to prevent corrosion caused by hydrochloric acid and to reduce its production. Optimization parameters were percentage of excess air, furnace temperature, the amount of gas consumed, the amount of water entering the furnace, the amount of chlorinated hydrocarbons input as hydrocarbons with high boiling temperature (H. B), and hydrocarbons with low boiling temperature (L. B). Changes in the above parameters applied to optimize the concentration of measured output hydrochloric acid. Then, using QUALITEK software and Taguchi method, the values were optimized. The results showed that at the temperature of 1230 ° C, flow rate of hydrocarbons with a high boiling point of 880 kg/h, flow rate of hydrocarbons with a low boiling point of 250 kg/h, a water entering the furnace of 200 kg/h and an excess air of 3%, the acid concentration was 15. 8%. After the practical test in optimal conditions, the concentration of acid was 15. 2%. Hence, the output results of the software are in good agreement with the experimental results obtained in the industrial unit. Also, after optimization, the use of caustic and gas fuel decreased significantly.

In this study, mesoporous titanium dioxide nanoparticles were synthesized by sol-gel method. The effect of calcination temperature on structural, photocatalytic, and optical properties of nanoparticles was investigated. Tetrabutylorthotitanate )TBT( was used as a precursor of titanium and ethanol as a solvent. Differential thermal analysis )TG-DTA( for selecting the appropriate temperature range for calcination, phase analysis by X-ray diffraction )XRD(, BET analysis for the specific surface area and porosity of the nanoparticles, spectrophotometric analysis for the study of photocatalytic properties, and scanning electron microscopy structural characteristics including morphology and particle size were used. The results show that by increasing the temperature up to 550 ° C, anatase phase transformation into rutile is performed, and the presence of two crystalline phases improves photocatalytic properties. The band gap energy of titanium dioxide nanoparticles has decreased with increasing temperature, so that shifted from the ultraviolet range to the visible light range. The highest degradation percentage of ultraviolet radiation was obtained by sample with calcination temperature of 350 ° C )57. 33%( and was exposed to visible light with a calcination temperature of 550 ° C )55. 56%(. The results of adsorption analysis indicated the mesoporous structure with H4 and H2 type hysteresis loop for the samples prepared at 350 ° C and 550 ° C, respectively. The average pore diameters for the samples prepared at 350 ° C and 550 ° C were 1. 20 and 7. 99 nm, respectively. The TEM images indicated that the particle size of the samples prepared at 350 ° C and 550 ° C were 25-30 nm and 30-45 nm, respectively.

Sodium dioctyl sulfosuccinate is one of the diester anionic surfactant that has been developed as a drug and surfactant by an easy and economical synthetic method. This diester salt synthesized in the two stages. In the first step, under certain conditions, bis(2-ethyl hexyl) maleate is prepared by esterification reaction and in the next step, the salt of this diester is prepared by sulfonation. The usual method for esterification is to make use of the homogenous catalysts which is needed for the neutralization of the catalysts at the end of process. In this study, we used amberlyst heterogeneous catalysts that have mild and selective properties. In this paper, Amberlyst-15 was selected as a heterogeneous recyclable Brø nsted solid acid for this synthesis both in the esterification of maleic anhydride and sulfonation of dioctyl maleate ester. This catalyst is easily recyclable and can be used for at least 13 consecutive steps without significantly reducing catalytic activity.

Nowadays, tissue engineering is known as one of the effective treatments to repair soft and hard tissues; although, the design of the substrates that mimic the cell growth pattern and mechanobiological function of tissue is a great challenge. In the present study, to evaluate the role of natural and synthetic polymers combination in mimicking biological environment, the porous scaffolds of PEPC )PEG/PCL(, and PCP )PEG/Chitosan/PCL( were designed by the freeze-dried method. Then, the physicochemical, mechanical and biological properties of the mentioned scaffolds were evaluated and compared with those of designed scaffolds )Chitosan, PEG, PCL(. The results showed that the combination of polymers )natural/synthetic( plays a major role in the formation of micro-porous media and extracellular matrix-like elasticity. So that, the PCP hybrid scaffold provided a higher porosity )with lower pores diameter( and elastic modulus of soft tissue-like )5. 11 MPa(, compared to PEPC composite scaffold. Moreover, the presence of chitosan in PCP scaffold led to an increase in the swelling, the control of degradation rate, and improvement of cell proliferation (96%) as compared to other groups. Therefore, it seems that PCP hybrid scaffold can play an important role in tissue regeneration via mimicking morphology and mechanobiological behaviors of soft tissues such as skin, ligament, endothelium, and blood vessels.

In this study, polyaniline was formed by voltammetric cycles in an acidic environment on a glassy carbon electrode surface. Subsequently, nickel ions were placed on the polyaniline surface by immersing the electrode in a nickel solution. By applying voltammetric cycles in the range of 0 to 1 volt, nickel was formed on the surface of polyaniline. Then, by using cyclic voltammetric and chronoamperometry techniques, electrocatalytic properties of the modified electrode were studied for methanol oxidation. In addition, the performance of the polyaniline/nickel electrode was evaluated using the Density Functional Theory method. The results of the cyclic voltammetric test showed that with increasing the scan rate, the current density of anodic peak increased, and also the chronoamperometry test showed that the polyaniline/nickel had a good stability over time. In a computational study, using the energy of methanol absorption on three different positions of polyaniline/nickel, it was determined that the best position for methanol adsorption was the position of M1, which had the least adsorption energy and the most stable state. The results of the reaction path analysis showed that the best pathway with the lowest activation energy was the separation of the first hydrogen atom from the oxygen in the methanol.

Due to the importance of coumarin derivatives and specially pyrano coumarins, as well as their different chemical and biological properties, we synthesized pyrano [2, 3-h] coumarins by using reactions of 5, 7-dihydroxy-4-methylcoumarin, aryl aldehydes, and malononitrile in the presence of Ti– Al/Al2 O3 nanocomposite in methanol. The structures of the products were identified by FIIR, 1 H-NMR, and 13 C-NMR spectroscopy. The excellent yields, simplicity, easy work-up and short reaction times are the most significant advantages of this method. Some antibacterial activities were evaluated via the disk diffusion method and the results showed that 8-amino-5-hydroxy-4-methyl-2-oxo-10-phenyl-2, 10-dihydropyrano[2, 3-f] chromene-9-carbonitrile (7) has significant pharmaceutical activities as antibacterial reagent comparing to Staphylococcus aureus and Escherichia coli.

The Titanium dioxide nanolayers were synthesized at constant potentials on stainless steel substrate. The prepared nanolayers had different thicknesses, due to the variation of applied potential. The physical properties of fabricated TiO2 nanolayers were characterized by SEM, EDS, XRD, and Ellipsometery spectroscopy methods. The corrosion resistance of coated stainless steel were studied using electrochemical voltammetry )Tofel plot). The obtained results showed that the optimized TiO2 nanolayer had improved the stainless steel corrosion resistance more than 3 times compared to the bare stainless steel at salty ambient. In addition, the electrochemical results displayed ultra-violet light irradiation effect on the corrosion properties of the prepared layers. The UV-light caused the corrosion potential shifted to the more negative voltage.

In order to develop efficient and low-cost non-metallic electrocatalysts for oxygen reduction reaction, in this study, a combination of carbon-based layered double hydroxide has been utilized. Thus, graphene oxide (GO) firstly was reduced and functionalized with nitrogen and sulfur atoms (N, S-rGO). Then, aluminum and zinc layered double hydroxide (ZnAl-LDH) were deposited on graphene oxide by use of the hydrothermal method. The structure, composition, morphology, and electrocatalytic activity of ZnAl-LDH/N, S-rGO compound were investigated in oxygen reduction reaction )ORR( by employing physical and electrochemical analyses. The results were compared with the electrocatalytic performance of commercial 20% Pt/C catalyst in the oxygen reduction reaction. According to the results of the physical experiments, in addition to the uniformity and the correct depositing of the synthesized electrocatalyst, the particle size also reached the nanometer range. According to the electrochemical results, the ZnAl-LDH/N, SrGO electrocatalyst had significant electrochemical activity and its function was very close to the commercial Pt/C 20% catalyst. These results indicate a good synergistic effect between N, S-rGO, and ZnAl-LDH. The onset of this sample was-0. 01 V. The electrocatalytic stability was favorable in the alkaline medium. It can be concluded that hybrids of layered double hydroxide )LDHs( and carbon bases improve the electrical conductivity, electrocatalytic activity, active surface, and stability for the oxygen reduction reaction.