Pub Date : 2020-12-01DOI: 10.22036/PCR.2020.217921.1727
Fatemeh Tabesh, H. Sabzyan
Precursor spectroelectrochemical behavior of guanine is investigated based on UV-Vis absorption and fluorescence, and IR and Raman spectra of guanine and its radical cation in the presence of a model electrode, computed using (TD)M06/6-31++G** method. Effects of electrode potential ( ), molecule-electrode distance (d) and molecular orientations (θ) on this behavior are investigated. Results indicate that application of electric potential causes changes in the molecular structure and distribution of charge and spin densities, which consequently changes the electronic and vibrational characteristics of the system. Also, perturbation due to the applied electric potential, changes both the intensities and frequencies of the vibrational bands of the studied species. The absorption wavelength, and the peak intensity and width of the electronic spectra of guanine and its radical cation also show sensitivity to the applied electrode potential. Presence of solvent both as electrostatic medium and as explicit solvent (molecules) have significant effects on the spectroelectrochemical properties of guanine, and change the chemical activity of guanine radical cation formed by the electrode reaction. Furthermore, population and orbital analyses show that for all orientations, application of the electric potential by the electrode increases contribution of the inter-molecular (guanine→water) charge density displacement to the UV-Vis transitions.
{"title":"Computational Study of the Precursor Spectroelectrochemistry of Guanine","authors":"Fatemeh Tabesh, H. Sabzyan","doi":"10.22036/PCR.2020.217921.1727","DOIUrl":"https://doi.org/10.22036/PCR.2020.217921.1727","url":null,"abstract":"Precursor spectroelectrochemical behavior of guanine is investigated based on UV-Vis absorption and fluorescence, and IR and Raman spectra of guanine and its radical cation in the presence of a model electrode, computed using (TD)M06/6-31++G** method. Effects of electrode potential ( ), molecule-electrode distance (d) and molecular orientations (θ) on this behavior are investigated. Results indicate that application of electric potential causes changes in the molecular structure and distribution of charge and spin densities, which consequently changes the electronic and vibrational characteristics of the system. Also, perturbation due to the applied electric potential, changes both the intensities and frequencies of the vibrational bands of the studied species. The absorption wavelength, and the peak intensity and width of the electronic spectra of guanine and its radical cation also show sensitivity to the applied electrode potential. Presence of solvent both as electrostatic medium and as explicit solvent (molecules) have significant effects on the spectroelectrochemical properties of guanine, and change the chemical activity of guanine radical cation formed by the electrode reaction. Furthermore, population and orbital analyses show that for all orientations, application of the electric potential by the electrode increases contribution of the inter-molecular (guanine→water) charge density displacement to the UV-Vis transitions.","PeriodicalId":20084,"journal":{"name":"Physical Chemistry Research","volume":"8 1","pages":"719-735"},"PeriodicalIF":1.2,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45906031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.22036/PCR.2020.227546.1763
Sandip S. Pathade, Bapusonu Jagdale
In the present work 4,6-bis(4-fluorophenyl)-5,6-dihydropyrimidin-2(1H)-one was synthesized by condensation of (2E)-1,3-bis(4-fluorophenyl)prop-2-en-1-one with urea in basic medium. The synthesized compound was characterized by using FT-IR and 1H NMR spectroscopic techniques. To determine the molecular structure of synthesized molecule some quantum chemical calculations were carried out by density functional theory (DFT) with employing B3LYP level at 6-311++G(d,p) basis set in gas phase, water and CCl4 solvents by using Gaussian-03 package. The optimized geometrical parameters, thermochemical parameters and global reactivity descriptors have been computed. The frontier molecular orbital (FMO) and molecular electrostatic potential (MEP) analysis also performed to explore the reactivity of title molecule at same level of theory. The vibrational frequencies of title molecule were analysed and compared with the corresponding experimental data. The results show fair correlation between the calculated frequencies in gas phase and experimental frequencies. The effect of water and CCl4 solvents on vibrational frequencies and global chemical reactivity descriptors were also examined. Obtained results show that polar solvent water decreased the carbonyl stretching frequency largely while other frequencies in water and CCl4 are slightly different than gas phase. There is no significant change by solvents were observed on energy gap (∆E) and global reactivity descriptors of studied molecule.
{"title":"Experimental and Computational Investigations on the Molecular Structure, Vibrational Spectra, Electronic Properties, FMO and MEP Analyses of 4,6-Bis(4-Fluorophenyl)-5,6-dihydropyrimidin-2(1H)-one: A DFT Insight","authors":"Sandip S. Pathade, Bapusonu Jagdale","doi":"10.22036/PCR.2020.227546.1763","DOIUrl":"https://doi.org/10.22036/PCR.2020.227546.1763","url":null,"abstract":"In the present work 4,6-bis(4-fluorophenyl)-5,6-dihydropyrimidin-2(1H)-one was synthesized by condensation of (2E)-1,3-bis(4-fluorophenyl)prop-2-en-1-one with urea in basic medium. The synthesized compound was characterized by using FT-IR and 1H NMR spectroscopic techniques. To determine the molecular structure of synthesized molecule some quantum chemical calculations were carried out by density functional theory (DFT) with employing B3LYP level at 6-311++G(d,p) basis set in gas phase, water and CCl4 solvents by using Gaussian-03 package. The optimized geometrical parameters, thermochemical parameters and global reactivity descriptors have been computed. The frontier molecular orbital (FMO) and molecular electrostatic potential (MEP) analysis also performed to explore the reactivity of title molecule at same level of theory. The vibrational frequencies of title molecule were analysed and compared with the corresponding experimental data. The results show fair correlation between the calculated frequencies in gas phase and experimental frequencies. The effect of water and CCl4 solvents on vibrational frequencies and global chemical reactivity descriptors were also examined. Obtained results show that polar solvent water decreased the carbonyl stretching frequency largely while other frequencies in water and CCl4 are slightly different than gas phase. There is no significant change by solvents were observed on energy gap (∆E) and global reactivity descriptors of studied molecule.","PeriodicalId":20084,"journal":{"name":"Physical Chemistry Research","volume":"8 1","pages":"671-687"},"PeriodicalIF":1.2,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42428679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.22036/PCR.2020.227164.1757
Narmin Noorani, Abbas Mehrdad
To improve the gas separation performance of poly (vinyl chloride) membrane, 1-vinyl imidazole was grafted onto the poly (vinyl chloride) by free radical graft copolymerization. The synthesized of the graft copolymer was characterized by the elemental analyzer technique (CHN). The prepared membrane morphology was surveyed by Scanning Electron Microscope (SEM). The properties of thermodynamics of CO2 adsorption were investigated at various temperatures and pressures by quartz crystal microbalance (QCM). The experimental data were correlated by the dual-mode model. The calculated thermodynamics parameters of CO2 adsorption display that CO2 adsorption has the nature of exothermic. Also, methane and carbon dioxide gas permeability was measured. The effects of variation of temperature and feed pressure on the membrane performance were surveyed. The increment in temperature cause to decrement the selectivity of membrane for carbon dioxide/methane gases; whiles, the selectivity of the membrane was incremented by incrementing feed pressure. The outcomes indicate that the permeation selectivity of the grafted copolymer is more than those of the poly (vinyl chloride) membrane for CO2/CH4 gasses. Moreover, Density functional theory (DFT) computes corroborated that the interaction energy of grafted copolymer with CO2 is stronger than this of CH4.
{"title":"Modification of PVC with 1-Vinylimidazole for CO2/CH4 Separation: Sorption, Permeation and DFT Studies","authors":"Narmin Noorani, Abbas Mehrdad","doi":"10.22036/PCR.2020.227164.1757","DOIUrl":"https://doi.org/10.22036/PCR.2020.227164.1757","url":null,"abstract":"To improve the gas separation performance of poly (vinyl chloride) membrane, 1-vinyl imidazole was grafted onto the poly (vinyl chloride) by free radical graft copolymerization. The synthesized of the graft copolymer was characterized by the elemental analyzer technique (CHN). The prepared membrane morphology was surveyed by Scanning Electron Microscope (SEM). The properties of thermodynamics of CO2 adsorption were investigated at various temperatures and pressures by quartz crystal microbalance (QCM). The experimental data were correlated by the dual-mode model. The calculated thermodynamics parameters of CO2 adsorption display that CO2 adsorption has the nature of exothermic. Also, methane and carbon dioxide gas permeability was measured. The effects of variation of temperature and feed pressure on the membrane performance were surveyed. The increment in temperature cause to decrement the selectivity of membrane for carbon dioxide/methane gases; whiles, the selectivity of the membrane was incremented by incrementing feed pressure. The outcomes indicate that the permeation selectivity of the grafted copolymer is more than those of the poly (vinyl chloride) membrane for CO2/CH4 gasses. Moreover, Density functional theory (DFT) computes corroborated that the interaction energy of grafted copolymer with CO2 is stronger than this of CH4.","PeriodicalId":20084,"journal":{"name":"Physical Chemistry Research","volume":"8 1","pages":"689-703"},"PeriodicalIF":1.2,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47933393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.22036/PCR.2020.221177.1737
M. Abdul-Hammed, Ebhohimen Ehizuelen Israel, I. Abdulwahab, Abdulrafiu Olakunle Jaji
Oils of vegetable origin are of great importance in food, soap, and cosmetic industries and they may also be used as lubricants and raw materials for biodiesel production depending on their viscosity and thermal stability. This work provides insight into the fatty acid components, physicochemical properties and thermal stability of some refined vegetable oils. The Saponification values, peroxide values, acid values, iodine values and refractive index of these oils range from 185.38 to 209.26 mg/g KOH, 2.00 to 37.00 meq O2/ kg, 2.50 to 5.50 mg KOH/ g, 31.09 to 89.46 g / 100g and 1.441 to 1.488 respectively The activation energies obtained from Arrhenius-type equation range from 11.32 to 3.85 kJ mol-1, while the enthalpy (∆H҂) and entropy (∆S҂) of activation obtained from Eyring-type equation range from 6.852 to 14.317 kJ mol-1 and -31.85 to -29.06 J mol-1 K-1 respectively. The Gibbs free energy of activation (∆G҂) ranges from 15.51 to 23.81 k J mol-1. The Pw oil brand has the highest thermal stability and resistance to shear stress due to its high activation energy and a low degree of unsaturation. The heat was absorbed during the process, the reaction mechanism was associative and the entire process was non-spontaneous.
植物油在食品、肥皂和化妆品工业中非常重要，根据其粘度和热稳定性，它们也可以用作润滑油和生产生物柴油的原料。这项工作深入了解了一些精制植物油的脂肪酸成分、理化性质和热稳定性。这些油的皂化值、过氧化值、酸值、碘值和折射率分别为185.38至209.26mg/gKOH、2.00至37.00meq O2/kg、2.50至5.50mgKOH/g、31.09至89.46g/100g和1.441至1.488，由Eyring型方程得到的活化焓（∆H҂）和活化熵（∆S 1154）分别为6.852～14.317 kJ mol-1和-31.85～-29.06 kJ mol-1K-1。活化的吉布斯自由能（∆G҂）范围为15.51至23.81 k J mol-1。Pw油品牌由于其高活化能和低不饱和度而具有最高的热稳定性和抗剪应力性。在这个过程中热量被吸收，反应机制是关联的，整个过程是非自发的。
{"title":"Viscosity-Temperature Stability, Chemical Characterization, and Fatty Acid Profiles of some Brands of Refined Vegetable Oil","authors":"M. Abdul-Hammed, Ebhohimen Ehizuelen Israel, I. Abdulwahab, Abdulrafiu Olakunle Jaji","doi":"10.22036/PCR.2020.221177.1737","DOIUrl":"https://doi.org/10.22036/PCR.2020.221177.1737","url":null,"abstract":"Oils of vegetable origin are of great importance in food, soap, and cosmetic industries and they may also be used as lubricants and raw materials for biodiesel production depending on their viscosity and thermal stability. This work provides insight into the fatty acid components, physicochemical properties and thermal stability of some refined vegetable oils. The Saponification values, peroxide values, acid values, iodine values and refractive index of these oils range from 185.38 to 209.26 mg/g KOH, 2.00 to 37.00 meq O2/ kg, 2.50 to 5.50 mg KOH/ g, 31.09 to 89.46 g / 100g and 1.441 to 1.488 respectively The activation energies obtained from Arrhenius-type equation range from 11.32 to 3.85 kJ mol-1, while the enthalpy (∆H҂) and entropy (∆S҂) of activation obtained from Eyring-type equation range from 6.852 to 14.317 kJ mol-1 and -31.85 to -29.06 J mol-1 K-1 respectively. The Gibbs free energy of activation (∆G҂) ranges from 15.51 to 23.81 k J mol-1. The Pw oil brand has the highest thermal stability and resistance to shear stress due to its high activation energy and a low degree of unsaturation. The heat was absorbed during the process, the reaction mechanism was associative and the entire process was non-spontaneous.","PeriodicalId":20084,"journal":{"name":"Physical Chemistry Research","volume":"8 1","pages":"417-427"},"PeriodicalIF":1.2,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46901157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.22036/PCR.2020.222456.1740
B. Ghalami-Choobar, Tayyebe Nosrati Fallahkar
In this work, we determined thermophysical properties such as electrical conductivity and refractive index for 1-propyl-3-methylimidazolium bromide, [PrMIm]Br in ternary mixtures of [PrMIm]Br + ethylene carbonate + water at T = (298.2, 308.2 and 318.2) K and 0.1MPa. Conductometric measurements were carried out for [PrMIm]Br ionic liquid in ethylene carbonate + water solvent mixture in various composition 10, 20 and 30 mass% of ethylene carbonate (EC) in the ionic strength ranging from 0.0029 to 0.2500 mol.kg-1. These data were treated by Fuoss-Onsager equation, and the values of limiting molar conductivity ( ) and ion association constant (KA) were obtained. These results used to calculate the Walden product ( ) and the corresponding standard thermodynamic functions of ion association process including Gibbs free energy ( ), enthalpy ( ) and entropy ( ) for the investigated system. In addition, refractive indices were measured for the binary and ternary [PrMIm]Br + water + EC mixtures at T = (298.2, 308.2 and 318.2) K. The refractive index deviations (ΔnD) were calculated and the binary and ternary data of ΔnD were correlated using Redlich-Kister and the Cibulka equations, respectively. Also, the measured refractive indices were compared to the calculated values using some mixing rules.
{"title":"Conductometric and Refractometric Studies of 1-Propyl-3-methylimidazolium Bromide Ionic Liquid in Water + Ethylene Carbonate Mixtures at T = (298.2, 308.2 and 318.2) K","authors":"B. Ghalami-Choobar, Tayyebe Nosrati Fallahkar","doi":"10.22036/PCR.2020.222456.1740","DOIUrl":"https://doi.org/10.22036/PCR.2020.222456.1740","url":null,"abstract":"In this work, we determined thermophysical properties such as electrical conductivity and refractive index for 1-propyl-3-methylimidazolium bromide, [PrMIm]Br in ternary mixtures of [PrMIm]Br + ethylene carbonate + water at T = (298.2, 308.2 and 318.2) K and 0.1MPa. Conductometric measurements were carried out for [PrMIm]Br ionic liquid in ethylene carbonate + water solvent mixture in various composition 10, 20 and 30 mass% of ethylene carbonate (EC) in the ionic strength ranging from 0.0029 to 0.2500 mol.kg-1. These data were treated by Fuoss-Onsager equation, and the values of limiting molar conductivity ( ) and ion association constant (KA) were obtained. These results used to calculate the Walden product ( ) and the corresponding standard thermodynamic functions of ion association process including Gibbs free energy ( ), enthalpy ( ) and entropy ( ) for the investigated system. In addition, refractive indices were measured for the binary and ternary [PrMIm]Br + water + EC mixtures at T = (298.2, 308.2 and 318.2) K. The refractive index deviations (ΔnD) were calculated and the binary and ternary data of ΔnD were correlated using Redlich-Kister and the Cibulka equations, respectively. Also, the measured refractive indices were compared to the calculated values using some mixing rules.","PeriodicalId":20084,"journal":{"name":"Physical Chemistry Research","volume":"8 1","pages":"429-455"},"PeriodicalIF":1.2,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44731548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.22036/PCR.2020.211346.1707
Freidoon Esmaelizadeh, F. Zarei, S. M. Mousavi, G. Vakili-Nezhaad
Application of deep eutectic solvents in industrial chemical processes are improved over time in last decades. In this work, vapor pressures of 13 classes of DESs (DES 1-13) based on 5 salts and 7 hydrogen bond donors with various combinations of molar ratio were used between 343-393 K. The vapor pressure of the pure and aqueous solutions of DESs was calculated by different equations of state, which are based on “φ-φ” and "γ-φ" approachs. Additionally, Voutsas and Wagner models as corresponding-state models were modified to predict the vapor pressure of the pure and aqueous solutions of DESs. The total average absolute relative deviations of the Modified-Voutsas and Modified-Wagner models for the vapor pressure calculation of the pure and aqueous solutions of DESs were 7.03, 9.08 % and 5.47, 7.15 %, respectively. Moreover, the validity of vapor pressure calculation using the two modified models was checked with the aid of a linear equation for the average specific heat capacity of different DESs (23 classes of DESs) between 278.15-353.15 K. Results showed that the total average absolute relative deviations of the specific heat capacity of DESs using the Modified-Voutsas and Modified-Wagner models from the experimental data were 4.128 and 4.056 %, respectively.
{"title":"Prediction of DES’ Vapor Pressure Using a New Corresponding State Model","authors":"Freidoon Esmaelizadeh, F. Zarei, S. M. Mousavi, G. Vakili-Nezhaad","doi":"10.22036/PCR.2020.211346.1707","DOIUrl":"https://doi.org/10.22036/PCR.2020.211346.1707","url":null,"abstract":"Application of deep eutectic solvents in industrial chemical processes are improved over time in last decades. In this work, vapor pressures of 13 classes of DESs (DES 1-13) based on 5 salts and 7 hydrogen bond donors with various combinations of molar ratio were used between 343-393 K. The vapor pressure of the pure and aqueous solutions of DESs was calculated by different equations of state, which are based on “φ-φ” and \"γ-φ\" approachs. Additionally, Voutsas and Wagner models as corresponding-state models were modified to predict the vapor pressure of the pure and aqueous solutions of DESs. The total average absolute relative deviations of the Modified-Voutsas and Modified-Wagner models for the vapor pressure calculation of the pure and aqueous solutions of DESs were 7.03, 9.08 % and 5.47, 7.15 %, respectively. Moreover, the validity of vapor pressure calculation using the two modified models was checked with the aid of a linear equation for the average specific heat capacity of different DESs (23 classes of DESs) between 278.15-353.15 K. Results showed that the total average absolute relative deviations of the specific heat capacity of DESs using the Modified-Voutsas and Modified-Wagner models from the experimental data were 4.128 and 4.056 %, respectively.","PeriodicalId":20084,"journal":{"name":"Physical Chemistry Research","volume":"8 1","pages":"471-496"},"PeriodicalIF":1.2,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41860826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.22036/PCR.2020.225170.1751
I. Loulidi, F. Boukhlifi, M. Ouchabi, A. Amar, Maria Jabri, Abderahim Kali, F. Aziz
This work examines the possibility of removing the crystal violet (a cationic dye), used in the dyeing of cotton, wood, and silk, onto untreated coffee waste. The influence of various experimental parameters on the adsorption of crystal violet has been analysed: pH, adsorbent dose and initial dye concentration. Optimum adsorption of crystal violet took place at pH 6 and at lower temperatures. Further, the adsorbent was characterised by Fourier Transform Infrared Spectroscopy (FTIR). FTIR analysis revealed the presence of several functional groups that are responsible for the adsorption process. Adsorption equilibrium follows Langmuir’s model with maximum retention of 63.3 mg/g. The kinetics of the crystal violet adsorption were studied using the pseudo-first order and pseudo-second order equations. Adsorption of the dye can be described by pseudo-second order kinetics, reaching the equilibrium at 40 min. The value of the activation energy shows that adsorption is physisorption. Weber-Morris model indicates that this adsorption occurs in two steps. Thermodynamic parameters suggest that the adsorption is spontaneous and exothermic.
{"title":"Kinetic, Isotherm and Mechanism Investigations of the Removal of Basic Violet 3 from Water by Raw Spent Coffee Grounds","authors":"I. Loulidi, F. Boukhlifi, M. Ouchabi, A. Amar, Maria Jabri, Abderahim Kali, F. Aziz","doi":"10.22036/PCR.2020.225170.1751","DOIUrl":"https://doi.org/10.22036/PCR.2020.225170.1751","url":null,"abstract":"This work examines the possibility of removing the crystal violet (a cationic dye), used in the dyeing of cotton, wood, and silk, onto untreated coffee waste. The influence of various experimental parameters on the adsorption of crystal violet has been analysed: pH, adsorbent dose and initial dye concentration. Optimum adsorption of crystal violet took place at pH 6 and at lower temperatures. Further, the adsorbent was characterised by Fourier Transform Infrared Spectroscopy (FTIR). FTIR analysis revealed the presence of several functional groups that are responsible for the adsorption process. Adsorption equilibrium follows Langmuir’s model with maximum retention of 63.3 mg/g. The kinetics of the crystal violet adsorption were studied using the pseudo-first order and pseudo-second order equations. Adsorption of the dye can be described by pseudo-second order kinetics, reaching the equilibrium at 40 min. The value of the activation energy shows that adsorption is physisorption. Weber-Morris model indicates that this adsorption occurs in two steps. Thermodynamic parameters suggest that the adsorption is spontaneous and exothermic.","PeriodicalId":20084,"journal":{"name":"Physical Chemistry Research","volume":"8 1","pages":"569-584"},"PeriodicalIF":1.2,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43492495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.22036/PCR.2020.213588.1714
M. Sameti, H. Zanganeh
In the present study, the capability of the pristine and P-doped Al12N12 nanocage to deliver and detect of 5-Fluorouracil (5-FU) anticancer drug are investigated using the density functional theory (DFT) at the cam-B3LYP/6-31G(d, P) level of theory. The adsorption energy, thermodynamic parameters, natural bond orbital (NBO), atom in molecule theory (AIM), quantum parameters, reduced density gradient (RDG) and UV-visible spectrum for all selected models are calculated and results are analyzed. The values of adsorption energy (Eads) and thermodynamic parameters (ΔG and ΔH) for 5-FU@Al12N12 and 5-FU@Al12N11P complexes are negative and obtained results reveal that all adsorption processes are spontaneous and suitable to make a delivery of drug. The ΔΔG(sol) values of the all studied systems in the presence of water and ethanol solvent are positive and this property is favourable to shooting drug in biological system. The AIM, RDG, NBO calculated results indicate that the interaction between 5-FU drug and Al12N12 nanocage is weak covalent or strong electrostatic type. The bandgap energy of the 5-FU/Al12N12 nanocage complex alters slightly from original values, and so the pristine and P doped Al12N12 nanocage is not an excellent candidate for making a sensitive sensor for the 5-FU drug.
{"title":"TD-DFT, NBO, AIM, RDG and Thermodynamic Studies of Interactions of 5-Fluorouracil Drug with Pristine and P-doped Al12N12 Nanocage","authors":"M. Sameti, H. Zanganeh","doi":"10.22036/PCR.2020.213588.1714","DOIUrl":"https://doi.org/10.22036/PCR.2020.213588.1714","url":null,"abstract":"In the present study, the capability of the pristine and P-doped Al12N12 nanocage to deliver and detect of 5-Fluorouracil (5-FU) anticancer drug are investigated using the density functional theory (DFT) at the cam-B3LYP/6-31G(d, P) level of theory. The adsorption energy, thermodynamic parameters, natural bond orbital (NBO), atom in molecule theory (AIM), quantum parameters, reduced density gradient (RDG) and UV-visible spectrum for all selected models are calculated and results are analyzed. The values of adsorption energy (Eads) and thermodynamic parameters (ΔG and ΔH) for 5-FU@Al12N12 and 5-FU@Al12N11P complexes are negative and obtained results reveal that all adsorption processes are spontaneous and suitable to make a delivery of drug. The ΔΔG(sol) values of the all studied systems in the presence of water and ethanol solvent are positive and this property is favourable to shooting drug in biological system. The AIM, RDG, NBO calculated results indicate that the interaction between 5-FU drug and Al12N12 nanocage is weak covalent or strong electrostatic type. The bandgap energy of the 5-FU/Al12N12 nanocage complex alters slightly from original values, and so the pristine and P doped Al12N12 nanocage is not an excellent candidate for making a sensitive sensor for the 5-FU drug.","PeriodicalId":20084,"journal":{"name":"Physical Chemistry Research","volume":"8 1","pages":"511-527"},"PeriodicalIF":1.2,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47823724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.22036/PCR.2020.217825.1725
J. Amoko, O. Akinyele, O. Oyeneyin, Dare Olayanju, C. Aboluwoye
Corrosion of metal surfaces amongst other problems is one major disaster militating against proper functioning of the oil and gas and other manufacturing industries. To therefore lessen the risk, organic corrosion inhibitors have been applied to lessen the rate of corrosion and its effects. However, materials with optimal properties, better than content that allow corrosion are used for this empirical research. (E)-4-hydroxy-3-(2,4,6-tribromophenyl)diazenyl)benzaldehyde was synthesized and elucidated via FTIR, UV/Vis and NMR (1H and 13C) spectroscopy. Weight loss and potentiodynamic polarization methods were understudy to determine the rate of corrosion (Cr) and percentage inhibition efficiency (%IE). The mechanism of adsorption agrees with the Langmuir adsorption isotherm. The surface morphology of the mild steel was determined using the SEM in the bi-condition of the presence and absence of inhibitor. Inhibition efficiency (IE) was varied with concentration and temperature. The results revealed that IE increased with high concentration of the inhibitor but reduced while the temperature was increased. The SEM revealed the formation of protective layer of the attachment of the inhibitor to the metal surface. The results from the experiments agreed well with those obtained from DFT methods. AD3 could therefore be used as an anticorrosive agent in the petroleum industry.
{"title":"Experimental and Theoretical Investigation of Corrosion Inhibitive Potentials of (E)-4-hydroxy-3-[(2,4,6-tribromophenyl)diazenyl]benzaldehyde on Mild Steel in Acidic Media","authors":"J. Amoko, O. Akinyele, O. Oyeneyin, Dare Olayanju, C. Aboluwoye","doi":"10.22036/PCR.2020.217825.1725","DOIUrl":"https://doi.org/10.22036/PCR.2020.217825.1725","url":null,"abstract":"Corrosion of metal surfaces amongst other problems is one major disaster militating against proper functioning of the oil and gas and other manufacturing industries. To therefore lessen the risk, organic corrosion inhibitors have been applied to lessen the rate of corrosion and its effects. However, materials with optimal properties, better than content that allow corrosion are used for this empirical research. (E)-4-hydroxy-3-(2,4,6-tribromophenyl)diazenyl)benzaldehyde was synthesized and elucidated via FTIR, UV/Vis and NMR (1H and 13C) spectroscopy. Weight loss and potentiodynamic polarization methods were understudy to determine the rate of corrosion (Cr) and percentage inhibition efficiency (%IE). The mechanism of adsorption agrees with the Langmuir adsorption isotherm. The surface morphology of the mild steel was determined using the SEM in the bi-condition of the presence and absence of inhibitor. Inhibition efficiency (IE) was varied with concentration and temperature. The results revealed that IE increased with high concentration of the inhibitor but reduced while the temperature was increased. The SEM revealed the formation of protective layer of the attachment of the inhibitor to the metal surface. The results from the experiments agreed well with those obtained from DFT methods. AD3 could therefore be used as an anticorrosive agent in the petroleum industry.","PeriodicalId":20084,"journal":{"name":"Physical Chemistry Research","volume":"8 1","pages":"399-416"},"PeriodicalIF":1.2,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45783712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.22036/PCR.2020.224503.1746
S. Shekarsaraee, A. Gilani, M. Pir
Solubility data and tie-line points were experimentally determined for the ternary system (water + phosphoric acid + Heptyl acetate) at T = 298.2 K and ambient pressure. The cloud point method was used to measure the immiscibility region. Type-1 LLE behavior was observed for the investigated system and the plait point data were calculated using the Treybal’s method. The compositions of both aqueous and esteric layers were determined by using of acid-base titration, HPLC method and mass balance equation. The Othmer–Tobias and Hand equations were applied to prove the reliability of tie-line data. Obtained tie-line points were then correlated using the UNIQUAC model and the rmsd results showed that the measured points were satisfactorily regressed by the thermodynamic model. To evaluate the ability of the studied solvent for purification of phosphoric acid, distribution coefficients and separation factors were calculated over the biphasic area. Separation factors were greater than one in all investigated feeds of phosphoric acid for the studied system. Heptyl acetate showed the highest separation factors between all the investigated n-alkyl acetate esters.
{"title":"Liquid-Liquid Equilibrium Data of the Ternary Mixture of (Water + Phosphoric Acid + Heptyl Acetate) at 298.2 K and ≈ 102 kPa","authors":"S. Shekarsaraee, A. Gilani, M. Pir","doi":"10.22036/PCR.2020.224503.1746","DOIUrl":"https://doi.org/10.22036/PCR.2020.224503.1746","url":null,"abstract":"Solubility data and tie-line points were experimentally determined for the ternary system (water + phosphoric acid + Heptyl acetate) at T = 298.2 K and ambient pressure. The cloud point method was used to measure the immiscibility region. Type-1 LLE behavior was observed for the investigated system and the plait point data were calculated using the Treybal’s method. The compositions of both aqueous and esteric layers were determined by using of acid-base titration, HPLC method and mass balance equation. The Othmer–Tobias and Hand equations were applied to prove the reliability of tie-line data. Obtained tie-line points were then correlated using the UNIQUAC model and the rmsd results showed that the measured points were satisfactorily regressed by the thermodynamic model. To evaluate the ability of the studied solvent for purification of phosphoric acid, distribution coefficients and separation factors were calculated over the biphasic area. Separation factors were greater than one in all investigated feeds of phosphoric acid for the studied system. Heptyl acetate showed the highest separation factors between all the investigated n-alkyl acetate esters.","PeriodicalId":20084,"journal":{"name":"Physical Chemistry Research","volume":"8 1","pages":"497-509"},"PeriodicalIF":1.2,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45893118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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