Pub Date : 2017-08-11DOI: 10.4172/2161-0398.1000251
S. Ak
The solvent effect of ethanol on the alkali catalyzed solvolysis reaction was studied by carring out of the hydrolysis of ester namely ethyl cinnamate in water-methanol media of varying composition consisting of 30 to 70% of methanol (v/v) at different Temperature ranging from 20°C to 70°C. The Specific rate constant values of the reaction were found to depleted with increasing concentration of methanol in reaction media. Enhancement in ΔG* with simultaneous depletion in ΔH* and ΔS* of the reaction, it has been concluded that reaction is enthalpy stimulating and entropy inhibiting and specific salvation take place in water- methanol media. From the evaluated value of Iso kinetic temperature, which is less than 300 indicates that this reaction in water-methanol media obey Barclay-Butler rule and there is weak but considerable solvent –solute interaction taking place in reaction media.
{"title":"Studies of Solvent Effect of Aquo-Methanol Solvent System on Kinetics and Activation Parameters of Base Catalised Hydrolysis of Ethyl Cinnamate","authors":"S. Ak","doi":"10.4172/2161-0398.1000251","DOIUrl":"https://doi.org/10.4172/2161-0398.1000251","url":null,"abstract":"The solvent effect of ethanol on the alkali catalyzed solvolysis reaction was studied by carring out of the hydrolysis of ester namely ethyl cinnamate in water-methanol media of varying composition consisting of 30 to 70% of methanol (v/v) at different Temperature ranging from 20°C to 70°C. The Specific rate constant values of the reaction were found to depleted with increasing concentration of methanol in reaction media. Enhancement in ΔG* with simultaneous depletion in ΔH* and ΔS* of the reaction, it has been concluded that reaction is enthalpy stimulating and entropy inhibiting and specific salvation take place in water- methanol media. From the evaluated value of Iso kinetic temperature, which is less than 300 indicates that this reaction in water-methanol media obey Barclay-Butler rule and there is weak but considerable solvent –solute interaction taking place in reaction media.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81881993","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 : 2017-08-01DOI: 10.4172/2161-0398.1000255
S. Hammami, S. Sebai, D. Jegouso, V. Reita, N. Boudjada, A. Megriche
A signal crystal of NaGd(PO3)4 (NGP) was successfully grown with the solid-state reaction method under appropriate synthesis conditions. Structure refinements and the purity of the samples were determined by XRD patterns. It reveals that NaGd(PO3)4 compound crystallizes in the monoclinic system with P 21/n space group and with cell parameters a=7.174(1) A, b=13.033(2) A, c=9.781(1) A, β=90.65(2)°, V=914.47(20) A3 and Z=4. The IR and Raman spectra also indicated that the phosphoric polyhedra of NaGd(PO3)4 has a acyclic symmetry. Differential thermal analysis is given. This compound is thermally stable until 852°C. The magnetic susceptibilities of gadolinium polyphosphate as a function of temperature are reported along with corresponding magnetization measurements. This polyphosphate displays a paramagnetic response, without magnetic phase transitions, and with effective magnetic moments close to those of the corresponding free Gd3+ ions. The luminescence proprieties of Gd3+ was investigated. The emission spectra NGP exhibit intense band at 315 nm due to 6P7/2 →8S7/2 transition of Gd3+ ions when excited at 273 nm. The photon cascade emission (PCE) of Gd3+ has been proved at 164 and 254 nm excitation.
在合适的合成条件下，采用固相反应法制备了NaGd(PO3)4 (NGP)信号晶体。通过XRD谱图测定了样品的结构细化程度和纯度。结果表明，NaGd(PO3)4化合物在p21 /n空间群的单斜晶系中结晶，晶胞参数为a=7.174(1) a, b=13.033(2) a, c=9.781(1) a， β=90.65(2)°，V=914.47(20) A3, Z=4。红外光谱和拉曼光谱也表明NaGd(PO3)4的磷酸多面体具有非环对称性。给出了差热分析。这种化合物在852°C之前是热稳定的。本文报道了聚磷酸钆的磁化率随温度的变化规律，并进行了相应的磁化强度测量。该聚磷酸盐表现出顺磁响应，无磁相变，有效磁矩接近于相应的自由Gd3+离子。研究了Gd3+的发光特性。由于Gd3+离子在273 nm处发生6P7/2→8S7/2跃迁，NGP的发射光谱在315 nm处呈现出强波段。证实了Gd3+在164和254 nm激发下的光子级联发射(PCE)。
{"title":"Magnetic and Photon Cascade Emission of Gd3+ of NaGd(PO3)4 Monocrystal Under Appropriate Synthesis Conditions","authors":"S. Hammami, S. Sebai, D. Jegouso, V. Reita, N. Boudjada, A. Megriche","doi":"10.4172/2161-0398.1000255","DOIUrl":"https://doi.org/10.4172/2161-0398.1000255","url":null,"abstract":"A signal crystal of NaGd(PO3)4 (NGP) was successfully grown with the solid-state reaction method under appropriate synthesis conditions. Structure refinements and the purity of the samples were determined by XRD patterns. It reveals that NaGd(PO3)4 compound crystallizes in the monoclinic system with P 21/n space group and with cell parameters a=7.174(1) A, b=13.033(2) A, c=9.781(1) A, β=90.65(2)°, V=914.47(20) A3 and Z=4. The IR and Raman spectra also indicated that the phosphoric polyhedra of NaGd(PO3)4 has a acyclic symmetry. Differential thermal analysis is given. This compound is thermally stable until 852°C. The magnetic susceptibilities of gadolinium polyphosphate as a function of temperature are reported along with corresponding magnetization measurements. This polyphosphate displays a paramagnetic response, without magnetic phase transitions, and with effective magnetic moments close to those of the corresponding free Gd3+ ions. The luminescence proprieties of Gd3+ was investigated. The emission spectra NGP exhibit intense band at 315 nm due to 6P7/2 →8S7/2 transition of Gd3+ ions when excited at 273 nm. The photon cascade emission (PCE) of Gd3+ has been proved at 164 and 254 nm excitation.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82229536","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 : 2017-08-01DOI: 10.4172/2161-0398.1000253
Udowo Vm, Uwah Ie, Daniel Fe, F. Abeng, S. Ivara
The alkaloid and non-alkaloid fractions of purple sweet potato (Ipomoea batatas) written as AEIB and NEIB respectively were used as inhibitors in the corrosion reaction of mild steel in 1.0 M H2SO4 solutions. The corrosion rate decreased with increase in the concentration of the AEIB and NEIB as evidenced in the experimental results obtained from the gravimetric and gasometric techniques. This proved that the AEIB and NEIB are effective inhibitors of mild steel corrosion. Also, the experimentally obtained data fitted well into the Temkin isotherm while the computed thermodynamic parameter values showed that the inhibitors effectively reduced the rate of metal dissolution by becoming physically adsorbed on the mild steel surface.
用紫甘薯(Ipomoea batatas)的生物碱和非生物碱组分分别记为AEIB和NEIB作为缓蚀剂，在1.0 M H2SO4溶液中对低碳钢进行腐蚀反应。重量法和气相法的实验结果表明，随着AEIB和NEIB浓度的增加，腐蚀速率降低。这证明了AEIB和NEIB是低碳钢腐蚀的有效缓蚀剂。实验得到的数据符合Temkin等温线，而计算的热力学参数值表明，缓蚀剂通过物理吸附在低碳钢表面，有效地降低了金属的溶解速度。
{"title":"Computational and Experimental Study of the Inhibition Effects of Purple Sweet Potato Leaves Extract on Mild Steel Corrosion in 1M H2SO4","authors":"Udowo Vm, Uwah Ie, Daniel Fe, F. Abeng, S. Ivara","doi":"10.4172/2161-0398.1000253","DOIUrl":"https://doi.org/10.4172/2161-0398.1000253","url":null,"abstract":"The alkaloid and non-alkaloid fractions of purple sweet potato (Ipomoea batatas) written as AEIB and NEIB respectively were used as inhibitors in the corrosion reaction of mild steel in 1.0 M H2SO4 solutions. The corrosion rate decreased with increase in the concentration of the AEIB and NEIB as evidenced in the experimental results obtained from the gravimetric and gasometric techniques. This proved that the AEIB and NEIB are effective inhibitors of mild steel corrosion. Also, the experimentally obtained data fitted well into the Temkin isotherm while the computed thermodynamic parameter values showed that the inhibitors effectively reduced the rate of metal dissolution by becoming physically adsorbed on the mild steel surface.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90731231","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 : 2017-07-10DOI: 10.4172/2161-0398.1000249
Ulyana V Girich, S. Lazarev, Ilya G. Vyatchin, O. Matusovsky, N. Shelud’ko
In this work, the main proteins of thin filaments (actin and tropomyosin) were isolated from the catch muscle of the mussel Crenomytilus grayanus and the rabbit skeletal muscles. Rabbit actin and tropomyosin and mussel tropomyosin were isolated by traditional methods as opposed to "natural" mussel actin (isolation of the mussel actin from acetone powder is impossible). These proteins were used to reconstruct actin+tropomyosin complexes in nonhybrid and hybrid manner. A non-hybrid complex, reconstructed from rabbit actin and tropomyosin, has higher reduced viscosity than complex of mussel proteins where reduced viscosity was nearly indistinguishable from the intrinsic viscosity. ÐÂ’oth rabbit and mussel actin were purified by polymerization-repolymerization cycles followed by gel filtration chromatography. During purification, the viscosity of both actins increased, and the difference in viscosity between them decreased. Based on the SDS-electrophoresis, we did not find any of the other proteins in the chromatographic fractions, except actin. However, obtained chromatographic fractions have significant differences in viscosity and rate of polymerization. We believe that these properties caused by the presence of an "ending factor” (such as β-actinin or Cap Z) in actin preparations. The data obtained indicate that isolation of “natural” actin is accompanied by a coextraction of an unknown or known "ending factor" in amounts that may be greater than those obtained from the acetone powder of rabbit skeletal muscles.
{"title":"Natural Actin and Tropomyosin from Molluscan Catch Muscle","authors":"Ulyana V Girich, S. Lazarev, Ilya G. Vyatchin, O. Matusovsky, N. Shelud’ko","doi":"10.4172/2161-0398.1000249","DOIUrl":"https://doi.org/10.4172/2161-0398.1000249","url":null,"abstract":"In this work, the main proteins of thin filaments (actin and tropomyosin) were isolated from the catch muscle of the mussel Crenomytilus grayanus and the rabbit skeletal muscles. Rabbit actin and tropomyosin and mussel tropomyosin were isolated by traditional methods as opposed to \"natural\" mussel actin (isolation of the mussel actin from acetone powder is impossible). These proteins were used to reconstruct actin+tropomyosin complexes in nonhybrid and hybrid manner. A non-hybrid complex, reconstructed from rabbit actin and tropomyosin, has higher reduced viscosity than complex of mussel proteins where reduced viscosity was nearly indistinguishable from the intrinsic viscosity. ÐÂ’oth rabbit and mussel actin were purified by polymerization-repolymerization cycles followed by gel filtration chromatography. During purification, the viscosity of both actins increased, and the difference in viscosity between them decreased. Based on the SDS-electrophoresis, we did not find any of the other proteins in the chromatographic fractions, except actin. However, obtained chromatographic fractions have significant differences in viscosity and rate of polymerization. We believe that these properties caused by the presence of an \"ending factor” (such as β-actinin or Cap Z) in actin preparations. The data obtained indicate that isolation of “natural” actin is accompanied by a coextraction of an unknown or known \"ending factor\" in amounts that may be greater than those obtained from the acetone powder of rabbit skeletal muscles.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84899781","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 : 2017-06-07DOI: 10.4172/2161-0398.1000247
Samira Davoudmanesh, Shahrzad Hadichegeni, B. Goliaei, M. Taghizadeh, S. H. Tackallou, F. Taghavi, M. Hashemi
Fenvalerate is an insecticide which is widely utilized in agriculture. In this research, the interaction of fenvalerate with HSA, which is a blood carrier of small molecules such as drugs and toxins, is investigated. Four different methods, UV-Vis, FT-IR spectroscopy, Fluorescence spectroscopy, and molecular modeling were used to characterize the binding properties of fenvalerate with HSA at the molecular level under physiological conditions. The binding constant, which was obtained via UV-Vis spectroscopy, was computed to be KHSA/Fen=3.78 × 10+4 M-1, which indicated a relatively strong binding interactions between ligands and receptors. FT-IR results indicated a decrease in α-helixes from 55% to 50.23% and an increase in β-sheet from 13.96% to 16.82%, β-antiparallel from 6% to 8.93%, were observed on first and thirtieth day and a major decrease of α-helix from 42.99% to 38.82% and an increase in β-sheet from 1.9% to 13.9%, β-antiparallel from 2.21% to 2.53% were observed during ligand binding especially at high concentrations of ligand. The fluorescence intensity of HSA decreased regularly with the gradually increasing concentration of fenvalerate. These results also could be an evidence for binding ligands to the receptors and they were in good agreement with UV-Vis results. On the other hand, a potential binding site in the region III-B of HSA protein was determined via docking calculations. In addition, the obtained results indicate a binding site for interaction of fenvalerate with HSA, which is a chance for excreting this toxin by utilizing HSA protein.
{"title":"Spectroscopic and Molecular Docking Approaches for Investigating theInteraction of Fenvalerate with Human Serum Albumin","authors":"Samira Davoudmanesh, Shahrzad Hadichegeni, B. Goliaei, M. Taghizadeh, S. H. Tackallou, F. Taghavi, M. Hashemi","doi":"10.4172/2161-0398.1000247","DOIUrl":"https://doi.org/10.4172/2161-0398.1000247","url":null,"abstract":"Fenvalerate is an insecticide which is widely utilized in agriculture. In this research, the interaction of fenvalerate with HSA, which is a blood carrier of small molecules such as drugs and toxins, is investigated. Four different methods, UV-Vis, FT-IR spectroscopy, Fluorescence spectroscopy, and molecular modeling were used to characterize the binding properties of fenvalerate with HSA at the molecular level under physiological conditions. The binding constant, which was obtained via UV-Vis spectroscopy, was computed to be KHSA/Fen=3.78 × 10+4 M-1, which indicated a relatively strong binding interactions between ligands and receptors. FT-IR results indicated a decrease in α-helixes from 55% to 50.23% and an increase in β-sheet from 13.96% to 16.82%, β-antiparallel from 6% to 8.93%, were observed on first and thirtieth day and a major decrease of α-helix from 42.99% to 38.82% and an increase in β-sheet from 1.9% to 13.9%, β-antiparallel from 2.21% to 2.53% were observed during ligand binding especially at high concentrations of ligand. The fluorescence intensity of HSA decreased regularly with the gradually increasing concentration of fenvalerate. These results also could be an evidence for binding ligands to the receptors and they were in good agreement with UV-Vis results. On the other hand, a potential binding site in the region III-B of HSA protein was determined via docking calculations. In addition, the obtained results indicate a binding site for interaction of fenvalerate with HSA, which is a chance for excreting this toxin by utilizing HSA protein.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91440047","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 : 2017-06-02DOI: 10.4172/2161-0398.1000244
Nesrine Mechi, Ismahene Ben Khemis, H. Dhaou, S. Zghal, A. B. Lamine
The Mg50Ni45Ti5 alloy for the hydrogen storage is prepared by mechanical alloying. The structure and the morphology of the alloy are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). These techniques esteemed that this alloy is a good candidate for hydrogen storage, since it is both nanocristallin and dsuctile. This is confirmed by the modeling of the hydrogen equilibrium pressure-composition-temperature (PCT) relationships for this alloy. These isotherms were experimentally generated for three temperatures 313 K, 327 K and 340 K and modeled through the statistical physics using the monolayer model with two energies levels. Energetic, steric and thermodynamic studies were released thanks to this model which proved the efficiency and the security of this alloy to the storage of hydrogen.
{"title":"Morphologic, Structural, Steric, Energetic and Thermodynamic Studies of the Mechanical Alloy Mg50Ni45Ti5 for Hydrogen Storage","authors":"Nesrine Mechi, Ismahene Ben Khemis, H. Dhaou, S. Zghal, A. B. Lamine","doi":"10.4172/2161-0398.1000244","DOIUrl":"https://doi.org/10.4172/2161-0398.1000244","url":null,"abstract":"The Mg50Ni45Ti5 alloy for the hydrogen storage is prepared by mechanical alloying. The structure and the morphology of the alloy are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). These techniques esteemed that this alloy is a good candidate for hydrogen storage, since it is both nanocristallin and dsuctile. This is confirmed by the modeling of the hydrogen equilibrium pressure-composition-temperature (PCT) relationships for this alloy. These isotherms were experimentally generated for three temperatures 313 K, 327 K and 340 K and modeled through the statistical physics using the monolayer model with two energies levels. Energetic, steric and thermodynamic studies were released thanks to this model which proved the efficiency and the security of this alloy to the storage of hydrogen.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73629132","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 : 2017-05-23DOI: 10.4172/2161-0398.1000243
Bernard Baituti
Understanding the structure of oxygen evolving complex (OEC) fully still remains a challenge. Lately computational chemistry with the data from more detailed X-ray diffraction (XRD) OEC structure, has been used extensively in exploring the mechanisms of water oxidation in the OEC. The present study involves simulation studies of the X-band continuous wave electron-magnetic resonance (CW-EPR) generated S2 state signals, to investigate whether the data is in agreement with the four manganese ions in the OEC, being organised as a ‘3+1’ model or ‘dimer of dimers’ model. The question that still remains is how much does each Mn ion contribute to the “g2multiline” signal through its hyperfine interactions in OEC? This is revealed in part by the structure of multiline signal studied in this project. The method of data analysis involves numerical simulations of the experimental spectra on relevant models of the OEC cluster. The simulations of the X-band CW-EPR multiline spectra, revealed three manganese ions having hyperfine couplings with large anisotropy. These are most likely MnIII centres and these clearly support the ‘low’ oxidation state OEC paradigm model, with a mean oxidation of 3.25 in the S2 state. This is consistent with the earlier data, but the present results clearly indicate that heterogeneity in hyperfine couplings exist in samples as typically prepared.
{"title":"The Possible Mn Hyperfine Interactions and Oxidation States of the Manganese Cluster in OEC Using Multiline Signal (MLS) Simulation Data with Average of Weighted Computations","authors":"Bernard Baituti","doi":"10.4172/2161-0398.1000243","DOIUrl":"https://doi.org/10.4172/2161-0398.1000243","url":null,"abstract":"Understanding the structure of oxygen evolving complex (OEC) fully still remains a challenge. Lately computational chemistry with the data from more detailed X-ray diffraction (XRD) OEC structure, has been used extensively in exploring the mechanisms of water oxidation in the OEC. The present study involves simulation studies of the X-band continuous wave electron-magnetic resonance (CW-EPR) generated S2 state signals, to investigate whether the data is in agreement with the four manganese ions in the OEC, being organised as a ‘3+1’ model or ‘dimer of dimers’ model. The question that still remains is how much does each Mn ion contribute to the “g2multiline” signal through its hyperfine interactions in OEC? This is revealed in part by the structure of multiline signal studied in this project. The method of data analysis involves numerical simulations of the experimental spectra on relevant models of the OEC cluster. The simulations of the X-band CW-EPR multiline spectra, revealed three manganese ions having hyperfine couplings with large anisotropy. These are most likely MnIII centres and these clearly support the ‘low’ oxidation state OEC paradigm model, with a mean oxidation of 3.25 in the S2 state. This is consistent with the earlier data, but the present results clearly indicate that heterogeneity in hyperfine couplings exist in samples as typically prepared.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83014402","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 : 2017-03-22DOI: 10.4172/2161-0398.1000239
M. Al-Marri, Al-Saad Ka, Sa Ma, Cortes Dj, Khader Mm
A thermodynamic study of the enthalpies of adsorption of CO2 was conducted on polyethyleneimine 10k/ mesoporous silica (PEI-10k/MPS) and activated carbon (AC). These materials were chosen because of their high CO2 sorption capacities at about 85°C for PEI and about 20°C for the AC, therefore can capture CO2 with high efficiency in a wide temperature range. The absolute quantity of adsorbed CO2 as a function of equilibrium pressure at various temperatures was determined experimentally and fitted to isotherms of generalized Langmuir and Toth equations for PEI and AC, respectively. The adsorption of CO2 on PEI was favored with temperature revealing the endothermic nature of the process. On the other hand, CO2 adsorption on the AC was exothermic. The isosteric enthalpy of adsorption on PEI was about constant with CO2 loading at a value of 93 kJ.mol-1, confirming its chemical nature and corroboration with the Langmuir model. The corresponding isosteric enthalpy of the AC was in the range of ~-25 kJ.mol-1 and was continuously decreasing with CO2 loading; confirming the physisorption nature of the process and also that CO2/ CO2 interactions within the adsorption layer was significant.
{"title":"Thermodynamics of CO2 Adsorption on Polyethyleneimine Mesoporous Silica and Activated Carbon","authors":"M. Al-Marri, Al-Saad Ka, Sa Ma, Cortes Dj, Khader Mm","doi":"10.4172/2161-0398.1000239","DOIUrl":"https://doi.org/10.4172/2161-0398.1000239","url":null,"abstract":"A thermodynamic study of the enthalpies of adsorption of CO2 was conducted on polyethyleneimine 10k/ mesoporous silica (PEI-10k/MPS) and activated carbon (AC). These materials were chosen because of their high CO2 sorption capacities at about 85°C for PEI and about 20°C for the AC, therefore can capture CO2 with high efficiency in a wide temperature range. The absolute quantity of adsorbed CO2 as a function of equilibrium pressure at various temperatures was determined experimentally and fitted to isotherms of generalized Langmuir and Toth equations for PEI and AC, respectively. The adsorption of CO2 on PEI was favored with temperature revealing the endothermic nature of the process. On the other hand, CO2 adsorption on the AC was exothermic. The isosteric enthalpy of adsorption on PEI was about constant with CO2 loading at a value of 93 kJ.mol-1, confirming its chemical nature and corroboration with the Langmuir model. The corresponding isosteric enthalpy of the AC was in the range of ~-25 kJ.mol-1 and was continuously decreasing with CO2 loading; confirming the physisorption nature of the process and also that CO2/ CO2 interactions within the adsorption layer was significant.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77095745","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 : 2017-03-20DOI: 10.4172/2161-0398.1000240
Prema Kadappa Reddy, F. Omar, Asha T Iyengar
Fast Green FCF is a synthetic food dye. The kinetics study of Fast Green FCF with 1-chlorobenzotiale in HCl medium in presence of RuCl3 catalyst has been spectrophotometrically investigated at AE›max 625 nm and at the temperature of 301 K. The reaction exhibited a pseudo -first order rate on [FGF] and first order on each of [CBT], [H+] and [Ru(III)]. Negligible effect was observed by the addition of reduced product [BTA] to the reaction mixture. The addition acrylonitrile under the experimental conditions fails to induce the polymerization. Thermodynamic parameters are calculated. The absence of hydride transfer during oxidation reaction was indicated by the observed solvent isotope effect. Effects of ionic strength dielectric constant of the medium on the reaction rate have been also studied. LC-MS spectral data identifies the oxidation products. An appropriate rate law is deduced by the proposed reaction scheme, which is account for the observed kinetic data.
Fast Green FCF是一种合成食用染料。采用分光光度法，在AE›max 625 nm、301 K条件下，研究了含有1-氯苯甲醚的Fast Green FCF在HCl介质中在RuCl3催化剂存在下的动力学。在[FGF]和[CBT]、[H+]和[Ru(III)]上均表现出伪一级反应速率。在反应混合物中加入还原物[BTA]的影响可以忽略不计。在实验条件下加入丙烯腈不能引起聚合。计算了热力学参数。观察到的溶剂同位素效应表明氧化反应过程中没有氢化物转移。研究了介质的离子强度、介电常数对反应速率的影响。LC-MS光谱数据鉴定了氧化产物。根据所提出的反应方案，推导出了一个与所观察到的动力学数据相符的反应速率规律。
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Pub Date : 2017-03-20DOI: 10.4172/2161-0398.1000238
S. Ak
The rate of alkaline hydrolysis of ethyl cinnamate was measured over the temperature range of 20°C to 40°C in water-acetone mixture at different composition 30 to 70% (v/v). The influence of solvent variation on reaction rate was examined in term of changes in the Activation parameter. Depletion of ?H* and ?S* value with simultaneous increase in ?G* of the reaction in reaction media, reveals that the reaction is Enthalpy domination and Entropy controlled. The Iso- dielectric activation energy (ED) of reaction was found to decrease from 52.43 to 47.28. The Values of Iso-kinetic Temperature which is less than 300, clearly indicates that there is no appreciable interaction between solvent and solute present in the reaction media, i.e., reaction is not ion-dipole but ion-molecule type.
{"title":"Solvent Effect on the Enthalpy and Entropy of Activation for the Hydrolysis of Ethyl Cinnamate in Mixed Solvent System","authors":"S. Ak","doi":"10.4172/2161-0398.1000238","DOIUrl":"https://doi.org/10.4172/2161-0398.1000238","url":null,"abstract":"The rate of alkaline hydrolysis of ethyl cinnamate was measured over the temperature range of 20°C to 40°C in water-acetone mixture at different composition 30 to 70% (v/v). The influence of solvent variation on reaction rate was examined in term of changes in the Activation parameter. Depletion of ?H* and ?S* value with simultaneous increase in ?G* of the reaction in reaction media, reveals that the reaction is Enthalpy domination and Entropy controlled. The Iso- dielectric activation energy (ED) of reaction was found to decrease from 52.43 to 47.28. The Values of Iso-kinetic Temperature which is less than 300, clearly indicates that there is no appreciable interaction between solvent and solute present in the reaction media, i.e., reaction is not ion-dipole but ion-molecule type.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84217477","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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