Current Physical Chemistry - Volume 8, Issue 2, 2018

Background: Bile salts possess unique chemical structural characteristics and are very different from conventional surfactants. Due to the fascinating physiological functions, the bile salts have been widely studied by various physical methods. Last three decades are the witness about rapid studies on bile salts aggregation with surfactant but yet uncertain related to mixed micellar system. Objective: The primary objective of this study was to undertake systematic studies on the mixed systems comprising of cationic surfactant CPyCl + bile salts in water and NaCl solution by surface tension and viscosity method. Methods: Drop weight method (surface tension method) and viscometry methods are chosen to discuss the interaction between bile salts and surfactant mixed system. Results: Systematic studies on CPyCl + bile salts were carried out using Rubingh's regular solution theory in presence/absence of NaCl. The CMC and viscosity data measurements were recorded. Molecular interaction parameters β was calculated to determine the depth of synergism between the micellar systems. Conclusions: Synergisms occur when cationic surfactant CPyCl and bile salts such as NaDC/NaC were mixed. NaCl has the ability to modify the structure of CPyCl and bile salts. Micelle size grows with increase in NaCl concentration. CMC of CPyCl decreases as the concentration of salts increases. Viscosity data reveals that size of CPyCl micelle increases with increasing NaCl concentration.

Background: Gaussian 09 program package was used to optimize the molecular structures and calculate the vibrational wavenumber of cis and trans isomers of oligo acetylene and functionalized oligo acetylene. The geometrical parameters of the more stable conformers are reported and the total energies of the optimized structures were used to calculate the cis-trans relative energies in gas and aqueous phases. Objective: To carryout theoretical investigation of the conformational preference and vibrational spectroscopy of mono-terminal substituted oligo acetylene with carboxylic acid and phosphonic acid groups in gas and aqueous phases. Methods: Computations were performed using Density Functional Theory adopting Becke-3– Lee–Yang–Parr (B3LYP) with the 6-31+G(d,p) standard basis set. The Integral Equation Formalism in the Polarizable Continuum Model was used as a solvation model for the aqueous phase computations. Results: The trans isomers of un-substituted and substituted oligo acetylene are found to be more stable in both gas phase and aqueous phases. The order of stability in gas phase is as follows: CnHn+1 (CO2H)> CnHn+1 (H2PO3)> CnHn+2, (n=3-5). Solvation results for the substituted systems showed that the solvent effect on trans isomers of mono-substituted phosphonic acid is higher than that of mono-substituted carboxylic acid and the solubility increases with the increase in the number of monomer unit. Conclusion: The use of B3LYP/6-31+G(d,p) method shows successful results for the calculated properties of the studied systems which in agreement with results are reported in literature.

Background: The alkali borate glasses containing transition metal ions are of great interest for opto-electronic applications. However, there is no systematic study on the lithium strontium borate glasses doped with CuO. Objectives: The aim of this study is to present a complete structural and optical view of this glass system and the influence of CuO content on these parameters. Methods: Li2O-SrO-B2O3 glasses containing different concentrations of CuO were prepared using the melt quenching technique. The prepared glasses have been investigated by measuring physical properties like density and molar volume, structural properties using FTIR spectroscopy and Raman spectroscopy, optical properties using UV-Vis spectroscopy and the compositional effects on spin-Hamiltonian parameters using EPR spectroscopy. Results: The X-ray diffraction patterns of all the studied samples revealed the amorphous nature. The density, molar volume and refractive index, optical band gap energy and Urbach energy vary with the concentration of CuO. The IR and Raman spectroscopic studies revealed that copper ions lead to structural rearrangements through the conversion of three-coordinated boron into four-coordinated boron and thereby reducing the number of non-bridging oxygen atoms. The electron paramagnetic resonance spectra of all the studied glasses exhibit resonance signals characteristic of Cu2+ ions. The values of spin- Hamiltonian parameters indicate that the Cu2+ ions are present in the distorted octahedral sites. Conclusion: The analysis of these results indicated that majority of the copper ions exist in Cu2+ state in these glasses up to 0.8 mol% of CuO and above this concentration some of these ions may convert into Cu+ state. The dependency of various physical, structural and optical properties on the concentration of copper ions shows good application prospective of this glass system for different applications.

Background: Highly drawn ultrahigh molecular weight polyethylene (UHMWPE) is known as an ultrahigh strength material. There are few reports on the relation between the phase structure and molecular mobility depending on temperature. Objective: The purpose of this investigation is to elucidate the phase structure such as crystal, amorphous, and interphase and its temperature dependence for highly drawn UHMWPE. In addition, the phase structure of highly drawn UHMWPE was compared with non-stretched UHMWPE and high density polyethylene. Methods: High resolution solid-state 13C NMR was used to quantify the phase fraction by taking advantage of spin-lattice relaxation time (T1C). Results: The T1C for orthorhombic crystalline phase consists of three components for three polyethylenes. Highly drawn UHMWPE provided the longest T1C of all. The amorphous and interphase between crystalline and amorphous provided a single T1C's. In addition, the resonance lines of monoclinic crystalline phase and lattice defect were also observed and these components decreased in intensity with increment of temperature. Conclusion: The orthorhombic crystalline phase in lamellar had different molecular mobility between the lamellar surface and core part. The molecular mobility of crystalline lamellar was the lowest for highly drawn UHMWPE, leading to high mechanical strength. With increasing temperature, the crystalline lamellar transformed to the interphase and then to the amorphous phase. The monoclinic and lattice defect locate in the orthorhombic lamellar phase.

Radiocarbon dating of an archeological parchment sample was carried out by carbosorb and benzene synthesis methods. The sample, with few symbolic letters written on it, was claimed to belong to the Harappa civilization (ca. 3000-1500 BC). Objective: Carbosorb and benzene synthesis methods were optimized for radiocarbon dating of parchment samples. Radiocarbon analysis conditions were optimized for liquid scintillation counter. Methods: Archeological parchment sample and a commercial parchment sample (control sample) were processed by chemical and carbonization methods to remove inorganic and organic impurities. Samples were converted into carbamate and benzene through carbosorb and benzene synthesis systems, respectively. The conditions were optimized to achieve 74 % efficiency of carbosorb method and 78% yield in benzene synthesis system. Results and Conclusion: The pMC of both samples were calculated by using statistical templates. The fractionation in 14C for sample was corrected for and normalized to 13C composition of -25 ‰ PDB by measuring the 13C composition of the sample, standard and background samples. The pMC of parchment sample, claimed to belong to old civilization, was calculated as 119.3±1.4 in case of carbosorb method and 118.6 ±2.1 in case of benzene synthesis system. Whereas, the commercial parchment sample showed pMC=121±3.4 for carbosorb method and pMC= 123±4.1 for benzene synthesis method. The age of parchment sample was equal to 1958-1962 AD, when bomb NH3 calibration curve was applied. Based on results, it was concluded that archeological sample was indeed have the post 1950 origin and thus has nothing to do with ancient Harappa civilization.

Background: The organocadmium halide complexes, RCdX (R= alkyl/aryl halide) in single step by direct electrochemical synthetic technique in a solution of acetonitrile, alkyl/aryl halide, tetrabutylammonium chloride (as supporting electrolyte) under nitrogen atmosphere by using a high-surface platinum cathode and sacrificial cadmium anode were synthesized. Objective: The coordination complexes were also synthesized in same conditions in the attendance of nitrogen containing bidentate ligands such as 1,10-phenanthroline and 2,2'- bipyridyl. Methods: This method affords the formation of complexes with higher yields at ambient temperature. The synthesized compounds was characterized and confirmed by physical parameters, elemental analyses and IR spectroscopy. Conclusion: All these complexes exhibit significant high electrochemical efficiency.

Background: Exact information about micellar feature of Cu (II) Soaps play a vital role in its selection in specific phenomena such as foaming, wetting, detergency, emulsification, etc. and also in their use as herbicides, fungicides, pesticides and insecticides. Copper soaps having a tendency of complex formation with the compounds containing donor atoms like N, O, Br, S, etc. It is well known that benzothiazoles are derivatives of anilines and play significant role in biological activities and having sufficient industrial and analytical applications. Objective: Coherence of biological activities of copper soaps and benzothiazole stimulated our interest to extend the studies in their cumulative form as complexes. It is anticipated that it will generate new hopes in the pharmacological activities. Critical micelle concentration, revelation of the nature and size of micelles formed and surface active properties have been investigated in the proximity of mixed solvents having wide difference in degree of polarity. Methods: Copper soap complex solutions in polar and non-polar solvent (methanol and benzene) mixtures have been chosen for the surface tension studies. Their micellar and colloidal behaviour have been analysed and these results confirm that CMC values depend upon composition of solvent mixture and are found to decrease with increase in chain length of copper surfactant (caprylate, caprate and laurate) in the referred molecule taken for study. Results: The results of surface tensions have been explained on the basis of Szyszkowski's empirical equation and it is observed that X, Y and (-XlnY) lead to the confirmation of fact that the change in the behaviour of copper surfactant complex occurs differently at two different compositions (40% & 80%) of methanol-benzene mixture. The results reveals that the numerical value of X for all the complexes in 40% and 80% methanol-benzene mixture below CMC are higher than above CMC. The area covered by 1 g. mole of the complex decreases gradually from 40% methanol to 80% methanol. The values of parachor of the complex solution increase with increase in the mole fraction and volume percent of methanol below CMC and decrease above CMC. The plots of parachor against the mole fraction of the copper surfactant complex are characterized by an intersection of two straight-lines at the CMC of copper surfactant complex. Conclusion: Hammic and Andrew's equations has been successfully applied to explain the behaviour of copper surfactant complex in two different compositions of methanolbenzene mixtures.