Tween-80–n-Butanol–Diesel–Water Microemulsion System—A Class of Alternative Diesel Fuel

Tween-80–n–butanol–diesel–water microemulsion systems with various surfactant:cosurfactant (S:C) ratio have been reported as a class of alternative diesel fuel from their phase behavior, clouding phenomena, conductivity, turbidity, and inflammation studies. Temperature induced clouding of microemulsion containing 2% brine at an S:C ratio of 1:1 from a suitable turbid zone has been examined to see the stability of the diesel–water microemulsion systems. Regression models have been proposed to understand the impact of various components of the microemulsion on their cloud point (CP) values. Conductivity of the microemulsions at various S:C ratio increases with the volume of brine having two cut points depicting the presence of three microheterogenous phases within the system, whereas turbidity shows a linear increase. Dye-probed investigation of water-rich and oil-rich zones of the microemulsions indicates the involvement of a dynamic mass transfer process within the various zones. The intensities of flames produced during burning of the microemulsions with various O:E:W weight percentages selected from the isotropic regions of the phase diagrams have been estimated using MATLAB image processing method and the impacts of various components on the fuel use of the microemulsions have been analyzed.     

Miscibility and Thermal Behavior of Pullulan/Polyacrylamide Blends

Blends of Pullulan (PU) and Polyacrylamide (PAM) having biomedical applications were prepared and characterized in order to evaluate the miscibility of natural component with the synthetic one. Blends with different composition ratios were prepared using water as common solvent. Viscosity, ultrasonic velocity and density were measured at 30 and 40°C. Furthermore, the blend films were prepared by a solution casting method and analyzed by DSC, FTIR and TGA methods. Results of ultrasonic and density methods revealed the semi-miscibility of the blend. Using viscosity data, interaction parameters (Chee's ‘μ’ and Sun's ‘α’) were computed. The values confirmed that the blend is miscible when the Pullulan content is less than 20% in the blend. Change in temperature had no effect on the miscibility nature of the blends. Intermolecular interactions of hydrogen bonding type were confirmed by DSC and FTIR methods. Thermal behavior of blends was investigated using TGA method.     

Nonionic latices in aqueous media part 1. Preparation and characterization of polystyrene latices

A series of non-ionic polystyrene latices in aqueous media containing particles with a narrow size distribution have been prepared using a nonyl phenol poly(ehylene glycol) condensate as the surfactant, methoxy poly(ethylene glycol methacrylate) as the comonomer/stabilizer, and ascorbic acid/hydrogen peroxide as the initiator system. As a control synthesis for comparison with the above latex, a charge stabilized polystyrene latex was prepared, using an anionic surfactant and potassium persulphate as the initiator. Latices employing a combination of charge plus steric stabilization mechanisms were also prepared, in order to investigate the effect of the non-ionic surfactant and the comonomer/stabilizer. The particle size of the latices was measured by transmission electron microscopy, the surface charge density by conductimetric titration and the glass transition temperature of the polymer by differential scanning calorimetry. The latex prepared using non-ionic ingredients, showed no titratable charge and exhibited a profound lowering of the glass transition temperature, with respect to the charge stabilized latex. On the basis of these results, schematic models for the polymerization mechanism and the morphology of the latex particles are proposed.     

Base hydrolysis ofcis-(methyl/ethylamine)bis(ethylenediamine) (salicylato)cobalt(III) complexes

The kinetics of the base hydrolysis ofcis-[Co(en)₂(RNH₂)-(SalH)]²⁺ (R=Me or Et; SalH=HOC₆H₄CO ₂ ⁻ ) were investigated in aqueous ClO ₄ ⁻ in the 0.004–0.450 mol dm⁻³ [OH⁻] range, I=0.50 mol dm⁻³ at 30–40°C. The phenoxide species is hydrolysed via [OH⁻]-independent and [OH⁻]-dependent paths, the latter being first order in [OH⁻]. The high rate of alkali-independent hydrolysis of the phenoxide species is associated with high ΔH^≠ and ΔS^≠ values, in keeping with the SNICB mechanism involving an amido conjugate base generated by the phenoxide-assisted NH-deprotonation of the coordinated amine. The [OH⁻]-dependent path also involves the conventional SN₁ CB mechanism. The rate constant, k₁, for the SNICB path exhibits a steric acceleration with the increasing size of the non-labile alkylamine, whereas the rate constant, k₂, for the SN₁CB path shows a reverse trend. TMC 2578     

Dynamics of certain class of critically bounded entire transcendental functions

Let E denote the class of all transcendental entire functions for z∈C and an?0 for all n?0 such that f(x)>0 for x<0 and the set of all (finite) singular values of f forms a bounded subset of R. For each f∈E, one parameter family is considered. In this paper, we mainly study the dynamics of functions in the one parameter family S. If f(0)≠0, we show that there exists a positive real number λ^∗ (depending on f) such that the bifurcation and the chaotic burst occur in the dynamics of functions in the one parameter family S at the parameter value λ=λ^∗. If f(0)=0, it is proved that the Julia set of fλ is equal to the complement of the basin of attraction of the super attracting fixed point 0 for all λ>0. It is also shown that the Fatou set F(fλ) of fλ is connected whenever it is an attracting basin and the immediate basin contains all the finite singular values of fλ. Finally, a number of interesting examples of entire transcendental functions from the class E are discussed.     

A family of oxorhenium(v) complexes incorporating chelated monoanionic ONN reduced Schiff base and dianionic ONNO tetradentate ligands: synthesis, spectroscopic and electrochemical studies

The green colored complexes of the type Re(V)O(L(SB))Cl(2), 1, have been synthesised by reacting NBu(4)[ReOCl(4)] with HL(SB) in dry ethanol. Here, L(SB)(-) are the deprotonated forms of N-(2-hydroxybenzyl)-2-picolylamine (HL(SB)(1)); N-(2-hydroxybenzyl)-N',N'-dimethylethylenediamine (HL(SB)(2)) and N-(2-hydroxybenzyl)-N',N'-diethylethylenediamine (HL(SB)(3)). Similarly, NBu(4)[ReOCl(4)] reacted with N,N-bis(2-hydroxybenzyl)-2-picolylamine (H(2)L(1)); N,N-bis(2-hydroxybenzyl)-N',N'-dimethylethylenediamine (H(2)L(2)); N,N-bis(2-hydroxybenzyl)-N',N'-diethylethylenediamine (H(2)L(3)); [N-(2-hydroxybenzyl)-N-(2-pyridylmethyl)]-2-aminoethanol (H(2)L(4)); [N-(2-hydroxybenzyl)-N-(2-pyridylmethyl)]-2-methyl-2-amino-1-propanol (H(2)L(5)); N,N-bis(1-hydroxyethyl)-2-picolylamine (H(2)L(6)), to give the monochloro complexes Re(V)O(L)Cl, 2. The X-ray structures of the complexes are reported. The molecular structures observed in the solid state are preserved in solution ((1)H NMR). In acetonitrile solution the Re(V)O(L)Cl, 2, display a one-electron couple, Re(VI)O(L)Cl(+)-Re(V)O(L)Cl, near 1.0 V vs SCE. The electrogenerated hexavalent complexes [Re(VI)O(L)Cl]ClO(4), 3, are paramagnetic and display sextet EPR spectra in solution at room temperature (A(av) approximately 417 (G), g approximately 1.914).     

4‐(4‐Fluoro‐3‐phenoxy­phen­yl)‐6‐(4‐fluoro­phen­yl)‐2‐oxo‐1,2‐dihydro­pyridine‐3‐carbonitrile and the 6‐(4‐methyl­phen­yl)‐ analogue

The crystal structures of the title compounds, viz. C₂₄H₁₄F₂N₂O₂, (I), and C₂₅H₁₇FN₂O₂, (II), respectively, have been determined in order to unravel the role of an ordered F atom in generating stable supra­molecular assemblies. On changing the substitution from fluorine to a methyl group, C—H⋯F inter­actions are replaced by C—H⋯π inter­actions, revealing the importance of such weak inter­actions when present alongside N—H⋯O and C—H⋯O hydrogen bonds. The dihedral angle between the planes of the 4‐fluoro­phenyl ring and the pyridine ring is 26.8 (1)° in (I), while that between the planes of the 4‐methyl­phenyl and pyridine rings is 29.5 (1)° in (II).     

Rapid bioenabled formation of ferroelectric BaTiO3 at room temperature from an aqueous salt solution at near neutral pH

A 12-mer peptide, identified through phage display biopanning, has been used for the first time to induce the rapid formation of ferroelectric (tetragonal) nanocrystalline BaTiO3 at room temperature from an aqueous salt precursor solution at near neutral pH. BaTiO3 is widely used in capacitors, thermistors, displays, and sensors owing to its attractive dielectric, ferroelectric, pyroelectric, optical, and electrochemical properties. Two 12-mer peptides (BT1 and BT2) were selected from a phage-displayed peptide library via binding to tetragonal BaTiO3 powder. While these peptides possessed various types of amino acids, 8 of the 12 amino acids were common to both peptides. Each of these peptides induced the formation of faceted nanoparticles (50-100 nm diameter) from an aqueous precursor solution. X-ray diffraction and selected area electron diffraction patterns obtained from these faceted nanoparticles were consistent with the BaTiO3 compound. Rietveld analyses of the X-ray diffraction patterns yielded good fits to tetragonal crystal structures, with the BaTiO3 formed in the presence of the BT2 peptide exhibiting the most tetragonal character. A coating of the latter BaTiO3 nanoparticles exhibited polarization hysteresis (a well-known characteristic of ferroelectric materials) at room temperature and a relative permittivity of 2200. Such rapid, peptide-induced precipitation at room temperature provides new opportunities for direct BaTiO3 formation on low-melting or reactive materials (e.g., plastics, cloths, bio-organics) and the low temperature integration of BaTiO3 into electronic devices (e.g., on silicon or flexible polymer substrates).