Volume 225, Issue 4 -

A simple and efficient method for the preparation of highly ordered 3-dimensional macroporous polyparaphenylene (3DOM-PPP) conducting polymer films is reported for the first time. The method involves the simple electropolymerization of benzene inside a polystyrene opal template at mild reaction conditions. The ionic liquid 1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([HMIm]FAP) containing benzene as a precursor is used as the electrolyte. Polystyrene colloidal crystals with average sphere-diameters of 240, 370 and 600 nm on ITO-glass substrates were used as templates. The obtained PPP inverse opal structures showed strong blue, green, yellow and red colors due to light diffraction caused by the 3-D highly ordered macroporous structure. A complete filling of the PS template with PPP can be easily achieved at room temperature. The electrochemical process was investigated by cyclic voltammetry and the deposits were characterized by SEM and IR analysis.

Experimental technique is proposed to excite oscillations of a hanging liquid droplet by applying interfacial dielectric force directly upon the droplet surface. The force proved to be applicable for all kinds of liquids and solutions including non-conductive, isolating liquids. The oscillations are detected optically, with the help of a laser beam. The measured resonant frequency modes and resonance half-widths may be used to retrieve information about the surface properties of the droplet (surface tension and surface charge, in particular). The method is applicable to a wide variety of liquids and interfaces. Possible applications are analyzed and discussed.

Thermal properties of CoCl 2 , MnCl 2 and their mixed crystals are investigated by means of temperature dependent neutron powder diffraction and time-resolved small angle neutron scattering. The coefficients of thermal expansion of these crystals have been determined as a function of temperature. The temperature-induced structural variations can be explained by distortions of CoCl 6 /MnCl 6 octahedra and changes in Co/Mn–Cl bond lengths. CoCl 2 and MnCl 2 form homogeneous solid solutions in the entire temperature range between the solidus and 50 K. There is no indication of any miscibility gap as predicted from thermodynamic calculations.

Ultrasonic velocities and densities of some copper(I) and silver(I) salts have been measured in the concentration range 0.002–0.28 mol kg −1 in binary mixtures of acetonitrile (AN) + N,N -dimethylacetamide (DMA) containing 100, 80, 60, 40, 20 and 0 mol % AN at 298 K. The isentropic compressibility ( K s ) and apparent molal isentropic compressibility in various solvent systems have been calculated by using ultrasonic velocity ( u ) and partial molal volume ( V φ ) respectively. Limiting apparent molal isentropic compressibilities ( K s, φ 0 ) for various salts have been evaluated from vs. m 1/2 plots and split into the contributions of individual ions ( K s, φ 0 ) ± . The ( K s, φ 0 ) ± values for copper(I) and silver(I) ions are found to be negative over the entire composition range which indicate strong solvation of these complex ions. The ( K s, φ 0 ) ± values for these ions increase with increase in DMA composition shows that the extent of solvation increases with increase in DMA composition.

The aqueous solubility of otherwise slightly soluble organic substances can be enhanced by the incorporation of surfactant micelles. In this research, the water solubility enhancements of polycyclic aromatic hydrocarbons (PAHs) viz. naphthalene, anthracene and pyrene, by micellar solutions at 30 ºC using gemini-conventional (ionic and nonionic) surfactants in their single and binary systems have been measured and compared. The solubilization capabilities of gemini surfactant butanediyl-1,4-bis(dimethylcetylammonium bromide) (G4) with cationic cetyltrimethylammonium bromide (CTAB), anionic sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and nonioinic polyoxyethylene (20) cetyl ether (Brij 58) have been quantified in terms of molar solubilization ratio (MSR), partition coefficient ( K m ) and free energy of solubilization (Δ G s 0 ) of the PAHs. The order of solubilizing power of pure surfactants is Brij 58 > G4 > CTAB > AOT and in binary systems G4-Brij 58 > G4-CTAB > G4-AOT.

Rutin is an anticancer herbal drug. The interaction between rutin and bovine serum albumin (BSA) was studied by using absorption, steady-state, time resolved and synchronous fluorescence spectroscopic techniques. The results of fluorescence titration revealed that rutin could strongly quench the intrinsic fluorescence of BSA through a static quenching process. The binding constant and number of binding sites of rutin with BSA were obtained by fluorescence quenching method. The distance between donor and acceptor is calculated according to Förster's non-radiative energy transfer theory. The results of synchronous fluorescence spectra showed that the binding of rutin with BSA can induce conformational changes in BSA and it was further confirmed by docking studies. Molecular docking of rutin with BSA indicated that it docked close to Trp 212, which is present within the hydrophobic subdomain. In addition, the effect of metal ions on the binding constants of BSA⋯rutin complex has also been discussed.

The conjugation between bovine serum albumin (BSA) and three synthetic food colorants like tartrazine (TTZ), sunset yellow (SY) and erythrosine (ETS) was investigated by fluorescence spectroscopy in tris-HCl buffer solution of pH 7.40. The results indicated that TTZ, SY and ETS could form non-covalent compounds with BSA, which led to the static quenching of endogenous fluorescence of BSA. The binding ability followed the pattern: ETS > TTZ > SY. The values of Hill's coefficients were slightly more than 1 in all systems. Thermodynamic parameters indicated that hydrogen bond and Van der Waals played a major role in the binding of synthetic food colorants to BSA; besides, the competitive experiments suggested that the primary binding site for three synthetic food colorants was located at site I in sub-domain II A of BSA. According to Förster's non-radiative energy transfer theory, the binding distances ( r ) between synthetic food colorants and BSA were much smaller than 7ߙnm. Meanwhile, synthetic food colorants reduced the binding constants between ciprofloxacin hydrochloride (CPFX) and BSA, leading to the change of medicinal efficacy.