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A systematic study aimed at obtaining new organoclays for the treatment of Olive Mill Waste water (OMW) has been performed. Several organoclays have been prepared by loading different amounts of the biocompatible surfactant Tween20 onto the K10 montmorillonite (MMT). Complementary kinetic and equilibrium studies on the adsorption of the Tween20 onto the MMT have been carried out and the characterization of the new tailor-made bio-materials has been performed by means of the XRD and FT-IR measurements. Finally the prepared bio-organoclays have been successfully applied for the OMW remediation and they proved to be highly effective in decreasing the organic content (OC) to an extent that depends on both the amount of loaded surfactant and the experimental protocols applied.

We studied thermal frontal polymerization using a re-dox systeminan attempt to lower the temperature of thefrontallypolymerizable system while increasing the front velocity so as toobtain a self-sustaining front in a thinner layer than without theredox components. A cobalt-containing polymer with a meltingpoint of 63 C (Intelimer 6050X11) and cumene hydroperoxidewere used with a triacrylate. The use of the Intelimer decreasedthe front velocity but allowed fronts to propagate in thinner layersand with more filler while still having a pot life of days. Nonplanarmodes of propagation occurred. Fronts propagated faster when6-O-palmitoyl- L -ascorbic acid was used as a reductant. Interest-ingly, fronts were also faster with the reductant even without theIntelimer if kaolin clay was the filler; however, the pot life was sig-nificantly reduced. V C 2012 Wiley Periodicals, Inc. J Polym Sci PartA: Polym Chem 50: 2337–2343, 2012 KEYWORDS: acrylate; addition polymerization; frontal polymer-ization; kinetics; radical polymerization; redox polymersINTRODUCTION

The Belousov–Zhabotinsky (BZ) reaction is the best known example of far from equilibrium self-organizing chemical reaction. Among the many dynamical behaviors that this reaction can exhibit, spatio-temporal chaos attracted particular interest, both for the ferroin and cerium catalyzed systems. In recent years transient chaos was found in the cerium catalyzed BZ reaction, when conducted in batch and unstirred reactors. It was established that the chaotic oscillations, originated by the coupling among chemical kinetics and transport phenomena, appeared and disappeared following a Ruelle–Takens–Newhouse scenario. In this Letter, we show results about the ferroin catalyzed system conducted in batch and unstirred reactors. An aperiodic transient regime was detected and we show that this is a genuine manifestation of spatio-temporal chaos.

The binding of the [(pentamethylcyclopentadienyl) (2,2′-bipyridyl)(aquo)rhodium(III)] complex [Cp*RhIII(bpy)H2O]2+, to l -α-dipalmitoylphosphatidyl choline (DPPC) vesicles has been estimated by studying the kinetics of the electron transfer reaction between the rhodium(III) complex and formiate ions. Kinetic measurements carried out under anaerobic conditions in absence and presence of DPPC show that the total reaction is composed of two steps. The rate of the first reaction increases with the phospholipid concentration, while that of the second process is independent of the concentration of DPPC. This is consistent with a reaction, where the two reacting species are partitioned between the aqueous and the vesicular pseudo-phases. The determined binding constants of [Cp*RhIII(bpy)H2O]2+ and formiate to the DPPC bilayers suggest that the palisade layer and the phospholipid head-group region of the DPPC vesicles are the respective solubilization sites.

The incorporation of the bidentate ligand pyridine-2-azo-p-dimethylaniline (PADA) into micellar aggregates of the dimeric cationic surfactants propanediyl-, hexanediyl- and dodecanediyl-alpha,omega-bis(dimethylcetylammonium nitrate) (16-3-16,2NO(3)(-), 16-6-16,2NO(3)(-) and 16-12-16,2NO(3)(-), respectively) has been studied at 25 degreesC by examining the kinetics of the complexation reaction of the Ni(II) ion with this ligand. For comparison, cetyltrimethylammonium nitrate ( CTAN), which can be considered as the "monomeric'' surfactant of 16-3-16,2NO(3)(-), has also been used. The kinetic data have shown that, for 16-3-16,2NO(3)(-) and CTAN, at a surfactant concentration below the critical micelle concentration (cmc) the rate of the complex formation reaction does not significantly depend on the surfactant concentration, while it slightly decreases in the presence of the other two gemini surfactants. Beyond this critical value, in all cases examined, the rate constant is conspicuously inhibited by the presence of surfactant. The results below the cmc have been explained in the light of conductometric measurements, which have evidenced that both 16-6-16,2NO(3)(-) and 16-12-16,2NO(3)(-) form premicellar aggregates while 16-3-16,2NO(3)(-) and CTAN do not. The kinetic data above the cmc conform to a reaction mechanism that implies partitioning of the ligand only between the aqueous and the micellar pseudo-phases. The quantitative analysis of the kinetic data allows us to estimate the binding of PADA to the cationic micellar aggregates used. Solubilization of PADA in the micelles markedly depends on the nature of the surfactant used and, in particular, decreases on either increasing the spacer chain length or changing the surfactant type, namely conventional or gemini. These trends have been ascribed to the change in the shape of the micellar aggregates and, consequently, the hydrophobic character of the micelles, which can be modulated either by insertion of the spacer in the micellar interior or by using a conventional surfactant. The incremental free energy of transfer of a methylene group in the spacer chain from the aqueous to the micellar pseudo-phase has also been determined. The present data evidence that binding of PADA to micellar aggregates is primarily governed by hydrophobic interactions and the solubilization capability of gemini aggregates is superior to that of conventional micelles.

Rate constants for the mononuclear rearrangement (MRH) of Z -phenylhydrazones of some 5-substituted-3-benzoyl-1,2,4-oxadiazoles in water have been measured in the presence of zwitterionic micelles. The use of micellized N -tetradecyl- N , N -dimethylamineoxide (C 14 DMAO) as the reaction medium allowed to solubilize the otherwise water-insoluble oxadiazoles. Micellar rate effects were analyzed by using a simple pseudo-phase model and compared with those obtained in non-ionic micelles (Triton X-100). Evidence that both the rate of the rearrangement reaction and the binding of the substrates to the micelles are mainly governed by substrate hydrophobicity is obtained. The disagreement with the primarily sterically controlled MRH in Triton X-100 micelles highlights large and intriguing differences between the two micellar environments.

The adsorption thermodynamics of copolymers, based on ethylene oxide (EO) and propylene oxide ( PO) units, at the laponite (RD) clay/liquid interface was determined at 298 K. The copolymer nature was tuned at molecular level by changing the hydrophilicity, the architecture and the molecular weight (Mw) keeping constant the EO/PO ratio. Polyethylene (PEGs) and polypropylene (PPGs) glycols with varying Mw and their mixture were also investigated to discriminate the role of the EO and the PO segments in the adsorption process. Enthalpies of transfer of RD, at fixed concentration, from water to the aqueous macromolecule solutions as functions of the macromolecule molality were determined. They were treated quantitatively by means of a model based on two equilibria: ( 1) one-to-one binding between the macromolecule and the site on the solid and ( 2) two-to-one binding following which one macromolecule interacts with another one adsorbed onto the solid. The good agreement between the equilibrium constants obtained from calorimetry and those determined from kinetic experiments conformed the reliability of the experimental and theoretical approaches. Almost all of the systems investigated are highlighted by the one-to-one binding; the L35 and 10R5 systems present both equilibria. The insights provided by the thermodynamics of adsorption of their homopolymers onto RD were fruitful in obtaining detailed information on the nature of the forces involved between RD and the copolymers. The data obtained in the present work clearly evidenced that for comparable polymer Mw, PPG is more suitable in building up a steric barrier around the RD particles and, indeed, exhibits several advantages and no drawbacks. Moreover, the parent copolymers may properly functionalize the RD surface by exploiting both their high affinity to the solid surface and the ability to self-assemble onto it as L35 and 10R5 clearly showed.