0000000000014597
AUTHOR
Federico Rossi
showing 41 related works from this author
New Features in the dynamics of a ferroin-catalyzed Belousov-Zhabotinsky reaction induced by a zwitterionic surfactant
2008
Abstract Interactions between reaction–diffusion systems and aggregated host environments are a subject of widespread interest. In this work, the behavior of the Belousov–Zhabotinsky reaction was investigated in a micellar environment formed by the zwitterionic surfactant N-tetradecyl-N,N-dimethylamine oxide (C14DMAO). The appearance of an induction period with a threshold-like dependence upon the surfactant concentration, was detected at [C14DMAO] = 5.0 × 10−3 mol dm−3. These new features were explained in terms of the segregation ability typical of the amphiphilic self-assembling systems. Numerical simulations were also performed to confirm the proposed mechanism.
L’influenza dei siti archeominerari nella geochimica della Toscana meridionale
2004
Passi Verso una Fisica Evolutiva
2006
Deuterium isotope effect on the induction period of the cerium catalyzed Belousov-Zhabotinsky reaction
2009
Abstract In this work we present results about the deuterium isotopic effect on the global kinetics of a cerium catalyzed Belousov–Zhabotinsky reaction. A nonlinear dependence of the induction period upon the percentage of deuterated reactants was found in batch conditions. In order to understand this result, we investigated two reaction pathways responsible for the length of the induction period, namely: (a) the reaction between the enolic form of the malonic acid with molecular bromine and (b) the oxidation of malonic acid by the Ce(IV) ion. In both cases we obtained a linear dependence of the kinetic constants on the percentage of deuterated reactants. Nevertheless, by inserting the expe…
Isotopic Effect on the Kinetics of the Belousov-Zhabotinsky Reaction
2007
In this work we present results about the deuterium isotope effect on the global kinetics of a Belousov-Zhabotinsky reaction in batch conditions. A nonlinear dependence of the Induction Period upon the percentage of deuterated reactants was found. The isotopic effect on the bromination reaction of malonic acid was evaluated.
An experimental model for mimicking biological systems: the Belousov-Zhabotinsky reaction in Lipid membranes
2006
Arsenic Pollution in the Southwest of Tuscany: Monitoring of Cornia Catchment Basin
2006
The territory of Colline Metallifere, in SW Tuscany, is characterized by the presence of strong arsenic anomalies. Some hypotheses, formulated in the last 20 years, based on geological and mineralogical factors have failed to explain the peculiar distribution of this toxic element in soil, fluvial sediments and ground water. Our research group has been studying for four years the problem of arsenic pollution in this district to investigate the origin and the mechanism of As diffusion in the environment. In particular we started a comparative study based on the extensive sampling of the stream sediments of the main waterways of Colline Metallifere (Pecora, Bruna and Cornia and their tributar…
Chaotic dynamics in an unstirred ferroin catalyzed Belousov–Zhabotinsky reaction
2009
Abstract 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 condu…
The effect of N-tetradecyl-N,N-dimethylamine oxide micelles on the kinetics of the electron transfer reaction of Ce(IV) with substituted malonic acids
2009
Abstract The kinetics of the oxidation of malonic acid and (its substituted compounds, methyl-, ethyl-, butyl- and benzyl-malonic acid) by ceric ions has been studied at 20.0 °C in the absence and the presence of the surfactant N-tetradecyl-N,N-dimethylamine oxide (C 14 DMAO). The addition of increasing amounts of C 14 DMAO influences the rate of the redox process to an extent that significantly depends on the hydrophobicity of the reducing species. The reactivity data together with the estimated binding constants and the standard transfer free energies of the malonic acids from water to the micelles suggest that the malonic acid is confined to the aqueous pseudo-phase while for the other s…
Chemical self-organization in self-assembling biomimetic systems
2009
Abstract Far-from-equillibrium oscillating chemical reactions are among the simplest systems showing complex behaviors and emergent properties. This class of reactions is often employed to mimic and understand the mechanisms of a great variety of biological processes. In this context, pattern formation due to the coupling between reaction and transport phenomena represent an active and promising research area. In this paper, we present results coming from experiments where we tried to blend the structural properties of self-assembled matrixes (sodium dodecyl sulphate micelles and phospholipid bilayers) together with the evolutive peculiarities of the Belousov–Zhabotinsky reaction. A series …
Dynamics of Pattern Formation in Biomimetic Systems
2008
This paper is an attempt to conceptualize pattern formation in self-organizing systems and, in particular, to understand how structures, oscillations or waves arise in a steady and homogenous environment, a phenomenon called symmetry breaking. The route followed to develop these ideas was to couple chemical oscillations produced by Belousov-Zhabotinsky reaction with confined reaction environments, the latter being an essential requirement for any process of Life. Special focus was placed on systems showing organic or lipidic compartments, which represent more reliable biomimetic matrices.
Interplay between the Belousov-Zhabotinsky reaction-diffusion system and biomimetic matrices
2007
Abstract Interactions between reaction–diffusion systems and restricted host environments are a subject of widespread interest. In this work the behaviour of the Belousov–Zhabotinsky reaction was investigated in lamellar phases formed by phospholipid bilayers with relevance for biological systems. The influence of the reactive medium on the structure of the lipid matrix and, in turn, the influence of the matrix on the dynamical evolution of chemical patterns, were studied by small angle scattering.
Control of spontaneous spiral formation in a zwitterionic micellar medium
2011
The transition from planar fronts, trigger waves or solitary pulses to spirals in excitable media, has attracted increasing interest in the past few decades, mainly because of its relevance for biological and medical applications. In this paper we describe a new and convenient method for spiral generation starting from symmetric wavefronts. By using the micelle-forming zwitterionic surfactant N-tetradecyl- N,N-dimethylamine oxide in a Belousov–Zhabotinsky solution, it is possible to control to a large extent the domains where spirals can be spontaneously generated. The mechanism responsible for the wavefront break up lies in the interaction of the propagating waves with the unexcitable regi…
Influence of ancient mining settlements on Arsenic pollution in the southwest of Tuscany
2004
Inquinamento da arsenico nella Toscana meridionale: studio comparativo tra i fiumi delle Colline Metallifere
2004
Spatio-temporal perturbation of the dynamics of the ferroin catalyzed Belousov-Zhabotinsky reaction in a batch reactor caused by sodium dodecyl sulfa…
2008
The effects of the anionic surfactant sodium dodecyl sulfate (SDS) on the spatio-temporal and temporal dynamics of the ferroin-catalyzed Belousov-Zhabotinsky (BZ) reaction have been studied over a wide surfactant concentration range. For the first time, investigations were performed also for unstirred systems. The presence of SDS in the reaction mixture influences the oscillatory parameters to an extent that significantly depends on the surfactant concentration. The trend of the wave speed v upon the increasing amount of SDS was found to have a maximum at [SDS] = 0.075 mol dm (-3) ( v = 0.071 mm s (-1)), after which the speed decreased to 0.043 mm s (-1) at [SDS] = 0.5 mol dm (-3), which is…
Role of the reagents consumption in the chaotic dynamics of the Belousov-Zhabotitinsky oscillator in closed unstirred reactors
2010
Chemical oscillations generated by the Belousov–Zhabotinsky reaction in batch unstirred reactors, show a characteristic chaotic transient in their dynamical regime, which is generally found between two periodic regions. Chemical chaos starts and finishes by following a direct and an inverse Ruelle–Takens–Newhouse scenario, respectively. In previous works we showed, both experimentally and theoretically, that the complex oscillations are generated by the coupling among the nonlinear kinetics and the transport phenomena, the latter due to concentration and density gradients. In particular, convection was found to play a fundamental role. In this paper, we develop a reaction–diffusion–convecti…
The two velocities of technology and nature: A conversation with Adolfo Pèrez Esquivel
2007
Entropy
2008
A brief tale on how chemical oscillations became popular an interview with Anatol Zhabotinsky
2007
Spatial recurrence strategies reveal different routes to Turing pattern formation in chemical systems
2009
We analyze the temporal evolution of hexagonal Turing patterns in two Belousov–Zhabotinsky reactions performed in water-in-oil reverse micro-emulsions under different experimental conditions. The two reactions show different routes to pattern formation through localized spots and through a self replication mechanism. The Generalized Recurrence Plot (GRP) and the Generalized Recurrence Quantification Analysis (GRQA) are used for the investigation of spatial patterns and clearly reveal the different routes leading to the formation of stationary Turing structures.
Oscillatory dynamics of the Belousov-Zhabotinsky system in the presence of a self-assembling nonionic polymer. Role of the reactants concentration.
2010
In the present study, the role played by the reactants concentration on the nonlinear response of a Belousov–Zhabotinsky (BZ) system to the addition of a self-assembling non-ionic polymer, poly(ethylene glycol) (PEG), has been assessed. The oscillatory parameters are influenced to an extent that significantly depends on the concentration of both the polymer and the Belousov–Zhabotinsky components. The effects obtained were attributed to the reaction among some of the BZ key species and the backbone and the alcoholic functional groups of the polymer, both in its monomeric and aggregated forms. Support to the proposed perturbation mechanism has been provided by performing numerical simulation…