Microemulsions Research Papers - Academia.edu (original) (raw)

M odern civilization's inherited artworks have a powerful impact on society, from political, sociological, and anthropological points of view, so the conservation of our Cultural Heritage is fundamental for conveying to future generations our culture, traditions, and ways of thinking and behaving. In the conservation of cultural artifacts, scientists intervene in the degradation of often unique handcrafts, resulting from a delicate balance of aging, unpredicted events, environmental conditions, and sometimes incorrect previous restoration treatments, the details of which are often not precisely known.

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- Cultural Heritage, Soft Matter, Self Assembly, Nanoparticles

The application of a new class of organogels as cleaning tools for painted surfaces is described. It combines some of the most attractive features of cleaning liquids and normal gels while diminishing the deleterious characteristics of both. Thus, the 'latent' gellant, polyethyleneimine (PEI), reacts with CO 2 at room temperature in solutions of several organic liquids to produce an ammonium carbamate form (PEICO 2 ). This charged species organizes itself into 3D polymer networks which immobilize the liquids as gels. The properties of the original solution (i.e. a free-flowing liquid) are re-established immediately after addition of a small amount of a weak acid which displaces the CO 2 molecules and makes the PEI chains positively charged. The visual changes are substantiated by rheological analyses. Results from analytical tests to determine the utility of these gels as cleaning tools for painted surfaces of historical and artistic interest, have been obtained from contact angle and FTIR measurements as well as visual comparisons of the surfaces before and after application of the gels. The analyses indicate that the PEICO 2 -based organogels were very effective in removing different surface patinas from painted supports. A surface layer of dammar was completely removed from a test canvas with oil paint, an aged painting from the XIX century, and a XV century oil-on-wood panel attributed to Mariotto di Cristoforo. Finally, a surface acrylic polymeric resin (used in a restoration performed during the 1960s) was also successfully removed from Renaissance wall paintings decorating the Santa Maria della Scala Sacristy in Siena, Italy. The isothermally rheoreversible gel approach described in this work represents a new, highly versatile, and very efficient method for removing aged surface patinas from works of art.

- by PIERO BAGLIONI
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- Archaeology, Cultural Heritage, Soft Matter, Rheology

T he works of art and artifacts that constitute our cultural heritage are subject to deterioration, both from internal and from external factors. Surfaces that interact with the environment are the most prone to aging and decay; accordingly, soiling is a prime factor in the degradation of surfaces and the attendant disfigurement of a piece. Coatings that were originally intended to protect or contribute aesthetically to an artwork should be removed if they begin to have a destructive impact on its appearance or surface chemistry.

- by Lora Angelova and +2
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- Materials Science, Soft Matter, Art and Science, Self Assembly

The present work shows that salt anions affect the activity of Pseudomonas cepacia lipase both in aqueous and in nonaqueous media (NAM) according to a Hofmeister series. The biocatalytic assay in water was the hydrolysis of p-nitrophenyl acetate, whereas the esterification between 1-hexyl--D-galactopyranoside and palmitic acid was followed in an organic solvent. The solid lipase preparations to be used in NAM were obtained through lyophilization in the presence of concentrated solutions of Hofmeister salts (Na 2 SO 4 , NaH 2 PO 4 / Na 2 HPO 4 , NaCl, NaBr, NaI, NaSCN). Salts affect enzyme activity in organic media through two mechanisms:

- by Maura Monduzzi
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- Engineering, Water, Soft Matter, Self Assembly

Ga-doped Li-Mn-spinels Li 1.02 Ga x Mn 1.98-x O 4 with 0.00 e x e 0.20 are investigated to verify the lattice capability to allocate the Ga 3+ ions on both tetrahedral and octahedral sites and to determine the lowest amount of dopant that prevents the occurrence of the Jahn-Teller (J-T) transition observed near room temperature in LiMn 2 O 4 . XRPD, NMR, and EPR spectra and static magnetic susceptibility and conductivity data are related to the site occupancy, the Mn valence state and the homogeneous distribution of the dopant. The electronic and magnetic features of the spinel framework are strongly dependent on substitution in its cationic sublattice: dopant amounts as low as 1% significantly modify the temperature of the conductivity drop associated with the J-T distortion. Ga 3+ ions substitute chiefly in the octahedral sites, Mn 4+ ions occupy regular and distorted octahedral sites and, at the same time, the value of lattice parameter remains unchanged. Mn 2+ ions are present in the tetrahedral site and Li + increases in the octahedral site as a consequence of Li-Mn/Ga inversion. Such a mechanism increases the efficiency of J-T inhibition by Ga doping, in comparison with transition cations having the same valence.

- by Vincenzo Massarotti
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- Engineering, Soft Matter, Self Assembly, Nanoparticles

In this paper we evaluate the environmental sustainability of a small combined heat and power (CHP) plant operating through an Organic Rankine Cycle (ORC). The heat sources of the system are from geothermal energy at low temperature (90-95°C) and solar energy. The designed system uses a solar field composed only of evacuated, non-concentrating solar collectors, and work is produced by a single turbine of 50 kW. The project addresses an area of Tuscany, but it could be reproduced in areas where geothermal energy is extensively developed. Therefore, the aim is to exploit existing wells that are either unfit for high-enthalpy technology, abandoned or never fully developed. Furthermore, this project aims to aid in downsizing the geothermal technology in order to reduce the environmental impact and better tailor the production system to the local demand of combined electric and thermal energy. The environmental impact assessment was performed through a Life Cycle Analysis and an Exergy Life Cycle Analysis. According to our findings the reservoir is suitable for a long-term exploitation of the designed system, however, the sustainability and the energy return of this latter is edged by the surface of the heat exchanger and the limited running hours due to the solar plant. Therefore, in order to be comparable to other renewable resources or geothermal systems, the system needs to develop existing wells, previously abandoned.

- by Franco Ruzzenenti
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- Geography, Soil, Soft Matter, Agriculture

The conductor-like solvation model, as developed in the framework of the polarizable continuum model (PCM), has been reformulated and newly implemented in order to compute energies, geometric structures, harmonic frequencies, and electronic properties in solution for any chemical system that can be studied in vacuo. Particular attention is devoted to large systems requiring suitable iterative algorithms to compute the solvation charges: the fast multipole method (FMM) has been extensively used to ensure a linear scaling of the computational times with the size of the solute. A number of test applications are presented to evaluate the performances of the method.

- by Maurizio Cossi
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- Computational Chemistry, Soft Matter, Self Assembly, Nanoparticles

Oxygen vacancies at the SnO2(110) and (101) surface and subsurface sites have been studied in the framework of density functional theory by using both all-electron Gaussian and pseudopotential plane-wave methods. The all-electron calculations have been performed using the B3LYP exchange-correlation functional with accurate estimations of energy gaps and density of states. We show that bulk oxygen vacancies are responsible for the appearance of a fully occupied flat energy level lying at about 1 eV above the top valence band, and an empty level resonant with the conduction band. Surface oxygen vacancies strongly modify the surface band structures with the appearance of intragap states covering most of the forbidden energy window, or only a small part of it, depending on the vacancy depth from the surface. Oxygen vacancies can account for electron affinity variations with respect to the stoichiometric surfaces as well. A significant support to the present results is found by comparing them to the available experimental data.

- by Giovanni Cantele
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- Materials Science, Soft Matter, Self Assembly, Nanoparticles

The evolution of the microemulsion technique in the last years is revised with special emphasis in the mechanisms of control of particle size, namely the control by the proper microemulsions and the control by the surfactant adsorption (capping). The kinetics of the particle formation; the possibility of the preparation of coatings, core-shell and 'onion-like' structures with a very precise size control; the use of microemulsions to produce fine ceramics and finally their use in the preparation of superlattices is addressed. ᮊ

- by karen perez
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- Thermodynamics, Nanoparticles, Nanotechnology, Nanoscience

This paper describes the structure and properties of the drug domperidone and a novel 1:1 domperidone succinate salt. The new salt is characterized by means of thermal, spectroscopic, microscopic and powder diffraction measurements. The crystal structures of the salt and, for the first time, of pure domperidone have been determined by means of singlecrystal X-ray diffraction. In both structures, the piperidine ring of domperidone adopts the expected chair conformation, and supramolecular centrosymmetric R 2 2 (8) motifs are formed by N-HÁ Á ÁO hydrogen bonds between chlorine-substituted oxobenzimidazolyl groups. Further N-HÁ Á ÁO hydrogen bonds occur between non-substituted oxobenzimidazolyl groups and the resulting C(4) motifs originates hydrogenbonded chains, extending along the crystallographic b axis. In the salt, a single N-HÁ Á ÁO hydrogen bond forms between the protonated nitrogen of the piperidine ring and the carboxylic O atom of the succinate ion. Two alternative and mutually exclusive positions for the nonsubstituted oxobenzimidazolyl group have also been observed; this disorder makes the hydrogen-bonded chains originating from the bicyclic group polar. The dissolution behaviour of the salt in dosage form is compared with two reference commercial products. The salt shows an increased solubility, a characteristic that could be of great advantage from a pharmaceutical view point.

- by Marcella Bini and +2
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- Soft Matter, Self Assembly, Nanoparticles, Macromolecular X-Ray Crystallography

Nanotechnology provides new concepts and materials for the consolidation and protection of wall paintings. In particular, humble calcium and barium hydroxide nanoparticles offer a versatile and highly efficient tool to combat the main degradation processes altering wall paintings. Clear example of the efficacy and potentiality of nanotechnology is represented by the conservation in situ of Maya wall paintings in the archaeological area in Calakmul (Mexico). Scheme 1. Schematic representation of the stratigraphy of a wall painting executed by the fresco technique. Pigments are entrapped in the growing calcite originating from the carbonation of lime.

- by PIERO BAGLIONI
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- Cultural Heritage, Conservation, Soft Matter, Calcium

- by Debora Berti
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- Cultural Heritage, Soft Matter, Self Assembly, Nanoparticles

Why ice floats on water is an unresolved question that underlines the special properties of water. We argue that it is resolved by taking a different approach to structure than is usual, the "exponential scale" description. The exponential scale is placed on a firm foundation based on underlying quantum mechanics. The approach includes and is more general than conventional approaches to molecular and chemical interactions, based on separate and different kinds of "bonds". These are based on perturbation theories applied to few-atom systems. The present approach to the many-body problem is in the same spirit as, but more general than Lifshitz theory of intermolecular interactions.

- by Barry Ninham
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- Condensed Matter Physics, Inorganic Chemistry, Water, Soft Matter

Surfactants have already been distinguished as having commercial application in oil industry especially Enhanced Oil Recovery (EOR) processes. During EOR processes, surfactants or a mixture of surfactants and polymers are injected into the reservoir to reduce the interfacial tension of microemulsion typically from about 30 dyn/cm to 10 −3 dyn/cm. Polymers are added to reduce the mobility by increasing the viscosity of the solution. The geometrical micelle shape of a number of surfactants might change from spherical to cylindrical above a concentration generally known as critical micelle concentration. Although previous studies haven't considered the effect of surfactants on solution viscosity, this shape transition could significantly affect the viscosity of solution. In this study, a previously developed model is used in conjunction with experimental data to investigate the effect of surfactant and salt concentrations on the micelle shape transition. It is found that for some ranges of surfactant and salt concentrations; shape transition from spherical to cylindrical causes a considerable increase in the viscosity of dodecyl ammonium chloride (DeAC) solution. Based on the results of this study, a number of surfactants could be used for simultaneous modification of the IFT and viscosity of the microemulsion rather than using both polymers and surfactant.

- by peyman kamranfar
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- Enhanced Oil Recovery, Microemulsions, chemical EOR, Petroleum Engineering
- by mario vincenzo russo
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- Forensic Science, Soft Matter, Mass Spectrometry, Forensic chemistry

The aging of cellulose, the main constituent of paper, is due to depolymerization of cellulose fibers and is promoted by acid pH. Paper deacidification is a fundamental process for the conservation and restoration of probably the most important material used to transmit cultural heritage. Several methods are currently used for paper deacidification. We applied nanotechnologies to produce kinetically stable dispersions of nano-and micron-sized calcium hydroxide particles in alcohol media. Although calcium hydroxide possesses the best deacidification properties, it has never been used so far as dispersion in nonaqueous media. Calcium hydroxide particles, once deposited onto paper cellulose fibers, deacidify them and react with carbon dioxide from the air, forming a calcium carbonate reservoir on the paper fibers. This process allows a long-term control of paper pH, with excellent deacidification properties. Deacidification of 14th, 17th, 19th, and 20th century acid yellowed paper samples coming from rag and wood pulp (20th century) has been performed with excellent results. Moreover, the nano-and microparticle dispersions can be applied to paper or canvases using conventional procedures. This new method is environmentally clean, is inexpensive, and can also be used for industrial applications.

- by PIERO BAGLIONI and +2
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- Cultural Heritage, Soft Matter, Self Assembly, Nanoparticles

In this work, we illustrate the usefulness of cyclodextrins, namely, methyl-β-cyclodextrin (MβCD), an amorphous, methylated derivative of the natural β-cyclodextrin (βCD), as a tool to form an inclusion complex with omeprazole (OME), a poorly water soluble drug. Solid binary systems between OME and MβCD were prepared experimentally in a stoichiometry 1:1 by different techniques (physical mixing, kneading, spray-drying and freeze-drying).

Semi-interpenetrating (IPN) poly (2-hydroxyethyl methacrylate)/polyvinylpyrrolidone hydrogels were synthesized and used for the removal of adhesives from the back of canvas paintings. The high water retention capability and the specific mechanical properties of these gels allow the safe cleaning of water-sensitive artifacts using water-based detergent systems. The cleaning action is limited to the contact area and layer-by-layer removal is achieved while avoiding water spreading and absorption within water-sensitive substrates, which could lead, for example, to paint detachment. The use of these chemical gels also avoids leaving residues over the treated surface because the gel network is formed by covalent bonds that provide high mechanical strength. In this contribution, the physicochemical characterization of semi-IPN chemical hydrogels is reported. The successful application of an o/w microemulsion confined in the hydrogel for the removal of adhesives from linen canvas is also illustrated.

- by Joana Domingues and +1
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- Condensed Matter Physics, Soft Matter, Self Assembly, Nanoparticles

- by Luigi Dei
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- Cultural Heritage, Soft Matter, Self Assembly, Nanoparticles

A series of novel N-substituted N 0 -(2-arylmethylthio-4-chloro-5-methylbenzenesulfonyl)guanidines 9 e41 have been synthesized and investigated as inhibitors of four isoforms of zinc enzyme carbonic anhydrase (CA.EC 4.2.1.1), that is the cytosolic CA I and II, and cancer-associated isozymes CA IX and XII. Against the human CA I investigated compounds showed K I in the range of 87e6506 nM, toward hCA II ranging from 7.8 to 4500 nM, against hCA IX in the range of 4.7e416 nM and against hCA XII at range of 0.96e540 nM. Compounds 10, 12e14, 16, 18e20, 24e26, 31 and 32 exhibited a powerful inhibitory potency toward hCA IX (K I ¼ 4.7e21 nM) in comparison to the reference sulfonamides AAZ, MZA, EZA, DCP and IND (K I ¼ 24e50 nM). Compound 14 was the most potent inhibitor of hCA I (K I ¼ 87 nM), hCA IX (K I ¼ 4.7 nM) and hCA XII (K I ¼ 0.96 nM), while 26 was the most effective inhibitor of hCA II (K I ¼ 7.8 nM). The most promising compound 32 exerted the highest selectivity ratios toward hCA IX versus hCA I (hCA I/hCA IX ¼ 261) and hCA II (hCA II/hCA IX ¼ 26). The in vitro antitumor activity of compounds 32, 38 and 41 was evaluated at the US National Cancer Institute (NCI) against a panel of 60 human tumor cell lines. The most active antitumor agents 21 and 25, inhibiting 32e35 human tumor cell lines with GI 50 in the range of 2.1e5.0 mM also showed relatively high inhibitory activity toward hCA IX and XII with K I from 18 to 40 nM.

- by Jaroslaw Chojnacki
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- Organic Chemistry, Soft Matter, Self Assembly, Nanoparticles

The electrical conductivity of D 2 O-in-n-heptane microemulsions stabilized by cationic/nonionic surfactant mixtures was studied as a function of D 2 O content, surfactant concentration, and surfactant mixture composition. The surfactants employed were cationic di-ndidodecyldimethylammonium bromide, DDAB, nonionic poly(oxyethylene) monododecyl ethers, C 12 E J , with J = 3-8 and 23, nonionic polymeric surfactants of the type PEO-PPO-PEO (Pluronic), and the reverse structure analogues (Pluronic R). Qualitative structural information was drawn from a comparison between the measured conductivity and that predicted by the charge fluctuation model for spherical droplets. The conductivity versus water content curves were found to be typical for water-in-oil systems composed of spherical droplets. From the effect of blending nonionic surfactant with DDAB on the measured conductivities, it was concluded that microemulsion conductivity is independent of the concentration of cationic surfactant (DDAB). This finding agrees well with theoretical microemulsion conductivity models.  2004 Elsevier Inc. All rights reserved.

- by Ali Bumajdad
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- Engineering, Surface Science, Surfactant Science & Technology, Physical sciences

An effective time-independent approach to compute vibrationally resolved optical spectra from first principles is generalized toward the computation of one-photon electronic spectra induced by either electric or magnetic transition dipoles or by their mutual interaction. These encompass absorption, emission, and circular dichroism spectra. Additionally, the proposed computational scheme is extended to cover a broad range of approximations to evaluate vibronic transitions within both vertical and adiabatic frameworks and to be able to take into account the effects of the temperature. The presented computational tool is integrated into a general purpose computational chemistry package and offers a simple and an easy-touse way to evaluate one-photon electronic spectra, starting from electronic structure calculations chosen according to the system under study, from fully quantum mechanical descriptions to discrete/continuum quantum mechanical/MM/polarizable continuum models.

- by Malgorzata Biczysko and +1
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- Soft Matter, Self Assembly, Nanoparticles, DNA

Time domain dielectric spectroscopy of reverse water/acrylamide/Aerosol-OT (AOT)/toluene microemulsions shows that percolation induced by increasing cosurfactant concentration (increasing cosurfactant chemical potential) obeys scaling above and below a percolation threshold. This scaling analysis suggests that the observed percolation is close to static percolation limits. Self-diffusion measurements derived from nuclear magnetic resonance pulsed-gradient spin-echo experiments reveal an increase in water proton diffusion above the percolation threshold. This increase is assigned to water transport through fractally chained assemblies of microemulsion droplets. The diffusion of water, cosurfactant, and surfactant (AOT) below threshold is modeled quantitatively taking into account the chemical partitioning equilibria between the microemulsion droplets and the toluene continuous pseudophase. Above threshold, the apparent increasing water and cosurfactant partitioning into the toluene (continuous) pseudophase suggests facilitated transport through fractal aggregates. A dynamic partitioning model is used to estimate the volume of percolating fractal clusters, and yields an order parameter for water-in-oil to percolating cluster microstructural transitions. This same order parameter is also illustrated to derive from self-diffusion data wherein percolation and transformation to sponge phase microstructure are driven by increases in temperature and in disperse phase volume fraction. For microstructural transitions driven by three different field variables, chemical potential, temperature, and disperse phase volume fraction, this order parameter shows that the onset of percolation corresponds to the onset of increasing water proton sell-diffusion, and that the onset of increasing surfactant self-diffusion corresponds to the formation of bicontinuous microstructures and the onset of transformation to middle phase microemulsion. © 1997 Elsevier Science B.V.

- by Antony J Williams and +1
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- Microstructure, Microemulsion, Microemulsions

This review concerns recent research on the synthesis of cerium oxide (also known as ceria, CeO 2 ) in colloidal dispersions media for obtaining high surface area catalyst materials. Nanoparticles as small as 5 nm and surface area as high as 250 m 2 /g can be readily prepared by this method. Both normal micelles and water-inoil microemulsions have been employed to directly precipitate nanoceria or other cerium precursors which can be converted into ceria by calcination.

- by Ali Bumajdad
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- Engineering, Microeconomics, Surface Science, Surfactant Science & Technology

Scientific [1] and technological interest [2] in microemulsions arises from the possibility of controlling through confinement the activity of hydrophilic/hydrophobic molecules in a nonpolar or polar matrix. The microstructural properties of microemulsions have been characterized extensively; investigations into the application of microemulsions have mainly been focused on their use as nanoreactors in catalysis and biocatalysis, and their use in drug delivery. [7] Our research group has explored their application for the conservation of cultural heritage and designed novel systems containing low amounts of volatile oils as low-impact cleaning tools for the removal of aged polymeric coatings from the surface of paintings. In spite of the well-established importance of direct microemulsions in many technological fields and the ecological relevance of some environmentally friendly applications, the applicative potential of oil-in-water microemulsions (o/w mE) embedded into an aqueous polymeric dispersion, or bicontinuous microemulsions in which the oil phase is gelled by means of a low-molecular-weight gelator, is still underestimated.

- by Emiliano Carretti and +1
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- Soft Matter, Small Angle X Ray Scattering, Self Assembly, Art Conservation

A solid state synthesis of calcium manganite (CaMnO3) is described where equimolecular mixtures CaCO3:MnCO3 have been subjected to mechanical stress (high energy milling) so yielding CaCO3-MnCO3 solid solutions of nanometric particle size. TG measurements have shown that a link exists between milling time, the extent of non-stoichiometry and the milling-induced decomposition of MnCO3 to Mn3O4. A short (2 h) annealing at 850 °C performed on a sample mixture milled for 25 h leads to non-stoichiometric CaMnO3−x. No sure conclusion could be drawn for the stoichiometry of CaMnO3 obtained, under the same annealing conditions, from a mixture milled for longer time (150 h). No synthesis of CaMnO3 could be effected by long (48 h) annealing at 1200 °C of mixtures that had not been subjected to mechanical stress.

- by Giovanna Bruni
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- Chemistry, Soft Matter, Self Assembly, Nanoparticles
- by jesus Ontiveros
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- Engineering, Physical sciences, Microemulsions, CHEMICAL SCIENCES
- by Alane Beatriz Vermelho
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- Bioinformatics, Soft Matter, Life Sciences, Self Assembly

Gels are becoming one of the most important tools for the conservation of cultural heritage. They are very versatile systems and can be easily adapted to the cleaning and consolidation of works of art. This perspective reviews the major... more

- by rodorico giorgi
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- Cultural Heritage, Viscoelasticity, Soft Matter, Self Assembly

All four isotropic contributions to the NMR fluorine-fluorine coupling constants (Fermi contact, FC, spindipolar, SD, paramagnetic spin-orbit, PSO, and diamagnetic spin-orbit, DSO) have been calculated for 2,6-difluoropyridine, 2,4,6-trifluoropyridine, perfluoropyridine, and 2-Br-3,4,5,6,7,8-hexafluoroquinoline by means of density functional theory in combination with the rather modest 6-311G** basis set. Experimental values ranging from -20.3 to +45.8 Hz are semiquantitatively reproduced for three-to seven-bond couplings, suggesting that the different electronic effects responsible for the spin-spin interactions are adequately taken into account. In all cases, the relative importance of noncontact terms was examined. With few exceptions, the sum of the SD and PSO noncontact terms is larger than the FC contact contribution, even though in most cases the two noncontact values have opposite signs. The widespread assumption that the Fermi contact term dominates scalar spin-spin couplings in the case of light atoms would appear to be an oversimplification for J FF in polyfluorinated organic molecules. In addition, the CPU performance of the Fermi contact contribution calculated separately by the coupled-perturbed and the finite-perturbation methods was investigated showing the latter to be slightly more efficient.

- by Juan Peralta
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- Soft Matter, Self Assembly, Nanoparticles, DNA

at molecular level by means of the NMR technique, we discuss the physical properties of water in the thermal denaturation of proteins. The main aim of our work is to highlight the role of water in this essential biological process.

- by PIERO BAGLIONI
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- Engineering, Physics, Biophysics, Materials Science

The solubilities of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in supercritical CO 2 (scCO 2) in the presence of ethanol, 1-pentanol and 2,2,3,3,4,4,5,5-octafluoro-1-pentanol (F-pentanol) at 38.0 • C and different pressures were determined. It was found that AOT (0.01-0.07 M) could be solubilized in scCO 2 with smaller amount of F-pentanol (0.20-0.30 M) compared with ethanol (1.00-1.40 M) and 1-pentanol (0.60-1.00 M), because F-pentanol has 'CO 2-philic' fluorinated alkane chain. The phase behavior studies for AOT (0.03 M)/F-pentanol (0.18-0.35 M)/scCO 2 system ranging in temperature from 38.0 to 52.2 • C and pressures up to 35.00 MPa indicated that the cloud point pressure of AOT decreased significantly with the addition of F-pentanol, and the lower temperature, the lower cloud point pressure of AOT especially at higher concentrations of F-pentanol. In addition, 0.016 M AOT/0.24 M F-pentanol/scCO 2 system could solubilize a significant amount of water (W total 0 = 11.5, and W corr 0 = 6.0) at moderate conditions, which implied the formation of water-in-CO 2 reverse microemulsions. Visual observation using a video camera on the solubilization of methyl orange (MO) further proved the existence of polar micro-water domains within the AOT W/C reverse microemulsions. Besides that, bio-macromolecules such as cytochrome c and lysozyme and 8-hydroxy-1,3,6pyrenetrisulphonic acid trisodium salt (HPTS) characteristic of highly ionic property could be solubilized in the microemulsions, which was obviously reflected by the UV-vis spectra.

- by Poovathinthodiyil Raveendran
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- Engineering, Environmental Sciences, Cytochrome C, Microemulsions
- by Rita Cortesi
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- Micelles, Liposomes, Microemulsions, Delivery System

The term retinitis pigmentosa (RP) indicates a heterogeneous group of genetic rare ocular diseases in which either rods or cones are prevalently damaged. RP represents the most common hereditary cause of blindness in people from 20 to 60 years old. In general, the different RP forms consist of progressive photo-receptorial neuro-degenerations, which are characterized by variable visual disabilities and considerable socio-sanitary burden. Sometimes, RP patients do not become visually impaired or legally blind until their 40-50 years of age and/or maintain a quite acceptable sight for all their life. Other individuals with RP become completely blind very early or in middle childhood. Although there is no treatment that can effectively cure RP, in some case-series the disease's progression seems to be reducible by specific preventive approaches. In the most part of RP patients, the quality of vision can be considerably increased by means of nanometer-controlled filters. In the present review, the main aspects of the routine clinical and rehabilitative managements for RP patients are described, particularly focusing on the importance of specific referral Centers to practice a real multidisciplinary governance of these dramatic diseases.

- by Francesco Parmeggiani and +1
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- Genetics, Soft Matter, Self Assembly, Nanoparticles

Resonance enhanced multiphoton ionization and rotationally resolved S 1 r S 0 electronic spectra of the anisole-2 H 2 O complex have been obtained. The experimental results are compared with high level quantum mechanical calculations and with data already available in the literature. Quite surprisingly, the equilibrium structure of the anisole-2 H 2 O complex in the S 0 state shows some non-negligible differences from that of the isotopomer anisole-1 H 2 O complex. Actually, the structure of the deuterated complex is more similar to the corresponding structure of the anisole-1 H 2 O complex in the S 1 state. In anisole-water, two equivalent H(D) atoms exist as revealed by line splitting in the rotationally resolved spectra. It is possible to suggest a mechanism for the proton/deuteron exchange ruled by a bifurcated transition state for the exchange reaction, with both water hydrogen atoms interacting with the anisole oxygen atom. From the analysis of all of the available experimental data and of computational results, we can demonstrate that in the S 1 excited state the hydrogen bond in which the water molecule acts as an acid is weaker than in the electronic ground state but is still the principal interaction between water and the anisole molecules. † Part of the "Giacinto Scoles Festschrift". * Corresponding authors.

- by Giovanni Piani
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- Soft Matter, Self Assembly, Nanoparticles, DNA

Ultra-transparent glass-ceramics are synthesized in the GeO 2 -PbO-PbF 2 system by rare-earth heterogeneous nucleation of PbF 2 . The influence of YbF 3 on the nucleation process is studied through differential thermal analysis (DTA) and the morphology is observed by transmission electron microscopy (TEM). The optical properties of the glass-ceramics are compared to those of the starting glass as well as to those of a PbF 2 single crystal. Thanks to the RE segregation inside the PbF 2 crystallites, the optical characteristics of the glassceramics are found to be equivalent to those of the single crystal.

- by G. Dantelle
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- Materials Engineering, Transmission Electron Microscopy, Micelle, Ceramics
- by Alfonso Pedone and +1
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- Algorithms, Computational Chemistry, Spectroscopy, Soft Matter

Rapid and simple determination of acrylamide in conventional cereal-based foods and potato chips through conversion to 3-[bis(trifluoroethanoyl)amino]-3-oxopropyl trifluoroacetate by gas chromatography coupled with electron capture and ion trap mass spectrometry detectors a b s t r a c t A new, simple, rapid and fully validated method based on gas chromatography coupled with Electron capture and ion trap mass spectrometry detectors (GC-ECD and GC-IT/MS) is presented for quantitative analysis of acrylamide contaminant in conventional cereal-based foods and potato chips. Before analysis acrylamide was efficiently derivatized with trifluoroacetic anhydride, the effects of temperature, reaction time and catalyst on the acylation reaction were evaluated. Chromatographic analysis was performed on SE-54 capillary column; good retention and peak response of the acrylamide derivative achieved under the optimal conditions. The analytical method has been fully validated by assessment of the following parameters: LODs and LOQs (1 and 25 ng g À1 by GC-ECD and 2 and 36 ng g À1 by GC-IT/MS, with a Relative Standard Deviations <4 and <6, respectively), linearity (R 2 above 0.981 in the range 0.005-50 lg g À1 ) and extraction recovery (ranging between 91% and 99%, RSD below 4.0, for acrylamide spiked at levels of 1, 20, 50 and 100 ng g À1 ). Furthermore, the method proposed requires no clean-up step of the acrylamide derivative to be performed prior to injection.

- by mario vincenzo russo
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- Soft Matter, Self Assembly, Nanoparticles, Food Chemistry

Based on the conventional approach, the trapped oil in rock pores can be easily displaced when a Winsor type (III) micro-emulsion is formed in the reservoir during surfactant flooding. On the other hand, the Winsor type (III) involves three phase flow of water, oil, and micro-emulsion that causes considerable oil phase trapping and surfactant retention. This work presents an experimental study on the effect of micro-emulsion phase behavior during surfactant flooding in sandstone and carbonate core samples. In this study, after accomplishing salinity scan of a cationic surfactant (C 16 -N(CH 3 ) 3 Br), the effects of Winsor (I), Winsor (III) and Winsor (II) on oil recovery factor, differential pressure drop, relative permeability, and relative permeability ratio were investigated extensively. To carry out a comparative study, homogeneous and similar sandstone and carbonate rocks were selected and the effects of wettability alteration and dynamic surfactant adsorption were studied on them. The results of oil recovery factor in both rock types showed that Winsor (I) and Winsor (III) are preferred compared to Winsor (II) phase behavior. In addition, comparison of normalized relative permeability ratio at high water saturations revealed that Winsor (I) has more appropriate oil and water relative permeability than Winsor (II). The results presented in this paper demonstrate that optimum salinity which results in higher recovery factor and better oil displacement may occur at salinities out of Winsor (III) range. Therefore, the best way to specify optimum salinity is to perform core flood experiments at several salinities, which cover all phase behaviors of Winsor (I), Winsor (III), and Winsor (II).

- by Mahmood Reza Yassin
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- Water, Permeability, Microemulsions
- by Nikolaos Laskaris
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- Condensed Matter Physics, Soft Matter, Self Assembly, Nanoparticles

Thermodynamic control of crystallization has been achieved to produce stable polymorphs directly by using 3D nano-confinement in microemulsions. The theoretical basis for thermodynamic control of crystallization using 3D nano-confinement is outlined. Our approach leapfrogs the usual metastable polymorph pathway because crystallization becomes governed by the ability to form stable nuclei, rather than critical nuclei. The generality of this approach is demonstrated by crystallizing the stable polymorph of three 'problem' compounds from microemulsions under conditions yielding metastable forms in bulk solution. The polymorphic compounds are mefenamic acid (2-[(2,3-(dimethylphenyl)amino] benzoic acid), glycine (aminoethanoic acid) and the highly polymorphic 5methyl-2-[(2-nitrophenyl) amino]-3-thiophenecarbonitrile, commonly known as ROY because of its red, orange and yellow polymorphs. Application of this methodology should prevent another Ritonavir-type disaster, whereby a marketed drug transforms into a more stable form, reducing its bioavailability and effectiveness. The lowest energy nuclei selectively grow in our approach. Consequently this also provides a generic method for producing higher crystallinity materials, which may prove beneficial for crystallizing proteins and inorganic nanocrystals. Statement of urgency and brief summary of significant findings. We believe the paper fulfills the requirements of urgency for a Communication because it details for the first time a generic method to obtain thermodynamic control of crystallization. This enables stable polymorphs to be crystallized directly, to prevent another Ritonavir-type disaster. The methodology used selectively grows the lowest energy crystal nuclei, so it can also produce materials with higher crystallinity, which may prove of use for a wide range of crystalline materials, including potentially proteins.

- by Sharon Cooper
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- Materials Engineering, Inorganic Chemistry, Polymorphism, Crystal Growth

Representative conductivity and ion-selective electrode (ISE) measurements.

- by Gerardo Palazzo
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- Engineering, Soft Matter, Self Assembly, Nanoparticles

Accurel MP1004, a porous polypropylene powder, was characterised for lipase immobilisation. The particle size ranges between 40-80 mesh, corresponding to particle diameters of 177-420 m. The pore distribution falls between macroporous and mesoporous domains. A crude lipase preparation from Mucor javanicus was immobilised on Accurel MP1004 by adsorption. During the adsorption process, by measuring the variation of pore volume and of pore size distribution of mesopores as a function of enzyme loading, a significant penetration of the enzyme molecules into the pores was found to occur.

- by Enrico Sanjust
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- Soft Matter, Self Assembly, Nanoparticles, Adsorption

Casein is a well-known and highly studied protein present in milk found in the form of large colloidal particles called casein micelles. Here we assessed the influence of two solvents, H 2 O and D 2 O, on the precipitation temperatures of sodium caseinate induced by calcium and magnesium ions. The intrinsic fluorescence of casein was correlated with the suspended and precipitated protein fractions in order to extrapolate the precipitation temperature. The precipitation temperature values were determined for several calcium and magnesium concentrations in H 2 O, demonstrating the strong differences in the association behaviour induced by the two divalent cations. The precipitation temperatures of caseinate, in the presence of calcium induced by heating the samples in D 2 O, were significantly lower compared with the one performed in H 2 O. On the contrary, the precipitation temperatures of casein in the presence of magnesium were very close to those obtained in the samples tested in H 2 O. Thus, calcium interaction with the protein depends on temperature and solvents, two parameters that modify the accessibility of the binding site of the cation. Conversely, the interaction of the divalent magnesium ion with casein was shown to depend only upon the temperature. Remarkably, this evidence indicates that the two ions have different binding sites on the protein, suggesting that the D 2 O solvent plays an important role in the detection of the different binding sites for calcium and magnesium. Additionally, the results obtained with the simultaneous presence of both cations suggest the existence of a cooperative mechanism between the two ions, in which the presence of calcium makes more sites available for the binding of magnesium.

- by Francesco Lopez
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- Soft Matter, Self Assembly, Nanoparticles, Food Chemistry

In this review we report the most recent applications of nanotechnology to the conservation and restoration of the world's cultural heritage. Nanoparticles of humble calcium and magnesium hydroxide and carbonate can be used to restore and protect wall paints and to de-acidify paper and wood. We highlight the synthetic pathways that can be used to produce nanoparticles, and some applications for the conservation of Maya wall paints in Mexico and to the de-acidification of paper documents and wood.

- by rodorico giorgi
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- Engineering, Cultural Heritage, Soft Matter, Self Assembly

In this paper we present the theory and implementation of analytic derivatives of time-dependent density functional theory ͑TDDFT͒ excited states energies, both in vacuo and including solvent effects by means of the polarizable continuum model. The method is applied to two case studies: p-nitroaniline and 4-͑dimethyl͒aminobenzonitrile. For both molecules PCM-TDDFT is shown to be successful in supporting the analysis of experimental data with useful insights for a better understanding of photophysical and photochemical pathways in solution.

- by Roberto Cammi
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- Engineering, Soft Matter, Self Assembly, Nanoparticles

We review some recent advances in quantum mechanical methods devised specifically for the study of excited electronic state of large size molecules in solution. The adopted theoretical/computational framework is rooted in the density functional theory (DFT) and its time-dependent extension (TD-DFT) for the characterization of ground and excited states, in the polarizable continuum model (PCM) for the treatment of bulk solvent effects, and in time-dependent quantum mechanical methods for chemical dynamics. Selected applications to the simulation of absorption spectra, to the interpretation of time-resolved experiments, and to the computation of dissociative electron transfer rates are presented and discussed.

- by Roberto Improta
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- Soft Matter, Quantum Mechanics, Self Assembly, Nanoparticles