Browsing by Author "Macovez, Roberto"Més informacióMés informació

Now showing items 1-20 of 29

  • C60 solvate with (1,1,2)-trichloroethane: dynamic statistical disorder and mixed conformation 

    Mitsari, Efstratia; Romanini, Michela; Qureshi, Navid; Tamarit Mur, José Luis; Barrio Casado, María del; Macovez, Roberto (2016-05-27)
    Article
    Open Access
    We present a full characterization of the orientationally disordered cocrystal of C-60 with (1,1,2)-triChloroethane (C2H3Cl3), by means of X-ray diffraction, Raman spectroscopy, and broadband dielectric spectroscopy. Our ...

  • Collective relaxation dynamics and crystallization kinetics of the amorphous Biclotymol antiseptic 

    Tripathi, Pragya; Romanini, Michela; Tamarit Mur, José Luis; Macovez, Roberto (2015-11-10)
    Article
    Open Access
    We employ dielectric spectroscopy to monitor the relaxation dynamics and crystallization kinetics of the Biclotymol antiseptic in its amorphous phase. The glass transition temperature of the material as determined by ...

  • Double primary relaxation in a highly anisotropic orientational glass-former with low-dimensional disorder 

    Romanini, Michela; Barrio Casado, María del; Capaccioli, Simon; Ruíz Martín, María Dolores; Macovez, Roberto; Tamarit Mur, José Luis (2016-04-26)
    Article
    Open Access
    The freezing of the cooperative reorientational motions in orientationally disordered (OD) molecular crystals marks the so-called \glassy" transition, which may be considered a lower-dimensional version of the structural ...

  • Enhancement of the physical and chemical stability of amorphous drug-polymer mixtures via cryogenic comilling 

    Romanini, Michela; Lorente, Marta; Schammé, Benjamin; Delbreilh, Laurent; Dupray, Valérie; Coquerel, Gerard; Tamarit Mur, José Luis; Macovez, Roberto (American Chemical Society (ACS), 2018-11-27)
    Article
    Open Access
    Amorphous dispersions of the Biclotymol antiseptic are obtained in polyvinylpyrrolidone (PVP), for different drug loadings, by comilling at temperatures below the glass transition of both components. Characterization of ...

  • Formulation and characterization of mucoadhesive controlled release matrix tablets of captopril 

    Saurí, J.; Zachariah, Manesh; Macovez, Roberto; Tamarit Mur, José Luis; Millán, Daniel; Suñé Pou, M.; García Montoya, E.; Pérez Lozano, P.; Miñarro, M.; Ticó, J. R.; Suñé Negr, J. M. (2017-12-01)
    Article
    Open Access
    The purpose of this study is to characterize controlled release matrix tablets of captopril and to find out the physicochemical properties that have an effect on the mucoadhesion process. The hydrophilic matrix tablets ...

  • Genuine antiplasticizing effect of water on a glass-former drug 

    Ruiz Tabbia, Guadalupe Natalia; Romanini, Michela; Hauptmann, Astrid; Loerting, Thomas; Shalaev, Evgenyi; Tamarit Mur, José Luis; Pardo Soto, Luis Carlos; Macovez, Roberto (Macmillan Publishers, 2017-08-07)
    Article
    Open Access
    Water is the most important plasticizer of biological and organic hydrophilic materials, which generally exhibit enhanced mechanical softness and molecular mobility upon hydration. The enhancement of the molecular dynamics ...

  • Hopping conductivity and polarization effects in a fullerene derivative salt 

    Macovez, Roberto; Zachariah, Manesh; Romanini, Michela; Zygouri, Panagiota; Gournis, Dimitrios; Tamarit Mur, José Luis (2014-06-12)
    Article
    Restricted access - publisher's policy
    Impedance spectroscopy is employed to probe the frequency-dependent conductivity and dielectric response of the C60O24Na 24 fulleride. The conduction properties of this organic material match the so-called universal behavior ...

  • Measurement of the dispersion of air and of refractive index anomalies by wavelength- dependent nonlinear interferometry 

    Macovez, Roberto; Mariano, Marina; Di Finizio, Sergio; Martorell Pena, Jordi (2009-07-27)
    Article
    Open Access
    We carry out wavelength-dependent second harmonic interference experiments using thin films of an organic dye as nonlinear optical sources. While the measured difference of refractive index between the fundamental and ...

  • Molecular ¿(2) gratings via electron-beam lithography 

    Domínguez Juárez, Jorge Luis; Macovez, Roberto; Gonzalez, M.U.; Martorell Pena, Jordi (2010-07)
    Article
    Restricted access - publisher's policy
    We show that the nonlinear optical activity of an organic molecule may be quenched by electron irradiation. Exploiting this effect, we inscribe periodic χ(2) patterns in the molecular films by means of a scanning electron ...

  • Molecular conformation in organic films from quantum chemistry ab initio calculations and second harmonic spectroscopy 

    Macovez, Roberto; López, Núria; Mariano, Marina; Maymó Camós, Marc; Martorell Pena, Jordi (2012-11-30)
    Article
    Restricted access - publisher's policy
    Identifying molecular species and conformations at surfaces is of interest for both catalytic and biointerfacial research. Here, we present an extinction and second harmonic spectroscopy study of films of crystal violet ...

  • Molecular diffusion and dc conductivity perfectly correlated with molecular rotational dynamics in a plastic crystalline electrolyte 

    Zachariah, Manesh; Romanini, Michela; Tripathi, Pragya; Tamarit Mur, José Luis; Macovez, Roberto (2015-01-01)
    Article
    Open Access

  • New approaches for the fabrication of photonic structures of nonlinear optical materials 

    Carvajal, J J; Peña, A; Kumar, R.; Pujol, M. C.; Mateos, X.; Aguiló Díaz, Magdalena; Díaz, F; Vázquez De Aldana, J. R.; Méndez, Carlos Alberto; Moreno, P; Roso, L; Todorov Trifonov, Trifon; Rodríguez Martínez, Ángel; Alcubilla González, Ramón; Král, Z; Ferré Borrull, J.; Pallarès Marzal, Josep; Marsal, L F; Finizio, Sergio Di; Martorell Pena, Jordi; Macovez, Roberto (2009-12)
    Article
    Restricted access - publisher's policy
    We revisited two different strategies to fabricate 1D photonic crystals of nonlinear optical dielectric materials based on ultrafast laser ablation of the surface of an RbTiOPO4 crystal, and selective etching of ferroelectric ...

  • Orientational relaxations in solid (1,1,2,2)tetrachloroethane 

    Tripathi, Pragya; Mitsari, Efstratia; Romanini, Michela; Serra, Pablo; Tamarit Mur, José Luis; Zuriaga, Jose Mariano; Macovez, Roberto (2016)
    Article
    Open Access
    We employ dielectricspectroscopy and molecular dynamic simulations to investigate the dipolar dynamics in the orientationally disordered solid phase of (1,1,2,2)tetrachloroethane. Three distinct orientational dynamics are ...

  • Physical properties of organic fullerene cocrystals 

    Macovez, Roberto (2018-01-04)
    Article
    Open Access

  • Protonic surface conductivity and proton space-charge relaxation in hydrated fullerol 

    Mitsari, Efstratia; Romanini, Michela; Barrio Casado, María del; Tamarit Mur, José Luis; Macovez, Roberto (2017-03-09)
    Article
    Restricted access - publisher's policy
    The ac dielectric properties of both anhydrous fullerol (C-60(OH)(24)) and hydrated fullerol with 20% water mass content are investigated by means of temperature-dependent dielectric spectroscopy. Anhydrous polycrystalline ...

  • Relaxation dynamics vs crystallization kinetics in the amorphous state: the case of Stiripentol 

    Ruiz, Guadalupe N.; Romanini, Michela; Barrio Casado, María del; Tamarit Mur, José Luis; Pardo Soto, Luis Carlos; Macovez, Roberto (2017-11-06)
    Article
    Open Access
    With the aim of finding a correlation between the crystallization kinetics and the molecular dynamics of a substance that would allow prediction of its crystallization time as a function of temperature for a given a ...

  • Segmental relaxation and partial crystallization of chain-extended Poly(l-lactic acid) reinforced with carboxylated carbon nanotube 

    Yousefzade, Omid; Valenti, Sofia; Puiggalí Bellalta, Jordi; Garmabi, Hamid; Macovez, Roberto (2019-02-15)
    Article
    Restricted access - publisher's policy
    Temperature-modulated differential scanning calorimetry (TMDSC) and broadband dielectric spectroscopy (BDS) were employed to study the glass transition, size of the cooperative rearranging regions (CRRs), crystallization ...

  • Self-Diffusion, Phase Behavior, and Li+ Ion Conduction in Succinonitrile-Based Plastic Cocrystals 

    Zachariah, Manesh; Romanini, Michela; Tripathi, Pragya; Barrio Casado, María del; Tamarit Mur, José Luis; Macovez, Roberto (2015-11-11)
    Article
    Open Access
    We study the temperature-dependent molecular dynamics, ion conduction, and phase behavior of plastic-crystal electrolytes based on the succinonitrile molecule. We employ calorimetry and dielectric spectroscopy to probe ...

  • Silicon-Chip-Based Dielectric Spectroscopy for Conductivity and Molecular Dynamics Studies of Organic Films 

    Tripathi, Pragya; Gonzalo Ruiz, Javier; Mitsari, Efstratia; Zachariah, Manesh; Romanini, Michela; Tamarit Mur, José Luis; Muñoz Berbel, F. Xavier; Macovez, Roberto (2014-07-29)
    Article
    Restricted access - publisher's policy
    Interdigital electrodes fabricated by standard lithography on silicon chips are employed to probe the dipolar molecular dynamics and electric conduction properties of thin rhodamine films grown with two different methods. ...

  • Simultaneous orientational and conformational molecular dynamics in solid 1,1,2-Trichloroethane 

    Romanini, Michela; Mitsari, Efstratia; Tripathi, Pragya; Serra, Pablo; Zuriaga, Jose Mariano; Tamarit Mur, José Luis; Macovez, Roberto (2018-03-15)
    Article
    Open Access
    The molecular dynamics in the ambient-pressure solid phase of 1,1,2-trichloroethane is studied by means of broadband dielectric spectroscopy and molecular dynamics simulations. The dielectric spectra of polycrystalline ...