A5004506711- Aerogels and thermal insulation
- Membrane Separation and Gas Transport
- Polymer Nanocomposites and Properties
- Metal-Organic Frameworks: Synthesis and Applications
- Polymer crystallization and properties
- Conducting polymers and applications
- Covalent Organic Framework Applications
- Mesoporous Materials and Catalysis
- Advanced Sensor and Energy Harvesting Materials
- biodegradable polymer synthesis and properties
- Surfactants and Colloidal Systems
- Synthesis and properties of polymers
- Surface Modification and Superhydrophobicity
- Carbon dioxide utilization in catalysis
- Advanced Photocatalysis Techniques
- Supercapacitor Materials and Fabrication
- Phase Equilibria and Thermodynamics
- Block Copolymer Self-Assembly
- TiO2 Photocatalysis and Solar Cells
- Silicone and Siloxane Chemistry
- Material Dynamics and Properties
- Rheology and Fluid Dynamics Studies
- Advanced Thermodynamic Systems and Engines
- Fuel Cells and Related Materials
- Polymer composites and self-healing
University of Salerno
2015-2024
National Interuniversity Consortium of Materials Science and Technology
2012-2023
Centre National d'Études Spatiales
2012-2020
University of Port Harcourt
2018
University of Leeds
2000-2002
National and Kapodistrian University of Athens
2000
University of Manchester
2000
University of Sheffield
2000
Laboratoire de Dynamique des Fluides
1994-1997
Centre National de la Recherche Scientifique
1994
Abstract Natural and anthropogenic gas radionuclides such as radon, xenon, hydrogen krypton isotopes must be monitored to managed pathogenic agents, radioactive diagnostic agents or nuclear activity indicators. State-of-the-art detectors based on liquid scintillators suffer from laborious preparation limited solubility for gases, which affect the accuracy of measurements. The actual challenge is find solid scintillating materials simultaneously capable concentrating gases efficiently...
High-porosity syndiotactic polystyrene aerogels characterized by nanofibrils that give rise to a microporous crystalline δ-phase (see Figure) present high sorption capacity for volatile organic compounds at low concentrations, typical of the δ-phase, as well kinetics, aerogels. These properties make these new very promising industrial applications in chemical separations and water purification.
Abstract Polymeric “cocrystalline forms,” that is, structures were a polymeric host and low‐molecular‐mass guest are cocrystallized, early recognized, in many cases also well characterized by X‐ray diffraction studies. However, only the last two decades cocrystalline forms have received attention material science, due to ability (of few of them) maintain an ordered polymer structure even after removal, thus leading formation “nanoporous‐crystalline for which applications fields molecular...
The influence of thermal treatments and supercritical carbon dioxide extraction procedures on the crystal structure morphology sPS aerogels is investigated mainly by wide-angle X-ray diffraction scanning electron microscopy. use CO2 allows obtaining high porosity with fibrillar morphology, not only exhibiting nanoporous δ phase but also dense γ β crystalline phases. Moreover, a procedure to obtain high-porosity recently discovered ε-form described. Measurements sorption capacity organic...
Crystalline modifications, exhibiting largely different X-ray diffraction patterns, have been obtained for poly(2,6-dimethyl-1,4-phenylene)oxide (PPO), by gel desiccation procedures as well solvent-induced crystallization of amorphous films. The choice the solvent allows controlling nature crystalline phase. Both and semicrystalline samples this commercial thermoplastic polymer exhibit a high uptake large guest molecules (like, e.g., benzene or carbon tetrachloride), both from vapor phases...
In this contribution is presented an analysis of mass transport properties low molecular weight compounds in amorphous PPO and two semicrystalline PPOs obtained by treating with benzene carbon tetrachloride the sample. It found that samples are endowed larger gas sorption capacity diffusivity as compared to ones: behavior has been attributed prevalently nanoporous nature crystalline phases induced treatment solvents. particular, experiments, carried out at 30 °C methane, dioxide, propane...
Extensive characterizations, mainly by wide-angle X-ray diffraction (WAXD) and Fourier transform infrared (FTIR) techniques, are reported for co-crystalline (CC) poly(2,6-dimethyl-1,4-phenylene)oxide (PPO) films with many different low-molecular-mass guest molecules. These characterizations also the corresponding nanoporous crystalline (NC) phases, as obtained suitable guest-removal procedures. Two well-separated NC forms, hereafter named α β, removal from two groups of CC forms. β forms can...
Small-angle X-ray scattering (SAXS) was used to determine the packing of micelles in cubic phases formed by poly(oxyethylene)−poly(oxybutylene) (EB) diblock copolymers water. SAXS with large amplitude oscillatory shear identify structures highly asymmetric molecules E96B18, E184B18, E315B17, and E398B19 (where subscripts denote number repeats). At a constant temperature (20 °C) concentration (10 wt %), we find that two shorter hydrophilic blocks form face-centered (fcc) gels, whereas longer...
Sorption experiments have been conducted for syndiotactic polystyrene (s-PS) aerogels with different crystalline forms and of porosities. Nitrogen uptake at 77 K confirmed that δ-form present nanocavities as well amorphous porosity. The equilibrium organic molecules, from dilute aqueous solutions, is high (e.g., more than 5 wt % 1,2-dichloroethane, DCE, 1 ppm solutions) independent aerogel Gravimetric experiments, FTIR conformational studies on absorbed clearly indicate guest absorption...
A new host crystalline form of syndiotactic polystyrene (ε), able to cocrystals with guests high polarity and hyperpolarizability, has been discovered. The guest dipoles are nearly parallel the chain axes, which allows us easily obtain stable polymeric films dipole orientation perpendicular their surface.
The paper compares X-ray diffraction patterns of δ-clathrates s-PS with a large number guests, having molecular volume in the range 0.058−0.195 nm3, mainly focusing on distance between ac layers enantiomorphous polymer helices (d010), as precisely evaluated by measurements films exhibiting a∥c∥ uniplanar orientation. reported data and crystal structure determination dinitrobenzene dibenzofuran allow concluding that beside already known monoclinic unit cells there is also triclinic cells. In...
The detailed description of the crystalline structure a channel type ε clathrate cocrystal syndiotactic polystyrene (s-PS) is presented here for first time. proposed based on X-ray diffraction experiments, molecular mechanics calculations and infrared measurements. guest molecule p-nitroaniline (NA), highly polar which makes its cocrystals possibly suitable nonlinear optical piezo-electric materials. data are interpretable in terms orthorhombic unit cell (a = 1.62 nm, b 2.20 nm c 0.79 nm)...
Stable syndiotactic polystyrene (s-PS) co-crystals with highly polar guests have been prepared by sorption in δ or co-crystalline phases of molecules dissolved suitable solvent carriers. These are clathrates, that is, isolated imprisoned as a guest into cavities formed between layers polymer helices, and the maximum molecular volume is close to 0.25 nm3. Infrared linear dichroism measurements show included s-PS complexes oriented nearly perpendicular chain axes polymeric crystalline phase....
A study of the thermal stability outstanding sorption properties nanoporous-crystalline and amorphous phases poly(2,6-dimethyl-1,4-phenylene) oxide (PPO) is presented. In particular, structural changes, as induced by treatments in temperature range 100–270 °C, two limit modifications have been investigated wide-angle X-ray diffraction (WAXD) differential scanning calorimetry (DSC). Although both PPO are metastable, their crystallinity reduction small for up to 200 °C. For entire treatment...
Monolithic and highly crystalline aerogels of isotactic poly(4-methyl-pentene-1) (i-P4MP1) have been prepared by sudden solvent extraction with supercritical carbon dioxide from thermoreversible gels. The cross-link junctions i-P4MP1 gels, depending on the solvent, can be constituted pure polymer phases (I or III IV) polymer-solvent cocrystalline (for cyclohexane tetrachloride gels). Gels lead to exhibiting denser form II, whereas all other considered gels thermodynamically stable I....
Films and fibers of syndiotactic polystyrene (sPS), being amorphous or exhibiting nanoporous crystalline (NC) dense phases, were loaded with salicylic acid (SA), a relevant non-volatile antimicrobial molecule. In the first section paper, sPS/SA co-crystalline (CC) δ form is characterized, mainly by wide angle X-ray diffraction (WAXD) patterns polarized Fourier transform infrared (FTIR) spectra. The formation CC phases allows preparation sPS even high content antibacterial guest, which also...
Gels and semicrystalline clathrate samples formed by syndiotactic polystyrene (sPS) with 1,2-dichloroethane (DCE) 1-chloropropane (CP) have been investigated, for the entire composition range from pure solvent to polymer, wide-angle X-ray diffraction (WAXD) Fourier transform infrared spectroscopy (FTIR). WAXD measurements show that, at least gels polymer concentration higher than 0.1 g/g, peaks typical of sPS/DCE sPS/CP structures are present. FTIR occurrence same kind conformational...
The H2 uptake from s-PS samples exhibiting different crystalline phases and morphologies has been studied by gravimetric measurements at 77 K in the hydrogen pressure range 0 up to 1.7 MPa compared with molecular simulations relative crystals. Gravimetric experiments show that sorption is strongly dependent on sample morphology maximum for low-density polymer aerogels. However, independently of morphology, minimum dense β γ phases, intermediate channel-shaped nanoporous ε phase,...
For an industrially relevant specialty polymer, poly(2,6-dimethyl-1,4-phenylene)oxide (PPO), for the first time, a crystalline structure is resolved. It co-crystalline of polymer with chiral guest molecule (α-pinene), exhibiting 2/1 monomer-unit–guest molar ratio. The most feature this its chirality. In fact, unit cell includes all left- or right-handed helices and (1S)-(−)- (1R)-(+)-α-pinene molecules, respectively. induction non-racemic macromolecular helicity in structure, clearly...