Maurizio Lanza

• Italian National Research Council

Thermochemical materials (TCM) are among the most promising systems to store high energy density for long-term energy storage. To be eligible as candidates, the materials have to fit many criteria such as complete reversibility of the reaction and cycling stability, high availability of the material at low cost, environmentally friendliness, and no...

Featured Application Innovative material for thermochemical energy storage applications. Abstract In this paper, tricalcium aluminate hexahydrate (Ca3Al2O6·6H2O), thanks to its appropriate features, was assessed as an innovative, low-cost and nontoxic material for thermochemical energy storage applications. The high dehydration heat and the occurr...

Cardiovascular diseases are some of the today major cause of death in the world. C-reactive protein (CRP) is well known as the main biomarker related to cardiovascular risk and heart attack occurrence. The standard CRP analyses are performed in a hospital or in a biochemical laboratory with blood analysis after a long chemical and labelling prepara...

This work deals with the study of influence of multi walled carbon nanotubes (CNTs) characteristics on thermochemical performance of hybrid materials based on Mg(OH)2 (M) as heat storage medium. Two different functionalized CNTs samples are investigated, separated curly tubes (SN) and bundles of straight nanotubes (BN). Hybrids were synthesized by...

It is here investigated the effect of the addition of the cationic surfactant cetyl trimethyl ammonium bromide (CTAB) during the precipitation of Mg(OH)2 on structural, morphological and physical properties of the resulting hydroxide. The thermochemical behaviour as heat storage material of the final samples is investigated. Mg(OH)2 is precipitated...

MgO/H2O/Mg(OH)2 thermochemical storage system is still at an early stage of development and several research efforts are accomplished to bring this technology at an applicative stage. The material development is the key point for the system implementation. Among the investigated strategies, the synthesis route for the preparation of Mg(OH)2 over a...

Photoactive TiO2-only transparent coatings having self-cleaning and antireflection (AR) properties were prepared by forming first a nanosol through controlled hydrolysis of tetraisopropyl orthotitanate (TIPT), followed by deposition of this nanosol on glass substrates by dip-coating with a final calcination step to form the surface nano-textured th...

The design of β-cyclodextrin/multiwalled carbon nanotubes hybrid (β-CD-MWCNT) as nanoplatform for the entrapment and delivery of guanine based drugs is described here. The functionalized carbon nanomaterials have been characterized by XPS spectroscopy, electron microscopy (FEG-SEM and TEM), AFM, TGA, and FT-IR to achieve insights on structure, morp...

A conducting composite prepared by dispersing multi-walled carbon nanotubes (MWCNTs) into a host matrix consisting of Nafion, electrochemically doped with copper, has been prepared, characterized and used to modify one of the gold electrodes of simply designed electrochemical cells having copier grade transparency sheets as substrates. Electrical m...

In this work, the influence of the cobalt phase on the growth of carbon nanotubes by the catalytic chemical vapour deposition of CH4 with catalysts containing Co, Mo and Mg is investigated. To this end, the catalytic behaviour of physically mixed CoO/MgO+MgMoO4 and CoMoO4+MgMoO4 is studied. The results obtained show that CoMoO4+MgMoO4 allows for th...

The functionalization by nitric acid vapors at azeotropic concentration has been recently proposed to eliminate drawbacks of the widely utilized liquid phase functionalization method. This work suggests to exploit the so-called “salt effect” to improve the vapor phase oxidation method in terms of safety and flexibility. Increasing the relative vola...

Pristine and annealed multi-walled C nanotubes are preliminarily tested as catalysts towards the degradation of p-coumaric acid with better performances than the widely used activated carbon. In order to clarify the origin of their different catalytic efficiency, the samples are analysed by means of high-resolution transmission electron microscopy,...

Surface-enhanced Raman scattering (SERS) takes advantage of the giant electromagnetic field enhancement provided by localized surface plasmons in metal nanoparticles to amplify the weak Raman scattering of the molecules. Optical fibers coated with noble metal nanoparticles can therefore be used as SERS-based sensors for remote detection of molecula...

A set of nanotubes with moderate contents of amorphous phases (0.4–5.1 wt %) are systematically investigated by Raman spectroscopy, kinetic thermal analysis, and complementary techniques. Results show that, in spite of their small amount, the presence of amorphous phases has a strong impact on the oxidation path of nanotubes. The apparent activatio...

Novel hybrid materials, obtained by direct Catalytic Chemical Vapour Deposition (CCVD) growth of carbon nanotubes (CNT) over a clay mineral catalyst, were incorporated into Polylactic acid (PLA) through melt mixing. Nanocomposites in the form of films were exposed to UV irradiation at constant temperature (30 °C) and relative humidity (50%). Young'...

A novel free-standing and flexible counter electrode for dye solar cells has been developed by conveniently transferring a vertically aligned carbon nanotube forest onto an oxygen-plasma-treated flexible, free-standing and conductive nanocomposite foil. Vertically aligned carbon nanotubes were first grown onto an aluminium foil by chemical vapour d...

This work presents a novel cascade of chemical functionalization of multiwalled carbon nanotubes which allows the conjugation with differently substituted coumarins. Aim of the present work is to synthesize new materials able to rescue cells from the adverse effect of CNT particles since pristine CNTs are practically insoluble and tend to accumulat...

C nanotubes are synthesized by catalytic route on ceramic supports (Al2O3, MgO and CaO), usually utilized for polymer reinforcing/flame-retardancy, aiming at nanotube-based hybrid preparation. Chemical vapor deposition is carried out in i-C4H10+H2 atmosphere over 17 wt% Fe-catalysts upon different conditions. In order to clarify the influence of su...

The acidic oxidation with HNO3/H2SO4 mixtures is widely reported as an effective method to functionalize multi-walled carbon nanotubes (MWCNT). Although effective, a bad control of the oxidation conditions frequently cause serious modifications of carbon nanotube network, limiting further potential applications. Investigations about the effect of f...

This work reports for the first time a straightforward solvent-free chemical procedure to gain access to Δ-1-pyrroline grafted onto multiwalled carbon nanotubes by the 1,3-dipolar cycloaddition of the mesoionic 4-methyl-2-phenyloxazol-5(4H)-one.

Taguchi's robust design method is for the first time employed to optimize many aspects of the production of nanohybrids based on C nanotubes by iron-catalyzed chemical vapor deposition in i-C4H10 + H2 atmosphere. By analyzing the outcomes of the catalytic process in terms of selectivity, carbon yield, purity and crystalline arrangement of the hybri...

Taguchi method, extensively applied for the optimization of multifactor processes in the most diverse fields, is for the first time applied to the synthesis of hybrids based on C nanotubes by iron-catalyzed chemical vapor deposition in 1:1 i-C4H10 + H2 atmosphere. For this purpose, assumed synthesis-temperature (500 °C, 600 °C or 700 °C), support-m...

This work is a continuation and a completion of a previous study on the synthesis of multi-walled carbon nanotubes by iron-catalyzed chemical vapor deposition over sodium-exchanged K10-montmorillonite (Na+-K10) based catalysts. The influence of iron-addition (5–25 wt.%) on the catalyst performances is investigated. By comparing results here obtaine...

We report the synthesis and the characterization of different multi-walled carbon nanotubes (MWCNTs) linked to natural molecules, 5,7-coumarins and/or oleic acid, obtained from purified pristine MWCNTs by a cascade of chemical functionalization. The activities of these modified MWCNTs were investigated in vitro on human umbilical vein endothelial c...

The synthesis of carbon nanotubes (CNTs) by chemical vapor deposition (CVD) of isobutane (i-C4H10) over sodium-exchanged K10-montmorillonite based iron-catalysts is investigated. By studying the influence of iron-addition (5–25 wt%) on the catalyst performances, at 700°C, an empirical relationship is derived relating the mass of CNTs synthesized wi...

In order to prepare polylactide nanocomposites, hybrid fillers were synthesized by direct growth of carbon nanotubes over as-purchased and Na+-exchanged clay catalysts with 15 wt.% iron load. The sorptive and electrical behavior of nanocomposites obtained by the incorporation of 1–5 wt.% filler was investigated. Results show that polylactide nanoco...

The catalytic wet air oxidation of p-coumaric acid, a representative substrate of biorecalcitrant phenolic compounds typically found in olive oil processing wastewater, was carried out under mild conditions (in air at T = 353 K and P = 2 MPa) with activated carbon (AC) and multiwalled carbon nanotubes (CNTs). The influence of the CNT textural and s...

Commercially available and laboratory-prepared multi-walled carbon nanotubes (MWCNTs) are systematically investigated by the use of micro-Raman spectroscopy (MRS), thermogravimetric analysis (TGA) and complementary techniques (scanning electron microscopy (SEM) and transmission electron microscopy (TEM)) with the aim of establishing a standardised...

Nanotubes-based nanocomposites to be used as polymer reinforcing/flame-retardant additives are synthesized by decomposition of isobutane at 600°C. Catalytic chemical vapor deposition (CCVD) is carried out over 17wt%Fe-catalysts supported on various oxides (Al2O3, MgO, CaO, SrO or BaO) reduced at 600°C. Catalysts utilized and carbonaceous deposits o...

This work is a continuation and a completion of our previous studies on the synthesis of multi-walled carbon nanotubes (MWCNTs) by i-C4H10 decomposition at moderate temperature (600 °C). It intends to show the existence of well-defined relationships between the variations of the reaction parameters and the changes of yield and graphitization degree...

We demonstrate that the crystalline quality of multi-walled carbon nanotubes (MWCNTs) is better estimated by the apparent activation energy of the oxidation reaction, obtained by kinetic analysis in quasi-isothermal conditions, than by the peak-temperature position in the derivative mass loss curves. This is proven by the existence of a good correl...

Nanotubes-clay hybrid systems are synthesized by decomposition of isobutane at 700°C over as-purchased and iron-loaded montmorillonite catalysts. The changes produced by the variations of total iron content (2–17wt.%) and of reduction-temperature (500°C or 700°C) in catalyst surface properties, as well as, in reaction yield and crystalline quality...

Multiwalled carbon nanotubes (MWCNT) are synthesized by isobutane decomposition at 700 °C over as-purchased and iron-loaded K10-montmorillonite catalysts. The results show that, upon reduction at 500 °C, K10 catalyzes isobutane decomposition. Few carbon fibers accompany the prevailing carbon flakes formation. Upon Na+ exchange or by increasing the...

The synthesis of C nanotubes by catalyzed chemical vapor deposition at 600 degrees C is investigated, using yield and purity degree of C deposits to monitor the reaction outcome. From the reaction, carried out in C4H10-H2-He environment over Al2O3 supported Fe catalysts, multi-walled C nanotubes are attained, which, after purification, are analyzed...

Catalytic activity of iron based catalysts in the production of multi-walled carbon nanotubes (MWCNTs) has been investigated. The effect of the carbon source (ethane or isobutane), catalyst support (Al2O3 or SiO2), iron loading, catalyst reduction temperature and reaction temperature on yield and quality of carbon products has been examined. The st...

The results of Raman analysis on multi-walled carbon nanotubes, prepared by catalysed chemical vapour deposition, are used as a guide for the calibration of the growth parameters, directed to improve crystalline quality and resulting thermal stability of nanotubes. Under selective growth conditions, the resistance to oxidation in air, as assessed b...

Present work concerns iron-catalyzed growth of multi-walled C nanotubes (MWCNTs) by decomposition of isobutane (C4H10). MWCNTs are prepared, by chemical vapor deposition (CVD) at 600 °C, in C4H10−H2−He atmosphere over 29 wt.%Fe/Al2O3 catalysts. After purification, reaction products are analyzed by scanning electron microscopy (SEM), Raman spectrosc...

The efficiency of iron-catalysts in hydrocarbon decomposition, aimed at growth of carbon nanotubes by chemical vapour deposition (CVD), is systematically investigated. The synthesis reaction is carried out at different temperatures (873–1123 K), for various durations (0.5–6.0 h), using diverse precursor gases (C2H6 or C4H10) and catalyst suppo...

Multi-walled carbon nanotubes (MWCNTs) are prepared by chemical vapor deposition (CVD) in C2H6 + H2 mixture over 20%Fe/SiO2 catalysts. The effects, in terms of yield and selectivity of the growth process, of the changes in composition (H2 at 0–75%) and flow-rate (100–150 sccm) of gas-mixture, catalyst reduction-temperature (400 °C and 650 °C), temp...

The crucial role of precursor gas (PG) and of catalyst support (CS) in the growth of multi-walled C nanotubes (MWCNTs) by iron-catalysed chemical vapour deposition (CVD) is evidenced. This is accomplished by comparing structural and morphological properties of MWCNTs synthesised by the use of different PGs (ethane and isobutane) and CSs (silica and...

The segmental relaxation in poly(ethylene terephthalate), crystallized from either an isotropic or a cold-drawn glass, is investigated by means of dielectric spectroscopy. It is shown that there exist two distinct alpha relaxation modes: a slow one, characterized by a rather wide frequency interval, and a faster, much narrower one. A simple phenome...

In this work, it is shown that some Raman-active modes may be detected, below 500 cm−1, in the spectrum of nanotubes synthesized by iron catalyzed chemical vapor deposition. By comparatively discussing results of Raman, high-resolution transmission electron microscopy, and thermogravimetric analyses, demonstration is given that these spectral featu...

An investigation of the thermal and mechanical characteristics of new full-interpenetrating polymer networks (full-IPNs), prepared by simultaneous and sequential synthesis paths, has been performed in the temperature regions above and below the glass transition. It has been observed that simultaneous full-IPNs exhibit higher values of density than...

Cold-drawn poly(ethylene terephthalate) (PET) samples annealed at different undercoolings are studied by means of differential scanning calorimetry and dynamic mechanical thermal analysis. When heating from room temperature, the onset of the glass transition region in cold-drawn, un-annealed samples is found to be significantly lower than in the ca...

Differential scanning calorimetry and dynamic mechanical spectroscopy studies have been performed between 120 and 600 K in a new series of sequential full-interpenetrating polymer networks (full-IPNs) of crosslinked polyurethane and polycyanurate network (PCN), based on dicyanate ester of 1,1′-bis-4,cyanatophenyl-ethane. The measurements have revea...

Comparative measurements of specific heat capacities (temperature interval between 2 and 500 K), and of low frequency mechanical spectroscopy (temperature interval between 120 and 400 K) in poly(methyl methacrylate) (PMMA) and poly(vinylidene fluoride) (PVDF) amorphous blends show the existence of single calorimetric and mechanical glass transition...

Porphyrins based on platinum(II) (PtOEP), palladium(II) (PdOEP) octaethylporphyrin and Ru(II) (RuOEP) octaethylporphyrin pyridyl carbonyl are immobilized in poly(ethylene glycol)ethyl ether methacrylate (pPEGMA) solid matrices, which possess two different average molecular weights. The phosphorescence quenching by molecular oxygen in the resulting...

Optical and electrical properties of transmissive solid state electrochromic devices based on a sandwich structure of conductive K-glass®1/WO3/polymeric electrolyte/conductive K-glass®, have been investigated in correlation with the type of salt added to the polymer in order to increase its ionic conductivity. Lithium, sodium and ammonium triflate...

An original device was made using complementary electrochromic materials. The active working electrode was tungsten trioxide, deposited by r.f. sputtering onto `K-glass'. The storage counter electrode was nickel oxide lithium doped, electrochemically deposited. The solid ion conductor was a poly (ethylene glycol methacrylate) (PEGMA), containing ap...

Oxygen quenching of the luminescence of mononuclear and dinuclear Ir(III) cyclometalated complexes immobilized in the pPEGMA matrixes has been studied. Linear Stern-Volmer plots, even when experiments at different emission wavelengths have been performed, were evidenced. Despite the different luminescence lifetimes of the chromophores in the absenc...

The investigation of the structural relaxation properties of poly(ethylene glycol) methacrylates are of practical interest, due to their ability to work as the inert backbone to which poly(ethylene oxide) oligomers can be attached to obtain highly amorphous polymeric matrices. Two poly(ethylene glycol) methacrylate, PEGMA, macromonomers, with diff...

A study of the thermal and mechanical properties of new semi-interpenetrating polymer networks (IPN's) based on linear polyurethane (PU) and crosslinked trimerized dicyanate (TDC) reveals the existence of structures characterized by the absence of chemical interactions. Two distinct glass transitions are observed in the thermograms, as an indicatio...

X-ray Photoelectron Spectroscopy (XPS) and optical studies have been performed on P(EO)n –NaI–TCNQ (n = 1, 10) systems, obtained by means of a solid state reaction technique. The electron spectroscopy, the absorption in the ultraviolet visible near infrared range, and the infrared transmission findings allow us to conclude that the interaction amon...

The effect of the introduction of poly(ethylene glycol)methacrylate (PEGMA) on structural, thermal and electrical properties of solid electrolytes based on poly(ethylene oxide) (PEO) and sodium thiocyanate, is investigated by means of calorimetric, mechanical, X-ray diffraction and conductivity measurements. PEO-PEGMA systems show in general a lowe...

A thermodynamic model is used to describe the two-dimensional crystallization kinetics (as observed by means of a calorimeter) of polypropylene nucleated with small amounts of indigo. The customary expression of the free enthalpy associated to secondary nucleation is initially used to analyze the experimental data. A significant dependence of the a...

Communication: In luminescence-based oxygen sensors the active luminescent species is usually a transition metal complex immobilized in a polymeric matrix-in most cases a ruthenium(II) polypyridine complex. In an attempt to overcome some of the disadvantages of these systems, a polymer-immobilized iridium(III) complex has been prepared and used for...

A methodology for the determination of chiral forms through the analysis of the crystallization thermograms is presented. It is based on a model equation for the description of the crystallization kinetics. It is shown that the two chiral forms of menthol are characterized by markedly different values of a relevant parameter of the model, which can...

Electrical impedance measurements have been made in the frequency range 5 Hz to 10 MHz in pure poly(ethylene oxide) having a molecular weight of 600,000 from 12 K nearly up to the melting point of the crystalline phase (about 330 K). A pronounced relaxation peak in the dielectric loss and a corresponding step in the dielectric constant have been ob...

A thermodynamic model for the description of spherulitic growth in (semi-) crystalline polymers is presented. Its validity is restricted to the free growth stage of crystallization. The relevance of the role played by surface tension in the early stage of the process is pointed out. With the due approximations the predicted growth rate is found to...

Oxygen sensors based on polymer-immobilized transition-metal complexes are reported representing an interesting example of solid-state luminescent sensors. The sensitivity of the luminescence lifetime of these systems is examined in relation to the mechanical properties and it is found that the plasticizing effect due to the monomer is a necessary...

A study of the thermal and mechanical characteristics of polyethylene oxide-Fe(SCN)3 complexes shows the existence of structures which can be described by considering a crystalline phase of pure polyethelene oxide (PEO) and an amorphous phase of PEO with dissolved salt. Increasing salt contents decrease the content of crystals, favoring the formati...

A short review of the structural phase behavior of polymer electrolytes based on complexes of poly(ethylene) oxide (PEO) and alkaline metal salts is presented. These polymeric blends are semicrystalline and show a degree of crystallinity which is strongly affected by the salt concentration and the cation size. The experimental evidence obtained by...

The thermal differential analysis of new polyethylene oxide (PEO)-Fe(SCN)3 solid blends reveals the presence of a single glass transition, which shifts to higher temperatures with increasing salt content. The observed features ensure the presence of strong polymer-salt interactions and the formation of homogeneous complexes on a scale of microscopi...

The elastic modulus and tg δ of poly(2-hydroxyethyl methacrylate) (PHEMA) and its hydrogels have been measured over, the frequency range 0.3–30Hz and the temperature range 120–450 K. The mechanical spectra reveal the presence of a low-temperature γ-relaxation plus a shoulder (β-relaxation) that merges into the α-relaxation. The absorbed water lower...

The effects of the storage at room temperature of PEO-KSCN polymer electrolytes have been studied by differential scanning calorimetry (DSC) and dynamical mechanical analysis. It has been revealed that, over the explored time interval, the annealing causes small variations in the anharmonic and relaxation properties of the samples, which are to be...

Electrical-impedance measurements have been made in the frequency range 5 Hz to10 MHz in pure poly(ethylene oxide) having a molecular weight of 600 000 from 254 K nearly up to the melting point of the crystalline phase (about 330 K). As the temperature approaches the melting point there are large increases in the realε′ and imaginaryε″ parts of the...

Summary Differential scanning calorimetric measurements in the early stage of isothermal crystal growth of polyethylene oxide are analysed in the light of irreversible thermodynamics. An accurate evaluation of the equilibrium melting temperature is done by fitting the thermograms obtained at different undercoolings and referring to the activation e...

Calorimetric measurements by DSC technique have been made in pure polyethylene glycol (PEG) and oxide (PEO) polymers having a very wide molecular-weight range (from 600 to 4 000 000) and in PEO (MW 600 000)-NaSCN complexes. It was found that the melting temperature increases with increasing molecular weight, ranging from 293 K in the polymer with M...

When a material is submitted to periodic forced oscillations, it gives some important rheological parameters e.p. elastic module (E') and loss module (E'') respectively connected to the rigidity and damping or internal friction. The dynamic technique allows to evaluate the relaxation, structural and molecular processes characterizing the examined m...

The behavior with temperature of the dynamic elastic modulus E' in pure poly(ethylene) oxide and poly(ethylene) oxide-potassium thiocyanate solid blends in the region below and at the glass-to-rubber transition is explained in terms of two physical contributions: the first is due to the anharmonicity of vibrational modes; the second to the alphaa o...

Real and imaginary dielectric spectra of pure, and sodium thiocyanate (NaSCN) salt complexed polyethylene oxide (PEO) have been measured as a function of temperature in the region of the relaxation peak. The results support previous assumptions; the concentration of the amorphous phase and the conductivity depend on the salt content. In this temper...

In this work, we present the results from dielectric measurements on soybean lecithin/isooctane/water gel. The pure solvent and the solution of lecithin in isooctane are also investigated for comparison. A low-frequency dielectric dispersion of the complex permittivity epsilon* is evidenced in the gel and analyzed within the framework of the phenom...