Nuova ricerca

Paola MISELLI

Personale tecnico amministrativo
Dipartimento di Ingegneria "Enzo Ferrari"

Home |


Pubblicazioni

2019 - Novel engineered lipid-based nanoparticles for pulmonary tuberculosis inhalation therapy [Poster]
Maretti, Eleonora; Truzzi, Eleonora; Costantino, Luca; Rustichelli, Cecilia; Martins Lima, Eliana; Leite Nascimento, Thais; Siligardi, Cristina; Gualtieri, Eva Magdalena; Miselli, Paola; Buttini, Francesca; Leo, Eliana Grazia; Iannuccelli, Valentina
abstract

Priorities to achieve the WHO goal of ending tuberculosis (TB) epidemic by 2030 include new drug treatments to simplify and shorter conventional drug regimens. TB is caused by Mycobacterium tuberculosis residing and surviving inside alveolar macrophages (AM). Considering that 75-80% of cases of infection remain localized in the lungs, the easiest and most successful therapy could involve the inhalation route offering benefits in terms of patient’s autonomy and compliance, by-passing hepatic metabolism, reducing dose amount, dose frequency, and treatment duration, thus minimising the risk of drug-resistant mutants, toxicity, and side effects. Inhalable powder formulations of repurposed drugs entail engineering techniques such as micro- or nanoparticulate carriers enabling drug emission by Dry Powder Inhaler devices, deposition onto alveolar epithelia, and transport into AM. Within this context, Solid Lipid Nanoparticle assemblies (SLNas) loaded with rifampicin, a clinically useful anti-TB drug, were produced by processing accepted excipients for DPI formulations through an optimized methodology that avoids organic solvents and is suitable for a large-scale production. The prototypes were functionalized by means of newly synthesized AM receptor-specific targeting agents as the ligands anchored on SLNas surface without chemical reactions. In vitro and in vivo preclinical studies highlighted functionalized SLNas with adequate respirability performance, safety, AM internalization ability, and mice lung deposition in an encouraging perspective of a potential efficacious pulmonary TB therapy. This research was supported by a grant on the project “FAR interdisciplinare 2017” from the University of Modena and Reggio Emilia, Modena, Italy (PI Prof. Luca Costantino)

2019 - Self-assembled organogelators as artificial stratum corneum models: key-role parameters for skin permeation prediction [Articolo su rivista]
Maretti, Eleonora; Rustichelli, Cecilia; Miselli, Paola; Leo, Eliana Grazia; Truzzi, Eleonora; Iannuccelli, Valentina
abstract

Self-assembled organogelators were explored as artificial stratum corneum (SC) models for the in vitro skin permeation assessment. Four SC models consisting of binary (organogels) or ternary (microemulsion-based organogels) mixtures were developed using stearic acid, tristearin, or sorbitan tristearate, at two different concentrations, gelled in squalene. The permeation of lipophilic butyl-methoxydibenzoylmethane and hydrophilic methylene blue as the permeant compounds across the SC models was compared with ex vivo experiments using excised porcine ear skin. A multi-analytical approach was adopted to provide detailed understanding about organogelator organization within the SC models and find possible parameters playing key-roles in SC permeation prediction. The SC models were investigated for gelling properties and microstructure. Parameters such as gel occurrence, organogelator concentration, and rheological properties appeared as negligible conditions for skin permeation prediction. Conversely, arrangement packing, interactions, and crystallinity extent of the self-assembled organogelator were found to play a fundamental role in the simulation of SC barrier function according to the permeant feature.

2019 - The Impact of Lipid Corona on Rifampicin Intramacrophagic Transport Using Inhaled Solid Lipid Nanoparticles Surface-Decorated with a Mannosylated Surfactant [Articolo su rivista]
Maretti, Eleonora; Rustichelli, Cecilia; Gualtieri, Eva Magdalena; Costantino, Luca; Siligardi, Cristina; Miselli, Paola; Buttini, Francesca; Montecchi, Monica; Leo, Eliana Grazia; Truzzi, Eleonora; Iannuccelli, Valentina
abstract

The mimicking of physiological conditions is crucial for the success of accurate in vitro studies. For inhaled nanoparticles, which are designed for being deposited on alveolar epithelium and taken up by macrophages, it is relevant to investigate the interactions with pulmonary surfactant lining alveoli. As a matter of fact, the formation of a lipid corona layer around the nanoparticles could modulate the cell internalization and the fate of the transported drugs. Based on this concept, the present research focused on the interactions between pulmonary surfactant and Solid Lipid Nanoparticle assemblies (SLNas), loaded with rifampicin, an anti-tuberculosis drug. SLNas were functionalized with a synthesized mannosylated surfactant, both alone and in a blend with sodium taurocholate, to achieve an active targeting to mannose receptors present on alveolar macrophages (AM). Physico-chemical properties of the mannosylated SLNas satisfied the requirements relative to suitable respirability, drug payload, and AM active targeting. Our studies have shown that a lipid corona is formed around SLNas in the presence of Curosurf, a commercial substitute of the natural pulmonary surfactant. The lipid corona promoted an additional resistance to the drug diffusion for SLNas functionalized with the mannosylated surfactant and this improved drug retention within SLNas before AM phagocytosis takes place. Moreover, lipid corona formation did not modify the role of nanoparticle mannosylation towards the specific receptors on MH-S cell membrane.

2018 - Self-assembling organogelators for artificial stratum corneum models: key-role parameters in skin permeation prediction [Poster]
Iannuccelli, V.; Maretti, E.; Rustichelli, C.; Miselli, P.; Truzzi, E.; Leo, E.
abstract

The development of in vitro methods to predict in vivo percutaneous absorption of bioactive molecules is a challenge to which the researchers are called in order to eliminate or reduce the pharmacological and toxicological tests on animal models. Artificial stratum corneum (SC) models obtained by self-assembled oganogelators were designed for skin permeation assessment of butyl methoxydibenzoylmethane (BMDBM, log Po/w = 4.68) and methylene blue (MB, log Po/w = 0.91). A multi-analytical approach was adopted to provide detailed understanding about the gelator organization within the models and find possible parameters playing a key-role in in vivo and ex vivo SC permeation prediction. The evaluation of in vitro skin permeation data compared with those obtained ex vivo and previously in vivo on humans for BMDBM showed good correlations vitro/ex vivo and vitro/vivo for both butyl BMDBM, as the lipophilic permeant, and MB, as the hydrophilic permeant, by using TS20 as well as both STS and ME models. With the aim of providing detailed understanding about the organogelator behaviour and organization within the models and find possible parameters playing a key-role in SC permeation prediction a multi-analytical approach was adopted. All the models did not flow upon tube tilting and could be described as gels, with the exception of STS10 model that appeared as thick liquid being gelator concentration lower than mgc value. Unlike SA and TS models that exhibited networks capable of immobilizing completely the solvent, STS and ME10 models revealed the syneresis phenomenon according to gelator concentration. The actual presence of water within STS aggregates (reverse micelles) of ME models was demonstrated by means of TG/DTA analysis showing two thermal events in the range of about 50-130°C related to removal of water molecules. Unlike the pure gelators, XRPD profiles from all the SC models exhibited a broad peak at about 20° 2θ indicating the presence of a networked structure of the gelators where the width of the peak at half maximum is dependent on the crystallinity of the sample, which in turn is dependent on non-covalent interactions amongst the gelator molecules responsible for the formation of an ordered structure. Intermolecular interactions also arisen from FT-IR spectra showing subsided ester group stretching in TS, STS, and ME models. Architectural arrangements of the organogelators within TS, STS, and ME models, as outlined by microscopy analyses, involved round or worm-like architectures of spherulitic clusters. Under polarized light, the occurrence of birefringence revealed the so-called “maltese crosses” in STS models that are characteristic of liquid crystals with lamellar structures. The results demonstrated the relevant role of both the arrangement of gelator packing and crystallinity extent in mimicking SC in vivo/ex vivo skin permeation of both lipophilic and hydrophilic compounds. These findings could account for the behaviour and development of other artificial skin models involving different materials for the skin permeation prediction.

2017 - Failure analysis of glazed LAS glass-ceramic containing cerium oxide [Articolo su rivista]
Barbi, Silvia; Miselli, Paola; Siligardi, Cristina
abstract

In this study a deep investigation of the correlation between microstructure and mechanical properties was performed on glass-ceramic materials containing cerium oxide. The glass-ceramic materials investigated were lithium-aluminum silicate based (LAS), obtained through different thermal cycles from the same parent glass. The mechanical properties were tested on the glass-ceramics with and without the application of a glaze. All the glass-ceramics were characterized by means of scanning electron microscopy (SEM), also in field emission guns geometry (FEG), energy-dispersive spectrometry (EDS), X-Ray diffraction (XRD), and 3-points mechanical flexural strength resistance test. This study has revealed that the microstructure of the glass-ceramic is mainly affected by the heating treatments holding times. The application of a glass coating leads to the formation of cerium oxide crystals at the glaze/glass-ceramic interface. This phenomenon is one of the main principal causes of the mechanical properties failure when a glaze is applied.

2017 - Temperature-induced microstructural changes of fiber-reinforced silica aerogel (FRAB) and rock wool thermal insulation materials: A comparative study [Articolo su rivista]
Siligardi, Cristina; Miselli, Paola; Francia, Elena; Gualtieri, Eva Magdalena
abstract

The strive for improved energy efficiency in the building sector has motivated extended research on high-performance thermal insulation materials, leading to new products available on the market. Fiber-reinforced aerogel is a state-of-the-art material suitable as a substitute for traditional ones such as rock wool, especially for retrofitting and refurbishment of historic buildings where interior insulation may be the only alternative. In view of fire safety, commercial products are already tested and classified according to European standards. However, these tests do not give information on microstructural changes which is important to gain full understanding of the material. Knowledge of the reaction dynamics leading to functional changes of the material is needed in order to take actions to improve product quality. Here, the thermally induced microstructure development of fiber-reinforced silica aerogel blankets and rock wool were investigated using in-situ techniques such as thermogravimetry and hot stage microscopy. In addition, X-ray powder diffraction and Scanning electron microscopy analyses were performed ex-situ on thermally treated materials. Flammability was evaluated using cone calorimetry. The results obtained for the two different materials were compared and discussed in view of relationship between microstructure development and fire performance.

2016 - Characterization of natural clays from italian deposits with focus on elemental composition and exchange estimated by edx analysis: potential pharmaceutical and cosmetic uses [Articolo su rivista]
Iannuccelli, Valentina; Maretti, Eleonora; Sacchetti, Francesca; Romagnoli, Marcello; Bellini, Alessia; Truzzi, Eleonora; Miselli, Paola; Leo, Eliana Grazia
abstract

Purification processes performed on natural clays to select specific clay minerals are complex and expensive and can lead to over-exploitation of some deposits. The present study aimed to examine physicochemical (mineralogy, morphology, size, surface charge, chemical composition, cation exchange capacity [CEC], and pH) and hydration (swelling, wettability, water sorption, and rheological behavior) properties of three native clays from Italian deposits for potential pharmaceutical and cosmetic uses due to the presence of phyllosilicate minerals. Particular emphasis was placed on energy dispersive X-ray (EDX) microanalysis coupled with the ‘cesium method’ to assay clay elemental composition and CEC. One bentonite of volcanic origin (BNT) and two kaolins, one of hydrothermal origin (K-H) and another of lacustrine-fluvial origin (K-L), were evaluated in comparison with a commercial, purified bentonite. The CEC assay revealed the complete substitution of exchangeable cations (Na+ and Ca2+) by Cs+ in BNT samples and CEC values consistent with those of typical smectites (100.64 7.33 meq/100 g). For kaolins, partial substitution of Na+ cations occurred only in the K-L samples because of the interstratified mineral component which has small CEC values (11.13 5.46 meq/100 g for the K-H sample and 14.75 6.58 meq/100 g for the K-L sample). The degree of isomorphous substitution of Al3+ by Mg2+ affected the hydration properties of BNT in terms of swelling, water sorption, and rheology, whereas both of the poorly expandable kaolins exhibited significant water-adsorption properties. The EDX microanalysis has proved to be of considerable interest in terms of providing more information about clay properties in comparison with other commonly used methods and to identify the role played by both chemical and mineralogical composition of natural clays for their appropriate use in pharmaceutical and cosmetic fields.

2014 - Calibration and use of the heating microscope for indirect evaluation of the viscosity and meltability of archeological glasses [Articolo su rivista]
Montanari, F.; Miselli, P.; Leonelli, C.; Boschetti, C.; Henderson, J.; Baraldi, P.
abstract

The heating microscope is a widely used instrument in many industrial applications, especially in the ceramic field, to obtain information on the sintering behavior and, indirectly, on the viscosity curve of glass. It is therefore important for the study of glass technology. Usually, heating microscopes work by taking images of the sample outline, during a preset thermal cycle, which define five characteristic temperatures corresponding to particular shapes of the specimen. The first two characteristic temperatures can also be extracted from the sintering curves provided by the instrument. In agreement with three published models, the five temperatures are associated with five viscosity values, producing the two best-fitting plots (Log10(η) - T). In this work, the heating microscope was calibrated using a glass with known properties, to determine the most reliable model, so that it can be applied successfully in the field of archeological science. The selected methodologies were used to analyze two opacified Roman mosaic glass tesserae excavated in Pompeii, previously characterized chemically. A Pompeiian transparent glass, sampled from a large block of base (raw) glass, and its experimental reproduction were also studied. Finally, the relationship between the opacifiers and the thermal behavior of base glass was investigated. © 2013 The American Ceramic Society and Wiley Periodicals, Inc.

2013 - Application of heating microscopy on sintering and melting behaviour of natural sands of archaeological interest [Articolo su rivista]
Montanari, F.; Boschetti, C.; Miselli, P.; Hanuskova, M.; Baraldi, P.; Leonelli, C.
abstract

In antiquity, beach sand was one of the main raw materials for glass-making and for the production of other vitreous materials, like Egyptian blue and faience. During the 1st century AD, glass and pigments manufacturing industry was active along the Gulf of Naples, Italy, where we sampled four littoral sands. Samples were analyzed with different techniques: chemical analysis was performed by means of X-Ray Fluorescence (XRF) and mineralogical analyses with X-Ray Powder Diffraction (XRPD) and Raman Spectroscopy. The complete sintering to melting thermal behaviour of the four sands was studied by heating microscopy or hot-stage microscope (HSM) equipped with an high resolution camera capable to collect sample profile during heating. The effect of the grain size on the sintering curves, which were automatically elaborated by specimen profile transformation, was also investigated. Finally, some deductions about the granulometry effect and the presence of alkaline and alkaline-earth oxides on sintering and melting behaviour were drawn. All the four sands were found suitable for highly sintered manufacts rather than glasses, to reach complete amorphous materials the addition of fluxes was necessary.

2013 - Sintering behaviors of two porcelainized stoneware compositions using pegmatite and nepheline syenite minerals [Articolo su rivista]
Tchakounte Bakop, T.; Tene Fongang, R. T.; Melo, U. C.; Kamseu, E.; Miselli, P.; Leonelli, C.
abstract

Semi-vitreous bodies, with flexural strength of ~78 MPa and water absorption of ~0.4 % for the optimal maturated specimens, were successfully prepared with solid solutions of pegmatite and nepheline syenite, respectively, for the full dense (P) and relatively porous composition (G). Despite the similarity on the bulk chemical composition of the two formulations, it was found that their thermal behaviors were significantly affected by the action of CaO on the flux system considered leading to earlier vitrification of P specimens with high flexural strength as from 1,175 C. Conversely, the flexural strength of G specimens increases progressively with soaking time and temperature development up to 1,225 C. The positive action of 5 mass% of CaO in the vitrification range of pegmatite solution, the relative low temperature of maturation of the semi-vitreous matrices, and the results of water absorption allow us to describe the formulations studied to offer promising potential in the production of sustainable and low-cost porcelainized stoneware. The high strength of P at relatively low temperature could be explained by the matrix-strengthening theory, while the extent of crystallization of G could be ascribed to the mullite theory. © 2013 Akadémiai Kiadó, Budapest, Hungary.

2012 - Full quantitative phase analysis of hydrated lime using the Rietveld method [Articolo su rivista]
Gualtieri, Eva Magdalena; Romagnoli, Marcello; Miselli, Paola; Cannio, Maria; Gualtieri, Alessandro
abstract

Full quantitative phase analysis (FQPA) using X-ray powder diffraction and Rietveld refinements is a well-established method for the characterization of various hydraulic binders such as Portland cement and hydraulic limes. In this paper, the Rietveld method is applied to hydrated lime, a non-hydraulic traditional binder. The potential presence of an amorphous phase in this material is generally ignored. Both synchrotron radiation and a conventional X-ray source were used for data collection. The applicability of the developed control file for the Rietveld refinements was investigated using samples spiked with glass. The results were cross-checked by other independent methods such as thermal and chemical analyses. The sample microstructure was observed by transmission electron microscopy. It was found that the consistency between the different methods was satisfactory, supporting the validity of FQPA for this material. For the samples studied in this work, the amount of amorphous material was in the range 2–15 wt.%.

2011 - Influence of CaO-ZrO2-Al2O3-SiO2 glass-ceramic frits on the technological properties of porcelain stoneware bodies [Articolo su rivista]
Siligardi, Cristina; Miselli, Paola; Lusvarghi, Luca; M., Reginelli
abstract

In the present work, the effect of the addition to a porcelain stoneware body of glass-ceramic frits belonging to the CaO-ZrO2-Al2O3-SiO2 (CZAS, containing 1, 3, 5, 10 mol% of Al2O3) system as replacement of the “state of art” frit belonging to CaO-ZrO2-SiO2 system (CZS) was evaluated. The firing process was performed in a furnace able to complete the thermal cycle in 50 min, in order to simulate the industrial process.Technological properties such as water absorption, firing shrinkage, flexural strength, thermal expansion behaviour were measured. Aesthetical properties were also evaluated. X-ray diffraction and scanning electron microscopy studies were also carried out to analyse the microstructure and the phase compositions of the studied samples. It was found that the sample containing the CZAS frit with 5%mol of Al2O3 shows, in general, the best combination of properties in term of mechanical, physical and aesthetical properties

2010 - Recycling of screen glass into new traditional ceramics materials [Articolo su rivista]
Andreola, Nora Maria; Barbieri, Luisa; F., Bondioli; Lancellotti, Isabella; Miselli, Paola; Ferrari, Anna Maria
abstract

The Cleaned cathode ray tube (CRT) glass comes from the dismantling plant of TV and PC color kinescopes and has been used to completely replace both feldspathic and inert components of a traditional ceramic body. Panel glass has been added (up to 20 wt%) to a mixture of two commercial ball clays in order to obtain laboratory tiles sintered at 12101C. Densification has been studied according to ISO rules, while sinterability has been estimated by optical dilatometry. The samples obtained showed main properties similar to commercial ceramic floor and/or wall tiles.

2009 - Controllo del contenuto di cristobalite in ceramica sanitaria in funzione della ricottura [Articolo su rivista]
Ferrari, Anna Maria; Miselli, Paola
abstract

Il processo di cottura dei sanitari rappresenta la fase più delicata dell’intero processo di fabbricazione poiché determina quell’insieme di trasformazioni chimicofisiche che conferiscono al prodotto finito le caratteristiche funzionali, tecniche ed estetiche che ne determinano le sue prestazioni.La trasformazione cristobalite alfa → cristobalite beta che si manifesta durantele fasi di consolidamento e densificazione, è caratterizzata da una notevole variazione di volume specifico che determina l’insorgere di microfratture durante il raffreddamento o l’eventuale ricottura dei pezzi.Al fine di comprendere l’effetto del numero di cicli termici di cottura sul contenuto di cristobalite e quindi sui difetti o fratture che si manifestano nei pezzi ceramici è statasa effettuataun’analisi quantitativa delle fasi presenti nei campioni, mediante diffrazione a raggi X.

2009 - La calce in architettura e nel restauro: un forum, un libro, un progetto di ricerca scientifica [Articolo su rivista]
Bondioli, Federica; Miselli, Paola; A., Rattazzi
abstract

Il Forum Italiano Calce (www.forumcalce.it) è una Associazione che nasce come luogo di incontro per tutti coloro che studiano, producono e utilizzano la calce in architettura e nel restauro. Il Forum promuove lo sviluppo di esperienze e di conoscenza dell’impiego della calce nel costruito e nel restauro di manufatti di interesse storico, artistico e monumentale attraverso: lo scambio, il confronto e la diffusione di notizie e informazioni sul mondo della calce; l’organizzazione di Congressi, Seminari, Incontri e Corsi; incoraggiando la ricerca scientifica e pratica sulla calce, le malte di calce, le pitture a calce, etc.; sostenendo lo sviluppo di tecniche appropriate a livello industriale e artigianale per la produzione di calce aerea e/o idraulica naturale; favorendo contatti tra gli iscritti che abbiano il desiderio di condividere esperienze e conoscenze sull’argomento. Una delle prime azioni è stata quella di siglare importanti accordi di ricerca scientifica con Università, CNR, Enea e altri centri. Tra gli altri, il Forum Italiano Calce ha recentemente siglato un protocollo di intesa per attività didattiche, di studio e di ricerca con il Dipartimento di Ingegneria dei Materiali e dell’Ambiente dell’Università di Modena e Reggio Emilia.Tra le prime azioni attivate a seguito di questa intesa, l’avvio di uno studio volto a determinare i parametri chimici, fisici e reologici di prova sul grassello di calce che possano fornire elementi di giudizio sufficienti a determinare la qualità del prodotto, che si sta per acquistare e/o impiegare. In particolare verranno definiti i metodi e parametri di prova ed eventuali norme metodologiche di riferimento che saranno successivamente sottoposti all’attenzione delle enti di normativa italiano e europeo, per un auspicabile aggiornamento delle norme che attualmente regolano la produzione e commercializzazione della calce aerea.

2009 - Use of noncontact dilatometry for the assessment of the sintering kinetics during mullitization of three kaolinitic clays from Cameroon [Articolo su rivista]
Kamseu, Elie; Rizzuti, Antonino; Miselli, Paola; Veronesi, Paolo; Leonelli, Cristina
abstract

Noncontact dilatometry, compared to differential scanning calorimetry (DSC), was used together with scanning electron microscopy and densification behavior studies to investigate the parameters that govern the kinetics of transformation of kaolin to mullite during sintering.Three kaolinitc clays from Cameroon, with different SiO2/Al2O3 molar ratio, were examined. The temperatures of mullite nucleation were 973, 979, and 984 deg C at 5 deg C/min heating rate, respectively, for values of SiO2/Al2O3 molar ratio equal to 4.22, 2.22, and 2.08. At 20 deg C/min heating rate, the temperatures are shifted to higher values, 992, 997, and 1,001 deg C. The mullitization phenomenon, which includes a first step of nucleation and a second one of crystal growth, presented activation energy in the range of 650–730 kJ/mol, depending on the nature of the sample investigated. These values, obtained by noncontact dilatometer measurements, were comparable to those obtained by means of DSC and are in agreement with literature values. The difference in sintering kinetics for the three kaolinitic clays could explain the different morphologies obtained for the mullite grains.

2008 - New Clay Based Ceramics Using Cathode Ray Tube (CRT) Glass as Secondary Raw Material [Relazione in Atti di Convegno]
Andreola, Nora Maria; Barbieri, Luisa; F., Bondioli; Ferrari, Anna Maria; Lancellotti, Isabella; Miselli, Paola
abstract

Cleaned panel glass was added in different percentages (5-20 wt%) to a mixture of two commercial ball clays in order to formulate new clay based ceramics replacing completely both fluxing and inert components of a traditional ceramic body. The samples obtained in laboratory were fired in industrial cycle (Tmax 1200oC for 40 min). The samples obtained were characterized from densification, microstructural, mechanical and aesthetical point of view. From the results achieved samples tiles, containing up to 15 wt% of panel glass, could be classified into BIa group (WA<0.5%) (UNI EN 14411 all.G) corresponding to impervious tiles used mainly for floor or wall covering.

2007 - Characterisation of porcelain compositions using two china clays from Cameroon [Articolo su rivista]
Kamseu, Elie; Leonelli, Cristina; Boccaccini, Dino Norberto; Veronesi, Paolo; Miselli, Paola; Pellacani, Gian Carlo; U., CHINJE MELO
abstract

Mayouom and Ntamuka china clays, from Cameroon were used to produce porcelain bodies. Two soft porcelain formulations: PSI (withMayouom) and PSII (with Ntamuka) and one hard porcelain, PH (with both Mayouom and Ntamuka) were prepared.The maximum density and flexural resistance for these formulations were obtained at 1200 8C for PSI, 1225 8C for PSII and 1350 8C for PH.Their properties and values were, respectively, density (2.42, 2.58 and 2.59 g/cm3), water absorption (0.15, 0.15 and 0.02%), porosity (4.3, 5.3 and4.2%) and flexural strength (148, 148 and 160 MPa). In addition to varying amounts of liquid phase, the soft porcelain formulations containedmullite and quartz crystals while the hard porcelains contained quartz and more intense mullite peaks. At 1250 8C PSI and PSII presented a selfglazingphenomenon which gave significant brightness and high aesthetic quality. PH with lower alkali (especially Na+) did not self-glaze even at1400 8C. Considering the soft porcelain formulations, the higher amounts of TiO2 (0.83%) and Fe2O3 (0.31%) in PSI (with Mayoum clay) resultedin a higher sintering effect at lower temperatures, giving lower water absorption and higher resistance. Both Mayouom and Ntamuka china clayswere found to be suitable raw materials for the production of porcelain stoneware tiles. Ntamuka could also be used for the manufacture of optimalquality whitewares.

2007 - Multitechnique approach to V-ZrSiO4 pigment characterization and synthesis optimization [Articolo su rivista]
C., Caselli; Lusvardi, Gigliola; Malavasi, Gianluca; Menabue, Ledi; Miselli, Paola
abstract

The synthesis of blue-turquoise V-ZrSiO4 Pigment from an aqueous solution of Na2O center dot 2.5SiO(2)center dot 5H(2)O (soluble glass) and the citrate complexes of zirconium and vanadium was investigated as a function of V2O5 contents, mineralizers (NaF and/or LiNO3) addition and thermal cycle. Blue V-ZrSiO4 was obtained without mineralizers addition for the (ZrO2)(SiO2)(V2O5)(0.09) composition; QPA analysis shows that a thermal cycle 3 h long, T-max = 800 degrees C, can lead to a 78.0 wt.% of ZrSiO4. The addition of mineralizers gave rise to 73.0 wt.% of ZrSiO4 for the (ZrO2)(SiO2)(NaF)(0.16)(V2O5)(0.09)(LiNO3)(0.09) composition and a thermal cycle 2 h long, T-max = 800 degrees C. LiN03 can favour both ZrSiO4 formation and a fairly blue colour, up to LiNO3 = 0.09 moles; NaF seems effective on ZrSiO4 formation only when mixed with LiNO3 through the formation of LiF HT-XRD analysis of this composition agrees with QPA results at the corresponding temperature; ZrSiO4 was present (64.0 wt.%) at 730 degrees C and good colour parameters were obtained. (c) 2006 Elsevier Ltd. All rights reserved.

2005 - The anorthite-diopside system: Structural and devitrification study. Part II: Crystallinity analysis by the Rietveld-RIR method [Articolo su rivista]
Barbieri, Luisa; Bondioli, Federica; Lancellotti, Isabella; Leonelli, Cristina; Montorsi, Monia; Ferrari, Anna Maria; Miselli, Paola
abstract

Abstract:The crystallization behavior of 10 binary glasses belonging to the CaO–MgO–Al2O3–SiO2 quaternary system and two glasses corresponding to anorthite and diopside composition was investigated by X-ray diffraction, thermal, and thermomechanical analyses, and scanning electron microscopy. Particular emphasis is laid on the quantitative X-ray diffraction analysis by the Rietveld–reference intensity ratio combined procedure, which seems to be a useful tool to obtain time–temperature–transformation diagrams. Results showed that to obtain glass–ceramics with a significant crystalline phase presence, it is necessary to treat samples at 1000°C for 4 h or at 1100°C for 1 h.

2002 - Deflocculant capability of sodium tripolyphosphates (TTT) [Articolo su rivista]
Bondioli, Federica; Ferrari, Anna Maria; Miselli, Paola
abstract

In this paper the deflocculant capability of 3 different tripolyphosphate has been evaluated and interpreted by mineralogical and chemical composition.

2002 - Il metodo Rietveld nello studio della capacità deflocculante di tripolifosfati di sodio [Articolo su rivista]
Bondioli, Federica; Ferrari, Anna Maria; Miselli, Paola
abstract

In questo articolo la capacità deflocculante di diversi tripolifosfati (TTT) è messa in corralazione con la loro analisi mineralogica e chimica

2002 - L'analisi di densita' per determinare la purezza di ossidi utilizzati per smalti ceramici [Relazione in Atti di Convegno]
Miselli, Paola; Romagnoli, Marcello
abstract

La misura della densità mediante picnometria ad Elio viene testata come metodo rapido di misura del grado di purezza di ossidi utilizzati per la produzione di smalti ceramici.

2000 - Techniques used to determine porosity [Articolo su rivista]
Andreola, Nora Maria; Leonelli, Cristina; Romagnoli, Marcello; Miselli, Paola
abstract

A comparison is made of the principal techniques (mercury porosimetry, helium pycnometry, image analysis and water absorption) that are used to measure porosity

1995 - Pigmenti inorganici sintetici contenenti cobalto per la colorazione del gres porcellanato [Articolo su rivista]
Ferrari, Anna Maria; Leonelli, Cristina; Manfredini, Tiziano; Miselli, Paola; Monari, G.; Pellacani, G. C.
abstract

L'articolo riporta uno studio sulla possibilità di utilizzare ossido, alluminato e silicato di cobalto per colorare piastrelle di gres porcellanato. L'aggiunta dei pigmenti all'impasto base ne aumenta il ritiro lineare causando in alcuni casi il rigonfiamento delle piastrelle. Controllando la quantità e il tipo di pigmento è possibile realizzare diverse sfumature di blu e ottenere maggiore brillantezza.