Cristina Leonelli

Cristina Leonelli
Università degli Studi di Modena e Reggio Emilia | UNIMO · Department of Engineering "Enzo Ferrari"

Ph. D.

About

483
Publications
107,577
Reads
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10,456
Citations
Citations since 2017
135 Research Items
6293 Citations
201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
Additional affiliations
November 2000 - present
Università degli Studi di Modena e Reggio Emilia
Position
  • Professor (Full)
Description
  • The Department of Engineering "Enzo Ferrari" - DIEF - is active from 30.06.2012 in teaching, research and technology transfer collecting the cultural heritage of the previous Faculty of Engineering founded in 1990.

Publications

Publications (483)
Article
Italian volcanic quarry scraps, with fine particle size and of little market interest, have been considered for the manufacturing of lightweight geopolymers and highly porous foams. Both powders have been alkali activated with NaOH solution at 8M and 3M, respectively. Geopolymers were characterized in terms of density, porosity, humidity absorption...
Article
Full-text available
In the present study, the performances of the end products prepared using calcined iron-rich laterite at 600 °C (LAT600) with different alkaline solution (AS) to calcined laterite (AS/LAT600) mass ratio (0.45-0.65) were investigated. The effect of AS/LAT600 mass ratio on microstructural and mechanical properties of consolidated geopolymer samples,...
Article
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Alkali activated binders, based on an aluminosilicate powder that is activated by an alkaline solution, have been proven to encapsulate a wide number of different wastes, both in the form of liquids and solids. In this study, we investigated the effect that the addition of a spent abrasive powder, mainly composed of corundum grains (RC), had on the...
Article
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A new approach for the synthesis of Y3Al2Ga3O12 (YAGG) nanophosphors allowing the preparation of crystallites with sizes starting from 45 nm is presented. The controllability of the energy and trap density of the resulting material samples by annealing temperature was confirmed by thermoluminescence (TL) measurements. It has been shown that the ann...
Article
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Weathered bottom ash (WBA) from municipal solid waste incineration is a calcium alu-minosilicate-rich material mainly used in construction and civil engineering as a secondary aggregate. However, its use is also being considered as a precursor in the manufacture of alkali-activated binders (AA-WBA). This preliminary research aimed to deepen underst...
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Over the years, many materials have been used to restore buildings, paintings, ceramics, and mosaic pieces exhibiting different types of dyes and colour hues. Recently, geopolymers have been used for restoration purposes owing to their high chemical and mechanical resistance. In this work, white metakaolin was used to obtain white geopolymers, cure...
Article
Glass recycling reduces the amount of waste to be treated or disposed in landfills, allowing both to limit environmental damage and to save on the costs of transportation and disposal of waste. In this paper, an advantageous method for recycling glass containers (bottles, jars, jars for food, glasses, and cans for drinks, etc.) is presented. The gl...
Article
The high amount of organic and inorganic wastes has increased the attention to new strategies aiming to reduce the waste disposals. Organic wastes, such as tomato wastes (TWs), are a good source from which the red color can be obtained. Among the different technologies, the geopolymers had been proposed as a powerful technology able to incorporate...
Article
A microstructural approach to the prediction of heat flux transport in porous geopolymers is used experimentally to under- stand the effects of the pore size distribution and pores connectivity to the transfer of the thermal flux across the porous network of geopolymers. Controlling the mix design and the concentration of porogen agent, capillary p...
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This article highlights recent experimental advances in the use of inorganic substances in the encapsulation of pollutants and, in particular, discusses the potential applicability and constraints of the geopolymerization process for the treatment of wastewater containing chromium. A great percentage of waste containing chromium salts is produced b...
Article
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Five different alkali activators were prepared by mixing sodium hydroxide with molar concentrations of 8, 10, 12, 14 and 16 M and sodium silicate, Na2SiO3 in volume ratio 1:1. The obtained alkaline activators were used for producing metakaolin/feldspathic rock-based geopolymer composites. These geopolymer composites were obtained by mixing differen...
Article
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Recycling corundum abrasive powder in metakaolin-based geopolymer formulations is proposed to reduce the amount of waste to be treated or disposed of in landfills, allowing to decrease ecological damage as well as to reduce transport costs for removal. The addition of waste corundum, as an important source of Al2O3, has proved to increase the sligh...
Article
Novel magnetic composites consisting of a polystyrene matrix containing La0.80Sr0.20Fe0.90Cu0.10O3-w (LSFC10) and La0.80Sr0.20Fe0.80Cu0.20O3-w (LSFC20) particles, each with two weight concentrations, 0.5% and 1.0%, are prepared by extrusion technique. The LSFC10 and LSFC20 filler phases are synthetized by citrate auto-combustion technique. From the...
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Biodiesel obtained through the transesterification in methanol of vegetable oils, such as soybean oil (SO) and waste cooking oil (WCO), cannot be used as a biofuel for automotive applications due to the presence of polyunsaturated fatty esters, which have a detrimental effect on oxidation stability (OS). A method of upgrading this material is the c...
Article
Understanding the structural and meso-scale properties of alkali activated matrices subjected to high temperature treatment, provides useful information on the stability of their self-life service or, fire resistance in extreme environments. The current project focuses on the transformation of phase and structural bonds within kyanite-reinforced re...
Article
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Microwave-assisted synthesis of nanoparticles usually leads to a smaller and more uniformly distributed particle size compared to conventional heating (e.g., oil bath). Numerical simulation can help to obtain a better insight into the process in terms of temperature distribution or to evidence existing different temperature profiles and heating rat...
Article
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Alkali-activated foams (AAFs) are inorganic porous materials that can be obtained at temperatures well below 100°C with the use of inorganic wastes as aluminosilicate precursors. In this case, fly ash derived from a Slovenian power plant has been investigated. Despite the environmental benefits per se , due to saving of energy and virgin materials,...
Article
The challenge for sustainable development is now constraining scientists, and policymakers to consider alternative materials and processes requiring low energy consumption and low emissions while prioritizing local materials and industrial waste recycling. This study investigates ways to valorize marble waste powders to design a new class of inorga...
Article
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Soluble silica content and the concentration of hydrogen peroxide were used to achieve porous geopolymers with nano, meso and milliporosity. The use of rice husk ash as a partial replacement for metakaolin allows to maintain the SiO2/Al2O3 ratio between 1.93 and 2.71 and achieve layered bulks with the desired moisture buffering capacity. Stereo Opt...
Article
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The present study deals with the use of locally prepared rice husk ash (RHA)-based sodium silicate for alkaline activation of laterites (uncalcined (LNW) and calcined (LCA)). RHA-based activator (SSR) was prepared by adding as-collected RHA to 6 M NaOH at a solid/liquid mass ratio of 0.56. The various proportions of metakaolin (MK) and basalt powde...
Article
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The development of eco- friendly environmental and sustainable building materials having low thermal conductivity and optimal physic-chemical abilities ensuring passive thermal comfort is imperative in the global quest for the minimization of greenhouse-gases (GHG) emission and energy needs in homes. To attend this objective, the present work under...
Article
Concrete structures built in granite-based aggregate develop and proliferate contour-like cracks as they aged. Such cracks are often associated to alkali-aggregate reactions (AAR). Though, in most cases, the alkali-silica reaction (ASR) involving these aggregates has shown to be non-destructive to concretes, their contents of iron-contained mineral...
Article
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The synthesis, mechanical behaviour, and microstructure of metakaolin-based geopolymer mortar reinforced with quartz sand are presented in this investigation. Fine sand (quartz sand) aggregate were added in different proportions of 50, 60, 70 or 80 wt.% to prepare the fresh metakaolin-based geopolymer paste. The geopolymer mortar was achieved by a...
Chapter
Learning about the action of alkali on aluminosilicate materials (natural ones or proceeding from industrial activities) is an old ambition of the scientific community. A few of those challenges established by scientists in this field are raw materials, manipulation of reactions, properties of the precipitated products, and fields for the applicati...
Article
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A new method for fast and simple synthesis of crystalline TiO2 nanoparticles with photocatalytic activity was developed by carrying out a classic sol–gel reaction directly under vacuum. The use of microwaves for fast heating of the reaction medium further reduces synthesis times. When the solvent is completely removed by vacuum, the product is obta...
Article
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The aim of this paper is to promote the use of mine clay washing residues for the preparation of alkali activated materials (AAMs). In particular, the influence of the calcination temperature of the clayey by-product on the geopolymerization process was investigated in terms of chemical stability and durability in water. The halloysitic clay, a min...
Article
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This paper investigates the direct transformation of laterites (natural iron‐rich aluminosilicates) to cementi- tious composites with principal mineral phases being Gismondine and Stratlingite. The effects of particles size distribution and cement content (2 to 8 wt%) on the mechanical properties and microstructure of laterite‐ cement composites ar...
Article
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The type of aluminosilicate precursor used in the synthesis of geopolymer binders plays a huge role in the resulting performance. Thus, it is critical to understand the properties of precursors and how they influence the corresponding performance of geopolymer binders. In this study, metakaolin and meta halloysite are used as the aluminosilicate pr...
Article
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The treatment of tannery wastewaters is a complex task due to the complexity of the waste: a mixture of several pollutants, both anionic and cationic as well as organic macromolecules which are very hard to treat for disposal all together. Geopolymers are a class of inorganic binders obtained by alkali activation of aluminosilicate powders at room...
Chapter
Combustion synthesis (CS) represents a very attractive synthetic methodology for a wide variety of materials, including ceramics, intermetallic compounds as well as different kinds of composite materials, so that it can be efficiently exploited to join similar as well as dissimilar materials, through the direct in-situ synthesis of the joining mate...
Article
The exploitation of different kind of clayey waste (halloysitic, smectitic/illitic, kaolinitic) for the production of geopolymers in the view of a circular economy of mines is the main goal of this study. In particular, the addition of low percentages of metakaolin (5-15%) was evaluated to improve the chemical-physical properties and the consolidat...
Article
This study investigates the high performance of feldspathic solid solution-based geopolymer composites. The results show that a feldspathic solid solution with incongruent dissolution in an alkaline medium produces a differential amount of N-A-S-H+ polysialate geopolymer, depending on the mineral nature of the raw solid precursor. In turn, the pres...
Article
Marble sludge wastes (MSW) are investigated as solid precursors for the production of low-temperature calcium silicate hydrate (CSH). Calcined powder of MSW is ball-milled with rice husk ash (RHA) and the slurries are treated in the oven at 100°C for 24 h in a context where water evaporation is minimized. The initial CaO:SiO2 molar ratio varies fro...
Article
The influence of a microwave hybrid heat treatment (MHH) on the surface and in-depth mineralogical transformation of pre-sintered 3Y-PSZ was investigated. 3Y-PSZ samples were prepared by slip casting and sintered by conventional firing (1270 °C). Then, different MHH treatments from 5 to 15 min. at 1200 °C were applied to obtain a fully stabilized 3...
Article
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Food containers made from glass are separately collected from urban solid waste at 76% in most parts of Europe. The cullet glass finds its way to re-melting, while the debris is often disposed of. With this contribution, we suggest an upcycling process where glass debris is simply ground without any washing operation and added to an alkali-activate...
Article
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Alternative cementitious binders, based on industrial side streams, characterized by a low carbon footprint, are profitably proposed to partially replace Portland cement. Among these alternatives, alkali-activated materials have attracted attention as a promising cementitious binder. In this paper, the chemical stability of the matrix, in fiber-rei...
Article
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In this study we compare the leaching behavior and the antibacterial and cytotoxic properties of 100% slag or stone wool derived alkali activated materials. The antibacterial activity was measured as the inhibiting capacity against two Gram-negative bacterial strains, Escherichia coli and Pseudomonas aeruginosa and one Gram-positive bacterial strai...
Chapter
This chapter aims at comprehensively overview the application of microwave energy to the processing of biomasses, leading to the production of chemicals. It is devoted to an accurate description of the fundamentals at the basis of microwave-matter interaction, highlighting the main advantages, together with its limitations. The microwave hydrolysis...
Article
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Thermophysical and microstructural behavior of eleven tropical woods widely available and commonly used was investigated. Experimental measurements of thermal conductivity and thermal diffusivity of wood were performed using the heat flow meter and transient plane source technique. The results show values in the range of 0.2–0.37 mm2/s for thermal...
Article
The present work carried out the influence of curing cycles on the performance of laterite-based geopolymer composites. To do so, the end products were obtained by altering laterite with 15, 20, and 25 wt% of rice husk ash (RHA). Alkaline solution in a constant solid/liquid ratio of 0.35 was added together with fine and coarse aggregates (represent...
Article
Full-text available
The addition of yttria-stabilized zirconia and cerium oxide to this mica glass ceramic was found to increase mechanical properties and decrease chemical solubility. They were also found to be able to control translucency. X-ray diffraction showed no significant change in phase formation with phlogopite-Ca mica, fluorapatite and tetragonal zirconia...
Article
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Reuse of waste glass can significantly decrease the quantity of waste to be treated or disposed of in landfills, allowing to both diminish the ecological damage and to reduce the costs of transportation for removal. Geopolymer mixes with diverse percentages (20, 50 and 60 wt%) and with different grain size ranges (37 μm < diam < 53 μm; 75 μm < diam...
Article
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This research reports on the influence of particle size and distribution on the physical, mechanical and microstructural features of solid solutions (feldspathic materials) based inorganic polymer composites (IPCs). Both granite and pegmatite were ground to different degree of finess making four different granulometry with particles of 63, 80, 125...
Article
The physical, mechanical and microstructural properties of metakaolin/volcanic ash-based geopolymer composites were investigated, as well as the influence of the incorporation of a reactive silica from rice husk ash (RHA) in their performance. The geopolymer composites were designed by replacing metakaolin with volcanic ash, VA (10-30 wt%) and RHA...
Article
The main goal of this study is to investigate the effects of the calcium aluminate hydrate (CA04) and the mixture of calcium aluminate and silicate hydrates (CA04 + CS04) on the compressive strengths and the microstructure of metakaolin-based geopolymer cements. Bauxite, rice husk and eggshells were calcined and mixed in proper amounts to prepare C...
Article
Full-text available
In this study, the role of two reactive fillers, specifically a sand from a clay washing process as an alternative to waste glass powder and a commercial metakaolin (MK), into the geopolymerization process of waste clay-based materials was assessed. Three kinds of clayey wastes from mining operations-halloysitic, kaolinitic and smectitic clays-were...
Article
The first frontal geopolymerization (FGP) took place in the same reaction medium in which the frontal polymerization (FP) of 1,6-hexanediol diacrylate (HDDA) was occurring, thus giving rise to an organic-inorganic hybrid in one step in just a few minutes. Because of their exothermicity, the two reactions support each other and sustain propagating f...
Article
This paper presents the results of experimental evaluation of curing conditions on the microstructure and performance of geopolymer binders developed from iron-rich laterite soils. Two calcined iron-rich laterites namely LB600 and LY600 were used as solid precursors in the preparation of geopolymer binders. The geopolymer samples were cured at 20,...
Article
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Two calcined clays (halloysite and kaolinite clays at 700 °C) were used as solid precursors for geopolymer synthesis. This study compares the physicochemical properties of the both resulting geopolymer series heated at 200, 400, 600 and 800 °C. The end specimens were characterized using Optical Dilatometer, XRD, FTIR, MIP and SEM analyses. Results...
Article
Full-text available
Aiming to fulfil the sustainability criteria of future biorefineries, a novel biomass pretreatment combining natural deep eutectic solvents (NaDESs) and microwave (MW) technology was developed. Results showed that NaDESs have a high potential as green solvents for lignin fractionation/recovery and sugar release in the following enzymatic hydrolysis...
Article
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Volcanic rocks have been used for building activity by the inhabitants of important cities located on the slopes of Mt. Etna, Italy. In this paper, the potential use of volcanic residues (code 20 03 03—“Municipal waste” residues from road cleaning in the European Waste Catalogue (EWC)) for the production of alkali activated material, especially dev...
Article
Syntheses of cobalt‐iron oxide composites starting from cobalt acetate and iron acetylacetonate are carried out by microwave‐assisted solvothermal process, using ethylene glycol as the solvent and (polyvinylpyrrolidone) PVP, as the stabilizer. Indeed, the reaction mechanism in the presence of ethylene glycol is well understood with the role of PVP...
Article
The present study addresses the possibility of using a frequency‐controllable microwave source, that is, a solid‐state microwave generator, to rapidly and efficiently heat PET. Based on dielectric properties measurement of PET, numerical simulation has been used to model dedicated microwave applicators, suitable for the rapid reheating of PET granu...
Article
A nickel containing monomer, Ni(AAEMA)2 (AAEMA− = deprotonated form of 2‐(acetoacetoxy) ethyl methacrylate) is co‐polymerized with ethyl methacrylate (co‐monomer) and ethylene glycol dimethacrylate (cross‐linker). The obtained polymer is a green methacrylic resin containing Ni(II) centers homogeneously dispersed in the catalyst, which results insol...
Article
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Alkali-activated materials (AAMs) represent a promising alternative to conventional building materials and ceramics. Being produced in large amounts as aluminosilicate-rich secondary products, such as slags, they can be utilized for the formulation of AAMs. Slags are partially crystalline metallurgical residues produced during the high temperature...
Article
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Co-doped Ce3+, Cr3+ and Pr3+ yttrium–aluminium–gallium garnet powders of various sizes were obtained by co-precipitation method. The microstructure and morphology were investigated by XRPD, TEM and gas porosimetry. The luminescence properties were studied by excitation and emission spectra, quantum yield and decay times. Thermoluminescence measurem...
Article
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The investigation on the reticulation degree of volcanic alkali-activated materials, AAMs, were experimentally determined in terms of chemico-physical properties: weight loss after leaching test in water, ionic conductivity and pH of the leachate and compressive strength. Artificial neural network (ANN) was successfully applied to predict the chemi...
Chapter
Nowadays, perovskite-structured (e.g., ferrite, cobaltite, and manganite) and other oxide (e.g., titania, zirconia, and yttria) coatings are of great interest in industrial applications such microelectronics, metal corrosion protection, photocatalytic degradation of organic pollutants, and electrochemical energy conversion devices. Different techni...
Article
The thermal performance of pegmatite-based geopolymer composites is investigated. Dense and compact matrix was prepared replacing metakaolin with pegmatite in the range of 70–85 wt% and activate with sodium hydroxide/sodium silicate solution in 1:1 vol ratio. The products of geopolymerization, cured at room temperature for 28 days, were heated at 1...
Article
Full-text available
In this paper we evaluate the effect of isopropanol arising from the reagent Ti(O-iPr)4 on the long-term stability of nanoparticle size of TiO2 produced during a microwave assisted sol-gel synthesis. Different configurations of microwave apparatus have been considered: the synthesis was carried out both in vessel or flask, and both performing or no...