The increase in concrete structures’ durability is a milestone to improve the sustainability of b... more The increase in concrete structures’ durability is a milestone to improve the sustainability of buildings and infrastructures. In order to ensure a prolonged service life, it is necessary to detect the deterioration of materials by means of monitoring systems aimed at evaluating not only the penetration of aggressive substances into concrete but also the corrosion of carbon-steel reinforcement. Therefore, proper data collection makes it possible to plan suitable restoration works which can be carried out with traditional or innovative techniques and materials. This work focuses on building heritage and it highlights the most recent findings for the conservation and restoration of reinforced concrete structures and masonry buildings.
Demolition activity plays an important role in the total energy consumption of the construction i... more Demolition activity plays an important role in the total energy consumption of the construction industry in the European Union. The indiscriminate use of non-renewable raw materials, energy consumption, and unsustainable design has led to a redefinition of the criteria to ensure environmental protection. This article introduces an experimental plan that determines the viability of a new type of construction material, obtained from crushed brick waste, to be introduced into the construction market. The potential of crushed brick waste as a raw material in the production of building precast products, obtained by curing a geopolymeric blend at 60 °C for 3 days, has been exploited. Geopolymers represent an important alternative in reducing emissions and energy consumption, whilst, at the same time, achieving a considerable mechanical performance. The results obtained from this study show that the geopolymers produced from crushed brick were characterized by good properties in terms of o...
The topic of sustainability of reinforced concrete structures is strictly related with their dura... more The topic of sustainability of reinforced concrete structures is strictly related with their durability in aggressive environments. In particular, at equal environmental impact, the higher the durability of construction materials, the higher the sustainability. The present review deals with the possible strategies aimed at producing sustainable and durable reinforced concrete structures in different environments. It focuses on the design methodologies as well as the use of unconventional corrosion-resistant reinforcements, alternative binders to Portland cement, and innovative or traditional solutions for reinforced concrete protection and prevention against rebars corrosion such as corrosion inhibitors, coatings, self-healing techniques, and waterproofing aggregates. Analysis of the scientific literature highlights that there is no preferential way for the production of “green” concrete but that the sustainability of the building materials can only be achieved by implementing simul...
The present paper assesses petrographic, mineralogical, chemical, and technological features of d... more The present paper assesses petrographic, mineralogical, chemical, and technological features of different zeolitic tuff samples from various western USA districts of the Basin and Range Province containing mainly erionite, mordenite, clinoptilolite/heulandite and phillipsite. The aim of this characterization is to evaluate the pozzolanic activity of these samples according to European normative UNI-EN 196/5 (Fratini test) to program a possible use as addition for blended cements. Petrographic and mineralogical results show that the two phillipsite-bearing tuffs have a higher theoretical Cation Exchange Capacity (CEC) than the other samples; technological characterization shows a pozzolanic behavior for all the samples but higher for the tuff samples containing phillipsite, which shows a higher reactivity with CaO. All the samples could be thus advantageously employed for the preparation of blended cements, potentially reducing CO2 emissions by 70–90%.
In this work, the design of a monolithic softener obtained by geopolymer gel conversion is propos... more In this work, the design of a monolithic softener obtained by geopolymer gel conversion is proposed. The softener used consists in a geopolymeric macroporous matrix functionalized by the co-crystallization of zeolite A and X in mixture. The dual nature of the proposed material promotes a softening process based on the synergistic effect of cation exchange and alkaline precipitation. A softening capacity of 90% and 54% for Ca2+ and Mg2+ respectively was attained in 24 h. In fact, the softener reported a Cation Exchange Capacity (CEC) value of 4.43 meq g−1. Technical features such as density, porosity and mechanical resistance were also measured. The use of this monolithic softener can improve performance and sustainability of hardness removal from tap water, reducing the production of sludge and adding the possibility to partially regenerate or reuse it.
Graffiti vandalism represents an aesthetic and structural phenomenon of degradation both for buil... more Graffiti vandalism represents an aesthetic and structural phenomenon of degradation both for buildings and cultural heritage: the most used sprays and markers can permeate the stone materials exposing them to degradation. Hence, great attention is being currently devoted to new non-invasive chemical approaches to face this urgent problem. This work is aimed at deeply examining the effects of some of the most sustainable chemical protective methods on the physical properties of natural building materials (e.g., tuff and limestone) by testing two commercial anti-graffiti products. It was found that the nanotechnological product Ector (E) was more effective than Nord Resine (NR) in anti-graffiti applications even if its permanent character hinders its application to the cultural heritage. Conversely, the less performant NR could be used in this field due to its sacrificial behavior, according to the guidelines of the Italian Ministry of Cultural Heritage and Activities and Tourism. The...
This paper reports the production of Lead-free (1-x)(BaZr0.2Ti0.8O3)-x(Ba0.7Ca0.3O3) ferro/piezoe... more This paper reports the production of Lead-free (1-x)(BaZr0.2Ti0.8O3)-x(Ba0.7Ca0.3O3) ferro/piezoelectric thin films by means of repeated chemical solution deposition routes. Two different kinds of precursor solutions were compared: i) a literature standard precursor solution involving the use of 2-methoxyethanol (2-MOE) which is a toxic and carcinogenic solvent and ii) a “greener” precursor solution based on 1-methoxy-2-propanol (PGME), a non-toxic and non-carcinogenic solvent. Morphology, crystal structure and ferroelectric behavior of the films is also reported.
Advances in nanoscale science and engineering are providing unprecedented opportunities to develo... more Advances in nanoscale science and engineering are providing unprecedented opportunities to develop more efficient and cost-effective materials and technologies for environmentally friendly processes. Zeolites and related materials, such as functionalised mesoporous silicas and the more recent metal-organic frameworks (MOFs), represent a class of nanoporous materials characterised by very interesting and useful adsorption and/or ion exchange properties. A brief overview on present and perspective utilizations of these materials in environmentally friendly processes, including solar and thermal energy storage, methane and hydrogen storage and CO2 capture, is here presented.
Natural zeolites are used as adsorbents in purification processes due to their cation-exchange ab... more Natural zeolites are used as adsorbents in purification processes due to their cation-exchange ability and molecular sieve properties. Surface modified natural zeolites (SMNZs), produced by attaching cationic organic surfactants to the external surface, can simultaneously act as ionic exchangers and organic molecule adsorbents. In this paper, SMNZs were produced and investigated as adsorbents for As(V) removal from wastewater: two natural zeolites, clinoptilolite and phillipsite, were modified using HDTMA-Br and HDTMA-Cl as surfactants. The obtained samples were then characterized under static and dynamic conditions. Results showed that As(V) removal follows a pseudo-second order kinetic, with fast adsorption rates: every sample reached 100 % removal in 2 h, while equilibrium data showed a Langmuir-like behavior, with a greater anion uptake by the HDTMA-Br modified SMNZs due to the formation of a compact and complete micellar structure. Finally, fixed-bed tests were performed to cha...
This review focuses on the use of metal–organic frameworks (MOFs) for adsorbing gas species that ... more This review focuses on the use of metal–organic frameworks (MOFs) for adsorbing gas species that are known to weaken the thermal self-regulation capacities of Earth’s atmosphere. A large section is dedicated to the adsorption of carbon dioxide, while another section is dedicated to the adsorption of other different gas typologies, whose emissions, for various reasons, represent a “wound” for Earth’s atmosphere. High emphasis is given to MOFs that have moved enough ahead in their development process to be currently considered as potentially usable in “real-world” (i.e., out-of-lab) adsorption processes. As a result, there is strong evidence of a wide gap between laboratory results and the industrial implementation of MOF-based adsorbents. Indeed, when a MOF that performs well in a specific process is commercially available in large quantities, economic observations still make designers tend toward more traditional adsorbents. Moreover, there are cases in which a specific MOF remarkab...
An innovative and facile synthesis of cobalt based inorganic pigment was carried out by means of ... more An innovative and facile synthesis of cobalt based inorganic pigment was carried out by means of a low energy thermal conversion of a cobalt-exchanged zeolite. The Na-A [LTA] zeolite was used, since it is a low cost and easily available raw material. The ion exchange mechanism allowed to control, at microscopic level, the composition of the zeolitic precursor. Several chromatic effects could be obtained by varying the treatment temperature and/or the cobalt concentration in the contact solution. The reliability of these new zeolite-based pigments was tested in porcelain manufacture, in collaboration with the Institute for the Capodimonte porcelain “Giovanni Caselli”. The developed cobalt pigments were successfully tested either in the porcelain mixture to obtain a coloured product or in the decoration step (such as ingobbio, colored glazes and “third fire decoration”).
Motivated by the hierarchical micro and nanoscale features in terms of porosity of diatomite, the... more Motivated by the hierarchical micro and nanoscale features in terms of porosity of diatomite, the production of ceramic-graded porous foams with tailored porosity, obtained by using it as raw material, has been proposed. The main challenge during the foam-production process has been the preservation of diatomite nanometric porosity and the addition of other levels of hierarchical porosity. The coupled use of two techniques of direct foaming (chemical and mechanical), combined with the use of 3D printing inverse replica method, assured the achievement of porosity of, respectively, microscopic and macroscopic dimensions. Optical and scanning electron microscopies have been performed for an in-depth characterization of the final microstructure. XRD analysis has been carried out to check the influence of sacrificial templates on the matrix mineralogical composition. The porosity of the diatomite-based foams has been investigated by means of nitrogen-adsorption analysis and mercury-intru...
A great challenge of research is the utilization of natural or synthetic zeolites, in place of na... more A great challenge of research is the utilization of natural or synthetic zeolites, in place of natural pozzolans, for manufacturing blended cements. The difficulties of interpretation of the pozzolanic behavior of natural zeolite-rich materials and the role played by their nature and composition can be overcome by studying more simple systems, such as pure synthetic zeolites. This study aims at investigating the pozzolanic ability of isostructural zeolites with different framework compositions, such as three sodium zeolites of the faujasite (FAU) framework type: LSX, X, and Y. The pozzolanic activity has been estimated by thermogravimetry and X-ray diffraction analysis. The overall outcome of the investigation is that the zeolite structure affects its pozzolanic activity, as zeolites with similar framework densities exhibit distinct abilities to fix lime. Moreover, the framework composition is effective either from a kinetic point of view or on the total amount of fixed lime. Zeolit...
Journal of applied biomaterials & functional materials, 2018
This review presents "a state of the art" report on sustainability in construction mate... more This review presents "a state of the art" report on sustainability in construction materials. The authors propose different solutions to make the concrete industry more environmentally friendly in order to reduce greenhouse gases emissions and consumption of non-renewable resources. Part 1-the present paper-focuses on the use of binders alternative to Portland cement, including sulfoaluminate cements, alkali-activated materials, and geopolymers. Part 2 will be dedicated to traditional Portland-free binders and waste management and recycling in mortar and concrete production.
An iron-activated carbon nanocomposite synthesized by a facile, low temperature technique was suc... more An iron-activated carbon nanocomposite synthesized by a facile, low temperature technique was successfully tested for Pb(ii) removal from aqueous solutions.
The adsorption of light hydrocarbons (C2–C5 olefins and paraffins, toluene) on HZSM-5, silicalite... more The adsorption of light hydrocarbons (C2–C5 olefins and paraffins, toluene) on HZSM-5, silicalite, and HY was studied for application in treatment of exhaust streams of the petrochemical industry and of vehicles under cold start conditions. At this aim the trapping capability was evaluated on hydrated zeolites by breakthrough curves at low hydrocarbon partial pressure (0-1 kPa), in the temperature range 298–523 K and at space velocity of 30000 h−1. The basic adsorption properties of materials were also verified for three selected hydrocarbons (ethylene, isobutene, and toluene) by equilibrium isotherms on dehydrated zeolites at 298 K. The role of physicochemical characteristics of adsorbent materials was discussed in relation with their trapping capability of different types of hydrocarbons.
The increase in concrete structures’ durability is a milestone to improve the sustainability of b... more The increase in concrete structures’ durability is a milestone to improve the sustainability of buildings and infrastructures. In order to ensure a prolonged service life, it is necessary to detect the deterioration of materials by means of monitoring systems aimed at evaluating not only the penetration of aggressive substances into concrete but also the corrosion of carbon-steel reinforcement. Therefore, proper data collection makes it possible to plan suitable restoration works which can be carried out with traditional or innovative techniques and materials. This work focuses on building heritage and it highlights the most recent findings for the conservation and restoration of reinforced concrete structures and masonry buildings.
Demolition activity plays an important role in the total energy consumption of the construction i... more Demolition activity plays an important role in the total energy consumption of the construction industry in the European Union. The indiscriminate use of non-renewable raw materials, energy consumption, and unsustainable design has led to a redefinition of the criteria to ensure environmental protection. This article introduces an experimental plan that determines the viability of a new type of construction material, obtained from crushed brick waste, to be introduced into the construction market. The potential of crushed brick waste as a raw material in the production of building precast products, obtained by curing a geopolymeric blend at 60 °C for 3 days, has been exploited. Geopolymers represent an important alternative in reducing emissions and energy consumption, whilst, at the same time, achieving a considerable mechanical performance. The results obtained from this study show that the geopolymers produced from crushed brick were characterized by good properties in terms of o...
The topic of sustainability of reinforced concrete structures is strictly related with their dura... more The topic of sustainability of reinforced concrete structures is strictly related with their durability in aggressive environments. In particular, at equal environmental impact, the higher the durability of construction materials, the higher the sustainability. The present review deals with the possible strategies aimed at producing sustainable and durable reinforced concrete structures in different environments. It focuses on the design methodologies as well as the use of unconventional corrosion-resistant reinforcements, alternative binders to Portland cement, and innovative or traditional solutions for reinforced concrete protection and prevention against rebars corrosion such as corrosion inhibitors, coatings, self-healing techniques, and waterproofing aggregates. Analysis of the scientific literature highlights that there is no preferential way for the production of “green” concrete but that the sustainability of the building materials can only be achieved by implementing simul...
The present paper assesses petrographic, mineralogical, chemical, and technological features of d... more The present paper assesses petrographic, mineralogical, chemical, and technological features of different zeolitic tuff samples from various western USA districts of the Basin and Range Province containing mainly erionite, mordenite, clinoptilolite/heulandite and phillipsite. The aim of this characterization is to evaluate the pozzolanic activity of these samples according to European normative UNI-EN 196/5 (Fratini test) to program a possible use as addition for blended cements. Petrographic and mineralogical results show that the two phillipsite-bearing tuffs have a higher theoretical Cation Exchange Capacity (CEC) than the other samples; technological characterization shows a pozzolanic behavior for all the samples but higher for the tuff samples containing phillipsite, which shows a higher reactivity with CaO. All the samples could be thus advantageously employed for the preparation of blended cements, potentially reducing CO2 emissions by 70–90%.
In this work, the design of a monolithic softener obtained by geopolymer gel conversion is propos... more In this work, the design of a monolithic softener obtained by geopolymer gel conversion is proposed. The softener used consists in a geopolymeric macroporous matrix functionalized by the co-crystallization of zeolite A and X in mixture. The dual nature of the proposed material promotes a softening process based on the synergistic effect of cation exchange and alkaline precipitation. A softening capacity of 90% and 54% for Ca2+ and Mg2+ respectively was attained in 24 h. In fact, the softener reported a Cation Exchange Capacity (CEC) value of 4.43 meq g−1. Technical features such as density, porosity and mechanical resistance were also measured. The use of this monolithic softener can improve performance and sustainability of hardness removal from tap water, reducing the production of sludge and adding the possibility to partially regenerate or reuse it.
Graffiti vandalism represents an aesthetic and structural phenomenon of degradation both for buil... more Graffiti vandalism represents an aesthetic and structural phenomenon of degradation both for buildings and cultural heritage: the most used sprays and markers can permeate the stone materials exposing them to degradation. Hence, great attention is being currently devoted to new non-invasive chemical approaches to face this urgent problem. This work is aimed at deeply examining the effects of some of the most sustainable chemical protective methods on the physical properties of natural building materials (e.g., tuff and limestone) by testing two commercial anti-graffiti products. It was found that the nanotechnological product Ector (E) was more effective than Nord Resine (NR) in anti-graffiti applications even if its permanent character hinders its application to the cultural heritage. Conversely, the less performant NR could be used in this field due to its sacrificial behavior, according to the guidelines of the Italian Ministry of Cultural Heritage and Activities and Tourism. The...
This paper reports the production of Lead-free (1-x)(BaZr0.2Ti0.8O3)-x(Ba0.7Ca0.3O3) ferro/piezoe... more This paper reports the production of Lead-free (1-x)(BaZr0.2Ti0.8O3)-x(Ba0.7Ca0.3O3) ferro/piezoelectric thin films by means of repeated chemical solution deposition routes. Two different kinds of precursor solutions were compared: i) a literature standard precursor solution involving the use of 2-methoxyethanol (2-MOE) which is a toxic and carcinogenic solvent and ii) a “greener” precursor solution based on 1-methoxy-2-propanol (PGME), a non-toxic and non-carcinogenic solvent. Morphology, crystal structure and ferroelectric behavior of the films is also reported.
Advances in nanoscale science and engineering are providing unprecedented opportunities to develo... more Advances in nanoscale science and engineering are providing unprecedented opportunities to develop more efficient and cost-effective materials and technologies for environmentally friendly processes. Zeolites and related materials, such as functionalised mesoporous silicas and the more recent metal-organic frameworks (MOFs), represent a class of nanoporous materials characterised by very interesting and useful adsorption and/or ion exchange properties. A brief overview on present and perspective utilizations of these materials in environmentally friendly processes, including solar and thermal energy storage, methane and hydrogen storage and CO2 capture, is here presented.
Natural zeolites are used as adsorbents in purification processes due to their cation-exchange ab... more Natural zeolites are used as adsorbents in purification processes due to their cation-exchange ability and molecular sieve properties. Surface modified natural zeolites (SMNZs), produced by attaching cationic organic surfactants to the external surface, can simultaneously act as ionic exchangers and organic molecule adsorbents. In this paper, SMNZs were produced and investigated as adsorbents for As(V) removal from wastewater: two natural zeolites, clinoptilolite and phillipsite, were modified using HDTMA-Br and HDTMA-Cl as surfactants. The obtained samples were then characterized under static and dynamic conditions. Results showed that As(V) removal follows a pseudo-second order kinetic, with fast adsorption rates: every sample reached 100 % removal in 2 h, while equilibrium data showed a Langmuir-like behavior, with a greater anion uptake by the HDTMA-Br modified SMNZs due to the formation of a compact and complete micellar structure. Finally, fixed-bed tests were performed to cha...
This review focuses on the use of metal–organic frameworks (MOFs) for adsorbing gas species that ... more This review focuses on the use of metal–organic frameworks (MOFs) for adsorbing gas species that are known to weaken the thermal self-regulation capacities of Earth’s atmosphere. A large section is dedicated to the adsorption of carbon dioxide, while another section is dedicated to the adsorption of other different gas typologies, whose emissions, for various reasons, represent a “wound” for Earth’s atmosphere. High emphasis is given to MOFs that have moved enough ahead in their development process to be currently considered as potentially usable in “real-world” (i.e., out-of-lab) adsorption processes. As a result, there is strong evidence of a wide gap between laboratory results and the industrial implementation of MOF-based adsorbents. Indeed, when a MOF that performs well in a specific process is commercially available in large quantities, economic observations still make designers tend toward more traditional adsorbents. Moreover, there are cases in which a specific MOF remarkab...
An innovative and facile synthesis of cobalt based inorganic pigment was carried out by means of ... more An innovative and facile synthesis of cobalt based inorganic pigment was carried out by means of a low energy thermal conversion of a cobalt-exchanged zeolite. The Na-A [LTA] zeolite was used, since it is a low cost and easily available raw material. The ion exchange mechanism allowed to control, at microscopic level, the composition of the zeolitic precursor. Several chromatic effects could be obtained by varying the treatment temperature and/or the cobalt concentration in the contact solution. The reliability of these new zeolite-based pigments was tested in porcelain manufacture, in collaboration with the Institute for the Capodimonte porcelain “Giovanni Caselli”. The developed cobalt pigments were successfully tested either in the porcelain mixture to obtain a coloured product or in the decoration step (such as ingobbio, colored glazes and “third fire decoration”).
Motivated by the hierarchical micro and nanoscale features in terms of porosity of diatomite, the... more Motivated by the hierarchical micro and nanoscale features in terms of porosity of diatomite, the production of ceramic-graded porous foams with tailored porosity, obtained by using it as raw material, has been proposed. The main challenge during the foam-production process has been the preservation of diatomite nanometric porosity and the addition of other levels of hierarchical porosity. The coupled use of two techniques of direct foaming (chemical and mechanical), combined with the use of 3D printing inverse replica method, assured the achievement of porosity of, respectively, microscopic and macroscopic dimensions. Optical and scanning electron microscopies have been performed for an in-depth characterization of the final microstructure. XRD analysis has been carried out to check the influence of sacrificial templates on the matrix mineralogical composition. The porosity of the diatomite-based foams has been investigated by means of nitrogen-adsorption analysis and mercury-intru...
A great challenge of research is the utilization of natural or synthetic zeolites, in place of na... more A great challenge of research is the utilization of natural or synthetic zeolites, in place of natural pozzolans, for manufacturing blended cements. The difficulties of interpretation of the pozzolanic behavior of natural zeolite-rich materials and the role played by their nature and composition can be overcome by studying more simple systems, such as pure synthetic zeolites. This study aims at investigating the pozzolanic ability of isostructural zeolites with different framework compositions, such as three sodium zeolites of the faujasite (FAU) framework type: LSX, X, and Y. The pozzolanic activity has been estimated by thermogravimetry and X-ray diffraction analysis. The overall outcome of the investigation is that the zeolite structure affects its pozzolanic activity, as zeolites with similar framework densities exhibit distinct abilities to fix lime. Moreover, the framework composition is effective either from a kinetic point of view or on the total amount of fixed lime. Zeolit...
Journal of applied biomaterials & functional materials, 2018
This review presents "a state of the art" report on sustainability in construction mate... more This review presents "a state of the art" report on sustainability in construction materials. The authors propose different solutions to make the concrete industry more environmentally friendly in order to reduce greenhouse gases emissions and consumption of non-renewable resources. Part 1-the present paper-focuses on the use of binders alternative to Portland cement, including sulfoaluminate cements, alkali-activated materials, and geopolymers. Part 2 will be dedicated to traditional Portland-free binders and waste management and recycling in mortar and concrete production.
An iron-activated carbon nanocomposite synthesized by a facile, low temperature technique was suc... more An iron-activated carbon nanocomposite synthesized by a facile, low temperature technique was successfully tested for Pb(ii) removal from aqueous solutions.
The adsorption of light hydrocarbons (C2–C5 olefins and paraffins, toluene) on HZSM-5, silicalite... more The adsorption of light hydrocarbons (C2–C5 olefins and paraffins, toluene) on HZSM-5, silicalite, and HY was studied for application in treatment of exhaust streams of the petrochemical industry and of vehicles under cold start conditions. At this aim the trapping capability was evaluated on hydrated zeolites by breakthrough curves at low hydrocarbon partial pressure (0-1 kPa), in the temperature range 298–523 K and at space velocity of 30000 h−1. The basic adsorption properties of materials were also verified for three selected hydrocarbons (ethylene, isobutene, and toluene) by equilibrium isotherms on dehydrated zeolites at 298 K. The role of physicochemical characteristics of adsorbent materials was discussed in relation with their trapping capability of different types of hydrocarbons.
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