Special Issue "New Insights in Stability, Structure and Properties of Porous Materials"

A special issue of Minerals (ISSN 2075-163X).

Deadline for manuscript submissions: closed (15 December 2016).

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editors

Prof. Dr. Annalisa Martucci
E-Mail Website
Guest Editor
Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1, 44122 Ferrara, Italy
Prof. Dr. Giuseppe Cruciani
E-Mail Website
Guest Editor
Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1, 44122 Ferrara, Italy

Special Issue Information

Dear Colleagues,

Porous materials (such as zeolites, clay minerals, and assemblies of oxide nanoparticles) are of great importance in many technological and environmental processes, such as catalysis, adsorption, separation and ion exchange, because of their unique pore topologies, tunable structures, and the possibility to introduce active reaction sites. The goal of this Special Issue is to provide a platform for scientists to discuss new insights in stability, structure and properties of porous materials, as well as in innovative aspects in their processing and applications. The emphasis is on the relationships between the structure and/or chemical composition and the specific physical properties of these materials, their role in mineralogical, technological, green and sustainable processes, as well as energy applications. We particularly wish to highlight works that explore physical, chemical and structural characterization of porous materials, synthesis of crystalline phases with pores in the appropriate range, structure-property relationships at ambient conditions, but also at low and high temperatures and/or at high pressures, adsorption and diffusion of mobile species in porous materials, host/guest interactions and confinement effects, ion exchange, modelling in geological and environmental processes, new insights in processing and applications.

Prof. Dr. Annalisa Martucci
Prof. Dr. Giuseppe Cruciani
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Minerals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Porous materials
  • Zeolites
  • Clay minerals
  • Oxide nanoparticles
  • Structure-property relationships
  • Processing and applications

Published Papers (10 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Editorial

Jump to: Research, Review

Open AccessEditorial
Editorial for Special Issue “New Insights in Stability, Structure and Properties of Porous Materials”
Minerals 2017, 7(5), 73; https://doi.org/10.3390/min7050073 - 11 May 2017
Abstract
Porous materials (such as zeolites, clay minerals, and assemblies of oxide nanoparticles) are of great importance for the progress in many technological and environmental fields, such as catalysis, adsorption, separation, and ion exchange, because of their unique pore topologies, tunable structures, and the [...] Read more.
Porous materials (such as zeolites, clay minerals, and assemblies of oxide nanoparticles) are of great importance for the progress in many technological and environmental fields, such as catalysis, adsorption, separation, and ion exchange, because of their unique pore topologies, tunable structures, and the possibility of introducing active reaction sites.[...] Full article

Research

Jump to: Editorial, Review

Open AccessArticle
Experimental Study of Montmorillonite Structure and Transformation of Its Properties under Treatment with Inorganic Acid Solutions
Minerals 2017, 7(4), 49; https://doi.org/10.3390/min7040049 - 23 Mar 2017
Cited by 25
Abstract
This paper discusses the mechanism of montmorillonite structural alteration and modification of bentonites’ properties (based on samples from clay deposits Taganskoye, Kazakhstan and Mukhortala, Buriatia) under thermochemical treatment (treatment with inorganic acid solutions at different temperatures, concentrations and reaction times). Treatment conditions were [...] Read more.
This paper discusses the mechanism of montmorillonite structural alteration and modification of bentonites’ properties (based on samples from clay deposits Taganskoye, Kazakhstan and Mukhortala, Buriatia) under thermochemical treatment (treatment with inorganic acid solutions at different temperatures, concentrations and reaction times). Treatment conditions were chosen according to those accepted in chemical industry for obtaining acid modified clays as catalysts or sorbents. Also, more intense treatment was carried out to simulate possible influence at the liquid radioactive site repositories. A series of methods was used: XRD, FTIR, ICP-AES, TEM, nitrogen adsorption, and particle size analysis. It allowed revealing certain processes: transformation of montmorillonite structure which appears in the leaching of interlayer and octahedral cations and protonation of the interlayer and –OH groups at octahedral sheets. In turn, changes in the structure of the 2:1 layer of montmorillonite and its interlayer result in significant alterations in the properties: reduction of cation exchange capacity and an increase of specific surface area. Acid treatment also leads to a redistribution of particle sizes and changes the pore system. The results of the work showed that bentonite clays retain a significant portion of their adsorption properties even after a prolonged and intense thermochemical treatment (1 M HNO3, 60 °C, 108 h). Full article
Show Figures

Graphical abstract

Open AccessArticle
Temperature-Induced Desorption of Methyl tert-Butyl Ether Confined on ZSM-5: An In Situ Synchrotron XRD Powder Diffraction Study
Minerals 2017, 7(3), 34; https://doi.org/10.3390/min7030034 - 28 Feb 2017
Cited by 6
Abstract
The temperature-induced desorption of methyl tert-butyl ether (MTBE) from aqueous solutions onto hydrophobic ZSM-5 was studied by in situ synchrotron powder diffraction and chromatographic techniques. This kind of information is crucial for designing and optimizing the regeneration treatment of such zeolite. The [...] Read more.
The temperature-induced desorption of methyl tert-butyl ether (MTBE) from aqueous solutions onto hydrophobic ZSM-5 was studied by in situ synchrotron powder diffraction and chromatographic techniques. This kind of information is crucial for designing and optimizing the regeneration treatment of such zeolite. The evolution of the structural features monitored by full profile Rietveld refinements revealed that a monoclinic (P21/n) to orthorhombic (Pnma) phase transition occurred at about 100 °C. The MTBE desorption process caused a remarkable change in the unit-cell parameters. Complete MTBE desorption was achieved upon heating at about 250 °C. Rietveld analysis demonstrated that the desorption process occurred without any significant zeolite crystallinity loss, but with slight deformations in the channel apertures. Full article
Show Figures

Figure 1

Open AccessArticle
Strength Reduction of Coal Pillar after CO2 Sequestration in Abandoned Coal Mines
Minerals 2017, 7(2), 26; https://doi.org/10.3390/min7020026 - 17 Feb 2017
Cited by 6
Abstract
CO2 geosequestration is currently considered to be the most effective and economical method to dispose of artificial greenhouse gases. There are a large number of coal mines that will be scrapped, and some of them are located in deep formations in China. [...] Read more.
CO2 geosequestration is currently considered to be the most effective and economical method to dispose of artificial greenhouse gases. There are a large number of coal mines that will be scrapped, and some of them are located in deep formations in China. CO2 storage in abandoned coal mines will be a potential option for greenhouse gas disposal. However, CO2 trapping in deep coal pillars would induce swelling effects of coal matrix. Adsorption-induced swelling not only modifies the volume and permeability of coal mass, but also causes the basic physical and mechanical properties changing, such as elastic modulus and Poisson ratio. It eventually results in some reduction in pillar strength. Based on the fractional swelling as a function of time and different loading pressure steps, the relationship between volumetric stress and adsorption pressure increment is acquired. Eventually, this paper presents a theory model to analyze the pillar strength reduction after CO2 adsorption. The model provides a method to quantitatively describe the interrelation of volumetric strain, swelling stress, and mechanical strength reduction after gas adsorption under the condition of step-by-step pressure loading and the non-Langmuir isothermal model. The model might have a significantly important implication for predicting the swelling stress and mechanical behaviors of coal pillars during CO2 sequestration in abandoned coal mines. Full article
Show Figures

Figure 1

Open AccessArticle
Use of Spent Zeolite Sorbents for the Preparation of Lightweight Aggregates Differing in Microstructure
Minerals 2017, 7(2), 25; https://doi.org/10.3390/min7020025 - 17 Feb 2017
Cited by 7
Abstract
Lightweight aggregates (LWAs) made by sintering beidellitic clay deposits at high temperatures, with and without the addition of spent zeolitic sorbents (clinoptilolitic tuff and Na-P1 made from fly ash) containing diesel oil, were investigated. Mineral composition of the aggregates determined by X-ray diffraction [...] Read more.
Lightweight aggregates (LWAs) made by sintering beidellitic clay deposits at high temperatures, with and without the addition of spent zeolitic sorbents (clinoptilolitic tuff and Na-P1 made from fly ash) containing diesel oil, were investigated. Mineral composition of the aggregates determined by X-ray diffraction was highly uniformized in respect of the initial composition of the substrates. The microstructure of the LWAs, which were studied with a combination of mercury porosimetry, microtomography, nitrogen adsorption/desorption isotherms and scanning electron microscopy, was markedly modified by the spent zeolites, which diminished bulk densities, increased porosities and pore radii. The addition of zeolites decreased water absorption and the compressive strength of the LWAs. The spent Na-P1 had a greater effect on the LWAs’ structure than the clinoptilolite. Full article
Show Figures

Figure 1

Open AccessArticle
Effect of Silica Alumina Ratio and Thermal Treatment of Beta Zeolites on the Adsorption of Toluene from Aqueous Solutions
Minerals 2017, 7(2), 22; https://doi.org/10.3390/min7020022 - 15 Feb 2017
Cited by 4
Abstract
The adsorption of toluene from aqueous solutions onto hydrophobic zeolites was studied by combining chromatographic, thermal and structural techniques. Three beta zeolites (notated BEAs, since they belong to BEA framework type), with different SiO2/Al2O3 ratios (i.e., 25, 38 [...] Read more.
The adsorption of toluene from aqueous solutions onto hydrophobic zeolites was studied by combining chromatographic, thermal and structural techniques. Three beta zeolites (notated BEAs, since they belong to BEA framework type), with different SiO2/Al2O3 ratios (i.e., 25, 38 and 360), before and after calcination, were tested as adsorbents of toluene from aqueous media. This was performed by measuring the adsorbed quantities of toluene onto zeolites in a wide concentration range of solute. The adsorption data were fitted with isotherms whose models are based on surface heterogeneity of the adsorbent, according to the defective structure of beta zeolites. The thermal treatment considerably increases the adsorption of toluene, in the low concentration range, on all BEAs, probably due to surface and structural modifications induced by calcination. Among the calcined BEAs, the most hydrophobic zeolite (i.e., that with SiO2/Al2O3 ratio of 360) showed the highest binding constant, probably due to its high affinity for an organophilic solute such as toluene. The high sorption capacity was confirmed by thermogravimetric analyses on BEAs, before and after saturation with toluene. Full article
Show Figures

Figure 1

Open AccessArticle
The Influence of the Framework and Extraframework Content on the High Pressure Behavior of the GIS Type Zeolites: The Case of Amicite
Minerals 2017, 7(2), 18; https://doi.org/10.3390/min7020018 - 05 Feb 2017
Cited by 2
Abstract
This paper reports a study, performed by in-situ synchrotron X-ray Powder Diffraction, of the high pressure behavior of the natural zeolite amicite [K4Na4(Al8Si8O32)·10H2O], the GIS-type phase with ordered (Si, Al) and [...] Read more.
This paper reports a study, performed by in-situ synchrotron X-ray Powder Diffraction, of the high pressure behavior of the natural zeolite amicite [K4Na4(Al8Si8O32)·10H2O], the GIS-type phase with ordered (Si, Al) and (Na, K) distribution. The experiments were carried out up to 8.13(5) GPa in methanol:ethanol:water = 16:3:1 (m.e.w.) and 8.68(5) GPa in silicone oil (s.o.). The crystal structure refinements of the patterns collected in m.e.w. were performed up to 4.71(5) GPa, while for the patterns collected in s.o. only the unit cell parameters were determined as a function of pressure. The observed framework deformation mechanism—similar to that reported for the other studied phases with GIS topology—is essentially driven by the distortion of the “double crankshaft” chains and the consequent changed shape of the 8-ring channels. The pressure-induced over-hydration observed in the experiment performed in aqueous medium occurs without unit cell volume expansion, and is substantially reversible. A comparison is made with the high pressure behavior of the other GIS-type phases, and the strong influence on compressibility of the chemical composition of both framework and extraframework species is discussed. Full article
Show Figures

Graphical abstract

Open AccessArticle
Thermal Transformation of NH4-Clinoptilolite to Mullite and Silica Polymorphs
Minerals 2017, 7(1), 11; https://doi.org/10.3390/min7010011 - 19 Jan 2017
Cited by 6
Abstract
Clinoptilolite is a natural zeolite used for the abatement of ammonium in the treatment of urban wastewater. By considering that mullite was obtained through thermal treatment of NH4-exchanged synthetic zeolites, this work aimed to evaluate if this phase can be obtained [...] Read more.
Clinoptilolite is a natural zeolite used for the abatement of ammonium in the treatment of urban wastewater. By considering that mullite was obtained through thermal treatment of NH4-exchanged synthetic zeolites, this work aimed to evaluate if this phase can be obtained from NH4-clinoptilolite. A material containing about 90 wt % of clinoptilolite, prepared using a Sardinian zeolite-rich rock, was NH4-exchanged and subjected to treatments up to 1200 °C. After dehydration, de-ammoniation, and dehydroxylation processes, the clinoptilolite structure collapsed at 600 °C. An association of mullite, silica polymorphs, and glass, whitish in color, was obtained for treatments between 1000 and 1200 °C. The higher degree of crystallinity was reached after a 32 h heating at 1100 °C: mullite 22 wt %, cristobalite 59 wt %, tridymite 10 wt %, glass 9 wt %. It is possible to speed up the kinetics of the transformation by increasing the temperature to 1200 °C, obtaining the same amount of mullite in 2 h, but increasing the residual amorphous fraction (16 wt %). These results indicate that NH4-clinoptilolite could represent a raw material of potential interest in the ceramic field, in particular in the production of acid refractory, opening scenarios for a possible reuse of clinoptilolite-based exchangers employed in ammonium decontamination. Full article
Show Figures

Figure 1

Open AccessArticle
Characterization of a Fine-Grained Interstratification of Turbostratic Talc and Saponite
Minerals 2017, 7(1), 5; https://doi.org/10.3390/min7010005 - 05 Jan 2017
Cited by 6
Abstract
Interstratifications of talc and trioctahedral smectites from different provenances are used as indicators for geological environments and for geotechnical and technical applications. However, comprehensive layer characterization of these interstratifications is rare. Sample EX M 1694, a clay with red-beige appearance from the Madrid [...] Read more.
Interstratifications of talc and trioctahedral smectites from different provenances are used as indicators for geological environments and for geotechnical and technical applications. However, comprehensive layer characterization of these interstratifications is rare. Sample EX M 1694, a clay with red-beige appearance from the Madrid basin was studied by X-ray diffraction analysis, X-ray fluorescence analysis, Fourier transformation infrared spectroscopy, simultaneous thermal analysis, gas adsorption measurements, cation exchange capacity, and environmental scanning electron microscopy. More than 95% of particles in EX M 1964 belong to the clay fraction <2 µm. It contains 75% interstratification of 30% turbostratic talc, and 70% saponite type III and 25% turbostratic talc. The turbostratic talc(0.3)/saponite interstratification is characterized by a low number of layers per stack (3), small lateral dimension of layers (60–80 nm) and, accordingly, a high specific surface area (283 m2/g) with nearly equal surface area of micro- and mesopores. Thus, the studied material can be used as mined for adsorption, in contrast to acid-treated clays that produce hazardous waste during production. Low particle size of the interstratification drastically reduced thermal stability and dehydroxylation was superimposed by recrystallization of high temperature phases already at 816 °C, which is low for trioctahedral 2:1 layer minerals. Full article
Show Figures

Figure 1

Review

Jump to: Editorial, Research

Open AccessReview
Application of Mineral Sorbents for Removal of Petroleum Substances: A Review
Minerals 2017, 7(3), 37; https://doi.org/10.3390/min7030037 - 08 Mar 2017
Cited by 14
Abstract
Environmental pollution with petroleum products has become a major problem worldwide, and is a consequence of industrial growth. The development of sustainable methods for the removal of petroleum substances and their derivatives from aquatic and terrestrial environments and from air has therefore become [...] Read more.
Environmental pollution with petroleum products has become a major problem worldwide, and is a consequence of industrial growth. The development of sustainable methods for the removal of petroleum substances and their derivatives from aquatic and terrestrial environments and from air has therefore become extremely important today. Advanced technologies and materials dedicated to this purpose are relatively expensive; sorption methods involving mineral sorbents are therefore popular and are widely described in the scientific literature. Mineral materials are easily available, low-cost, universal adsorbents and have a number of properties that make them suitable for the removal of petroleum substances. This review describes recent works on the use of natural, synthetic and modified mineral adsorbents for the removal of petroleum substances and their derivatives from roads, water and air. Full article
Show Figures

Figure 1

Back to TopTop