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Rosales-Reina B, Cruz-Quesada G, Pujol P, Reinoso S, Elosúa C, Arzamendi G, López-Ramón MV, Garrido JJ. Determination of hazardous vapors from the thermal decomposition of organochlorinated silica xerogels with adsorptive properties. ENVIRONMENTAL RESEARCH 2024; 256:119247. [PMID: 38815719 DOI: 10.1016/j.envres.2024.119247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 05/19/2024] [Accepted: 05/27/2024] [Indexed: 06/01/2024]
Abstract
The incorporation of organic groups into sol-gel silica materials is known to have a noticeable impact on the properties and structure of the resulting xerogels due to the combination of the properties inherent to the organic fragments (functionality and flexibility) with the mechanical and structural stability of the inorganic matrix. However, the reduction of the inorganic content in the materials could be detrimental to their thermal stability properties, limiting the range of their potential applications. Therefore, this work aims to evaluate the thermal stability of hybrid inorganic-organic silica xerogels prepared from mixtures of tetraethoxysilane and organochlorinated triethoxysilane precursors. To this end, a series of four materials with a molar percentage of organochlorinated precursor fixed at 10%, but differing in the type of organic group (chloroalkyls varying in the alkyl-chain length and chlorophenyl), has been selected as model case study. The gases and vapors released during the thermal decomposition of the samples under N2 atmosphere have been analyzed and their components determined and quantified using a thermogravimetric analyzer coupled to a Fourier-transform infrared spectrophotometer and to a gas chromatography-mass spectrometry unit. These analyses have allowed to identify up to three different thermal events for the pyrolysis of the organochlorinated xerogel materials and to elucidate the reaction pathways associated with such processes. These mechanisms have been found to be strongly dependent on the specific nature of the organic group.
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Affiliation(s)
- Beatriz Rosales-Reina
- Institute for Advanced Materials and Mathematics (INAMAT(2)), Departamento de Ciencias, Universidad Pública de Navarra (UPNA), Campus de Arrosadía, 31006, Pamplona, Spain.
| | - Guillermo Cruz-Quesada
- Institute for Advanced Materials and Mathematics (INAMAT(2)), Departamento de Ciencias, Universidad Pública de Navarra (UPNA), Campus de Arrosadía, 31006, Pamplona, Spain.
| | - Pablo Pujol
- Unidad Científico Técnica de Apoyo a La Investigación (UCTAI), Universidad Pública de Navarra (UPNA), Campus de Arrosadía, 31006, Pamplona, Spain.
| | - Santiago Reinoso
- Institute for Advanced Materials and Mathematics (INAMAT(2)), Departamento de Ciencias, Universidad Pública de Navarra (UPNA), Campus de Arrosadía, 31006, Pamplona, Spain.
| | - César Elosúa
- Institute of Smart Cities (ISC), Departamento de Ingeniería Eléctrica, Electrónica y de Comunicación, Universidad Pública de Navarra (UPNA), Campus de Arrosadía, 31006, Pamplona, Spain.
| | - Gurutze Arzamendi
- Institute for Advanced Materials and Mathematics (INAMAT(2)), Departamento de Ciencias, Universidad Pública de Navarra (UPNA), Campus de Arrosadía, 31006, Pamplona, Spain.
| | - María Victoria López-Ramón
- Departamento de Química Inorgánica y Orgánica, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071, Jaén, Spain.
| | - Julián J Garrido
- Institute for Advanced Materials and Mathematics (INAMAT(2)), Departamento de Ciencias, Universidad Pública de Navarra (UPNA), Campus de Arrosadía, 31006, Pamplona, Spain.
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Rosales-Reina B, Cruz-Quesada G, Padilla-Postigo N, Irigoyen-Razquin M, Alonso-Martínez E, López-Ramón MV, Espinal-Viguri M, Garrido JJ. Tunability of Hybrid Silica Xerogels: Surface Chemistry and Porous Texture Based on the Aromatic Precursor. Gels 2023; 9:gels9050382. [PMID: 37232974 DOI: 10.3390/gels9050382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/26/2023] [Accepted: 04/28/2023] [Indexed: 05/27/2023] Open
Abstract
The interest in new materials with specific properties has increased because they are essential for the environmental and technological needs of our society. Among them, silica hybrid xerogels have emerged as promising candidates due to their simple preparation and tunability: when they are synthesised, depending on the organic precursor and its concentration, their properties can be modulated, and thus, it is possible to prepare materials with à la carte porosity and surface chemistry. This research aims to design two new series of silica hybrid xerogels by co-condensation of tetraethoxysilane (TEOS) with triethoxy(p-tolyl)silane (MPhTEOS) or 1,4-bis(triethoxysilyl)benzene (Ph(TEOS)2 and to determine their chemical and textural properties based on a variety of characterisation techniques (FT-IR, 29Si NMR, X-ray diffraction and N2, CO2 and water vapour adsorption, among others). The information gathered from these techniques reveals that depending on the organic precursor and its molar percentage, materials with different porosity, hydrophilicity and local order are obtained, evidencing the easy modulation of their properties. The ultimate goal of this study is to prepare materials suitable for a variety of applications, such as adsorbents for pollutants, catalysts, films for solar cells or coatings for optic fibre sensors.
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Affiliation(s)
- Beatriz Rosales-Reina
- Department of Science, Institute for Advanced Materials and Mathematics (INAMAT2), Public University of Navarre (UPNA), Campus Arrosadía, 31006 Pamplona, Spain
| | - Guillermo Cruz-Quesada
- Department of Science, Institute for Advanced Materials and Mathematics (INAMAT2), Public University of Navarre (UPNA), Campus Arrosadía, 31006 Pamplona, Spain
| | | | | | | | - María Victoria López-Ramón
- Department of Inorganic and Organic Chemistry, Faculty of Experimental Sciences, University of Jaen, 23071 Jaen, Spain
| | - Maialen Espinal-Viguri
- Department of Science, Institute for Advanced Materials and Mathematics (INAMAT2), Public University of Navarre (UPNA), Campus Arrosadía, 31006 Pamplona, Spain
| | - Julián J Garrido
- Department of Science, Institute for Advanced Materials and Mathematics (INAMAT2), Public University of Navarre (UPNA), Campus Arrosadía, 31006 Pamplona, Spain
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Benedis DV, Dazzi A, Rivallan M, Pirngruber GD. Surface Heterogeneity in Amorphous Silica Nanoparticles Evidenced from Tapping AFM-IR Nanospectroscopy. Anal Chem 2023; 95:1505-1512. [PMID: 36535897 DOI: 10.1021/acs.analchem.2c04533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In this work, we propose to evaluate and validate an emerging spectroscopic space-resolved technique: atomic force microscopy coupled with infrared spectroscopy (AFM-IR) for inorganic materials in tapping mode at the nanoscale. For this aim, a preliminary investigation of sample preparation techniques was done and the stability of tapping AFM-IR spectra was evaluated on reference samples [poly(methyl methacrylate) and silica]. It was concluded that for a homogeneous polymer, it is possible to compare AFM-IR spectra with conventional Fourier-transform infrared (FTIR) spectra obtained in transmission. When an inorganic solid is considered, AFM-IR spectra are different from the global FTIR spectrum which indicates that the AFM-IR technique probes a volume which is not representative of global composition, that is, the external surface layer. Moreover, local infrared spectra recorded in the tapping mode of the external surface are significantly different depending on the analyzed regions of the same particle and between particles of the amorphous silica, implying surface heterogeneity. The AFM-IR technique allows surface description of amorphous inorganic materials at the nanoscale and opens new frontiers in the characterization of functional nanoscale and crystalline materials.
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Affiliation(s)
- Denys V Benedis
- Institute of Chemical Physics, Paris-Saclay University, 91400Orsay, France.,IFP Energies Nouvelles, Rond-Point de l'échangeur de Solaize, BP 3, 69360Solaize, France
| | - Alexandre Dazzi
- Institute of Chemical Physics, Paris-Saclay University, 91400Orsay, France
| | - Mickaël Rivallan
- IFP Energies Nouvelles, Rond-Point de l'échangeur de Solaize, BP 3, 69360Solaize, France
| | - Gerhard D Pirngruber
- IFP Energies Nouvelles, Rond-Point de l'échangeur de Solaize, BP 3, 69360Solaize, France
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The Methyl Functionality of Monolithic Silica Xerogels Synthesized via the Co-Gelation Approach Combined with Surface Silylation. Gels 2022; 9:gels9010033. [PMID: 36661800 PMCID: PMC9857546 DOI: 10.3390/gels9010033] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/18/2022] [Accepted: 12/27/2022] [Indexed: 01/04/2023] Open
Abstract
The present research aims to investigate the chemical and morphological properties of the methylated silica xerogels produced via the co-gelation approach combined with surface silylation. In the sol−gel synthesis, methyltrimethoxysilane (MTMS) and tetraethylorthosilicate (TEOS) were utilized as silica precursors and trimethylchlorosilane (TMCS) served as a silylating agent. Structural changes were observed depending on the MTMS/TEOS molar ratio and on the post-synthesis-performed surface silylation of the xerogels. Post-synthesis silylation plays a critical role in the exchanging of the surface silanols with methyl groups, preserving the monolithic form. The morphological and structural changes were followed by SEM, 29Si-MAS-NMR, FTIR spectroscopy, nitrogen porosimetry, and contact angle measurements. The results have shown significant structural variations depending especially on the MTMS content. With an increasing MTMS content, the morphology of the samples has changed from a micro/mesoporous texture to a meso/macroporous texture. A higher degree of methyl substitution has been achieved for the silylated samples both confirmed by the FTIR and 29Si-NMR results. On the other hand, only the samples with a high MTMS content could preserve their structural integrity after evaporative drying, and all have exhibited a high degree of hydrophobicity with θ > 140°.
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Novel Silica Hybrid Xerogels Prepared by Co-Condensation of TEOS and ClPhTEOS: A Chemical and Morphological Study. Gels 2022; 8:gels8100677. [PMID: 36286178 PMCID: PMC9601464 DOI: 10.3390/gels8100677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/15/2022] [Accepted: 10/17/2022] [Indexed: 11/29/2022] Open
Abstract
The search for new materials with improved properties for advanced applications is, nowadays, one of the most relevant and booming fields for scientists due to the environmental and technological needs of our society. Within this demand, hybrid siliceous materials, made out of organic and inorganic species (ORMOSILs), have emerged as an alternative with endless chemical and textural possibilities by incorporating in their structure the properties of inorganic compounds (i.e., mechanical, thermal, and structural stability) in synergy with those of organic compounds (functionality and flexibility), and thus, bestowing the material with unique properties, which allow access to multiple applications. In this work, synthesis using the sol-gel method of a series of new hybrid materials prepared by the co-condensation of tetraethoxysilane (TEOS) and 4-chlorophenyltriethoxysilane (ClPhTEOS) in different molar ratios is described. The aim of the study is not only the preparation of new materials but also their characterization by means of different techniques (FT-IR, 29Si NMR, X-ray Diffraction, and N2/CO2 adsorption, among others) to obtain information on their chemical behavior and porous structure. Understanding how the chemical and textural properties of these materials are modulated with respect to the molar percentage of organic precursor will help to envisage their possible applications: From the most conventional such as catalysis, adsorption, or separation, to the most advanced in nanotechnology such as microelectronics, photoluminescence, non-linear optics, or sensorics.
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Structural Properties of Epoxy–Silica Barrier Coatings for Corrosion Protection of Reinforcing Steel. Polymers (Basel) 2022; 14:polym14173474. [PMID: 36080551 PMCID: PMC9460649 DOI: 10.3390/polym14173474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/19/2022] [Accepted: 08/19/2022] [Indexed: 11/17/2022] Open
Abstract
Reinforcement steel extensively applied in civil construction is susceptible to corrosion due to the carbonation process in reinforced concrete and chloride ions diffusion. Epoxy-silica-based coatings are a promising option to guarantee the long-term stability of reinforced concrete structures. In this study, the influence of the proportion between the poly (bisphenol-A-co-epichlorhydrin) resin (DGEBA) and the curing agent diethylenetriamine (DETA) on the structural, morphological, and barrier properties of epoxy–silica nanocomposites were evaluated. To simulate different stages of concrete aging, electrochemical impedance spectroscopy (EIS) assays were performed for coated samples in a 3.5 wt.% NaCl solution (pH 7) and in simulated concrete pore solutions (SCPS), which represent the hydration environment in fresh concrete (SCPS1, pH 8) and after carbonation (SCPS2, pH 14). The results showed that coatings with an intermediate DETA to DGEBA ratio of 0.4, presented the best long-term corrosion protection with a low-frequency impedance modulus of up to 3.8 GΩ cm2 in NaCl and SCPS1 solutions. Small-angle X-ray scattering and atomic force microscopy analysis revealed that the best performance observed for the intermediate DETA proportion is associated with the presence of larger silica nanodomains, which act as a filler in the cross-linked epoxy matrix, thus favoring the formation of an efficient diffusion barrier.
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Bórquez-Mendivil A, Hurtado-Macías A, Leal-Pérez JE, Flores-Valenzuela J, Vargas-Ortíz RÁ, Cabrera-Covarrubias FG, Almaral-Sánchez JL. Hybrid Coatings of SiO 2-Recycled PET Unsaturated Polyester Resin by Sol-Gel Process. Polymers (Basel) 2022; 14:polym14163280. [PMID: 36015537 PMCID: PMC9415624 DOI: 10.3390/polym14163280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/05/2022] [Accepted: 08/08/2022] [Indexed: 11/23/2022] Open
Abstract
Hybrid coatings of SiO2 and recycled unsaturated polyester resin (R-UPR) from recycled polyethylene-terephthalate (PET) were prepared by the sol-gel process on glass substrates. First, SiO2 was synthesized by the sol-gel process using a tetraethyl orthosilicate (TEOS) solution. Next, bis(2-hydroxypropyl-terephthalate) (BHPT) was synthesized from mechanical and chemical recycling (glycolysis) of post-consumer PET bottles in propylene glycol (PG) using ZnA as catalyst, in a Vessel-type reactor (20–200 °C); maleic anhydride (MA) was added and, following the same procedure, the unsaturated polyester (UP) was synthetized, which was cooled to room temperature. Next, styrene (St) and benzoyl-peroxide (PBO)-initiator were added to obtain R–UPR. TEOS (T) and three hybrid solutions were synthesized, with molar ratios of 0:1:0 (T), 1:2:0.25 (H1), 1:1:0.25 (H2), and 1:0:0.25 (H3) for R–UPR:TEOS:3-trimethoxy-(silyl)-propyl-methacrylate (TMSPM), respectively, with which TC, HC1, HC2, and HC3 coatings were elaborated using the immersion technique and polymerized (120 °C for 24 h). The solutions were characterized by FT–IR and TGA, and the coatings by SEM, nanoindentation, AFM, adhesion, and contact angle. The results showed that SiO2 enhanced mechanical (hardness and Young’s modulus) and thermal properties of the R-UPR. The coatings adhered perfectly to the substrate, with thicknesses of micrometer units and a flat surface; in addition, hydrophilicity decreased as SiO2 decreased.
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Affiliation(s)
- Adrián Bórquez-Mendivil
- Facultad de Ingeniería Mochis, Universidad Autónoma de Sinaloa, Los Mochis C.P. 81223, Mexico
| | - Abel Hurtado-Macías
- Centro de Investigación en Materiales Avanzados, S. C., National Nanotechnology Laboratory, Department of Metallurgy and Structural Integrity, Chihuahua C.P. 31136, Mexico
| | | | - Joaquín Flores-Valenzuela
- Facultad de Ingeniería Mochis, Universidad Autónoma de Sinaloa, Los Mochis C.P. 81223, Mexico
- Correspondence: (J.F.-V.); (J.L.A.-S.)
| | | | | | - Jorge Luis Almaral-Sánchez
- Facultad de Ingeniería Mochis, Universidad Autónoma de Sinaloa, Los Mochis C.P. 81223, Mexico
- Correspondence: (J.F.-V.); (J.L.A.-S.)
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Pastore A, Badocco D, Pastore P. Determination of the relevant equilibrium constants working in pH Colorimetric Sensor Arrays (CSAs). Microchem J 2022. [DOI: 10.1016/j.microc.2022.107288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Organic-Inorganic Hybrid Materials II: Some Additional Contributions to the Topic. Polymers (Basel) 2021; 13:polym13152390. [PMID: 34371991 PMCID: PMC8347415 DOI: 10.3390/polym13152390] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 11/24/2022] Open
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