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Lahchich A, Álvarez-Lloret P, Reynes JF, Marcos C. Relationships Between Physicochemical and Structural Properties of Commercial Vermiculites. MATERIALS (BASEL, SWITZERLAND) 2025; 18:831. [PMID: 40004353 PMCID: PMC11857825 DOI: 10.3390/ma18040831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2025] [Revised: 01/24/2025] [Accepted: 01/27/2025] [Indexed: 02/27/2025]
Abstract
This study examines the effects of thermal (1000 °C), hydrothermal (100 °C), mechanochemical (ambient T), and microwave (~100 °C) treatments on three types of Chinese vermiculites, one with lower potassium content than the others. The goal was to obtain materials with enhanced properties related to specific surface areas. The response of the vermiculites to treatments and their physicochemical properties were analyzed using X-ray diffraction (XRD), thermal analysis (TG and DTG), and textural characterization via the BET method. XRD analyses showed similar mineral composition in treated and untreated samples, but the treatments affected the intensity and width of phase reflections, altering crystallinity and structural order, as well as the proportions of vermiculite, hydrobiotite, and phlogopite. Thermogravimetric analysis revealed two mass loss stages: water desorption (from 25 °C to about 250 °C) and recrystallization or dehydroxylation (above 800 °C). The isotherms indicated mesoporous characteristics, with hydrothermally CO2-treated samples having the highest specific surface area and adsorption capacity. The samples with vermiculite, hydrobiotite, and phlogopite generally showed moderate to high specific surface area (SBET) values, and mechanochemical treatments significantly increase SBET and pore volume (Vp) in the vermiculite and hydrobiotite samples. Crystallinity affects SBET, average Vp, and average pore size, and its monitoring is crucial to achieve the desired material characteristics, as higher crystallinity can reduce SBET but improve mechanical strength and thermal stability. This study highlights the influence of different treatments on vermiculite properties, providing valuable insights into their potential applications in various fields (such as thermal insulation in vehicles and aircraft, and the selective adsorption of gases and liquids in industrial processes, improving the strength and durability of building materials like cement and bricks).
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Affiliation(s)
- Ayoub Lahchich
- Departamento de Geología, Facultad de Geología, Universidad de Oviedo, C. Jesús Arias de Velasco s/n, 33005 Oviedo, Spain (P.Á.-L.)
| | - Pedro Álvarez-Lloret
- Departamento de Geología, Facultad de Geología, Universidad de Oviedo, C. Jesús Arias de Velasco s/n, 33005 Oviedo, Spain (P.Á.-L.)
| | - Javier F. Reynes
- Departamento de Química Orgánica e Inorgánica, Facultad de Química, Universidad de Oviedo, Av. Julián Clavería, 8, 33006 Oviedo, Spain;
| | - Celia Marcos
- Departamento de Geología, Facultad de Geología, Universidad de Oviedo, C. Jesús Arias de Velasco s/n, 33005 Oviedo, Spain (P.Á.-L.)
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Macías-Benítez P, Sierra-Padilla A, Yeste MP, Palacios-Santander JM, Cubillana-Aguilera L, Gatica JM, Vidal H, Guerra FM, Moreno-Dorado FJ. Ultrasound-promoted synthesis of a copper-iron-based catalyst for the microwave-assisted acyloxylation of 1,4-dioxane and cyclohexene. Org Biomol Chem 2023; 21:590-599. [PMID: 36545812 DOI: 10.1039/d2ob02117j] [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
A copper-iron-based catalyst has been prepared by a low-temperature co-precipitation and sonication method. The use of high-energy ultrasound reduces the time required for the preparation process from one workweek to one day with respect to the catalysts obtained by conventional coprecipitation and thermal treatment methods. The resulting material has been characterized at compositional, textural, structural, and chemical levels by ICP-AES, BET, SEM-EDS, XRD, TEM, and FTIR among other techniques. The material shows catalytic activity in the acyloxylation reaction of 1,4-dioxane and cyclohexene under microwave irradiation. In parallel with the optimized catalyst synthesis, the use of microwaves allowed for a substantial improvement in the outcome of the reaction in terms of cleanliness, yield, and time.
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Affiliation(s)
- Pablo Macías-Benítez
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain. .,Instituto de Biomoléculas (INBIO), Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - Alfonso Sierra-Padilla
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain. .,Departamento de Química Analítica Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain.,Instituto de Microscopía Electrónica y Materiales (IMEYMAT), Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - M Pilar Yeste
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Universidad de Cadiz, 11510 Puerto Real, Cádiz, Spain.,Instituto de Microscopía Electrónica y Materiales (IMEYMAT), Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - José María Palacios-Santander
- Departamento de Química Analítica Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain.,Instituto de Microscopía Electrónica y Materiales (IMEYMAT), Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - Laura Cubillana-Aguilera
- Departamento de Química Analítica Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain.,Instituto de Microscopía Electrónica y Materiales (IMEYMAT), Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - José M Gatica
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Universidad de Cadiz, 11510 Puerto Real, Cádiz, Spain.,Instituto de Microscopía Electrónica y Materiales (IMEYMAT), Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - Hilario Vidal
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Universidad de Cadiz, 11510 Puerto Real, Cádiz, Spain.,Instituto de Microscopía Electrónica y Materiales (IMEYMAT), Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - Francisco M Guerra
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain. .,Instituto de Biomoléculas (INBIO), Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - F Javier Moreno-Dorado
- Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain. .,Instituto de Biomoléculas (INBIO), Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
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