Formation of micro- and mesoporous substructures in the course of the leaching process of two-phase alkali borosilicate glass

Крейсберг, В. А.; Антропова, Т. В.; Kalinina, S. V.

doi:10.1134/s1087659614030110

Cited by 11 publications

(4 citation statements)

References 8 publications

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“…The SA of only mesopores was determined by the BET method with non-linear regression of the adsorption and desorption isotherms in the range of relative pressures p/p 0 = 0.05–0.20, taking into account the filling of micropores and with a constant in the BET Equation equal to 70, which is typical for silica adsorbents without micropores. The authors obtained this value of the BET Equation constant [ 62 , 63 , 64 ] based on the analysis of a large number of adsorption isotherms available in the literature for mesoporous silicas that do not contain micropores. The difference between the total BET-specific surface area and the mesopore-specific surface area can be considered as the micropore-specific surface area.…”

Section: Resultsmentioning

confidence: 99%

“…The analysis of nitrogen adsorption and desorption isotherms at 77 K was performed according to the modified Barret-Joyner-Halenda (BJH) method. Mesopores were recorded in the region of medium and high relative pressures in accordance with the mechanism of capillary condensation, and micropores were diagnosed in accordance with the mechanism of volume filling in the region of low relative pressures, using the dependence of partial pressure on the diameter of micropores, embedded in the software of the Quantachrome Instruments device, and found by the density functional theory (DFT method) [ 62 , 63 ]. The experimental equilibrium nitrogen adsorption and desorption isotherms at 77 K, which include both the region of medium and high relative pressures and the region of low pressures, were approximated by a five-modal equation with Boltzmann functions [ 62 , 63 , 64 , 65 ].…”

Section: Methodsmentioning

confidence: 99%

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Novel Inorganic Membranes Based on Magnetite-Containing Silica Porous Glasses for Ultrafiltration: Structure and Sorption Properties

et al. 2023

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Porous glasses (PGs) obtained from sodium borosilicate (NBS) phase-separated glasses via leaching are promising inorganic membranes. Introducing Fe2O3 into NBS glasses imparts ferrimagnetic properties due to magnetite crystallization. Leaching of such glasses leads to the formation of magnetic PGs with interesting electro-surface characteristics. This work aimed to investigate the process of obtaining magnetite-containing PGs from NBS glasses depending on silica content, using XRPD and Raman spectroscopy, studying the PG membranes’ structural characteristics and their sorption properties with respect to methylene blue (MB). Obtained PGs were characterized by a polymodal distribution of mesopores and a small number of micropores with specific surface area values of 32–135 m2/g and an average mesopore diameter of 5–41 nm. The kinetic data were analyzed using pseudo-first-order, pseudo-second-order, and intra-particle diffusion equations. The equilibrium isotherms were fitted with Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models. MB adsorption was found to be a complex process. The glass with the highest specific surface area demonstrated the maximum sorption capacity (10.5 mg/g). The pore size of PGs allowed them to be considered potential novel magnetic membranes for ultrafiltration.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Novel Inorganic Membranes Based on Magnetite-Containing Silica Porous Glasses for Ultrafiltration: Structure and Sorption Properties

et al. 2023

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“…In this work, the femtosecond laser-induced densification approach [ 32 , 33 ] was applied for the inscription of waveguides in PG with an average pore size ~10 nm, and total porosity 26%. Glass composition consists of high silica proportion, SiO 2 > 96% (mass fraction, %) [ 34 ]. These PG plates possess high transparency (~90%) in the visible spectra range, with an average refractive index n ≈ 1.34.…”

Section: Methodsmentioning

confidence: 99%

Optical Sensitivity of Waveguides Inscribed in Nanoporous Silicate Framework

et al. 2021

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Laser direct writing technique in glass is a powerful tool for various waveguides’ fabrication that highly develop the element base for designing photonic devices. We apply this technique to fabricate waveguides in porous glass (PG). Nanoporous optical materials for the inscription can elevate the sensing ability of such waveguides to higher standards. The waveguides were fabricated by a single-scan approach with femtosecond laser pulses in the densification mode, which resulted in the formation of a core and cladding. Experimental studies revealed three types of waveguides and quantified the refractive index contrast (up to Δn = 1.2·10−2) accompanied with ~1.2 dB/cm insertion losses. The waveguides demonstrated the sensitivity to small objects captured by the nanoporous framework. We noticed that the deposited ethanol molecules (3 µL) on the PG surface influence the waveguide optical properties indicating the penetration of the molecule to its cladding. Continuous monitoring of the output near field intensity distribution allowed us to determine the response time (6 s) of the waveguide buried at 400 µm below the glass surface. We found that the minimum distinguishable change of the refractive index contrast is 2 × 10−4. The results obtained pave the way to consider the waveguides inscribed into PG as primary transducers for sensor applications.

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“…GC chemical composition is the following: 0.25 Na 2 O – 3.42 B 2 O 3 – 96.09 SiO 2 – 0.24 Ag 2 O. The sample preparation is a complex and multi-stage procedure, which includes PG fabrication that is based on two-phase alkali borosilicate glass thermal treatment and the following chemical etching to delete a borate phase [ 21 , 22 ]. The final impregnation procedure with silver/copper halides is described elsewhere [ 23 ].…”

Section: Materials Laser Procedures and Modellingmentioning

confidence: 99%

Real-Time Analysis of Laser-Induced Plasmon Tuning in Nanoporous Glass Composite

et al. 2020

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Laser-induced structuring in nanoporous glass composites is promising for numerous emerging applications in photonics and plasmonics. Local laser irradiation activates an interplay of photo-thermo-chemical mechanisms that are extremely difficult to control. The choice of optimum laser parameters to fabricate structures with desired properties remains extremely challenging. Another challenging issue is the investigation of the properties of laser-induced buried structures. In this paper, we propose a way to control the plasmonic structures formation inside a nanoporous glass composite with doped silver/copper ions that are induced by laser irradiation. Experimental and numerical investigations both demonstrate the capacities of the procedure proving its validity and application potential. In particular, we register transmitted laser power to analyse and control the modification process. Spectral micro-analysis of the irradiated region shows a multilayer plasmonic structure inside the glass composite. Subsequently, the effective medium theory connects the measured spectral data to the numerically estimated size, concentration, and chemical composition of the secondary phase across the initial GC sample and the fabricated structure.

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Formation of micro- and mesoporous substructures in the course of the leaching process of two-phase alkali borosilicate glass

Cited by 11 publications

References 8 publications

Novel Inorganic Membranes Based on Magnetite-Containing Silica Porous Glasses for Ultrafiltration: Structure and Sorption Properties

Novel Inorganic Membranes Based on Magnetite-Containing Silica Porous Glasses for Ultrafiltration: Structure and Sorption Properties

Optical Sensitivity of Waveguides Inscribed in Nanoporous Silicate Framework

Real-Time Analysis of Laser-Induced Plasmon Tuning in Nanoporous Glass Composite

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