Non-bridging Oxygen Atoms Research Articles

Structure and vibrational properties of sodium silicate glass surfaces.

Using molecular dynamics simulations, we investigate how the structural and vibrational properties of the surfaces of sodo-silicate glasses depend on the sodium content as well as the nature of the surface. Two types of glass surfaces are considered: A melt-formed surface (MS) in which a liquid with a free surface has been cooled down into the glass phase and a fracture surface (FS) obtained by tensile loading of a glass sample. We find that the MS is more abundant in Na and non-bridging oxygen atoms than the FS and the bulk glass, whereas the FS has higher concentration of structural defects such as two-membered rings and under-coordinated Si than the MS. We associate these structural differences to the production histories of the glasses and the mobility of the Na ions. It is also found that for Na-poor systems, the fluctuations in composition and local atomic charge density decay with a power-law as a function of distance from the surface, while Na-rich systems show an exponential decay with a typical decay length of ≈2.3 Å. The vibrational density of states shows that the presence of the surfaces leads to a decrease in the characteristic frequencies in the system. The two-membered rings give rise to a pronounce band at ≈880 cm-1, which is in good agreement with experimental observations.

An in-depth investigation from mechanical durability to structural and nuclear radiation attenuation properties: B2O3–Na2O–Bi2O3–Nb2O5 glasses experience

This study aimed to determine various essential properties from mechanical durability to structural and nuclear radiation attenuation properties of newly synthesized B2O3–Na2O–Bi2O3–Nb2O5 glasses. Accordingly, a series of B2O3–Na2O–Bi2O3–Nb2O5 glass samples were fabricated via the melt-quenching technique. The gamma and neutron shielding, physical and mechanical properties of the prepared samples were investigated. The addition of Nb2O5 and Bi2O3 increased the density of the glass samples and decreased their molar volume. The mass attenuation coefficient (μm) decreased as photon energy decreased, while it increased as Nb2O5 and Bi2O3 concentration increased. The half value layer (HVL) and mean free path (MFP) of the glass samples increased when the photon energy increased and decreased as the Nb2O5 and Bi2O3 concentration increased. The increment effect of Bi2O3 and Nb2O5 manifests its self in two regions. One of them is the increment of Bi2O3 and Nb2O5 from 0 to 15 mol%, that weaken the structure of sodium borate network by creating BO3 units with non-bridging oxygen atoms. The increment beyond 15 mol% creates NbO4 structural units that strengthen the network and increase their mechanical parameters.

Ultraviolet laser damage properties of single-layer SiO2 film grown by atomic layer deposition

Optical properties and ultraviolet laser damage of single-layer atomic layer deposition (ALD) SiO2 films were investigated. ALD SiO2 films of high transparency shows weak absorption at 355nm. The absorption at 355 nm measured by laser calorimeter varies linearly with the film thickness with absorption coefficient of ∼0.76 ppm/nm. Such absorption is considered originating from various point defects in ALD SiO2 film. Fourier transform infrared (FTIR) spectra confirm the presence of point defects in ALD SiO2 films including non-bridging oxygen atoms and residual OH groups. Nanosecond laser-induced damage of ALD SiO2 film at 355 nm was investigated. The damage threshold and damage morphology suggest that laser-induced damage of ALD film is associated with point defect clusters which can absorb enough laser energy to initiate micro-explosion in ALD films. Furthermore, the ALD films were conditioned with sub-nanosecond ultraviolet laser. Significant improvement in damage resistance has been demonstrated after sub-nanosecond laser conditioning. After laser conditioning to 3 J/cm2, the damage threshold of 535 nm thick ALD film increased from 5.5 J/cm2 to 14.9 J/cm2 and improved about 170%. Annealing of point defects by sub-nanosecond ultraviolet laser is supposed to be the reason for the improvement of the damage resistance.

Extracellular Nucleotides Selectively Induce Migration of Chondrocytes and Expression of Type II Collagen.

The migration of chondrocytes from healthy to injured tissues is one of the most important challenges during cartilage repair. Additionally, maintenance of the chondrogenic phenotype remains another limitation, especially during monolayer culture in vitro. Using both the differentiated and undifferentiated chondrogenic ATDC5 cell line, we showed that extracellular nucleotides are able to increase the migration rate of chondrocytes without affecting their chondrogenic phenotype. We checked the potency of natural nucleotides (ATP, ADP, UTP, and UDP) as well as their stable phosphorothioate analogs, containing a sulfur atom in the place of one nonbridging oxygen atom in a phosphate group. We also detected P2y1, P2y2, P2y4, P2y6, P2y12, P2y13, and P2y14 mRNA transcripts for nucleotide receptors, demonstrating that P2y1 and P2y13 are highly upregulated in differentiated ATDC5 cells. We showed that ADPβS, UDPβS, and ADP are the best stimulators of migration of differentiated chondrocytes. Additionally, ADP and ADPβS positively affected the expression of type II collagen, a structural component of the cartilage matrix.

Towards superior optical and dielectric properties of borosilicate glasses containing tungsten and vanadium ions

Transparent glasses of the composition (20–x)V2O5–xWO3–20SiO2–60Li2B4O7, x = 2, 4, 8 and 16 mol %, have been successfully synthesized by a popular melt quenching technique. The main features regarding the structure of these glasses were determined via Fourier transform infrared (FTIR) spectroscopy. The structure change was occurred in the glasses containing 8 and 16 mol% of WO3 which, in turn, decreased non-bridging oxygen (NBO) atoms with further WO3 additions. In addition, the density of these glasses provided higher values with WO3 additions. Optical measurements were achieved through different ranges of wavelength, revealing that the degree of transparency improved, while the absorption decreased, with WO3 additions. Remarkably, the optical transitions of tungsten and vanadium ions embedded in lithium borosilicate glasses were examined. The energy of optical band gaps was decreased by introducing WO3 until 8 mol %, and then increased with further WO3 additions. Furthermore, the conductivity was slightly increased by introducing WO3 until 8 mol %, and then decreased with further WO3 additions, whereas the activation energy demonstrated the opposite behavior with WO3 additions. The dependence of dielectric permittivity, dielectric loss and electrical conductivity on temperatures at varying frequencies was applied. The loss factor revealed a peak that moves towards higher temperature as the frequency increased, indicating the Debye-type relaxation behavior. Finally, the outcomes demonstrated that WO3–V2O5–SiO2–Li2B4O7 glasses are promising optically and electrically tunable materials.

Oxygen fugacity and melt composition controls on nitrogen solubility in silicate melts

Knowledge of N solubility in silicate melts is key for understanding the origin of terrestrial N and the distribution and exchanges of N between the atmosphere, the silicate magma ocean, and the core forming metal. To place constraints on the incorporation mechanism(s) of N in silicate melts, we investigated the effect of the oxygen fugacity (fO2) and melt composition on the N solubility through N equilibration experiments at atmospheric pressure and high temperature (1425 °C). Oxygen fugacity (expressed in log units relative to the iron-wüstite buffer, IW) was varied from IW –8 to IW +4.1, and melt compositions covered a wide range of polymerization degrees, defined by the NBO/T ratio (the number of non-bridging oxygen atoms per tetrahedrally coordinated cations). The N contents of the quenched run products (silicate glasses) were analyzed by in-situ secondary ion mass spectrometry and bulk CO2 laser extraction static mass spectrometry, yielding results that are in excellent agreement even for N concentrations at the (sub-)ppm level. The data obtained here highlight the fundamental control of fO2 and the degree of polymerization of the silicate melt on N solubility. Under highly reduced conditions (fO2 = IW –8), the N solubility increased with increasing NBO/T from 17.4 ± 0.4 ppm·atm−1/2 in highly polymerized melts (NBO/T = 0) to 6710 ± 102 ppm·atm−1/2 in depolymerized melts (NBO/T ∼ 2.0). In contrast, under less reducing conditions (fO2 > IW –3.4), N solubility is very low (≤2 ppm·atm−1/2), irrespective of the NBO/T value. Our results provide constraints on N solubility in enstatite chondrite melts and in the shallow part of a planetary magma ocean. The nitrogen storage capacity of an enstatite chondrite melt, which may approximate that of planetesimals that accreted and melted early in the inner Solar System, varies between ∼60 and ∼6000 ppm at IW –5.1 and IW –8, respectively. In contrast, a mafic to ultra-mafic magma ocean could have incorporated ∼0.3 ppm to ∼35 ppm N under the fO2 conditions inferred for the young Earth (i.e., IW –5 to IW). The N storage capacity of a reduced magma ocean (i.e., IW –3.4 to IW) in equilibrium with a N-rich atmosphere is ≤1 ppm, comparable to the N content of the present-day mantle. However under more reducing conditions (i.e., IW –5 to IW –4), the N storage capacity is significantly higher (∼35 ppm); in this case, Earth would have lost N to the atmosphere and/or N would have been transported into and stored within its deep interior (i.e., deep mantle, core).

Structure, Reactivity, and Mechanical Properties of Sustainable Geopolymer Material: A Reactive Molecular Dynamics Study

Sodium aluminosilicate hydrate (NASH) gel, the primary binding phase in geopolymer, determines the mechanical properties and durability of environment-friendly construction materials. In this work, the models of NASH gel were obtained by two-step procedure: the temperature quenching method and Grand Canonical Monte Carlo water adsorption. The reactive force field molecular dynamics was utilized to investigate the structure, reactivity and mechanical performance of the NASH gel with Na/Al ratio ranging from 1 to 3. Q species, the connectivity factor, shows that the increase of sodium content in NASH gel leads to depolymerization of aluminosilicate network and more non-bridging oxygen atoms. The adsorbed water molecules dissociate near the non-bridging oxygen with high reactivity in defective aluminosilicate structure. The newly produced hydroxyls associate with the aluminate species, contributing to formation of pentahedron local structure. The sodium ions distributed in the cavity of the aluminosilicate skeleton have around 4 ~ 7 nearest neighbors. Furthermore, with increasing the amount of sodium, the molecular structure of the aluminosilicate skeleton is transformed from an integrity network to partial destroyed branch structures, which gradually decreases the stiffness and cohesive force of NASH gel characterized by the uniaxial tensile testing. During the large tensile deformation process, the reactive force field MD correlates the mechanical response with the chemical reaction pathway. The aluminosilicate skeleton is stretched broken to resist the tensile loading and the hydrolytic reaction of water molecules near the stretched Si-O and Al-O bond further accelerates the degradation of NASH gel. Hopefully, this work can shed light on material design for the high performance of sustainable geopolymer at nanoscale.

A Molecular Dynamics Study on the Structure, Interfaces, Mechanical Properties, and Mechanisms of a Calcium Silicate Hydrate/2D-Silica Nanocomposite

The incorporation of nano-reinforcements is believed to be a promising method to create high performance nanocomposites, which are largely dependent on the interfacial connections. In this work, the newly emerging two-dimensional (2D) material, 2D-silica is intentionally intercalated into the interlayer defective sites of calcium silicate hydrate (C-S-H), which is the primary hydration product of ordinary portland cements. The reactive molecular simulation results indicate the nano-reinforcement can strongly interact with the inorganic matrix to form a high-ductility nanocomposite. The uniaxial tensile loading tests show the plastic stage of the C-S-H is dramatically enhanced due to the intercalation of 2D-silica, which removes the intrinsic brittleness of cement-based materials at the nano-scale. It is observed that the dangling atoms at the edge of 2D-silica can react with non-bridging oxygen atoms of C-S-H, forming Si-O-Si bonds at interfaces. Those covalent bonds transform Q1 and Q2 in the C-S-H into high connectivity Q3 and Q4 species, which increases the integrity of the matrix and its resistance to crack propagation. During the tensile process, the elongation and breakage of those high-strength covalent bonds needs higher tensile stress and consumes higher energy, which leads to a strong plasticity and higher toughness. This work may shed new lights on the interaction mechanisms between 2D-materials and inorganic hosts, and provide solutions to modifying the brittleness of concrete.

Synthesis and physical characterization of gamma irradiated cadmium phosphate glass modified by copper oxide

The irradiation of Cu-doped Cd-phosphate glass mediated by gamma rays shows the conversion of Cu2+ ↔ Cu+ ion with subsequent glass defects which leads to the loss of glass structure. The physical evaluations encompassing FTIR studies, X-ray diffraction analysis, UV spectrophotometer analysis, EPR, differential scanning colorimetry, and elastic properties are performed. The optical band gap (Eg) values for both direct and indirect transition and refractive index are evaluated for varying irradiation doses and correlated with the data obtained for optical spectra, ultrasonic wave velocities and elastic moduli. Further, the evaluations such as optical basicity and average electro negativity have been determined. The obtained optical basicity values increases with concurrent increase in the dose of radiation, however the values of electron negativity have not displayed such variations. After irradiation at various doses, there is a significant elevation in non-bridging oxygen (NBO) atoms which lead to decreased glass polymerization, reduced glass stability and aids the formation of copper ions aggregates. The above stated process highly alters the structure and optical properties of glass which is confirmed by the results of the optical absorption, FTIR and EPR spectral analysis. The force constant values and the bond strength between Cu–O are lower as compared to P–O, which further decreases the glass rigidity thus decrease in glass rigidity affects the ultrasonic velocity, Eg and Tg. The thermal stability values of studied glass decreased with subsequent increases in the dose of irradiation. Thus this glass displays specific optical characteristic and thus can be employed as a bandpass filters.

Hydrogen bond-induced responses in mid- and far-infrared spectra of interfacial water at phospholipid bilayers

The vibrational spectra of interfacial water at phospholipid bilayers is critical to the understanding of cell membrane functions. In this work, we employ molecular dynamics simulations to explore simultaneous responses in both mid- and far-Infrared (IR) spectra of water at the interface with 3-palmitoyl-2-oleoyl-d-glycero-1-phosphatidyl choline (POPC) bilayers. Our results show that the interfacial water can exhibit both a red shift in the mid-IR region for the O–H stretching mode and a blue shift in the far-IR region due to the vibrational mode of water-water hydrogen bonds (HBs). More interestingly, our simulation results reveal that such shifts in both mid- and far-IR regions are essentially induced by the interfacial water molecules that form HBs with the POPC. In particular, the HBs between the interfacial water and the POPC are strong, especially for those with the non-bridging oxygen atoms connecting the phosphorus atom. Such preferential leads to the considerably enhanced HB strength which in return promotes shifts in the mid- and far-IR regions.

In situ formation of rare-earth-doped nanoparticles in a silica matrix from Molecular Dynamics simulations

Developing new rare-earth-doped optical glasses with "enhanced" spectroscopic properties requires the elaboration of new glass compositions. To overcome some typical limitations of silica glass, a strategy consists in encapsulating rare-earth (RE) ions within oxide nanoparticles (NPs) through a phase separation mechanism. In this paper, Molecular Dynamics simulations were performed using an interatomic potential reproducing the phase separation within a MgO–SiO2 binary melt to obtain RE-codoped glass models with RE = Eu or Er. In these structures, we observed that Mg-rich regions, included into a silica-rich matrix and identified as NPs, are amorphous and exhibit a large range of sizes. We showed that such nanoparticles are the host of a depolymerization phenomenon of the NPs’ SiO4 tetrahedral network leading to a release of non-bridging oxygen atoms. In the NPs, the MgO concentration increases and the doping RE ions are mainly located into the NPs where they are over-concentrated compared with the nominal doping concentration. However, the induced clustering effect is limited because of the non-bridging-oxygen-rich environment encountered in the NPs. This numerical analysis allows to give an insight on the chemical composition of the NPs, and especially on the local environment of the encapsulated rare-earth ions.

Effect of Gamma Irradiation on Structural and Optical Properties of Zirconium Incorporated Sodium Borate Glasses

ABSTRACT The effects of gamma irradiation in the dose rate of 25 kGy on the structural and optical properties of ZrO2 doped sodium borate glasses were studied. Glassy nature confirmed by XRD and all the physical parameters were calculated. IR spectra revealed the characteristic vibrational and stretching bands due to trigonal and tetrahedral borate network. Slight changes were caused by gamma irradiation in the intensities of the characteristic infrared borate bands and zirconium bands. Irradiated samples developed a noticeable absorption band similar to the F-band familiar in alkali halide crystals which clearly indicated that successive irradiation produced defects in the glass material. Substitution of ZrO2 to the glass matrix suppressed the formation of visible absorption band formed by irradiation whereas no extra peak was observed in the spectral regions. A nonlinear trend was ascribed in the energy band gap values due to the creation of more number of non-bridging oxygen atoms. Emission spectra showed five emission bands corresponding to the zirconium ions which decreased to a very low intensity with a red shift after irradiation. Matching the colour co-ordinates bright blue emission was found for 5 mol% ZrO2 in both irradiated and non irradiated sample.

GAMMA RAY SHIELDING PARAMETER OF BARIUM-BORO-TELLURITE GLASS

Boro-tellurite glasses have recently been attracting the attention of several researchers as a tremendous optical device and shielding material. In this work, we have synthesized borotellurite glasses with barium oxide (BaO) by melt quenching technique. The structural and shielding property changes after adding of barium oxide in boro-tellurite glass were studied using Fourier Transform Infrared (FTIR) and Lead Equivalent Thickness measurement (LET), respectively. The results show that the bismuth oxide increases glass density, changes the glass structure, and increases the radiation shielding properties. Changes in the glass structure are due to atomic rearrangements and formation of nonbridging oxygen (NBO). The density of boro-tellurite glass system increased when BaO content increased, which is due to the high molecular weight of BaO and the increasing number of non-bridging oxygen (NBO) atoms in the glass structure. In addition, the mass attenuation coefficient, μm of the glass system increases as BaO concentration increases and the half value layer, HVL and mean free path, MFP of 30BaBTe glass is better than some standard concretes.

Optical characteristics of the undamaged and laser damaged K9 glass in terahertz band

K9 glass is an important optical element of the high energy laser system. In an attempt to investigate the variation of optical properties of K9 glass before and after laser induced damage, based on the transmission terahertz time-domain spectral system, the undamaged and the damaged K9 glasses induced by laser were tested to obtain the terahertz time-domain and frequency-domain spectra and the refractive index and absorption coefficient of the samples were calculated in terahertz band for further analysis. Results show that with the increase of laser energy, from the undamaged to the damaged K9 glasses to different extent, the peak to peak value in time domain and the amplitude value in frequency domain present a decreasing trend in varying degrees, and in the 0.4 ∼ 0.5 THz band, the absorption coefficient increases continuously with a slight change of refractive index, which indicates that K9 glass not only appears the melting and fracture in the macroscopic morphology after laser-induced damage, but also forms non-bridged oxygen atoms in its microstructure with more ion bonds and free electrons and the change of ion polarization. In this regard, this paper provides a technical basis for exploring the micro characteristics of K9 glass after laser-induced damage, and lays a good foundation for the application of terahertz time-domain spectroscopy to laser-induced damage analysis.

Investigation of gamma and neutron shielding parameters for borosilicate glasses doped europium oxide for the immobilization of radioactive waste

Eu3+-doped borosilicate glasses were prepared by the melt-quenching method. Optical, physical and nuclear shielding properties of these glasses were studied. The FTIR measurements indicated that the continuous increase of europium concentration helped conversion of [BO4] to [BO3] groups. FTIR spectroscopy results were in good agreement with optical band energy gap, density and molar volume values revealing network modifications caused by europium ions in the glass structure. The amorphous natures of the samples were ascertained by XRD studies. Optical properties of the glass samples are studied before and after neutron at room temperature. The absorption spectra of all glasses indicated that there is a decrease in the optical band gap values due to the enhancement of the number of non-bridging oxygen (NBO) atoms with the addition of Eu2O3. Nuclear shielding properties of these have been investigated. The mass attenuation coefcients have been calculated using the XCOM program.

Effect of Li content in ion conductivity of lithium silicate glasses

We present the electrical and the phonon vibrational properties of Li2O–2SiO2 (LS12) and Li2O–SiO2 (LS11) glasses to exploit for lithium ion transport in the merits of solid electrolyte. Electrical impedance measurements are carried out in the frequency 100 Hz–30 MHz and temperature range 30–150 °C. Based on the theory of the modified fractional Rayleigh equation, we predict the number densities of the lithium ions in the lithium silicate glasses. As an increase in lithium content, the covalent interaction between the Li-cation and its local sites of network increases the number of the non-bridging oxygen (NBO) sites by the depolymerization of the silicate glass network. We find the fact that the number of NBOs in the LS11 glass increases a factor of two larger than the number of NBOs in the LS12 glass. A low conductivity of lithium oxide glasses is reflection of a long stay of the lithium ions in the NBO atoms. The partial Li+ ions in the lithium silicate glasses participate on the ac conduction through the NBO sites.

Concentration Dependent Spectroscopic Properties of Terbium Ion Doped Lead-Borate Glasses and Vitroceramics

Terbium ions doped lead borate glasses and vitroceramics with the composition of xTb4O7·(100-x)[4PbO·B2O3] where x is from 0 to 25 mol % Tb4O7 were prepared by the use of a melt-quenching protocol. Their structural and spectroscopic properties were characterized by x-ray diffraction (XRD), Fourier transform infrared (FTIR), Raman and ultraviolet-visible spectroscopies. The XRD patterns reveal the amorphous nature of the samples with low Tb4O7 content up to x equal to 1 mol % Tb4O7. Above this concentration, the analysis of XRD measurements indicates the presence of new crystaline phases in the vitroceramic samples. The FTIR and Raman measurements indicate that the addition of the rare earth oxides in the host network is realized by the deformation of the Pb-O-Pb or O-Pb-O angles, the formation of varied borate units and a large number of non-bridging oxygen atoms. The compositional evolution is conducted at the formation of crystalline phases of the terbium and lead atoms. The terbium atoms have a pronounced affinity toward the borate units while the lead atoms are attracted toward the oxygen atoms. Structural investigations by ultraviolet-visible spectroscopy show the presence of larger bands due to the f-f electron transitions of the Tb3+ ions and 6 s2 → 6s 6p transitions of Pb2+ ions, respectively. The optical gap energy values are dependent upon the concentration of the dopant level.

Structure and in vitro dissolution of Mg and Sr containing borosilicate bioactive glasses for bone tissue engineering

Borosilicate bioactive glasses are promising for bone tissue engineering. The objective was to assess the impact of magnesium and/or strontium, when substituted for calcium on the glasses' thermal and dissolution properties. Both Mg and Sr substitution appeared to enhance the hot forming domain, i.e. the ability to hot process (sinter, draw fibres) without adverse crystallization. Structural analysis indicated that substitution of MgO and/or SrO for CaO results in changes in the BO3/BO4 ratio as well as in the ratio between bridging and non-bridging oxygen atoms in the silicate structure. Additionally, a de-shielding effect was noticed when Ca, Mg and Sr are present together in the glass network, possibly owing to PO43− charge-balanced preferentially by Na+. The Mg and/or Sr substitution resulted in a lower ion release in simulated body fluid and delayed formation of hydroxyapatite. However, once this layer formed it consisted of a Mg/Sr-substituted apatite. This work highlights the effect of combined ionic substitutions on bioactive glass structure and properties.

Формирование кислородных пузырьков в стекле К-208 при электронном облучении

The formation of gas-filled bubbles, which is one of the indicators and quantitative criteria for radiation degradation of the surface layer of K-208 glass irradiated by 20-keV electrons, and the effect of ITO (Indium tin oxide) film deposited on the glass, are investigated. Using atomic force microscopy, the nucleation of oxygen bubbles in the surface layer of glass irradiated with a fluence (Φ) of the order of 1015 cm–2 at a particle flux density (φ) of 2·1010 cm–2·s–1 was detected. Gas-filled bubbles appear on the surface of samples with an ITO film at Φ ≥ 4·1015 cm–2 in smaller amounts but larger sizes than on glass without a film. The formation of oxygen bubbles is explained by the formation of a negative charge region in the surface layer of the irradiated glass, in the field of which sodium ions migrate, which plays a key role in the release of non-bridge oxygen atoms. Migration and aggregation of liberated oxygen atoms in defective places in the glass grid leads to the formation of gas-filled bubbles.

Insights into the Microstructure of Hydrothermal Synthesized Nanoscale K2O-Al2O3-SiO2-H2O Particles

K-A-S-H (K2O-Al2O3-SiO2-H2O) gel is a key phase that forms in most alkali-activated binders (eco-friendly binders which utilize a substantial amount of industrial by-product). An in-depth understanding of the microstructure and performance of this nano-sized key phase facilitates better application to alkali-activated binders. However, such studies remain little and undetailed. Therefore, our research aims to provide insights into the microstructure of K-A-S-H particles synthesized with accurate stoichiometric control by the hydrothermal method through thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and BET surface area. The results show that for materials prepared at the curing temperature lower than 80 °C, the K-A-S-H products were completely amorphous. With increased curing temperature and time, the K-A-S-H products were transformed from the amorphous phase to the crystalline zeolite phase structure, with a reduction in the specific surface area. The TG results indicate that the crystalline phase contains more non-evaporated water or zeolite water for structural rearrangement. The degree of tetrahedral polymerization slightly decreased with an increase of the K2O/SiO2 ratio as the amount of non-bridged oxygen atoms increased, whereas it gradually increased with an increase of curing temperature and time, as suggested by the FTIR and NMR results. Various K2O/SiO2 ratios resulted in the formation of zeolite K-H and K-G zeolite, both of which exhibited highly polymerized three-dimensional network structures. However, there was no significant effect of the SiO2/Al2O3 ratio on the structure of K-A-S-H products. Overall, these results provide insight into understanding the chemical stability of K-A-S-H.