Silica Network Research Articles

Development and Application of an Advanced Percolation Model for Pore Network Characterization by Physical Adsorption.

Physical adsorption is one of the most widely used techniques to characterize porous materials because it is reliable and able to assess micro- and mesopores within one approach. Challenges and open questions persist in characterizing disordered and hierarchically structured porous materials. This study introduces a pore network model aimed at enhancing the textural characterization of nanoporous materials. The model, based on percolation theory on a finite-sized Bethe lattice, includes all mechanisms known to contribute to adsorption hysteresis in mesoporous pore networks. The model accounts for delayed and initiated condensation during adsorption as well as equilibrium evaporation, pore blocking, and cavitation during desorption. Coupled with dedicated nonlocal-density functional theory kernels, the proposed method provides a unified framework for modeling the entire experimental adsorption-desorption isotherm, including desorption hysteresis scans. The applicability of the method is demonstrated on a selected set of nanoporous silica materials exhibiting distinct types of hysteresis loops (types H1, H2a, H1/H2a, and H5), including ordered mesoporous silica networks (KIT-6 and SBA-15/MCM-41 hybrid silica with plugged pores) and disordered mesoporous silica networks (hierarchical meso-macroporous monolith and porous Vycor glass). For all materials, a good correlation is found between calculated and experimental primary isotherms as well as desorption scans. The model allows us to determine key pore network characteristics such as pore connectivity and pore size distributions as well as a parameter correlated with the impact of pore network disorder on the adsorption behavior. The versatility and enriched textural insights provided by the proposed novel network model allow for a comprehensive characterization previously inaccessible and hence will contribute to further advancement in the textural characterization of novel nanoporous materials. It has the potential to provide important guidance for the design and selection of porous materials for optimizing various applications, including separation processes such as chromatography, heterogeneous catalysis and gas and energy storage.

Open-structured silica network based on silane-terminated telechelic polybutadiene for electric vehicle tires

The shift towards electric vehicles (EVs) is essential for a sustainable future. Tire manufacturers face challenges including accommodating extra weight, managing instant torque, reducing noise, and improving driving range. Meeting these demands involves substantially reducing the rolling resistance of tire tread composites while simultaneously enhancing their mechanical stiffness and wear resistance. To overcome these issues, an open-structured silica network based on silane-terminated liquid-like telechelic polybutadienes was introduced into rubber composites. This unique network consists of silica aggregates that are chemically bound together, but exhibit physical separation, enabling rubber chains to permeate. The infiltrated polymer chains were tightly constrained by the network, resulting in a notable increase in the crosslink density and mechanical strength of the composite. Furthermore, the tan δ values at 60 °C showed a notable decrease as a result of diminished interparticle friction caused by isolated silica structures and reduced mobility of polymer chains within the network. These findings provide the tire industry with crucial insights for the development of energy-efficient and durable tires for EVs. By addressing these specific requirements of EVs, our study paves the way for more sustainable tires and contributes to the broader adoption of EVs in a sustainable future.

Physical-chemical characterisation of an alum-based water treatment sludge in different raw water turbidity scenarios

Characterisation of the water treatment sludge (WTS) generated in drinking water treatment plants (DWTPs) is crucial to define alternatives for its adequate management, including potential reuse options. To define these alternatives, it is necessary to evaluate rainfall seasonality effect on WTS production and its physical and chemical characteristics. This study assessed the production and characterisation of four types of alum-based WTS. The WTS was generated in a pilot-scale system from different raw water turbidities (i.e., low: <5 NTU, medium: 5–10 NTU, high: ≥10 NTU, and very high turbidity: ∼300 NTU) and coagulant doses. To estimate WTS production, mathematical models based on variables such as raw water turbidity, coagulant dosage, and organic matter removed were used. The WTS characterisations included physical (solids and particle size distribution), chemical (metallic oxides, pH, mineral phases), and surface properties (functional groups and zero-charge point pH). The modified Kawamura model presented the best fit (R2 = 1.0, RMSE = 0.1062 and the lower Akaike Information Criterion) for the estimation of WTS production, indicating that at the DWTPs, it is possible to make sludge production projections using only two simple variables: coagulant dose and the raw water turbidity. The four types of WTS consist mainly of amorphous materials (45–65 %), featuring some mineral phases and exhibiting high contents of Al (Al2O3: 30–34 %), Si (SiO2: 21–26 %) and Fe (Fe2O3: 11–13 %). Nevertheless, very high turbidity WTS shows variations in its characteristics, notably a heightened content of clays. As a result of the high concentrations of Al and Fe, the WTS has the potential to be used as coagulants or for the recovery of coagulants, especially low turbidity WTS, which is produced from water with low turbidity and organic matter. The presence of aluminium–silicate clays and the surface functional groups of the silica network suggest that WTS, particularly very high turbidity WTS, also has the potential to be raw materials for generating adsorbents. The potential applications of WTS in coagulation and adsorption can be leveraged in wastewater treatment, promoting the circular economy in the water sector.

Silica-Ti3C2Tx MXene Nanoarchitectures with Simultaneous Adsorption and Photothermal Properties.

Layered Ti3C2Tx MXene has been successfully intercalated and exfoliated with the simultaneous generation of a 3D silica network by treating its cationic surfactant intercalation compound (MXene-CTAB) with an alkoxysilane (TMOS), resulting in a MXene-silica nanoarchitecture, which has high porosity and specific surface area, together with the intrinsic properties of MXene (e.g., photothermal response). The ability of these innovative MXene silica materials to induce thermal activation reactions of previously adsorbed compounds is demonstrated here using NIR laser irradiation. For this purpose, the pinacol rearrangement reaction has been selected as a first model example, testing the effectiveness of NIR laser-assisted photothermal irradiation in these processes. This work shows that Ti3C2Tx-based nanoarchitectures open new avenues for applications that rely on the combined properties inherent to their integrated nanocomponents, which could be extended to the broader MXene family.

Sustained Antibiotic Release from Biodegradable Gelatin–Silica Hybrid for Orthopedic Infections

AbstractAntibiotic‐loaded polymethylmethacrylate (PMMA) beads are commonly employed to treat prosthetic joint infections (PJI) and chronic osteomyelitis due to their excellent mechanical strength. However, PMMA's non‐degradability results in a burst release of antibiotics and potential renal toxicity, necessitating additional surgeries for bead removal. There is a critical need for infection control materials that can deliver antibiotics effectively, maintain adequate mechanical strength, and degrade uniformly. This study introduces a gelatin–silica hybrid antibiotic carrier, characterized by covalent bonds between the gelatin and silica networks. The incorporation of the silica network enhances the compressive strength to 32.53 ± 2.4 MPa and ensures uniform degradation over 6 months, aligning with clinical timelines. Furthermore, the gelatin–silica hybrid can support up to 10 wt% antibiotic loading without compromising its properties, making it a promising candidate for next‐generation infection control materials.

Synthesis and Characterization of Coenzyme Q10 onto Nanoporous Calcium Silicate-Based Systems for Wound Healing

This study explores the microstructure, spectroscopic, and bonding arrangements within bioactive calcium silicate and calcium magnesium silicate systems loaded with different values (1–2.5 wt%) Coenzyme (CoQ10) ratios, synthesized using sol-gel processes. The investigation utilizes X-ray diffraction (XRD), transmission electron microscopy, and Fourier transform infrared (FTIR) spectroscopy to analyze the samples. The study explores the assignment of FTIR bonds, examining changes in the silicate-based bonds environment under the effect of the CoQ10 ratio. The observed frequency shifts and intensity variations in FTIR bonds, linked with the bioactive silicate composition, are attributed to a reduction in local symmetry resulting from introducing the calcium and magnesium oxides and CoQ10 to the silica network. The XRD and FTIR results contribute valuable insights into the structural role of silicate-based materials loaded with CoQ10, thereby enhancing our understanding of the CoQ10 release process. Approval of the CoQ10 drug loading in both calcium silicate and calcium magnesium silicate nanosystems was recognized by shifts in FTIR bands, changes in particle distribution, and the valuation of drug release activity showed by the bioactive two calcium silicate-based nanoparticles. Additionally, wound healing studies revealed the biocompatibility and wound healing response of calcium magnesium silicate nanoparticles.

Fabrication and evaluation of a plasmonic biosensor based on silica-coated gold nanorods for highly-sensitive detection of anti-Müllerian hormone

Anti-müllerian hormone is a crucial biomarker for reproductive potential, but current detection methods are not cost-effective or time-efficient. In this study, we set out to develop a biosensor using gold nanorods (Au-NRs) coated with a functionalized silica network. The biosensor structure was completed by covalently binding the anti-Müllerian hormone antibody to SiO2@Au-NRs. We confirmed the proper coating of the gold nanorods using HR-TEM, EDS/EDAX, zeta potential, and FT-IR analysis. To assess the sensitivity of SiO2@Au-NRs, we analyzed the LSPR peak position redshift in different concentrations of ethylene glycol. The biosensor was then used to recognize the AMH antigen and determine the limit of detection (LoD) and quantification (LoQ) for the biosensor. Our research has shown that the SiO2@Au-NRs have a suitable thickness. The SiO2@Au-NRs demonstrated impressive sensitivity as a nano biosensor. The AMH antigen identification results indicated that the nano biosensor was highly sensitive. The LoD and LoQ values were 0.086 and 0.262 ng ml−1, respectively, very close to the values obtained by the ELISA kit. Furthermore, LSPR biosensors have reduced detection costs and measurement time. Their high sensitivity makes them excellent candidates for use in diagnostic kits.

Robust Transparent Photothermal Omniphobic Coating for Efficient Anti/Deicing and Antifogging.

Icing and fogging on optical material surfaces bring various problems in daily life. Recently, some photothermal coatings have been reported to prevent the condensation or freeze of water droplets by increasing the surface temperature. However, it is a great challenge to apply them in practical conditions due to their opaqueness and poor mechanical wear-resistant property. In this work, we constructed a robust transparent photothermal omniphobic coating with a simple dip-coating technique. In the coating system, photothermal polypyrrole nanoparticles are introduced into inorganic silica networks, and then polydimethylsiloxane (PDMS) brushes were grafted on the inorganic silica layer to endow the surface with omniphobicity and stain resistance. The transparency and photothermal capacity of the coating can be regulated by the deposition times of the coating. In addition, the coating has an excellent anti/deicing property and reduces ice adhesion obviously due to the existence of "liquid-like" PDMS brushes. More importantly, the coating presents outstanding mechanical wear-resistant and self-lubricating properties that can endure several thousand friction cycles without performance loss. The mechanically robust photothermal omniphobic coating gives a feasible approach to anti-icing and antifogging of transparent substrates under sunlight irradiation.

Intrinsic influence of the stress on the optical properties of Panda-type erbium-doped fibers.

In this study, erbium-doped fiber (EDF) and Panda-type polarization maintaining erbium-doped fiber (PM-EDF) were fabricated from the same erbium-doped preform. The intrinsic influence of stress induced by the Panda-type design on the optical properties was investigated. A local structural model of EDF was developed to simulate the introduction of stress by varying the length of non-bridging oxygen (NBO) bonds between erbium ions (Er3+) and the silica network, providing theoretical insights. An increase in bond length (indicative of tensile stress), results in decreased excitation and emission intensities for EDF, and the peaks exhibit redshifts. Conversely, a decrease in bond length (indicative of compressive stress), leads to increased excitation and emission intensities, with the peaks showing blueshifts. Experimentally, PM-EDF demonstrated a lower absorption coefficient compared to EDF, with absorption peaks experiencing redshifts of approximately 2 nm. Furthermore, the emission intensity was diminished, and the emission peak at 1530 nm displayed a redshift of around 3 nm. The fluorescence lifetime was shortened to 9.99 ms. Additionally, the total gain of PM-EDF decreased by approximately 4 dB, and the bandwidth narrowed by roughly 13%. The experimental outcomes largely align with the simulation predictions, further corroborating the significant impact of stress on the optical properties of PM-EDF.

Sol-Gel Synthesis of Silica-Poly (Vinylpyrrolidone) Hybrids with Prooxidant Activity and Antibacterial Properties.

The present work deals with the sol-gel synthesis of silica-poly (vinylpyrrolidone) hybrid materials. The nanohybrids (Si-PVP) have been prepared using an acidic catalyst at ambient temperature. Tetramethyl ortosilane (TMOS) was used as a silica precursor. Poly (vinylpyrrolidone) (PVP) was introduced into the reaction mixture as a solution in ethanol with a concentration of 20%. The XRD established that the as-prepared material is amorphous. The IR and 29Si MAS NMR spectra proved the formation of a polymerized silica network as well as the hydrogen bonding interactions between the silica matrix and OH hydrogens of the silanol groups. The TEM showed spherical particle formation along with increased agglomeration tendency. The efficacy of SiO2/PVP nanoparticles as a potential antimicrobial agent against a wide range of bacteria was evaluated as bacteriostatic, using agar diffusion and spot tests. Combined effects of hybrid nanomaterial and antibiotics could significantly reduce the bactericidal concentrations of both the antibiotic and the particles, and they could also eliminate the antibiotic resistance of the pathogen. The registered prooxidant activity of the newly synthesized material was confirmative and explicatory for the antibacterial properties of the tested substance and its synergetic combination with antibiotics. The effect of new hybrid material on Crustacea Daphnia magna was also estimated as harmless under concentration of 0.1 mg/mL.

The Synthesis and Characterization of Selenium-Doped Bioglass.

Background Bioactive glass, which can form strong bonds with tissues, particularly bones, has become pivotal in tissue engineering. Incorporating biologically active ions like selenium enhances its properties for various biomedical applications, including bone repair and cancer treatment. Selenium's antioxidative properties and role in bone health make it a promising addition to biomaterial. Aim The present study was aimed at the preparation and characterization of selenium-doped bioglass. Materials and methods Tetraethyl orthosilicate (TEOS) was mixed with ethanol, water, and nitric acid to form a silica network and then supplemented with calcium nitrate, selenium acid sodium nitrate, and orthophosphoric acid. Sequential addition ensured specific functionalities. After sintering at 300 °C for three hours, the viscous solution transformed into powdered selenium-doped bioglass. Characterization involved scanning electron microscope (SEM) for microstructure analysis, attenuated total reflection infrared spectroscopy (ATR-IR) for molecular structure, and X-ray diffraction (XRD)for crystal structure analysis. Results SEM analysis of selenium-doped bioglass reveals a uniform distribution of selenium dopants in an amorphous structure, enhancing bioactivity through spherical particles with consistent size, micro-porosity, and roughness, facilitating interactions with biological fluids and tissues. ATR-IR analysis shows peaks corresponding to Si-O-Si and P-O bonds, indicating the presence of phosphate groups essential for biomedical applications within the bioglass network. XRD analysis confirms the amorphous nature of selenium-doped bioglass, with shifts in diffraction peaks confirming selenium incorporation without significant crystallization induction. Conclusion The selenium-infused bioglass displays promising versatility due to its amorphous structure, potentially enhancing interactions with biological fluids and tissues. Further research is needed to assess its impact on bone regeneration activity.

Sol-gel coating containing carbon quantum dots for effective corrosion prevention

This study investigates the impact of carbon quantum dots (CQDs) on the corrosion protection properties of sol-gel coating on AM60B alloy. CQDs were synthesised via microwave technique and characterised using Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), and X-ray Diffraction (XRD). Adding 50 ppm CQDs eliminated micrometric cracks in the coating due to chemical bonding with the silica network. Transmission Electron Microscope (TEM) images revealed that CQDs are well dispersed at 50 ppm in the coating. Also, the Atomic Force Microscopy (AFM) confirmed that this concentration reduces the coating's roughness. Electrochemical Impedance Spectroscopy (EIS) in sodium chloride solution revealed a significant reduction in both electrical double- layer and sol-gel layer capacitances after adding 50 ppm CQDs. This indicates reduced penetration of the corrosive electrolyte, attributed to pore blocking and the elimination of micrometric cracks. After 48 h of immersion, the polarisation resistance (Rp) increased from 0.006 to 0.353 MΩ cm2, significantly enhancing the anti-corrosion performance. However, higher concentrations (100 and 200 ppm) of CQDs negatively impacted the corrosion resistance due to the accumulation and micrometric crack formation.

Spray-dried ternary bioactive glass microspheres: Direct and indirect structural effects of copper-doping on acellular degradation behavior

Silicate-based bioactive glass nano/microspheres hold significant promise for bone substitution by facilitating osteointegration through the release of biologically active ions and the formation of a biomimetic apatite layer. Cu-doping enhances properties such as pro-angiogenic and antibacterial behavior. While sol-gel methods usually yield homogeneous spherical particles for pure silica or binary glasses, synthesizing poorly aggregated Cu-doped ternary glass nano/microparticles without a secondary CuO crystalline phase remains challenging. This article introduces an alternative method for fabricating Cu-doped ternary microparticles using sol-gel chemistry combined with spray-drying. The resulting microspheres exhibit well-defined, poorly aggregated particles with spherical shapes and diameters of a few microns. Copper primarily integrates into the microspheres as Cu0 nanoparticles and as Cu2+ within the amorphous network. This doping affects silica network connectivity, as calcium and phosphorus are preferentially distributed in the glass network (respectively as network modifiers and formers) or involved in amorphous calcium phosphate nano-domains depending on the doping rate. These differences affect the interaction with simulated body fluid. Network depolymerization, ion release (SiO44−, Ca2+, PO43−, Cu2+), and apatite nanocrystal layer formation are impacted, as well as copper release. The latter is mainly provided by the copper involved in the silica network and not from metal nanoparticles, most of which remain in the microspheres after interaction. This understanding holds promising implications for potential therapeutic applications, offering possibilities for both short-term and long-term delivery of a tunable copper dose. Statement of significanceA novel methodology, scalable to industrial levels, enables the synthesis of copper-doped ternary bioactive glass microparticles by combining spray-drying and sol-gel chemistry. It provides precise control over the copper percentage in microspheres. This study explores the influence of synthesis conditions on the copper environment, notably Cu0 and Cu2+ ratios, characterized by EPR spectroscopy, an aspect poorly described for copper-doped bioactive glass. Additionally, copper indirectly affects silica network connectivity and calcium/phosphorus distribution, as revealed by SSNMR. Multiscale characterization illustrates how these features impact acellular degradation in simulated body fluid, highlighting the therapeutic potential for customizable copper dosing to address short- and long-term needs.

Silica-Poly(Vinyl Alcohol) Composite Aerogel: A Promising Electrolyte for Solid-State Sodium Batteries.

The transition from fossil fuels is in part limited by our inability to store energy at different scales. Batteries are therefore in high demand, and we need them to store more energy, be more reliable, durable and have less social and environmental impact. Silica-poly(vinyl alcohol) (PVA) composite aerogels doped with sodium perchlorate were synthesized as novel electrolytes for potential application in solid-state sodium batteries. The aerogels, synthesized by one-pot synthesis, are light (up to 214 kg m-3), porous (~85%), exhibit reduced shrinkage on drying (up to 12%) and a typical silica aerogel microstructure. The formation of a silica network and the presence of PVA and sodium perchlorate in the composite were confirmed by FTIR and TGA. The XRD analysis also shows that a predominantly amorphous structure is obtained, as crystalline phases of polymer and salt are present in a very reduced amount. The effects of increasing polymer and sodium salt concentrations on the ionic conductivity, assessed via electrochemical impedance spectroscopy, were studied. At a PVA concentration of 15% (w/w silica precursors), the sodium conduction improved significantly up to (1.1 ± 0.3) × 10-5 S cm-1. Thus, this novel material has promising properties for the envisaged application.

Diatom-inspired silicification process for development of green flexible silica composite aerogels

In this study, we have developed novel biomimetic silica composite aerogels and cryogels for the first time, drawing inspiration from the natural diatom’s silicification process. Our biomimetic approach involved the modification of tyrosinase-mediated oxidized silk fibroin (SFO) surfaces with polyethyleneimine (PEI). This modification introduced ample amine groups onto the SF polymer, which catalyzed the silicification of the SFO-PEI gel surface with silicic acid. This process emulates the catalytic function of long-chain polyamines and silaffin proteins found in diatoms, resulting in a silica network structure on the primary SFO-PEI network gel’s surface. The SFO-PEI gel matrix played a dual role in this process: (1) It provided numerous amine functional groups that directly catalyzed the silicification of silicic acid on the porous structure’s exterior surface, without encapsulating the created silica network in the gel. (2) It served as a flexible mechanical support facilitating the creation of the silica network. As a result, the final ceramic composite exhibits a mechanically flexible nature (e.g., cyclic compressibility up to 80% strain), distinguishing it from conventional composite aerogels. By mimicking the diatom’s silicification process, we were able to simplify the development of silica-polymer composite aerogels. It eliminates the need for surfactants, multi-step procedures involving solvent exchange, and gel washing. Instead, the reaction occurs under mild conditions, streamlining the composite aerogels fabrication process.

Bicontinuous silica-epoxy nanocomposites by aerogel infusion

Interpenetrated, bicontinuous nanocomposites are formed by fully infusing monolithic mesoporous silica (silica aerogel) with epoxy resin. The long-range connectivity of the silica network facilitates direct load transfer and enforces sample homogeneity. The silica networks are prepared using sol–gel chemistry, informed by new phase diagrams, adapted to maximise reinforcement content in the subsequent bicontinuous composite. The infusibility of the aerogels is correlated to pore characteristics determined by gas sorption, as a function of silica aerogel density. Silica reinforcement loadings of up to 22silica vol.% are fully consolidated, with only a modest reduction in glass transition temperature and no change in cure conditions. The reinforcement improves both hardness (+23 %) and reduced modulus (+17 %) of the baseline resin. These properties increase with aerogel content viaa power law relationship which demonstrates the direct role of the connected silica phase as a reinforcing network and motivates future studies to extend the applicable range.

Organo-inorganic hybrid IPN sourced porous carbons and their lead decontamination perspectives

The present communication is about generation of porous carbons through sacrificial template route, from organo-inorganic hybrid interpenetrating polymer networks (IPN's) and their use as a remediation tool for the removal of lead ions from contaminated water. The hybrid IPN's between phenol-formaldehyde (PF) polymer and silica were formed through sequential IPN formation route, in which, silica network was formed first through sol-gel process involving tetraethoxysilane (TEOS) dispersed in phenolic resin followed by thermal crosslinking of the later. The resulting PF/SiO2 IPNs were transformed to C/SiO2 composites through carbonization at 1000 °C under inert atmosphere with silica contents ranging from 10 to 70 %. The silica phase was sacrificed through hydrogen fluoride (HF) leaching to obtain porous carbons, which were further chemically activated with KOH. The derived porous carbons had hierarchical open pore geometry with majority of the pores belonging to the meso category. The carbons were employed to scavenge lead (Pb2+) ions from aqueous effluents and a maximum uptake of 177.3 mg of Pb2+ ions per gram of the adsorbent, was achieved with the present carbons. The adsorption was studied with standard adsorption models, such as Langmuir and Freundlich, of which a better compliance with Langmuir model was noted. Adsorption between the PFSiC carbons and Pb2+ ions obeyed second order kinetics.

Wear, thermal, corrosion, and physical properties of novel UV-cured nanocomposite hybrid coatings with fluorine-containing silica networks

Wear, thermal, corrosion, and physical properties of novel UV-cured nanocomposite hybrid coatings with fluorine-containing silica networks

Influence of Surface Roughness on Interfacial Properties of Particle Networks

The behavior of colloidal particles near fluid interfaces has attracted significant scientific interest, as particles minimize the contact area between the two fluid phases, stabilizing interfacial systems. This study explores the influence of surface roughness on the properties of particle monolayers at the air–water interface, focusing on colloidal silica particles and fumed silica particles of similar hydrodynamic diameter. This research involves comparing low-surface-area (LSA) and medium-surface-area (MSA) fumed silica particles with spherical colloidal silica particles (250 nm in diameter). Utilizing a Langmuir trough, the interfacial particle networks are compressed and expanded. Analysis of surface pressure isotherms reveals that fumed silica particle monolayers form networks at a lower particle surface coverage compared to spherical particles. The spherical particle monolayer exhibits a higher apparent surface elasticity, indicating greater resistance to the applied compression compared to fumed silica networks. Additionally, monolayers formed by fumed silica particles display hysteresis even after successive compressions and expansions due to irreversible particle interlocking and the formation of multilayered aggregates. These findings provide insights into the impact of surface roughness on the behavior of particle monolayers at fluid interfaces, offering valuable information for designing and optimizing mechanisms involved in emulsion and foam stabilization.

Silica Polymerization Driving Opposite Effects of pH on Aqueous Carbonation Using Crystalline and Amorphous Calcium Silicates.

The aqueous carbonation of calcium silicate (CS), a representative alkaline-earth silicate, has been widely explored in studies of carbon dioxide (CO2) mineralization. In this context, we conducted a specific comparison of the carbonation behaviors between the crystalline calcium silicate (CCS) and amorphous calcium silicate (ACS) across a pH range from 9.0 to 12.0. Interestingly, we observed opposite pH dependencies in the carbonation efficiencies (i.e., CaO conversion into CaCO3 in 1 M Na2CO3/NaHCO3 solution under ambient conditions) of CCS and ACS─the carbonation efficiency of CCS decreased with increasing the solution basicity, while that of ACS showed an inverse trend. In-depth insights were gained through in situ Raman characterizations, indicating that these differing trends appeared to originate from the polymerization/depolymerization behaviors of silicates released from minerals. More specifically, higher pH conditions seemed to favor the carbonation of minerals containing polymerized silica networks. These findings may contribute to a better understanding of the fundamental factors influencing the carbonation behaviors of alkaline earth silicates through interfacial coupled dissolution and precipitation processes. Moreover, they offer valuable insights for selecting optimal carbonation conditions for alkaline-earth silicate minerals.