Silica Materials Research Articles

Newly design and synthesis of Ni–Ir–Ru-doped mesoporous silica open-frameworks for admirable electrochemical water-oxidation application

As traditional non-renewable energy sources become scarcer, researchers are exploring effective strategies for producing sustainable and renewable energy. Oxygen evolution reaction through electrocatalytic water splitting (EC-OER) on the surface of a semiconductor has drawn much more attention in the worldwide as it has the principal role towards the several kind of energy applications viz. fuel cell, metal-ion rechargeable batteries and water oxidation. It is extremely difficult to develop eco-friendly, plentiful, and cost-effective nanomaterials as catalysts in order to achieve high efficiency of hydrogen production through water splitting. Furthermore, hierarchical nanostructures will become more valuable in future energy conversion applications due to their excellent physicochemical properties. Herein, we have synthesized total six different kinds of multi-metal-doped porous silica nanomaterials by utilizing the combination of nickel, iridium, and ruthenium metal slats in order to explore them as potential catalysts for electrochemical water oxidation process. We present a simple strategy to synthesize multi-metal-doped silica materials with spherical morphology, deploying a cation surfactant template (CTAB) as a structure directing agent in water-ethanol solvent mixtures. These materials are thoroughly characterized with the help of powder X-ray diffraction (PXRD), UV–Vis, FT-IR, X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FE-SEM), nitrogen-sorption isotherm, thermogravimetric (TGA) analysis. The particles are 550–600 nm in size with a fine-looking spherical morphology and surface area in the range of 111–419 m2/g. Among all of these metal-silica, Ni–Ir–Ru-doped mesoporous silica particles (NIRS) exhibit excellent electrocatalytic activity towards oxygen evolution reaction (100 mA/cm2 current density@0.5V) with long-term durability up to 10 h, and the Tafel slope is also very low (∼68 mV/dec) in 1 M KOH medium. The excellent electrical conductivity of Ni–Ir–Ru-doped silica makes it a superior electrocatalyst due to its spherical morphology, synergistic effects of the multi metallic components, and its hierarchical nanoporous structure.

Probing fluconazole deposition inside mesoporous silica using solid-state NMR spectroscopy: Crystallization of a confined metastable form and phase transformations under storage conditions

Encapsulation of molecules into mesoporous silica carriers continues to attract considerable interest in the area of drug delivery and crystal engineering. Here, MCM-41, SBA-15 and MCF silica matrices were used to encapsulate fluconazole (FLU), a pharmaceutically relevant molecule with known conformational flexibility, using the melting method. The composites have been characterized using 1H, 13C and 19F NMR spectroscopy, nitrogen adsorption, PXRD and thermal analysis (DSC, TGA). Drug loading up to 50 wt% allowed us to probe the crystallization process and to detect different local environments of confined FLU molecules. 19F NMR spectroscopy enabled us to detect the gradual pore filling of silica with FLU and differentiate the amorphous domains and surface species. The use of the complementary structural and thermal techniques enabled us to monitor crystallization of the metastable FLU form II in MCF. Using 1H and 19F NMR spectroscopy we observed pore-size dependent reversible dehydration/hydration behaviour in the MCM and SBA composites. As water content has considerable importance in understanding of physicochemical stability and shelf-life of pharmaceutical formulations, experimental evidence of the effect of API-water-carrier interactions on the API adsorption mechanism on silica surface is highlighted.

Spatial mapping and quantitative evaluation of protein corona on PEGylated mesoporous silica particles by super-resolution fluorescence microscopy

Nanoparticles (NPs) adsorb serum proteins when exposed to biological fluids, forming a dynamic protein corona that has a profound impact on their overall biological profile and fate. Polyethylene glycol (PEG) modification is the most widely used strategy to mitigate and inhibit protein corona formation. Nevertheless, the accurate mapping and quantification of PEG inhibition effects on protein corona formation have scarcely been reported. Herein, we demonstrate the direct observation and quantification of protein corona adsorbed onto PEGylated mesoporous silica particles by direct stochastic optical reconstruction microscopy (dSTORM). The variation tendency of protein penetration depth in terms of PEG molecular weights and incubated time is investigated for the first time. The maximum penetration depths present slight increase with the prolonged incubation time, while they tend to remarkably decrease with increased chain length of modified PEG. Moreover, the co-localization of preformed protein corona with lysosomes and the destination of adsorbed protein are demonstrated. Our method provides important technical characterization information and in-depth understanding of protein corona adsorbed onto PEGylated mesoporous silica particles. This shines new light on the behaviors of silica materials in cells and may promote their practical applications in biomedicine.

Robocasting of ordered mesoporous silica‐based monoliths: Rheological, textural, and mechanical characterization

AbstractHierarchically porous, high‐surface‐area silica materials are excellent candidates for multiple applications like catalysis and environmental remediation. Shaping these materials with additive manufacturing (AM) techniques, like robocasting, could enable their use with the benefit of on‐demand, customized shaping and maximizing performance. Herein, ordered mesoporous silica COK‐12 slurries were robocasted into monoliths, containing different ratios of uncalcined COK‐12 and sodium bentonite (0–25 wt.%). The rheology of the mixed slurries is characterized by lower flow indexes (0.69 vs. 0.32) and higher yield stresses (96 vs. 259 Pa) compared to pure COK‐12 ones. Monoliths were printed in woodpile structures and calcined at 600°C. Micro‐CT measurements showed a linear shrinkage of 25% after calcination. Mechanical characterization showed increased uniaxial strength (0.20 ± 0.07 to 1.0 ± 0.3 MPa) with increasing binder/solids ratio from 13 to 25%. The amorphous, mesoporous structure of COK‐12 was retained. The structures exhibited open porosities of 52 ± 4% and showed higher specific mesopore volumes, and increased average mesopore size (6 vs. 8 nm) compared to COK‐12. Small‐angle x‐ray scattering analysis revealed an increased lattice parameter (10.3 vs. 11.0 nm) and reduced wall thickness (3.1 nm vs. 4.1 nm) of the COK‐12 in the monoliths. These properties indicate suitability for their application as porous supports and adsorbents.

Development of a novel hierarchical porous and hydrophobic silica from montmorillonite for benzene adsorption

A hierarchical porous and hydrophobic adsorbent is the key to removing the volatile organic compounds through adsorption technology, especially under humidity conditions. In this work, we synthesized a hierarchical porous and hydrophobic montmorillonite-derived adsorbent by a facile strategy, i.e., a combination of ball milling, acid activation, and thermal treatment. Our results showed that ball milling could efficiently grind the montmorillonite sheets into small fragments, which caused the rapid dissolution of octahedral cations from the edges of these fragments during the subsequent acid activation process. The resulting porous silica showed more porosity (including micropores and mesopores) and a larger specific surface area (664 m2 g−1), compared with the product (345 m2 g−1) obtained by only acid washing without ball milling. The next thermal treatment readily removed the surface hydroxyl of porous silica, leading to the formation of the target product (HP-SiO2) with enhanced hydrophobicity and well-preserved pore structures. As an adsorbent for benzene molecules, HP-SiO2 exhibited a high dynamic benzene adsorption capacity (257.1 mg g−1) due to the large specific surface area and abundant micropores. Furthermore, HP-SiO2 maintained outstanding benzene adsorption performance under different humidity conditions (with a high adsorption capacity of 185.0 mg g−1 even under 40% relative humidity). Our work provided a low-cost and facile strategy for the synthesis of hierarchical porous and hydrophobic silica materials, and this adsorbent would serve as a promising adsorbent for the elimination of practical volatile organic compounds.

Prediction of the surface chemistry of calcium aluminosilicate glasses

We have used a combination of density functional theory, the implicit solvent model COSMO-RS and molecular dynamics simulations to predict the pKa of surface groups on calcium aluminosilicate glasses. We found that the average of pKa for deprotonation and protonation for silanols agrees well with the point of zero charge for pure silica materials. Similarly, the average of pKa for deprotonation and protonation for aluminols agrees well with the point of zero charge for pure alumina. We identified trends in the pKa related to the hydrogen bonding of the surface groups, as well as the influence of tri-briding oxygen defects.

(Digital Presentation) Electrochemical Reduction of Pressed Tungsten (VI) Oxide on a Solid Electrode in a Melt of Calcium and Sodium Chlorides

This report presents the results of research on the electrochemical reduction of tungsten (VI) oxide in a molten electrolytic mixture of CaCl2-NaCl of eutectic composition. The electrochemical behavior of tableted WO3 on a solid tungsten electrode was studied by voltammetry. Analysis of the obtained products was carried out by X-Ray diffraction and electron microscopy.During the electrochemical reduction, pressed cylindrical samples were placed on a tungsten disk, which served as a cathode. A silica cloth impregnated with a CaCl2-NaCl eutectic melt was placed on top of the tableted sample in order to prevent a short circuit in the cell. The silica cloth and tableted tungsten oxide were pressed to the cathode by the anode. The anode was made of low-porous graphite, and the current was supplied to it with a molybdenum wire. The electrode assembly prepared in this way was placed in a crucible with molten chlorides of calcium and sodium.Analysis of the obtained results indicates that reduction processes occur in pressed tungsten oxide (Fig. 1, a). According to the results of X-Ray phase analysis, in the surface layer of pressed tungsten (VI) oxide, which was in contact with the cathode, when the amount of electricity (Q) twice greater than that required for the complete recovery of loaded tungsten trioxide was passed, the following phases were detected: W, CaWO4 and a small amount of NaxWO3. Having studied the entire volume of the tableted sample, the following phases were recorded: NaxWO3 (main phase) and CaWO4, W (Fig. 1, b). The formation of phases of sodium and calcium tungstates is explained by the interaction of tungsten trioxide with the components of the melt. Passing electricity through the pressed sample causes electrochemical reactions to occur with the formation of tungsten metal, which grows from the cathode/WO3/electrolyte interface into the sample volume.During galvanostatic electrolysis (i=0.4 A/cm2) of a pressed sample of tungsten (VI) oxide with a mass of 0.43 g (r=0.4 cm, h=0.174 cm) and a duration of 6 hours (Qpractical/Qtheoretical = 6), the degree of extraction of tungsten from tungsten trioxide is not less than 97.48%, and the current yield is about 29.06%. The X-Ray diffraction pattern of the obtained product under such conditions confirms the presence of only a monophase of crystalline tungsten (Fig. 1, b). Figure 1

Wetting of typical silica materials by molten Sn3.5Ag-(2, 4)Ti at 800 °C

Wetting of molten SAT(Sn3.5Ag-(2, 4)Ti) alloys on typical silica substrates (vitreous silica, sintered quartz, translucent fused silica and microlite glass) and on the surface of the interfacial precipitation layer was investigated by a modified sessile drop method at 800 °C under high vacuum. After cooling the wetting couples, both TiO2-x and a small amount of Ti5Si3 were precipitated at the interface and Sn5Ti6 - segregation above TiO2-x layer was observed. However, this does not indicate that the precipitated TiO2-x determines the final wettability, rather the isothermal wetting process in which Ti is segregated and adsorbed at the solid/liquid interface, significantly improving the wettability. Among them, vitreous silica and microlite glass in one group; sintered quartz and translucent fused silica in another group, have the similar interfacial microstructures, which linked to the difference in macroscopic wettability and apparent spreading dynamics.

On the Selectivity of Simultaneous CO2 and N2 Reduction Using TiO2/Carbon Sphere Photocatalysts Prepared by Microwave Treatment and Mounted on Silica Cloth.

This paper presents new photocatalysts obtained by treating carbon spheres (CS) and TiO2 in a microwave reactor at a pressure of 20 atm and a temperature of up to 300 °C for 15 min and then depositing TiO2/CS composites on glass fibre cloths. Such highly CO2-adsorbing photocatalysts showed photoactivity in the simultaneous water-splitting process, generating H2, reducing CO2 to CO and CH4, and reducing N2 to NH3. In addition, calculations of the hydrogen balance involved in all reactions were performed. Adding 1 g of carbon spheres per 1 g of TiO2 maintained the high selectivity of nitrogen fixation at 95.87-99.5%, which was continuously removed from the gas phase into the water as NH4+ ions.

Palladium Nanoparticles Supported on Porous Silica Materials as Heterogeneous Catalysts of C−C Coupling and Cross‐Coupling Reactions

AbstractNoble metal nanoparticles supported on porous silica materials represent an important class of heterogeneous catalysts. Recently, a remarkable progress has been made concerning the synthesis, characterization, and catalytic application of noble metal nanoparticles immobilized on zeolites and mesoporous silica‐based materials. Various synthesis strategies have been developed, including the application of ligand‐assisted metal precursors, multistep synthesis procedures, post‐synthetic modifications, and magnetic mesoporous silica particles. Emphasis has been laid on the introduction of green procedures, based on the utilization of environmentally friendly solvents, efficient stabilizing agents, non‐toxic reagents, and mild reaction conditions. Palladium nanoparticles have long been recognized as the most efficient catalysts in a wide range of organic transformations, including the Heck, Suzuki, Stille, and Sonogashira reactions. Although these transformations have been extensively investigated in homogeneous catalytic systems, the application of heterogeneous catalysts, including silica‐supported Pd0 nanoparticles, has gained in increasing importance. This may be due to the easy handling and recovery of the latter catalysts, which facilitates their repeated applications. The aim of this review is to provide an outlook on the current research progress achieved on the development of novel synthetic procedures, affording highly dispersed Pd0 nanoparticles immobilized on porous silica materials, which proved to be efficient and recyclable catalysts in C−C coupling and cross‐coupling reactions. The focus of this review is on results published in the last six years with a handful of examples in previous years.

Matrix Effect of Properties of Au, ZnO and Eu2O3: Silica, Titania and Alumina Matrices

The composites Au/SiO2, Au/TiO2, Au/Al2O3, ZnO/TiO2, ZnO/TiO2, ZnO/Al2O3 and Eu2O3/SiO2, Eu2O3/TiO2 and Eu2O3/Al2O3 were prepared using a solid-state method. The effect of the polymer precursors was investigated using two precursor polymers, Chitosan and Poly(styrene-co-4vinylpyridine), (PS-co-4-PVP) in the M/MxLy•Chitosan//M’xO’y as well as M/MxLy•PS-co-4-PVP//M’xO’y with M’xO’y = SiO2, TiO2 and Al2O3. The effects on the particle size and morphology were observed. The new composites were characterized using X-ray powder diffraction, SEM-EDS mapping and HRTEM analysis. The distribution of the metallic nanoparticles as well as the metal oxide nanoparticles inside the matrices depend on the matrix. Marked optical and photocatalytic effects of the Au, ZnO and Eu2O3 inside the SiO2, TiO2 and Al2O3 matrices are expected. An experiment is in course.

Biomass and waste derived silica, activated carbon and ammonia-based materials for energy-related applications – A review

The present review article aims to highlight the importance and availability of biomass and focuses on energy applications such as fuel cells, supercapacitors, batteries, and solar cells from biomass-based materials like silica, activated carbon and ammonia because these materials play a major role in energy application. We specifically discuss the yield, purity, and availability of activated carbon and silica from waste biomass, as well as new developments in this field of biomass and waste-based materials manufacturing processes. This review shows that biomass and waste-based materials have great potential for energy applications. Among them, silica and activated carbon are mostly studying materials. However, ammonia production from biomass is very limited currently. It addresses and encourages additional research to support actual uses of biomass and waste-based materials, especially biomass-derived ammonia in energy storage and conversion domains. Here, we discuss the most recent advancements in biomass and waste-derived materials. In order to gain a better understanding ofthe processes underlying their improved performance, numerous new achievements have been noted. The best biomass and waste-derived materials for futuristic energy devices are then highlighted.

GREEN PROCEDURE INDEX ASSESSMENT OF THE NOVEL STABILITY-INDICATING RP-HPLC METHOD FOR THE DETERMINATION OF CAPTOPRIL FROM PHARMACEUTICAL DOSAGE FORM

Objective: In this study, it was aimed to develop a novel reverse-phase liquid chromatography method for the ultra-sensitive determination of the antihypertensive drug captopril, using paracetamol, which is the common pain killer, as the internal standard. Optimization of all experimental conditions including composition of mobile phase, flow rate, and column temperature was carried out step by step, and the method validity of the developed method was examined according to international validation guidelines. Calibration range, linearity, the limit of determination, the limit of quantification, robustness, accuracy from commercial tablet samples, and method stability were examined in detail. In addition, the greenness profile for the developed method was assessed with the Green Analytical Procedure Index and Analytical Greenness Calculator techniques, which are frequently used in the literature. Material and Method: The chromatographic method was conducted with an XBridge C18 column (25 cm x 4.6 mm ID; 5 µm) packed with fully porous silica materials. All analyses were performed isocratically with a mobile phase containing acetonitrile:5 mM, pH 7.0 ammonium acetate solution (50:50, v/v) at a flow rate of 1.5 ml min-1. The injection volume was 5 μl, and the column was kept at 25°C in a column oven. The column eluate was monitored at 220 nm. Under optimized conditions, retention times of captopril, and paracetamol were approximately 1.59, and 2.0 min, respectively. Result and Discussion: This study described a fully validated, simple, sensitive, accurate, linear, precise, and reproducible reversed-phase liquid chromatography method for the determination of captopril in tablet samples. Under optimal experimental conditions, the linear range was found in the range of 0.5-200 µg ml-1 and the correlation coefficient was greater than 0.99. Method precision was acceptable, with coefficients of variation between 0.05% and 0.61%. In addition, as a result of the recovery studies carried out on the tablet samples, the accuracy was found to be within satisfactory limits between 99.45% and 102.55%. Moreover, the greenness profile of the developed method also showed that the method is environmentally friendly.

Mesoporous silicas of MCM-48 and MCM-41 types doped with copper by modified template ion-exchange method as effective catalysts for low-temperature reduction of nitrogen oxide with ammonia

Mesoporous silica materials of MCM-48 and MCM-41 types were synthetized by surfactant directed methods and modified with copper by template ion-exchange (TIE) protocol and its extended version including post-treatment of modified silicas with ammonia solution. Obtained samples were characterized with respect to their textural parameters (low-temperature N2 sorption), porous structure, chemical composition, surface acidity (NH3-TPD), form and aggregation of deposited copper species (UV–vis-DRS) as well as their reducibility (H2-TPR). It was shown that application of TIE method resulted in deposition of copper into MCM-48 in more dispersed forms comparing to MCM-41. Both, in the case of MCM-41 and MCM-48, treatment of the samples with ammonia directly after copper introduction resulted in deposition mainly monomeric copper cations. The catalysts containing such dispersed copper species were more active in the low-temperature NH3-SCR process. The NO conversion above 90% with selectivity to N2 above 97% was obtained in the temperature range of 225–325 °C. CuO aggregates, deposited on mesoporous silicas, were found to be active in the side process of direct ammonia oxidation at higher temperatures.

Dual Role of Silicon-based Matrices in Electron Exchange Matrices for Waste Treatment.

Para chloro aniline (PCA) is a common toxic pollutant found in pharmaceutical wastewater. Our study suggests a novel PCA treatment method based on a heterogeneous advanced oxidation process (AOP) that proceeds in an electron exchange matrix (EEM) prepared by the incorporation of redox-active specie in silica matrices using the sol-gel synthesis route. The results, which are supported by DFT calculations, show that the silicon skeleton of the EEM has two important roles, both as a porous matrix that hosts the redox species and as an oxidant species involved in the AOP. The calculations indicate that the formation of a radical on the nitrogen is favored. The suggested mechanism could shed light on the AOP, which proceeds in a heterogenous system, and on its application inside the understudied EEMs that, until now, have been a virtual black box. A better understanding of the mechanism could lead to improved control over the heterogeneous processes that can play a critical role in industries with the need to treat small amounts of toxic compounds at low concentrations, such as in the pharmaceutical industry.

Hybrid Nanoplatforms Comprising Organic Nanocompartments Encapsulating Inorganic Nanoparticles for Enhanced Drug Delivery and Bioimaging Applications.

Organic and inorganic nanoparticles (NPs) have attracted significant attention due to their unique physico-chemical properties, which have paved the way for their application in numerous fields including diagnostics and therapy. Recently, hybrid nanomaterials consisting of organic nanocompartments (e.g., liposomes, micelles, poly (lactic-co-glycolic acid) NPs, dendrimers, or chitosan NPs) encapsulating inorganic NPs (quantum dots, or NPs made of gold, silver, silica, or magnetic materials) have been researched for usage in vivo as drug-delivery or theranostic agents. These classes of hybrid multi-particulate systems can enable or facilitate the use of inorganic NPs in biomedical applications. Notably, integration of inorganic NPs within organic nanocompartments results in improved NP stability, enhanced bioavailability, and reduced systemic toxicity. Moreover, these hybrid nanomaterials allow synergistic interactions between organic and inorganic NPs, leading to further improvements in therapeutic efficacy. Furthermore, these platforms can also serve as multifunctional agents capable of advanced bioimaging and targeted delivery of therapeutic agents, with great potential for clinical applications. By considering these advancements in the field of nanomedicine, this review aims to provide an overview of recent developments in the use of hybrid nanoparticulate systems that consist of organic nanocompartments encapsulating inorganic NPs for applications in drug delivery, bioimaging, and theranostics.

Insights into SnO2 Nanoparticles Supported on Fibrous Mesoporous Silica for CO Catalytic Oxidation

A large surface area dendritic mesoporous silica material (KCC-1) was successfully synthesized and used as a support to confine SnO2 nanoparticles (NPs). Owing to the large specific surface area and abundant mesoporous structure of dendritic KCC-1, the SnO2 NPs were highly dispersed, resulting in significantly improved CO catalytic oxidation activity. The obtained Snx/KCC-1 catalysts (x represents the mass fraction of SnO2 loading) exhibited excellent CO catalytic activity, with the Sn7@KCC-1 catalyst achieving 90% CO conversion at about 175 °C. The SnO2 NPs on the KCC-1 surface in a highly dispersed amorphous form, as well as the excellent interaction between SnO2 NPs and KCC-1, positively contributed to the catalytic removal process of CO on the catalyst surface. The CO catalytic removal pathway was established through a combination of in situ diffuse reflectance infrared transform spectroscopy and density-functional theory calculations, revealing the sequential steps: ① CO → CO32−ads, ② CO32−ads → CO2free+SnOx−1, ③ SnOx−1+O2 → SnOx+1. This study provides valuable insights into the design of high-efficiency non-precious metal catalysts for CO catalytic oxidation catalysts with high efficiency.

A Review of Optical Fiber Sensing Technology Based on Thin Film and Fabry–Perot Cavity

Fiber sensors possess characteristics such as compact structure, simplicity, electromagnetic interference resistance, and reusability, making them widely applicable in various practical engineering applications. Traditional fiber sensors based on different microstructures solely rely on the thermal expansion effect of silica material itself, limiting their usage primarily to temperature or pressure sensing. By employing thin film technology to form Fabry–Perot (FP) cavities on the end-face or inside the fiber, sensitivity to different physical quantities can be achieved using different materials, and this greatly expands the application range of fiber sensing. This paper provides a systematic introduction to the principle of FP cavity fiber optic sensors based on thin film technology and reviews the applications and development trends of this sensor in various measurement fields. Currently, there is a growing need for precise measurements in both scientific research and industrial production. This has led to an increase in the variety of structures and sensing materials used in fiber sensors. The thin film discussed in this paper, suitable for various types of sensing, not only applies to fiber optic FP cavity sensors but also contributes to the research and advancement of other types of fiber sensors.

Femtosecond-laser-inscribed Bragg grating in hollow-core fiber for highly sensitive optofluidic sensing.

An optofluidic sensor based on a Bragg grating in hollow-core fiber (HCF) is experimentally demonstrated. The grating is inscribed into the HCF by femtosecond laser illumination through a phase mask. Periodic index modulation is introduced into the silica material surrounding the hollow core, causing cladding mode resonance, and multiple reflection peaks are observed in the grating spectrum. These reflection peaks later shift to longer wavelengths when high-index liquid is infiltrated into the HCF. The new reflection peak results from the backward coupling of the liquid core mode of the waveguide, the mode field of which overlaps with the grating modulation surrounding the liquid core. The resonant wavelength of the liquid-core fiber grating increases with the index value of the infiltrating liquid, and optofluidic refractive index sensing is realized with the device. The highest refractive index sensitivity, 1117 nm/RIU, is obtained experimentally in the index range of 1.476-1.54. The infiltrated hollow-core fiber Bragg grating also exhibits high temperature sensitivity due to the high thermal-optic coefficient of the liquid, and a sensitivity of -301 pm/°C is achieved in the temperature range of 25°C to 60°C.

A comprehensive evaluation of amine-impregnated silica materials for direct air capture of carbon dioxide

The potential of amine-impregnated silica materials for Direct Air Capture (DAC) of CO2 was investigated. A commercially available mesoporous silica was impregnated with tetraethylenepentamine (TEPA) and polyethylenimine (PEI) with molecular weights of 600, 1200, and 1800, each using amine loadings of 10–50 wt%. The materials were screened for equilibrium CO2 uptake, amine efficiency, and adsorption kinetics at temperatures of 25–35 °C. For all loadings, the CO2 uptakes followed the order of TEPA > PEI-600 > PEI-1200 ≈ PEI-1800. Also, for all amines, the materials synthesized with 50% loading achieved the highest equilibrium CO2 uptakes despite suffering from low amine efficiency and slow adsorption kinetics due to diffusional limitations. For these materials, increasing the adsorption temperature from 25 to 30 and 35 °C enhanced equilibrium CO2 uptake and amine efficiency, indicating kinetically controlled adsorption. In contrast, for all amines, the materials synthesized with 40% loading achieved a combination of high equilibrium CO2 uptake, good amine efficiency, and fast adsorption kinetics; therefore, they were selected to undergo 50 successive adsorption–desorption cycles. Despite an initially high CO2 uptake, TEPA suffered from low thermal stability due to its volatility, resulting in an amine loss of 55% and CO2 uptake loss of 29%. In contrast, bulkier amines such as PEI-600 outperformed TEPA, showing high thermal stability (1.4% amine loss) and low CO2 uptake loss (0.8%). Selected materials underwent column-breakthrough experiments in the presence of 400 ppmv CO2 in N2. Under dry conditions, TEPA achieved a longer breakthrough time than PEI-600 (13 versus 4 min). Under humid conditions, the breakthrough time for PEI-600 increased from 4 to 15 min, confirming previous reports that humidity boosts the CO2 uptake of amine-modified materials.