CO2 Gas Pressure Research Articles

Integrating Umpolung and CO2 Shuttling Strategies for the Synthesis of 12C- and 13C-α-Ketoacids from Aldehydes.

The direct carboxylation of aldehydes with CO2 is rare due to the polarity mismatch between these two electrophilic substrates. To address this challenge, we propose a sequential approach for synthesizing α-ketoacids from commercially available aldehydes by integrating umpolung and CO2 shuttling strategies. This transition metal-free shuttle carboxylation method enables the transfer of CO2 from triphenylacetic acid potassium salt to thioacetal, eliminating the need for handling pressurized CO2 gas or using specialized equipment, while also enhancing the reaction's functional group tolerance. Furthermore, the use of stoichiometric or slightly excess amounts of triphenylacetic acid potassium salt as a formal CO2 donor makes it suitable for complete 13C labeling of α-ketoacids.

Dehardening of carbon dioxide: A highly efficient chemical precipitant used for the dehardening of deep coalbed methane produced water

The greenhouse gas CO2 is used as a precipitant to deharden the deep coalbed methane produced water (PW), allowing it to meet the reuse requirements. The pH of PW is the key factor affecting the absorption and dissolution of CO2. High raw water pH leads to higher CO2 absorption, callback pH, and CO32− release. The aeration rate and aeration time determine how quickly and how much CO2 is absorbed and dissolved. Increasing temperature enhances the removal effect. Smaller CO2 bubble facilitates more rapid CO2 absorption, and high CO2 gas pressure increases the final CO2 dissolution. Under normal temperature and pressure, the pH of raw water is adjusted to 11, with an aeration rate of 200 mL/min for 16 min. In addition, the callback pH is equal to 12.80, resulting in a final dehardening effect of 99.77 %, making the treated PW suitable for reuse. Mechanistic studies have shown that at the first level of dehardness, CO2 is not dissolved enough under constant pressure, causing some Ca2+ to precipitate as Ca(OH)2, which enhances hardness removal. To improve the dehardening effect, excessive callback pH can be used, and multi-stage dehardening ensures that Ca2+ precipitates as CaCO3. Meanwhile, Mg2+ is predominantly removed as Mg(OH)2 in the first stage. Dehardening can produce small CaCO3 microsphere by-products, which can be considered for further recycling. The cost of CO2 as a dehardening agent is 23.83 % better than Na2CO3, which not only achieves the dehardening of deep coalbed methane PW at a low cost, but also provides a feasibility reference for the early realization of the “dual carbon” target to a certain extent.

Experimental comparative analysis of an air-breath direct methanol fuel cell (DMFC) using serpentine and spiral flow fields

In the present study, an experimental comparative analysis of Air Breathe Direct Methanol Fuel Cells (DMFC) was conducted using two different flow field patterns, namely spiral and serpentine. The impact of flow field plates on cell performance, CO2 gas bubble behavior and pressure drop was examined at various mass flow rates and current densities. The experiments were conducted with the same hydraulic diameter and channel length for both flow field patterns, varying mass flow rates from 0.25 to 4 ml/min, and exploring reactant concentrations ranging from 0.25 M to 4 M. From the results it is observed that, for both the flow field patterns, pressure drop increases and CO2 bubble formation decreases with increase in mass flow rate. It is also observed that, under identical operating conditions, the serpentine flow field exhibits higher values for both pressure drop and peak power density compared to the spiral flow configuration. The study reveals that, the serpentine flow appears more efficient in terms of peak power density, while the spiral flow outperforms in terms of minimizing pressure drop under the specified operating condition.

Gynecological Laparoscopic Surgeries under Spinal Anesthesia: Benefits and Challenges.

This prospective study investigated the feasibility of performing laparoscopic pelvic surgery under spinal anesthesia and analyzed the intraoperative side effects, like pain, nausea, and vomitus, of 915 patients. The implementation and performance of laparoscopic surgery under local anesthesia on 915 patients (out of a total of 3212 who underwent laparoscopic pelvic surgery under spinal anesthesia) were analyzed in relation to BMI (body mass index), obesity, pain during surgery, amount of intraperitoneal mmHg CO2 gas pressure, and surgical complications. BMI > 30, intra-abdominal adhesions, increased duration of the operation, bleeding, and increased intraperitoneal CO2 pressure were statistically significant as the main causes of pain during laparoscopic surgery under spinal anesthesia. Underweight patients, on the other hand, had less pain when intra-abdominal pressure increased compared to those of normal weight. The appearance of pain, nausea, and vomitus occurred in 10.3% of patients, and these events were easy to manage and treat. They did not affect the surgeon's work or the course of the operation. In light of these observations, we are proposing spinal anesthesia for laparoscopic surgery as the first choice in patients who have no contraindications. To the best of our knowledge, this clinical study constitutes the largest clinical observation and dataset concerning spinal anesthesia in laparoscopic pelvic surgery. ISRCTN38987, 10 December 2019.

Spontaneous α‐C−H Carboxylation of Ketones by Gaseous CO2 at the Air‐water Interface of Aqueous Microdroplets

AbstractWe present a catalyst‐free route for the reduction of carbon dioxide integrated with the formation of a carbon‐carbon bond at the air/water interface of negatively charged aqueous microdroplets, at ambient temperature. The reactions proceed through carbanion generation at the α‐carbon of a ketone followed by nucleophilic addition to CO2. Online mass spectrometry reveals that the product is an α‐ketoacid. Several factors, such as the concentration of the reagents, pressure of CO2 gas, and distance traveled by the droplets, control the kinetics of the reaction. Theoretical calculations suggest that water in the microdroplets facilitates this unusual chemistry. Furthermore, such a microdroplet strategy has been extended to seven different ketones. This work demonstrates a green pathway for the reduction of CO2 to useful carboxylated organic products.

The Influence of Slim Tube Length on the Minimum Miscibility Pressure of CO2 Gas–Crude Oil

This study focuses on the Bozhong 25-1 oilfield formation oil as the experimental subject, systematically investigating the influence of different slim tube lengths (1 m, 12.5 m, 20 m, and 25 m) on the minimum miscibility pressure (MMP) of the CO2 and formation oil mixture system. Through slim tube experiments, the interaction process of CO2 with formation oil in slim tubes of different lengths was simulated, with a particular focus on analyzing how changes in slim tube length affect the MMP. The experiments revealed an important phenomenon: as the slim tube length gradually increased from shorter dimensions, the MMP showed a decreasing trend; when the slim tube length reached 12.5 m, this trend stabilized, meaning that further increasing the slim tube length no longer led to significant changes in the MMP, with its stable value determined to be 27.86 MPa. This phenomenon can be explained within the theoretical framework of fluid dynamics and interfacial science, where several key factors play a significant role. Firstly, the flow characteristics of the fluid inside the slim tube significantly influence it; secondly, the interfacial tension between phases is also a decisive factor; lastly, the impact of the internal microstructure of the slim tube cannot be overlooked. These aspects together form the basis for understanding the impact of slim tube length on MMP and reveal the underlying mechanisms. This research is significant for deeply understanding and quantifying this effect, providing a solid theoretical basis for optimizing CO2 flooding technology and guiding more precise operational strategies in oilfield development practices to enhance oil displacement efficiency and economic benefits.

Designing and prototyping a novel biosensor based on a volumetric bar-chart chip for urea detection.

A volumetric bar-chart chip (V-chip) is a microfluidic device based on distance-based quantitative measurement that visualizes analyte concentration without the need for apparatus or data processing. This typically utilizes special receptors and catalysis parts that generate oxygen, so ink can be moved inside the channels, and enables instant visual quantitation of the analyte. However, the low stability of some macromolecules, the use of expensive catalysts, and difficulty in controlling the process cause inaccurate readings, and therefore, limit further development and the use of these systems. In this article, we introduced a novel approach that eliminates the use of catalysts in V-chips and provides an efficient and simple path in the design of biosensors. The product of the enzymatic reaction of urease with urea is bicarbonate, which turns into CO2 gas in an acidic environment. Therefore, the amount of gas produced is proportional to the amount of urea in the sample, and it can be quantitatively measured by visual detection from the amount of ink movement caused by CO2 gas pressure. This biosensor has a linear response range of 0 to 1000 μg ml-1 and a detection limit of 3.6 μg ml-1 in raw milk. The recovery of urea in raw milk at 100 and 400 μg ml-1 concentrations was 96.5% and 98.9%, respectively. This volumetric chip shows potential for determining urea levels in real samples without requiring additional equipment. The combination of the sensitivity and specificity of enzymatic reactions, inherent gas-generating reactions, and the processability of microchips discussed in this paper can be the basis for the comprehensive development of volumetric chips, which can create a new path for the development of efficient and cheap biosensors.

Roll-to-roll manufacturing of large surface area PDMS devices, and application to a microfluidic artificial lung.

The ability to cost-effectively produce large surface area microfluidic devices would bring many small-scale technologies such as microfluidic artificial lungs (μALs) from the realm of research to clinical and commercial applications. However, efforts to scale up these devices, such as by stacking multiple flat μALs have been labor intensive and resulted in bulky devices. Here, we report an automated manufacturing system, and a series of cylindrical multi-layer lungs manufactured with the system and tested for fluidic fidelity and function. A roll-to-roll (R2R) system to engrave multiple-layer devices was assembled. Unlike typical applications of R2R, the rolling process is synchronized to achieve consistent radial positioning. This allows the fluidics in the final device to be accessed without being unwrapped. To demonstrate the capabilities of the R2R manufacturing system, this method was used to manufacture multi-layer μALs. Gas and blood are engraved in alternating layers and routed orthogonally to each other. The proximity of gas and blood separated by gas permeable PDMS permits CO2 and O2 exchange via diffusion. After manufacturing, they were evaluated using water for pressure drop and CO2 gas exchange. The best performing device was tested with fresh whole bovine blood for O2 exchange. Three μALs were successfully manufactured and passed leak testing. The top performing device had 15 alternating blood and gas layers. It oxygenated blood from 70% saturation to 95% saturation at a blood flow of 3 mL min-1 and blood side pressure drop of 234 mmHg. This new roll-to-roll manufacturing system is suitable for the automated construction of multi-layer microfluidic devices that are difficult to manufacture by conventional means. With some upgrades and improvements, this technology should allow for the automatic creation of large surface area microfluidic devices that can be employed for various applications including large-scale membrane gas exchange such as clinical-scale microfluidic artificial lungs.

Microstructure refinement of calcium-sulfate-aluminate and portland cement (CSA-PC) hybrids with accelerated CO2 curing (ACC)

Calcium-sulfate-aluminate and Portland cement (CSA-PC) hybrids with balanced engineering properties would be a preferable solution to mitigate the increasingly raised CO2 emissions by PC. Meanwhile, CSA hydrates are rather active to carbonation, therefore, it is urgent to clarify how accelerated CO2 curing (ACC) impacts the microstructure and engineering properties of CSA-PC hybrids. Herein, an ACC scheme with the CO2 gas pressure of 0.5 MPa and duration of 24 h was designed to treat hybrid CSA-PC pastes and mortars. Mechanical properties and capillary absorption of the ACC-treated CSA-PC hybrids were evaluated with profound analysis of microstructure and mineral characteristics by SEM, MIP, Nitrogen adsorption, XRD and TG/DTG. Results show that the ACC treatment can systematically increase compressive strength by up to 65.2 % and depress capillary absorption rate by up to 72.2 %, respectively, for the optimal CSA-PC mixes. Rapid carbonation of the cement clinkers and hydrates, e.g., calcium hydroxide, ettringite, and ye'elimite, results in precipitation of CaCO3 that refines the pore structure and improves the material compactness. 25 % replacement of PC with CSA shows the highest strength gain to CO2 uptake ratio (SGCUR) of 1.05. The findings deepen the mechanistic understandings in microstructure refinement of ACC-treated CSA-PC hybrids with lower CO2 emissions.

Copper iodide nanoparticles supported on modified graphene-based nanocomposite catalyzed CO2 conversion into oxazolidinone derivatives.

We report on the preparation of copper iodide nanoparticles (NPs) immobilized on vitamin B3-modified graphene (CuI/GO-VB) nanocomposite and its application for the synthesis of oxazolidinone compounds using a remarkable carboxylative cyclization method via the reaction of arylacetylene, aldehyde and benzylamine derivatives under an atmospheric pressure of CO2 gas. The CuI/GO-VB catalyst was prepared from graphene oxide (GO), vitamin B3 (VB) and CuI using a two-step procedure; firstly graphene-based composite (GO-VB) was synthesized by the reaction of GO and nicotinoyl chloride, followed by the immobilization of CuI NPs on GO-VB. The CuI/GO-VB nanocomposite was fully identified with X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), inductively coupled plasma optical emission spectroscopy (ICP-OES), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The catalytic performance of the CuI/GO-VB heterogeneous catalyst was investigated in carboxylative cyclization for the synthesis of oxazolidinone compounds under an atmospheric pressure of CO2 gas at 100οC in solvent-, base-, and additive-free conditions; the corresponding oxazolidinone compounds were obtained in 79-94% yield. The hot filtration results indicated that CuI/GO-VB nanocomposite was a heterogeneous catalyst and showed a good reusability for 5 runs without a significant decrease in its catalytic performance.

Temperature drop for CO2 gas flowing through multilayer micro-pin fin arrays

A reasonable theoretical calculation model is established, and an appropriate correlation formula is selected to calculate the flow and heat transfer of CO2 gas flowing through micro-pin fin arrays in a micro-cooler respectively under different working conditions. The inlet pressure of CO2 gas is 1.0 MPa, 1.5 MPa, and 2.0 MPa respectively, and the inlet temperature is 12 °C and 16 °C respectively. The results show that the cold end temperature of the gas decreases with the increase of CO2 gas inlet pressure and the decrease of inlet temperature, and the lowest temperature reaches -29.93 °C. The calculated results have the same trend as the experimental data, and the calculated values are consistent with the experimentally measured values, which demonstrates the calculation model’s logic.

Thermo-economic performance of a compressed CO2 energy storage system with a flexible gas holder

In recent years, engineers' eyes have been increasingly captured by the compressed CO2 energy storage since it is a competitive electricity storage technology equipped with massive renewable power plants. Nevertheless, how to design an effective system configuration, for instance the scenarios of storing CO2 in high and low pressures, vacillates to the left and right in the researchers. A CO2 energy storage cycle, configured by three section compression/expansion, two-tank heat storage, artificial tank for storing high pressure CO2 liquid and gas holder for storing ambient pressure CO2, is comprehensively examined in this paper. Both the thermodynamic and economic performances are considered. Results demonstrate that the round trip efficiency is capable of arriving at 71 % along with the levelized cost of electricity being 0.1252 $/kWh. Inspiringly, the system is operated with low pressures, charge pressure being 8 MPa and discharge pressure being 6 MPa. The turbomachineries are provided with the 68.18 % share of overall exergy destruction. The high pressure heater carries the largest exergy destruction among heat exchangers. By integrating with low grade waste heat of 39 °C, the efficiency can be further improved to 72.66 % with the levelized cost of electricity being 0.1242 $/kWh. Meanwhile, the discharge pressure should be raised to 6.58 MPa.

Direct hydrogenation of CO2 to formic acid using Ru supported Co3O4 oxide as an efficient heterogeneous catalyst

The concentration of CO2 in the atmosphere is rapidly increasing, posing serious environmental concerns. It is preferable to use CO2 as a feedstock for fine chemicals and fuel synthesis to address this challenge successfully. Herein, we report the synthesis of bimetallic oxide composite with significantly lower wt.% of active Ru loaded on spinel cubic phase Co3O4 oxide support. The synthesized catalyst formed cubic Ru-Co3O4 (Ruthenium and Cobalt oxide) nanocrystalline surface morphology with active Ru+3/+4 and Co+2/+3 oxidation states under hydrothermal conditions. The synthesized Ru-Co3O4 oxide catalyst facilitated the reduction of CO2 to formic acid under tailored conditions. The 2.9 wt.% Ru-Co3O4 catalyst exhibited highest formic acid yield (250 mmol) with a high turnover number of 182 under the mild reaction conditions, 1:1 CO2 and H2 (62 bar) gas pressure, 120 °C in 6 h. Ru-supported Co3O4 catalyst captures CO2 through the base. The activated CO2 is then hydrogenated to formic acid. The catalyst can be reused for multiple cycles without losing any activity due to its alkali tolerant properties. The study offers a simple synthesis and efficient industrially viable heterogeneous catalyst for CO2 hydrogenation.

Unusual CO2 Adsorption in ZIF-7: Insight from Raman Spectroscopy and Computational Studies.

Here, we use Raman spectroscopy to investigate temperature-dependent changes in the atomic-scale structure of the zeolitic imidazolate framework ZIF-7 in a CO2 atmosphere and uncover the mechanism of maximal CO2 adsorption at 206 K. At 301 K, the Raman spectra of ZIF-7 at various CO2 gas pressures reveal a narrow-pore (np) to large-pore (lp) phase transition commencing at 0.1 bar as a result of adsorption of CO2, as evident in the appearance of Fermi resonance bands of CO2 at 1272 and 1376 cm-1. Moreover, the Raman inactive bending mode of CO2 becomes active due to geometrical distortion of adsorbed CO2. It further splits into two peaks due to hydrogen bonding interactions between CO2 and the benzene ring of the benzimidazole linker ZIF-7, as supported by our computational studies. In addition, the interaction between CO2 molecules plays a key role. Upon reducing the temperature at 1 bar CO2 gas pressure, ZIF-7 exhibits softening of the imidazole puckering mode and the Fermi resonance CO2 band due to interactions between CO2 and the framework through hydrogen bonding. At 206 K, substantial modification in the lattice mode and disappearance of the Raman inactive CO2 bending mode confirm the changes in the size of the pore cavity through structural rearrangements of CO2.

Nickel‐Catalyzed Four‐Component Carbonylation of Ethers and Olefins: Direct Access toγ‐Oxy Esters and Amides

AbstractMulti‐component carbonylation of olefins, a reaction that installs both a carbon–carbon(heteroatom) bond and a carbonyl group across the double bond, is an attractive strategy for alkene functionalization. Herein, we developed a novel nickel‐catalyzed four‐component carbonylation of olefins with ethers under low CO gas pressure. Using alcohols and amines as the reaction partner, diverseγ‐oxy‐substituted esters and amides were produced in good yields with excellent functional group tolerance. Notably, Naftidrofuryl, a medicine for the treatment of cerebrovascular disease (CVD), can be synthesized by this process straightforwardly.

Nickel-Catalyzed Four-Component Carbonylation of Ethers and Olefins: Direct Access to γ-Oxy Esters and Amides.

Multi-component carbonylation of olefins, a reaction that installs both a carbon-carbon(heteroatom) bond and a carbonyl group across the double bond, is an attractive strategy for alkene functionalization. Herein, we developed a novel nickel-catalyzed four-component carbonylation of olefins with ethers under low CO gas pressure. Using alcohols and amines as the reaction partner, diverse γ-oxy-substituted esters and amides were produced in good yields with excellent functional group tolerance. Notably, Naftidrofuryl, a medicine for the treatment of cerebrovascular disease (CVD), can be synthesized by this process straightforwardly.

Study of the Effect of the Driving Force on the Kinetics of CO2 Hydrate Growth in Coal Particles

Coal and gas outbursts are geological disasters occurring in the process of coal mining that can cause serious casualties and economic losses, among which CH4 is the main component of coal mine gas. However, there are still many coal seams around the world that are dominated by CO2. Although the frequency of CO2 gas outburst accidents is relatively low, CO2 outbursts are very violent, notably difficult to control and highly dangerous. The application of hydration curing technology to reduce the pressure and gradient of CO2 gas in the coal can effectively reduce the occurrence of coal and CO2 outburst. Accordingly, in this paper, experimental studies on the growth kinetics of CO2 hydrate with three driving forces (2, 2.5, 3 MPa) were carried out under four different coal particle sizes (C1: 0.425–0.850 mm, C2: 0.250–0.425 mm, C3: 0.180–0.250 mm, C4: 0–0.180 mm) to obtain kinetic parameters such as gas consumption, growth rate, and heat of decomposition during the synthesis of CO2 hydrate. The results show that the hydrate nucleation time in the same particle size system does not follow the same decreasing trend with increasing driving force. Gas consumption of CO2 hydrates in the same particle size system increased with increasing driving force, and there exists a critical value regarding the effect of the driving force on CO2 hydrate generation in coal particles with the particle size. Under the same temperature conditions, increasing the driving force in the particle size system could increase the CO2 hydrate growth rate. With decreasing coal particle size and increasing driving force, the promoting effect gradually exceed the inhibiting effect, which promote CO2 hydrate formation. Through linear fitting, an equation of the average growth rate of CO2 hydrates versus the driving force for the C1-C4 systems is fitted to provide a reference to predict the average CO2 hydrate growth rate. In the same medium, with increasing driving force, more heat is required for complete decomposition, which remains relatively stable, and the heat of decomposition of CO2 hydrates is the highest in the C1 medium, indicating that the presence of CO2 hydrates in the C1 system represents the most stable state.

Improved diffusion and storage of lithium ions via recrystallization induced conducting pathways in a Li:Ta2O5-based electrolyte for all-solid-state electrochromic devices with enhanced performance

In this study, we have investigated the improvements in the performance of an all-solid-state complementary electrochromic device (ECD) by using the proposed high pressure treatment (HPT). The Li:Ta2O5 electrolyte layer was recrystallized by the HPT utilizing pressurized CO2 gas (∼200 atm) and at low temperature (<60 °C), which enhanced the coloration performance of the WO3/Li:Ta2O5/NiO complementary ECD by ∼20%. The reliability and durability of the ECD were confirmed by long term transmittance retention measurements, which indicated an improvement in the coloration performance by ∼14% upon the release of the bias voltages. The ability of the devices that were fabricated with and without the HPT process to withstand high temperature environments was also verified. In addition, photoluminescence (PL) and transmittance measurements were carried out to examine the effects of the bonding between WO3 and NiO. To determine the differences in lithium-ion (Li+) injection, electrical measurements were performed by utilizing varying pulse rising speeds to confirm device characteristics. The materials were characterized in terms of their composition and structure using high-resolution transmission electron microscopy along with energy-dispersive x-ray spectroscopy. Finally, a mechanistic model has been proposed to explain the improved EC characteristics based on the amorphous to crystalline transition accompanying the HPT process.

Micro-fractures in coal induced by high pressure CO2 gas fracturing

To effectively drain gas from coal seam, many technologies have been developed to fracture the coal which in turn to release the formation stress and increase permeability and finally achieve the desired gas drainage. CO2 gas fracturing is a newly developed technique for coal seam stimulation towards effective gas drainage. This technique can provide radial fracturing from centimeter to meters scales, but the small-scale fracture system that feeds into this radial system, at millimeter to micrometer scale, has not previously been systematically studied for quantifying the matrix damages. This study addresses this deficiency through blast-loading experiments with CO2 on anthracite specimens at overpressures of 120 MPa, 150 MPa and 185 MPa in the in-house novel experimental system. The Field Emission Scanning Electron Microscope (FESEM) images suggest that the cleat system is destroyed, and the intervening matrix effectively pulverized due to the impact load induced by the CO2 blasting. Radial and branching fractures are featured with the process, as typical in high velocity fracturing. The center point is a serious damage mark (DM) that always shows as a shallow pit, and number of smaller broken coal scatter surround the mark. These newly produced fractures are open and zigzag. Based on the observations, it is supposed that the matrix fracturing mechanism by CO2 gas impacting can be described as four consecutive steps: CO2 gas beam destroyed cleat system firstly, and coal broken to millimeter size particles. Meanwhile, CO2 gas jet beam impacting on coal matrix induce a DM and resulting in the matrix’s tensile deformation. Consequently, tri- fracture initiated from the DM and extending radially to different direction. When numerical tri-fracture connected and formed a complex fracture network in which permeability is expected to be significantly promoted for the effective gas drainage.

CO2 adsorption capacities of amine-functionalized microporous silica nanoparticles

Efforts on CO2 capture have intensified as climate change compromises ecosystems and biodiversity. Therefore, it is crucial to develop different methods for CO2 sequestration to improve solid sorbent capabilities (NPs). To this end, the surface of 200-nm silica nanoparticles (SiO2NPs) was covalently anchored with aminated ligands, 3-aminopropyltriethoxysilane (APTES), poly(amidoamine) dendrimers (PAMAM) and a short peptide comprising two lysine units, aiming for CO2 adsorption over a wide range of pressures. Our goal was to explore the influence of functional chemical groups (attached to the SiO2NPs) on CO2 sequestration. The observed results showed that at low and high CO2 gas pressure conditions, typical APTES functionalized SiO2Np surpassed the CO2 adsorption capacities of dendritic and peptide-based nanoparticles bearing amine-polymer functionalities, a remarkable effect that was investigated in this work. In addition, a convenient and facile method to decorate and quantify SiO2 nanoparticles with PAMAM and a short peptide is reported.