Polyethyleneimine-Modified Amorphous Silica for the Selective Adsorption of CO₂/N₂ at High Temperatures

Abstract

Mechanochemistry is very attractive as an efficient, solvent-free, and simplified technique for the preparation of composite adsorbents. Here, a series of polyethyleneimine (PEI)-modified SiO 2 adsorbents were prepared via mechanical ball milling for selective adsorption of CO 2 at high temperatures. The structural properties of these adsorbents were characterized by XRD, SEM, TGA, FTIR, and N 2 adsorption–desorption. This method can better disperse the PEI evenly in the SiO 2 as well as maintain the porous structure of the adsorbents by comparing with the impregnated adsorbents. These adsorbents presented appreciable performance in separating CO 2 at high temperatures, and the CO 2 adsorption capacity of PEI(70%)/SiO 2 is up to 2.47 mmol/g at 70 °C and 1.5 bar, which is significantly higher than that of the same type of CO 2 adsorbent reported in the literature. Furthermore, the adsorbent of PEI(70%)/SiO 2 provided an ideally infinite selectivity for CO 2 /N 2 (15:85) at 70 °C. These results showed that mechanical grinding methods are a simple and effective approach to producing amine-modified silica composite adsorbents.

Unlocking High‐Current Performance in Silicon Anode: Synergistic Phosphorus Doping and Nitrogen‐Doped Carbon Encapsulation to Enhance Lithium Diffusivity

“…The FTIR spectrum of PÀ Si shows the Si signatures, with the existence of OÀ H and SiÀ OÀ Si functional groups with peak characteristics at 3700-3000 and 1624 cm À 1 , respectively. [33][34][35] With the introduction of PPy, in addition to Si signatures, the C=C functional group of the pyrrole ring is detected with peaks at 1551 and 1461 cm À 1 in the FTIR spectra of PÀ Si@PPy. [36] There are also peaks appearing at 1294 and 1194 cm À 1 , which suggests the presence of CÀ N and CÀ H functional groups.…”

“…The FTIR spectra show the functional group alteration of the sample during the synthesis (Figure 3a). The FTIR spectrum of P−Si shows the Si signatures, with the existence of O−H and Si−O−Si functional groups with peak characteristics at 3700–3000 and 1624 cm −1 , respectively [33–35] . With the introduction of PPy, in addition to Si signatures, the C=C functional group of the pyrrole ring is detected with peaks at 1551 and 1461 cm −1 in the FTIR spectra of P−Si@PPy [36] .…”

α-C–H functionalization of glycine derivatives under mechanochemical accelerated aging en route the synthesis of 1,4-dihydropyridines and α-substituted glycine esters

“…This phenomenon was probably due to aggregation 24 (the particle size distribution was drastically changed, see Fig. S11 †) and the collapse of pore structure 25 of silica gel after the intensive mechanical grinding. While co-grinding the silica gel with organic substrates (BM-30) could largely weaken this disruption yet lead to a small decrease in the average pore diameter.…”

Interfacial Triboelectricity Lights Up Phosphor‐Polymer Elastic Composites: Unraveling the Mechanism of Mechanoluminescence in Zinc Sulfide Microparticle‐Embedded Polydimethylsiloxane Films

“…Moreover, Fourier-transform infrared (FT-IR) spectra indicated both oxide and hydroxide functional groups on all the oxide-layer surfaces, similar to the surface composition of typical oxide layers grown using other methods (Figure S10, Supporting Information). [42,43] Typically, high-quality oxide layers on commercial ZnS:Cu phosphor microparticles are grown using sophisticated atomic layer deposition processes in a fluidized bed reactor. [44] Contrarily, in this study, a simple solution-based oxide growth process involving MOPs was used for microparticle coating (see Experimental Section).…”