Fast and Reversible Direct CO₂ Capture from Air onto All-Polymer Nanofibrillated Cellulose—Polyethylenimine Foams

Abstract

Fully polymeric and biobased CO2 sorbents composed of oxidized nanofibrillated cellulose (NFC) and a high molar mass polyethylenimine (PEI) have been prepared via a freeze-drying process. This resulted in NFC/PEI foams displaying a sheet structure with porosity above 97% and specific surface area in the range 2.7-8.3 m(2)·g(-1). Systematic studies on the impact of both PEI content and relative humidity on the CO2 capture capacity of the amine functionalized sorbents have been conducted under atmospheric conditions (moist air with ∼400 ppm of CO2). At 80% RH and an optimum PEI content of 44 wt %, a CO2 capacity of 2.22 mmol·g(-1), a stability over five cycles, and an exceptionally low adsorption half time of 10.6 min were achieved. In the 20-80% RH range studied, the increase in relative humidity increased CO2 capacity of NFC/PEI foams at the expense of a high H2O uptake in the range 3.8-28 mmol·g(-1).

Climate‐friendly polyurethane blowing agent based on a carbon dioxide adduct from palmitic acid grafted polyethyleneimine

“…As shown in Figure 2( 21 in the n-pentadecylcarbonyl side chain) emerged in the C 16 -bPEI spectrum (as indicated by asterisks); this further confirmed the success of the grafting reaction. The CO 2 adduction formed carbamate anions and alkylammonium cations in both bPEI-CO 2 and C 16 -bPEI-CO 2 ( Figure 1).…”

“…The CO 2 adduction formed carbamate anions and alkylammonium cations in both bPEI-CO 2 and C 16 -bPEI-CO 2 ( Figure 1). As a result, a group of strong IR bands at 1630, 1570, 1477, and 1413 cm 21 [ Figure 2(B)] emerged in bPEI-CO 2 ; these could be assigned to d NAH in ammonium, 23 m C@O in carbamate, 24 and the asymmetrical and symmetrical skeletal stretching of carbamate anions, 22 respectively. The m NAH adsorptions in both alkylammonium (from 2200 to 3200 cm…”

“…[16][17][18][19][20][21] In a recent publication, 22 we proved that CO 2 adducts from PEIs can be used as climate-friendly blowing agents for PUs. In that study, a branched polyethyleneimine (bPEI) was grafted with a-glycidyl ether-x-butyl poly(propylene glycol) (PPG) with a molecular weight of 392 Da.…”

“…) and ANHCOO 2 (3420 cm 21 ) groups fused together and formed a very broad peak that spanned from 2200 to 3700 cm 21 and covered the aliphatic m CAH adsorptions. C 16 -bPEI-CO 2 inherited the typical adsorptions of bPEI-CO 2 and displayed new adsorptions from the n-pentadecylcarbonyl side chains [also indicated by asterisks, Figure 2(B)].…”

Polyethylenimine nanofibrous adsorbent for highly effective removal of anionic dyes from aqueous solution

“…Polyethylenimine (PEI) has a high amine density and accessible primary amine sites on the chain ends, which act as desirable building blocks for the construction of adsorbents. For instance, many excellent CO 2 adsorbents have been prepared by integrating PEI into porous materials, including silica [12], mesoporous carbon [13], titanate [14], polymeric supports [15], and other metal oxide nanocomposites [16]. In addition, because of the high positive charge density on the protonated PEI backbone or side chains, PEI-based adsorbents exhibit good adsorption capacity for acidic gas or anionic materials such as polyanions and negatively charged organic or inorganic matter, including various anionic dyes [16][17][18][19].…”