Infrared spectroscopic investigation and semi-empirical modeling of the structure of an adsorption complex formed with a nitroxide radical with functional groups

Dultsev, F. N.

doi:10.1016/j.tsf.2006.11.020

Cited by 2 publications

(1 citation statement)

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“…It is thus suggested that the new bands correspond to antisymmetric (∼1125 and ∼1170 cm –1 ) and bending (545 and 645 cm –1 ) vibrations of distorted SO 2 molecule in different SO 2 -amine adducts. These findings are in general agreement with data reported by others. ,,− For example, Vasilieva et al reported that the SO 2 -amine complex in a N,N -diethylpropylamine containing polysiloxane film exhibits three infrared bands at 643, 948, and 1245 cm –1 . Other researchers using ionic liquids with nitrogen atoms in different environments reported the occurrence of two bands at ca.…”

Section: Resultssupporting

confidence: 92%

Supported Polytertiary Amines: Highly Efficient and Selective SO₂ Adsorbents

Tailor

Abboud

Sayari

2014

Environ. Sci. Technol.

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Tertiary amine containing poly(propyleneimine) second (G2) and third (G3) generation dendrimers as well as polyethyleneimine (PEI) were developed for the selective removal of SO2. N-Alkylation of primary and secondary amines into tertiary amines was confirmed by FTIR and NMR analysis. Such modified polyamines were impregnated on two nanoporous supports, namely, SBA-15PL silica with platelet morphology and ethanol-extracted pore-expanded MCM-41 (PME) composite. In the presence of 0.1% SO2/N2 at 23 °C, the uptake of modified PEI, G2, and G3 supported on SBA-15PL was 2.07, 2.35, and 1.71 mmol/g, respectively; corresponding to SO2/N ratios of 0.22, 0.4, and 0.3. Under the same conditions, the SO2 adsorption capacity of PME-supported modified PEI and G3 was significantly higher, reaching 4.68 and 4.34 mmol/g, corresponding to SO2/N ratios of 0.41 and 0.82, respectively. The working SO2 adsorption capacity decreased with increasing temperature, reflecting the exothermic nature of the process. The adsorption capacity of these materials was enhanced dramatically in the presence of humidity in the gas mixture. FTIR data before SO2 adsorption and after adsorption and regeneration did not indicate any change in the materials. Nonetheless, the SO2 working capacity decreased in consecutive adsorption/regeneration cycles due to evaporation of impregnated polyamines, rather than actual deactivation. FTIR and (13)C and (15)N CP-MAS NMR of fresh and SO2 adsorbed modified G3 on PME confirmed the formation of a complexation adduct.

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