• Journal of Environmental Impact Assessment
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• v.29 no.3
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• pp.198-209
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• 2020

In this study, electrospun nanofibers made of PAN (polyacrylonitrile) were activated through a physical method to obtain an optimized pore structure. In particular, to enhance the surface alkalinity, the activated carbon fibers (ANFs) were impregnated with tetraethylenepentamine (TEPA) with the aid of HNO₃. Then, the low level (3,000 ppm) CO₂ adsorption capacity for each ANF sample was evaluated. The specific surface area of ANFs increased from 308.4 ㎡/g to 839.4 ㎡/g and the total pore volume increased from 7.882 ㎤/g to 27.50 ㎤/g. Although the TEPA impregnation reduced the specific surface area and pore volume of the ANFs due to blocking of micropores, the HNO₃ pre-oxidation enhanced the amino groups tethered, increasing the amine content from 6.42% to 17.19%, and finally, increased the adsorption capacity of CO₂. This study showed that the sample 60-ANF-HNO₃-TEPA, which was activated for 60 minutes and was impregnated with HNO₃ and TEPA, had the best adsorption capacity for low level (0.3%) CO₂ (in a binary mixture with N₂).

• Korean Chemical Engineering Research
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• v.53 no.3
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• pp.382-390
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• 2015

Poly(methyl methacrylate) (PMMA) supports and amine additives were investigated to adsorb $CO_2$. PMMA supports were fabricated by using different ratio of pore forming agents (porogen) to control the BET specific surface area, pore volume and distribution. Toluene and xylene are used for porogens. Supported amine sorbents were prepared by wet impregnation of tetraethylenepentamine (TEPA) on PMMA supports. So we could identify the effect of the pore structure of supports and the quantity of impregnated TEPA on the adsorption capacity. The increased amount of toluene as pore foaming agent resulted in the decreased average pore diameter and the increased BET surface area. Polymer supports with huge different pore distribution could be fabricated by controlling the ratio of porogen. After impregnation, the support with micropore structure is supposed the pore blocking and filling effect so that it has low $CO_2$ capacity and kinetics due to the difficulty of diffusing. Macropore structure indicates fast adsorption capacity and low influence of amine loading. In case of support with mesopore, it has high performance of adsorption capacity and kinetics. So high surface area and meso-/macro- pore structure is suitable for $CO_2$ capture.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3668-3674
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• 2010

Mesoporous SBA-15 was synthesized using tetraethylorthosilicate (TEOS) as the silica source and Pluronic (P123) as the structure-directing agent. The defective Si-OH groups present in SBA-15 were successively grafted with 3-chloropropyltrimethoxysilane (CPTMS) followed by tris-(2-aminoethyl) amine (TAEA) and/or tetraethylenepentamine (TEPA) for effective immobilization of silver nanoparticles. Grafting of TAEA and/or TEPA amine and immobilization of silver nanoparticles inside the channels of SBA-15 was verified by XRD, TEM, IR and BET techniques. The silver nanoparticles immobilized on TAEA and /or TEPA grafted SBA-15 was subjected for electrocatalytic reduction of hydrogen peroxide ($H_2O_2$). The TEPA stabilized silver nanoparticles show higher efficiency for reduction of $H_2O_2$ than that of TAEA, due to higher number of secondary amine groups present in TEPA. The amperometric analysis indicated that both the Ag/SBA-15/TAEA and Ag/SBA-15/TEPA modified electrodes required lower over-potential and hence possess high sensitivity towards the detection of $H_2O_2$. The reduction peak currents were linearly related to hydrogen peroxide concentration in the range between $3{\times}10^{-4}\;M$ and $2.5{\times}10^{-3}\;M$ with correlation coefficient of 0.997 and detection limit was $3{\times}10^{-4}\;M$.