• Journal of Korean Society of Water Science and Technology
• /
• v.26 no.6
• /
• pp.125-132
• /
• 2018

We studied a simple approach for synthesis of mesoporous Y(M-Y) from commercial zeolite Y precursors by treating of NaOH with $CH_3(CH_2)_{15}N(Br)(CH_3)_3$ as template. The physicochemical properties of the mesoporous zeolites Y were then analyzed using XRD, nitrogen full-isotherms at 77 K, SEM and TEM. The nitrogen adsorption-desorption analysis showed that surface area and pore diameter of synthesized mesoporous zeolite Y(M-Y) were $1072m^2/g$ and ~3.3 nm, respectively. And M-Y was applied for the removal of $Mn^{2+}$ and $Fe^{2+}$ from aqueous solution. This material, which introduces mesoporosity with zeolite Y character, displayed a superior adsorption capacity than commercial zeolite Y when used as an adsorbent for the removal of $Mn^{2+}$ and $Fe^{2+}$.

• Carbon letters
• /
• v.3 no.2
• /
• pp.93-98
• /
• 2002

Short pitch fibers were prepared from petroleum based isotropic precursor pitch by melt-blown technology. The pitch fibers were stabilized in oxidizing condition, followed by steam activations at various conditions. The fiber surface and pore structures of the activated carbon fibers (ACFs) were respectively characterized by using SEM and applying BET theory from nitrogen adsorption at 77 K. The weight loss of the oxidized fiber was proportional to activation temperature and activation time, independently. The adsorption isotherms of the nitrogen on the ACFs were constructed and analyzed to be as Type I consisting of micropores mainly. The specific surface area of the ACFs proportionally increased with the weight loss at a given activation temperature. The specific surface area was ranged 850~1900 $m^2/g$ with pores of narrow distribution in sizes. The average pore size was ranged 5.8~14.1 ${\AA}$ with the larger value from the more severe activation condition.

• Fibers and Polymers
• /
• v.5 no.1
• /
• pp.52-58
• /
• 2004

Previous investigation results revealed that after the Low Temperature Plasma (LTP) treatment, the hydrophilicity of wool fiber was improved significantly. Such improvement enhances the wool dyeing and finishing processes which might be due to the changes of the wool surface to a more reactive one. In this paper, wool fibers were treated with LTP with different gases, namely, oxygen, nitrogen and gas mixture (25 % hydrogen/75 % nitrogen). Investigations showed that chemical composition of wool fiber surface varied differently with the different plasma gas used. The surface chemical composition of the different LTP-treated wool fibers was evaluated with different characterization methods, namely FTIR-ATR, XPS and saturated adsorption value. The experimental results were thoroughly discussed.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.11
• /
• pp.3217-3220
• /
• 2010

The electronic structures and bonding configuration of histidine on Ge(100) have been investigated with various sample treatments using core-level photoemission spectroscopy (CLPES). Interpretation of the Ge 3d, C 1s, N 1s, and O 1s core level spectra being included in these systems revealed that both the imino nitrogen in the imidazole ring and the carboxyl group in the glycine moiety concurrently participate in the adsorption of histidine on a Ge(100) surface at 380 K. Moreover, we could clearly confirm that the imino nitrogen with a free lone pair in the imidazole group adsorbs on Ge(100) more strongly than the carboxyl group in the glycine moiety by examining systems annealed at various temperatures.

• Journal of Environmental Science International
• /
• v.17 no.5
• /
• pp.493-500
• /
• 2008

This paper describes the adsorption/desorpton efficiency of a modified activated carbon by irradiated microwave to treat toluene. By employing microwave energy, the regeneration time was considerably shortened compared with conventional thermal heating regeneration. New adsorbent called ACB (Activated Carbon-Bentonite) was prepared from powder activated carbon with mixing bentonite as a binder. Specific surface area, average pore size and total pore volume of ACB were calculated from the nitrogen adsorption/desorption isotherm. The surface of ACB was characterized with scanning electron microscope(SEM). The results showed that the specific surface area, total pore volume, average pore size of ABC was not influenced by regenerating cycle with microwave irradiation. Toluene was adsorbed onto ACB which desorbed by MW irradiation. Absorption capacity of ACB was 0.117 $g_{toluene}/g_{ACB}$. Desorption efficiency of toluene increased as higher microwave output was applied.

• Journal of the Korean Ceramic Society
• /
• v.36 no.6
• /
• pp.577-582
• /
• 1999

Activated carbon fibers were prepared from stabilized PAN fibers by chemical activation using hydroxide. The variations in specific surface area amount of iodine adsorption micro-structure and pore size distribution in the activated carbon fibers after the activation process were discussed. In the chemical activation using potassium hydroxide specific surface area of about 2545m2/g and amount of iodine adsorption of 2049 mg/g were obtained at the condition of KOH/fiber ratio of 1 and 800$^{\circ}C$ Nitrogen adsorption isotherms for PAN based activated carbon fibers showed the type I in the Brunauer-Deming-Deming-Teller classification indicating the micro-pores consisting the activated fibers.

• Korean Chemical Engineering Research
• /
• v.47 no.4
• /
• pp.495-500
• /
• 2009

Activated carbon was used as an adsorbent to capture benzene vapor from gaseous stream of nitrogen in a fixed-bed to obtain the breakthrough data. The deactivation model is used to analyze the adsorption kinetics of benzene vapor using the experimental breakthrough data. The experimental breakthrough data are fitted very well to the deactivation model than the adsorption isotherm models in the literature.

• Carbon letters
• /
• v.10 no.3
• /
• pp.221-224
• /
• 2009

In this work, the $CO_2$ adsorption behaviors of amine functionalized activated carbons (ACs) were investigated. The surface of ACs was modified with urea, melamine, diethylenetriamine (DETA), pentaethylenehexamine (PEHA), polyethylenimine (PEI), and 3-aminopropyl-triethoxysilane (ATPS). The various surface properties of amine functionalized ACs were characterized by Boehm's method, nitrogen full isotherms, XPS, and TGA analyses. The active ingredients impregnated on the ACs show significant influence on the adsorption for $CO_2$ and its volumes adsorbed on amine functionalized ACs are larger than that on the pristine ACs, which is due to the grafted amine groups of the AC surfaces.

• Carbon letters
• /
• v.6 no.3
• /
• pp.141-147
• /
• 2005

The carbon sample "O", phosphoric acid-activated carbon "OP", zinc chloride-activated carbon "OZ", and two steam activated carbons "OS" and "OS2" with different burn-off of 25% and 58% respectively, were prepared from olive stones. The textural properties were determined from the results of nitrogen adsorption at 77 K and by analyzing these results through the application of different adsorption models. The chemistry of the carbon surfaces was determined from the base neutralization capacities, acid neutralization capacity and surface pH. The sorption of $Pb^{2+}$ ions on to the carbons prepared was followed under dynamic and equilibrium conditions. The differences between the values of the textural parameters were attributed to the inapplicability of some adsorption models and to the heterogeneity of the microporous carbons. The sorption of $Pb^{2+}$ ions is favored on carbon and activated carbons. However, chemically activated carbons are more effective compared with steam-activated ones. The sorption of $Pb^{2+}$ ions were related to the chemistry of the surface rather than to the textural properties.

• Carbon letters
• /
• v.8 no.1
• /
• pp.17-24
• /
• 2007

Microporous carbons with narrow pore size distribution have been successfully synthesized by using hydrolyzed and calcined silica as templates and phenol formaldehyde (pf) resin as carbon precursor. Phenol formaldehyde-silica micro composites were prepared by solution route. Subsesequently, silica templates were removed by HF leaching. Resulting carbons were steam activated. The porous carbons were characterized by nitrogen adsorption-desorption isotherm, SEM, FTIR analysis, iodine adsorption, thermogravimetry analysis, etc. Adsorption isotherms show that the porous carbon prepared from calcined silica as templates are microporous with 88% pores of size <2 nm porosity and are of type I isotherm, while porous carbon prepared by using hydrolyzed silica are microporous with 89% microporosity, shows hysteresis loop at high relative pressure indicating the presence of some mesoporosity in samples. The microporosity in porous carbon materials has a bearing on the nature of silica templates used for pore formation.