• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.673-679
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• 2008

In this study, Mesoporous silica were prepared from hydrothermal synthesis using gel mixture of tetraethylorthosilcate (TEOS) as silica source and cetyltrimethylammonium bromide(CTMABr) as a template. In the optimum synthesis cause, molar ratio of template and silica changed. The surface and structure properties of Mesoporous silica were determined by XRD, SEM, and BET. N$_2$ adsorption isotherm characteristics, including the specific surface area(S$_{BET}$), total pore volume(V$_T$), and average pore diameter(D$_{BJH}$), were determined by BET. Also, the adsorption character of Pb(II) and Cd(II) ion on Mesoporous silica were measured using ICP. As a result, a SBET of 100$\sim$1,500 m$^2$/g was determined from the N$_2$ adsorption isotherm. Also, the average pore diameter of 2$\sim$4 nm. The adsorption of Pb ion and Cd ion on Mesoporous silica become different depending on the pH of solution. The adsorption amount of Mesoporus silica had higher than that of silicagel.

• Journal of the Korean Chemical Society
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• v.35 no.3
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• pp.204-210
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• 1991

Multilayer adsorption isotherms of nitrogen and argon on the perovskite-type mixed oxides, synthesized by a citrate coprecipitation method, are determined at the liquid nitrogen temperature using a gravimetric adsorption apparatus. The volume of the adsorbed gas are plotted against the statistical thickness of the adsorbed layer, calculated from several universal adsorption isotherms one after another. The t-method area obtained from this plot is compared with the BET area and finally the appropriateness of universal adsorption isotherms is then discussed on the basis of the plot.

• Journal of Environmental Health Sciences
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• v.19 no.4
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• pp.25-32
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• 1993

Granular activated carbon is commonly used in fixed-bed adsorbers to remove organic chemicals. In this experiment organic chemical solutions were prepared by adding the reagent grade organic chemical to distilled water. Isotherm adsorption tests of volatile organic chemicals were conducted using bottle-point technique and column test. Organic chemicals after passing through the column were extracted with hexane and analyzed with gas chromatography (Hewlett-Packard 5890) to check the adsorption capacity and breakthrough curve. The result were as follows: 1. The BET surface area of coconut activated carbon was 658~1,010 m$^2$/g where as coconut shell carbon was 6.6 m$^2$/g. Coconut activated carbon increased the BET surface area and adsorption capacity in bottle-point isotherm. 2. The adsorption capacity of coconut activated carbon for trichloroethylene (TCE) was reduced in the presence of humic substance. 3. A decrease in particle size of activated carbon resulted in higher adsorption capacity and lower intraparticle diffusion coefficient. It is reflected not only as a decrease in Freudlich adsorption capacity value (K) but also as an increase in Freudlich exponenent value (1/n).

• Journal of Environmental Science International
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• v.19 no.6
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• pp.681-687
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• 2010

Mesoporous silica was prepared from hydrothermal synthesis using gel mixture of tetraethylorthosilcate (TEOS) as silica source and cetyltrimethylammonium bromide (CTMABr) as a surfactant. In the optimum synthesis cause, molar ratio of template and silica changed. The surface and structure properties of mesoporous silica were determined by XRD, SEM, TEM and BET. Also, surface potential of mesoporous silica was measured using zeta potential. $N_2$ adsorption isotherm characteristics, including the specific surface area ($S_{BET}$), total pore volume $V_T$), and average pore diameter ($D_{BJH}$), were determined by BET. As a result, SBET of $100m^2/g{\sim}1500m^2/g$ was determined from the $N_2$ adsorption isotherm. Also, the average pore diameter was 2 nm∼4 nm. Mesoporous silica's surface potential of minus charge was determined from zeta potential.

• Analytical Science and Technology
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• v.13 no.2
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• pp.194-199
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• 2000

The study on the adsorption, the surface properties and the antibacterial effects of the Ni-treated PAN based activated carbon fibers was carried out. In the adsorption study on the Ni-treated PAN based ACFs, Type I isotherms for N1-N3 and Type II-Type III isotherms for N4-N6 were obtained, respectively. Futhermore, their adsorbed volumes slowly were decreased with the increase in the mole concentration of Ni on the treated PAN based ACFs. From the BET equation, the specific surface areas of the Ni-treated PAN based ACFs were in the range of $692.58-895.24m^2/g$. The micropore volumes obtained from ${\alpha}_s$-method using common-t value were $0.19-0.56cm^3/g$. The surfaces of PAN based ACFs partially blocked by metal after the treatment were observed from the SEM micrographs. Finally, from the antibacterial effects using Shake flask method against E. coli, the percentage of the effects was 92.5-100% and the antibacterial effect was increased with the increase in mole concentration of Ni treated.

• YAKHAK HOEJI
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• v.37 no.1
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• pp.66-75
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• 1993

Dental abrasive, dicalcium phosphate dehydrate (DCPD) was prepared and the several important factors affecting on the quality of toothpaste were investigated by means of set test, glycerine absorption, Coulter counter test, color difference, BET adsorption, mercury porosimetery, and rheogram comparing with two foreign DCPDs, MFO4 and Dentphos K. Sample DCPD was prepared by reaction between 85% H$_{3}$PO$_{4}$ and 15% milk of lime at $39^{\circ}C$ (pH6.5), and stabilized with TSPP and TMP. The physicochemical properties of Sample DCPD were obtained as follows: whiteness (98.99), average particle size (15.5 $\mu\textrm{m}$), pH (7.9), remainder particle weight (0.49w/w%), glycerine absorption value (64 ml), and set test (passed). N$_{2}$ adsorption curves (BET) of three kinds of DCPD showed non-porous type III isotherm. BET adsorption parameters of sample DCPD showed that surface area was 24.9 m$^{2}$/g, total pore volume 0.09 cm$^{3}$/g and average pore radius 72.0 $\AA$. The rheogram of the toothpaste containing each DCPD showed bulged plastic flow with yield vlaue and thixotropic behavior. These results meet standard requirements as abrasive standard, and suggested that synthesized sample DCPD could be used a dental abrasive such as a high quality grade in practice as foreign DCPDs.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.569-573
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• 2013

In this study, activated carbon fabric was prepared from a cellulose-based polymer (viscose rayon) via a combination of physical and chemical activation (mixed activation) processes by means of $CO_2$ as a gasifying agent and surface and adsorption properties were evaluated. Experiments were performed to investigate the consequence of activation temperature (750, 800, 850 and $925^{\circ}C$), activation time (15, 30, 45 and 60 minutes) and $CO_2$ flow rate (100, 200, 300 and 400 mL/min) on the surface and adsorption properties of ACF. The nitrogen adsorption isotherm at 77 K was measured and used for the determination of surface area, total pore volume, micropore volume, mesopore volume and pore size distribution using BET, t-plot, DR, BJH and DFT methods, respectively. It was observed that BET surface area and TPV increase with rising activation temperature and time due to the formation of new pores and the alteration of micropores into mesopores. It was also found that activation temperature dominantly affects the surface properties of ACF. The adsorption of iodine and $CCl_4$ onto ACF was investigated and both were found to correlate with surface area.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.6
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• pp.325-331
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• 2017

Adsorption experiments of carbon dioxide were performed on ZSM5 and Molecular Sieve 13X (MS13X) impregnated with Monoethanol Amine (MEA). Adsorption efficiency of $CO_2$ was investigated in a U type packed column with GC/TCD. The adsorption capacities of adsorbents are estimated in the temperature range of $30-80^{\circ}C$. The modified adsorbents was characterized by BET surface area, $N_2$ adsorption/desorption isotherms, X-ray diffraction and FT-IR. Surface analysis results showed that the impregnation method did not affect the crystallinity of any adsorbents. BET surface area of the MS13X impregnated amine decreased to $19.945m^2/g$ from $718.335m^2/g$. These reults showed that amine molecules were filled with the pore volume in MS13X, as a results restricting access of nitrogen into the pores. The MEA modified MS13X showed improvement in $CO_2$ adsorption capacity over the ZSM5 impregnated with MEA. The MS13X-MEA showed the highest adsorption capacity due to physical adsorption and chemical adsorption by amino-group content. This results also showed that adsorption capacity of MS13X-MEA increases with the temperature range of $60-80^{\circ}C$ compared with pristine MS13X.

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.920-923
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• 1998

In this work, the adsorption characteristics of the activated carbon treated with 30 wt. %HCl and 30 wt. % NaOH were investigated. The acid and base values were determined by Boehm's method and the surface area and porosity was measured by BET-method with $N_2$-adsorption. Also, the adsorption characteristics of the activated carbons treated with acid and base chemical solutions were investigated with $CO_2$ and $NH_3$-adsorption. From which, relatively different adsorption behaviors of the modified activated carbons were observed in the amounts of $CO_2$ and $NH_3$ adsorptions, even though the physical surface structures of the activated carbons, such as specific surface area, pore size and pore volume, were not significantly changed.

• Journal of Environmental Science International
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• v.20 no.7
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• pp.873-879
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• 2011

Adsorption experiment of carbon dioxide was performed on MCM41 silica impregnated with two kinds of EDA(ethylenediamine) and MEA(monoethanolamine). The prepared adsorbents were characterized by BET surface area, X-ray diffraction and FT-IR. The $CO_2$ capture study was investigated in a U type packed column with GC/TCD. The results of XRD for MCM-41 and amine-impregnated MCM41 showed typical the hexagonal pore system. BET results showed the MCM 41 impregnated amine to have a surface area of 141 $m^2/g$ to 595 $m^2/g$ and FT-IR revealed a N-H functional group at about 1400$cm^{-1}$ to 1600$cm^{-1}$. The $CO_2$ adsorption capacity on EDA and MEA was as follow: MCM41-EDA30 > MCM41 -EDA40 >MCM41-EDA20 >MCM-EDA10 and MCM41-MEA40 >MCM41-MEA30 > MCM41-MEA20> MCM41-MEA10. The MCM41-EDA30 showed the highest adsorption capacity due to physical adsorption and chemical adsorption by amino-group content. The results suggest that mesoporous media with EDA is effective adsorbent for $CO_2$ capture from flue gases.