• Carbon letters
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• v.2 no.2
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• pp.109-112
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• 2001

For the adsorption of ammonia, activated carbon fibers (ACFs) were subjected to sulfuric acid treatment in order to modify the surface functional groups. The surface acid and base value of ACFs were measured using titration and FT-IR spectrometry. SEM was used to investigate the surface morphology. Acid treatments by $H_3PO_4$, $H_2SO_4$, and $HNO_3$ were performed to increase the adsorption capacity of $NH_3$. As a result, Cellulose-based ACF has high adsorption capacity for ammonia. The ammonia removal efficiency of ACF was the maximum which was treated by 15 wt% sulfuric acid at $100^{\circ}C$ for 60 min. The average pore diameter little increased from $19{\AA}$ to $20.8{\AA}$ and the specific surface area of ACF considerably decreased and acid values increased by 15 wt% sulfuric acid treatment. Ammonia reacted with sulfonyl radicals. After adsorption of ammonia, white material was grown on the surface of ACF through the adsorption of ammonia and it was determined to ammonium sulfate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.254-255
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• 2005

In this work, the effects of plasma treatment on surface properties of semi conductive silicone rubber were investigated in terms of X-ray photoelectron spectroscopy(XPS). The adhesion characteristics of semiconductive-insulating interface layer of silicone rubber were studied by measuring the T-peel strengths. As a result, semiconductive silicone rubber surfaces treated with plasma discharge led to and increase in oxygen-containing functional groups, resulting in improving the degree of adhesion of the semiconductive-insulating interface layer of silicone rubber. these results are probably due to the modifications of surface functional groups or polar component of surface free energy of the semi conductive silicone rubber.

• Macromolecular Research
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• v.15 no.1
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• pp.51-58
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• 2007

The approach studied in the present work produced an exfoliated state of clay layers via confinement of the charged nano-sized polystyrene (PS) beads within the gallery of swollen pristine clay. It was demonstrated that adsorption of the polymer nanobeads dramatically promotes expansion of the clay gallery. A comparative study of incorporation was conducted by employing organo-modified clay along with two different colloid polymer systems: electrostatically stabilized PS nanobeads and cationic monomer-grafted PS nanobeads. The mechanism of adsorption of the monomer-grafted polymer beads onto clay via cationic exchange between the alkyl ammonium group of the polymer nanobeads and the interlayer sodium cation of the layered silicate was verified by using several techniques. As distinct from the polymer nanobeads formed using conventional miniemulsion polymerization method, competitive adsorption of stabilizing surfactant molecules was be prevented by grafting the surface functional groups into the polymer chain, thereby supporting the observed effective adsorption of the polymer beads. The presence of surface functional groups that support the establishment of strong polymer-clay interactions was suggested to improve the compatibility of the clay with the polymer matrix and eventually play a crucial role in the performance of the final nanocomposites.

• Carbon letters
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• v.20
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• pp.19-25
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• 2016

Activated carbon fiber (ACF) surfaces are modified using an electron beam under different aqueous solutions to improve the NO gas sensitivity of a gas sensor based on ACFs. The oxygen functional group on the ACF surface is changed, resulting in an increase of the number of non-carbonyl (-C-O-C-) groups from 32.5% for pristine ACFs to 39.53% and 41.75% for ACFs treated with hydrogen peroxide and potassium hydroxide solutions, respectively. We discover that the NO gas sensitivity of the gas sensor fabricated using the modified ACFs as an electrode material is increased, although the specific surface area of the ACFs is decreased because of the recovery of their crystal structure. This is attributed to the static electric interaction between NO gas and the non-carbonyl groups introduced onto the ACF surfaces.

• Carbon letters
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• v.16 no.2
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• pp.93-100
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• 2015

Surface modified carbon felts were utilized as an electrode for the removal of inorganic ions from seawater. The surfaces of the carbon felts were chemically modified by alkaline and acidic solutions, respectively. The potassium hydroxide (KOH) modified carbon felt exhibited high Brunauer-Emmett-Teller (BET) surface areas and large pore volume, and oxygen-containing functional groups were increased during KOH chemical modification. However, the BET surface area significantly decreased by nitric acid ($HNO_3$) chemical modification due to severe chemical dissolution of the pore structure. The capability of electrosorption by an electrical double-layer and the efficiency of capacitive deionization (CDI) thus showed the greatest enhancement by chemical KOH modification due to the appropriate increase of carboxyl and hydroxyl functional groups and the enlargement of the specific surface area.

• Korean Journal of Materials Research
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• v.12 no.9
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• pp.740-746
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• 2002

In this study, the polycarbonate surface was treated by $O_2$/ Ar gases plasma for the enhancement of adhesion with Cu electrode. From the point of view of hydrophilicity and the functionality, the micro-roughness, new functional groups and oxygen content of the polycarbonate surface were increased by the $O_2$/ Ar gases plasma treatment. The Cu films deposited on the as-received polycarbonate were easily detached while, after the$ O_2$/ Ar gases plasma treatment the adhesive Cu films on polycarbonate could be obtained. These results can be explained that the polycarbonate had a hydrophilic surface with uniform micro-roughness and new functional groups by $O_2$/ Ar gases plasma treatment. Therefore,$O_2$/ Ar gases plasma treatment is a promising method for improvement of adhesion between polycarbonate and Cu electrode.

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1775-1779
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• 2006

A liquid chromatographic chiral stationary phase (CSP) based on (+)-(18-crown-6)-2,3,11,12-tetracarboxilic acid without extra free aminopropyl groups on silica surface has been demonstrated to be quite effective for the resolution of various $\beta$-amino acids. The retention factors ($k_1$) for the resolution of $\beta$-amino acids on the CSP were quite large and the large retention factors might be quite attractive along with the reasonable separation factors ($\alpha$) for preparative scale enantioselective chromatography. The large retention factors on the CSP were found to be reduced effectively by adding ammonium ion to mobile phase without sacrificing the chiral recognition efficiency of the CSP. Consequently, the CSP is also quite applicable for use in analytical enantioselective chromatography.

• Journal of the Korean Society of Tobacco Science
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• v.31 no.1
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• pp.9-17
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• 2009

Activated carbon fiber (ACF) was surface modified by nitric acid to improve the adsorption efficiency of the propylamine. Functional groups and textural properties of modified ACF were investigated. The total surface acidity increased about 7 times to that of as-received ACF by modification with 1 M nitric acid solution, carboxylic and phenolic groups mainly increased. However, the specific surface areas and the total pore volumes of the modified ACFs were decreased by 5-8% due to the increased blocking (or demolition) of micropores in the presence of newly introduced complexes. Despite the decrease of textural properties, it was found that the amount of propylamine adsorbed by the modified ACFs was increased by approximately 17%. The oxygen and nitrogen contents on the modified ACF increased by 1.5 and 3 times compared with the as-received ACF. From the XPS results, it was observed that propylamine reacted with strong or weak acidic groups, such as -COOH or -OH on the ACF surfaces, resulting in the formation of pyrrolic-, pyridonic- or pyridine-like structures.

• Journal of the Korean institute of surface engineering
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• v.45 no.1
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• pp.8-14
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• 2012

The effects of the alkali surface modification process on the adhesion strength between electroless-plated Cu and polyimide films were investigated. The polyimide surfaces were effectively modified by alkali surface treatments from the hydrophobic to the hydrophilic states, and it was confirmed by the results of the contact angle measurement. The surface roughness increased by alkali surface treatments and the adhesion strength was proportional to the surface roughness. The adhesion strength of Cu/polyimide interface treated by KOH + EDA (Ethylenediamine) was 874 gf/cm which is better than that treated by KOH and KOH + $KMnO_4$. The results of XPS spectra revealed that the alkali treatment formed oxygen functional groups such as carboxyl and amide groups on the polyimide films which is closely related to the interfacial bonding mechanism between electroless-plated Cu and polyimide films. It could be suggested that the species and contents of functional group on polyimide films, surface roughness and contact angle were related with the adhesion strength of Cu/polyimide in combination.

• Journal of Adhesion and Interface
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• v.1 no.1
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• pp.23-29
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• 2000

Surface modification of hydrophobic polymeric materials to be hydrophilic or to have specific functional groups is of great importance for a diversity of applications of the materials. In this study, polyethylene (PE) film surfaces were modified by vapor phase photografting of hydrophilic vinyl monomers with different functional groups. The functional monomers were introduced on PE films by introducing the monomers in vapor phase using a vapor phase photografting apparatus designed by our laboratory. Functional monomers used were acrylic acid (negatively chargeable), acrylamide and allylalcohol (neutral), and allylamine and N,N-dimethyl aminopropyl acryamide (positively charged). The functional monomer-grafted PE film surfaces were characterized by the measurement of water contact angles and the attenuated total reflectance Fourier-transform infrared spectroscopy. The vapor phase photografting seems to be effective means for introduction of various functional groups onto polymeric substrates.