• Journal of the Korean Chemical Society
• /
• v.57 no.1
• /
• pp.104-108
• /
• 2013

The adsorption characteristics of Cd(II) and Pb(II) in aqueous solution using granular activated carbon (GAC), activated carbon fiber (ACF), modified ACF (NaACF), and a mixture of GAC and NaACF (GAC/NaACF) have been studied. The surface properties, such as morphology, surface functional groups, and composition of various adsorbents were determined using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) measurements. The specific surface area, total pore volume, and pore size distribution were investigated using nitrogen adsorption, Brunauer-Emmett-Teller (BET), and Barrett-Joyner-Halenda (BJH) methods. In this study, NaACF showed a high adsorption capacity and rate for heavy metal ions due to the improvement of its ion-exchange capabilities by additional oxygen functional groups. Moreover, the GAC and NaACF mixture was used as an adsorbent to determine the adsorbent-adsorbate interaction in the presence of two competitive adsorbents.

• Membrane and Water Treatment
• /
• v.15 no.3
• /
• pp.139-152
• /
• 2024

Mixed matrix membranes have gained significant recognition in the wastewater treatment industry for their effectiveness in removing dyes, proteins, and heavy metals from water sources. Researchers have developed an innovative technique to enhance properties of these membranes by incorporating amine-functionalized carbon nanotubes into the polymer matrix. This approach introduces amine functional groups onto the membrane surface, which are then modified with trimesoyl chloride and cyanuric chloride. The modified membranes are characterized by XPS to confirm successful bonding of amines with the trimesoyl chloride and cyanuric chloride. The surface charge of the modified membrane also plays a role in the modification process; the membrane modified with trimesoyl chloride has a negative surface charge, while the one modified with cyanuric chloride has a more positive charge. At the same acidic pH, the positive or negative charge of the mixed matrix membranes assists in enhancing the rejection of heavy metals. This results in improved antifouling properties for both modified membranes. The heavy metal rejection for all modified membranes is higher than for unmodified membranes, due to both adsorption and complexation abilities of the functional groups on the membrane surface with heavy metal ions. As the membrane surface functionalities increase through modification, the separation due to complexation also increases. The bulk morphology of the membrane remains unchanged, while roughness slightly increases due to the surface treatment.

• Carbon letters
• /
• v.4 no.4
• /
• pp.180-184
• /
• 2003

The role of KOH in the one-stage KOH-activation of rice straws was studied using FTIR, XPS, TGA, and DTG techniques. It was found that at the impregnation, KOH extracts to some extent the lignin component from rice straw and reacts with hydroxyl groups. On heat-treatment, the impregnated KOH facilitates intermolecular condensation reaction on one hand but retards the thermal degradation of cellulose molecules on the other hand. The oxygen-containing surface functional groups newly created by oxidation of KOH may facilitate the bulk, not controlled, consumption of carbon atoms so that the effective porosities may not be able to be developed by the one-stage activation process.

• KSBB Journal
• /
• v.7 no.4
• /
• pp.318-324
• /
• 1992

The adsorption characteristics of bovine serum albumin(BSA) on the modified carbon fiber and cellulose surfaces were investigated. In order to define the effects of solid surface characteristics on protein adsorption, surfaces of carbon fiber and cellulose were modified by physical and chemical treatment. The amounts of BSA adsorbed onto various solid surfaces were evaluated by batch method under various pH and ionic strength. The amount of adsorbed BSA was highly dependent on pH as well as surface functional groups.

• Carbon letters
• /
• v.4 no.2
• /
• pp.74-78
• /
• 2003

Four kinds of plasma blacks were prepared by plasma pyrolysis under various metallic catalysts coated on honeycomb, and investigated the catalytic effect on the characteristics of the plasma blacks prepared under plasma pyrolysis condition. Pt, Pt-Rh, and Pd catalysts were employed as active materials to prepare the plasma blacks. In the experimental range studied, the metallic catalysts influenced on surface area, particle size, surface oxygen content and electrical conductivity of the plasma blacks prepared. It was showed that more dense particle of plasma blacks were prepared under existence of metallic catalysts. Presence of the metallic catalyst reduces the electrical resistivity of plasma blacks due to the decrease in the amount of oxygen functional groups. The highest electrical conductivity of plasma black was observed in the Pt catalyst and then followed by those Pt-Rh, Pd and bare cordierite honeycomb.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.2
• /
• pp.188-192
• /
• 2007

In this work, the effects of chemical treatment of polyimide films were studied by FT-IR, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and contact angles. The adhesion characteristics of the films were also investigated in the peel strengths of polyimide/aluminum films. The increases of surface functional groups of KOH-treated polyimide films were greatly correlated with the polar component of surface free energy. The peel strength of polyimides to metal substrate was also greatly enhanced by increasing the KOH treatment time, which can be attributed to the formation of polar functional groups on the polyimide surfaces, resulting in enhancement of the work of adhesion between polymer film and metal plate.

• KSBB Journal
• /
• v.17 no.3
• /
• pp.235-240
• /
• 2002

The surface of polypropylene was modified by 1 keV $Ar^+$ ion beam in an $O_2$ environment in order to enhance wettability. Contact angle of deionized water on modified polypropylene was reduced from $78^{\circ}$to $22^{\circ}$. The enhanced wettability is originated from newly formed functional groups such as ether, carbonyl, and carbonyl groups. During immersion in deionized water, the enhanced wettability has remained nearly same. After washing in water, the hydrophilic functional groups on the polymer surface have been very stable. The modified polypropylene was adopted as bio-film media to remove organics in synthetic wastewater. Microbe adhesion on the polypropylene surface was improved due to the newly formed hydrophilic groups.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10a
• /
• pp.35-36
• /
• 2003

The purpose of this work is to investigate the surface modification of LDPE film via corona discharge treatment and subsequent graft polymerization, and their effect on the resulting dyeability is studied in terms of the surface functional groups, surface energetics, and acid-base interaction between the modified LDPE and the dyes used.

• Journal of the Korean Chemical Society
• /
• v.54 no.1
• /
• pp.93-98
• /
• 2010

In this work, the electrochemical properties of surface treated multi-walled carbon nanotubes (MWNTs) were studied. Nitrogen and oxygen functional groups of the MWNTs were introduced by urea and acidic treatment, respectively. The surface functional groups of the MWNTs were confirmed by X-ray photoelectron spectroscopy (XPS) measurements and zeta-potential method. The characteristics of $N_2$ adsorption isotherm at 77 K, specific surface area, and total pore volumes were investigated by BET eqaution, BJH method and t-plot method. Electrochemical properties of the functionalized MWNTs were accumulated by cyclic voltammetry at the scan rates of 50 $mVs^{-1}$ and 100 $mVs^{-1}$ in 1M $H_2SO_4$ as electrolytes. As a result, the functionalized MWNTs led to an increase of capacitance as compared with pristine MWNTs. It was found that the increase of capacitance for urea treated MWNTs was attributed to the increase in density of surface functional groups, resulting in improving the wettability between electrode materials and charge species.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2019.05a
• /
• pp.293-294
• /
• 2019