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Porous organic polymers possessing CO2-philic moieties have captured attention of the researchers due to efficient adsorption of gas molecules. By the condensation of organic rigid and contorted precursors, amide-linked organic framework polymers with low skeletal density have been prepared via a cost-effective protocol. Polyamide chains were synthesized via low temperature condensation of 2,4,6-triamino-1,3,5-triazine with terephthaloyl chloride and isophthaloyl chloride to yield PA-1 and PA-2, respectively. The synthesized polymers were further carbonized at 600°C to fabricate nitrogen-doped carbon materials (PA1-600 and PA2-600). The as-prepared materials were analyzed by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), thermal gravimetric analysis (TGA), CHN elemental analysis, textural analysis, and CO2 adsorption measurements. The maximum CO2 uptake determined is 42.85 mg/g at 273 K and 1 bar. The triazine rings with basic nitrogen atoms and amide bonds in the main chain are responsible for CO2 capture by the polymers.

A general and efficient method for C-3 functionalization of 2-phenylimidazo[1,2-a]pyridine has been developed. The reaction employs Cu(OTf)2 as a catalyst at 10 mol% loading, proceeds in dimethyl sulfoxide solvent, and utilizes bench-stable solid N-benzyloxycarbonylamino sulfones derived from aromatic and aliphatic aldehydes as N-acyliminium ion precursors. The imidazo[1,2-a]pyridine products are obtained in moderate to good yields.

Activated carbons (ACs) were impregnated with potassium halides (KX) to enhance the removal efficiency of elemental mercury (Hg0). In this work, the impregnation effect of potassium bromide (KBr) and potassium iodine (KI) were investigated. The surface properties of KX-ACs were determined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The pore structures and total pore volumes of the KX-ACs were analyzed using the N2 /77 K adsorption isotherms. The Hg0 removal efficiency of KBr-ACs and KI-ACs was studied under simulated flue gas conditions. The effects of KI and KBr loading, adsorption temperature, and flue gas components on Hg0 removal efficiency were also investigated. The results showed that the Hg0 removal efficiency of the ACs was significantly enhanced by KI or KBr impregnation, and KI-ACs showed higher Hg0 removal efficiency than KBr-ACs under the same conditions. An increase in KI or KBr loading and higher adsorption temperatures improved the Hg0 removal efficiency, indicating that chemisorption occurred due to the reaction between X− and Hg0. The lower extent of Hg0 removal exhibited by the KBr-ACs than by the KI-ACs was due to the difficulty of Br2 formation on the surfaces.

Pitch-based activated carbon fibers were prepared for application to methane storage. Chemical activation was accomplished by treatment with potassium hydroxide and heat, leading to increased specific surface area and micropore volume. Structural properties and morphology were evaluated by X-ray diffraction and scanning electron microscopy, respectively. Textural properties and microporosity were determined from N2 /77 K adsorption–desorption isotherms using the Brunauer–Emmett–Teller equation and the Horvath–Kawazoe method. The methane storage capacity is influenced by activation time. This is attributed to the creation of a narrow distribution of micropores, which is a factor closely related to the methane storage capacity. This indicates that the methane storage behavior depends on the pore volume. Although a large pore volume is desirable for methane storage, the size of the pores in the activated carbon fibers that facilitate the activation process is also a significant factor.

The effect of the back contact electrode in nanoparticle-ink-based CIGSSe solar cells was investigated using different glass substrates with either a fluorine-doped SnO2 (FTO) conducting layer or a molybdenum (Mo) conducting layer. The morphologies, crystal structures, and compositional distributions of the Cu(In x Ga1– x )(S y Se1– y )2(CIGSSe) films are very similar in spite of the different back contact materials. The observed performances of the solar cell device, however, are somewhat different. The device that was fabricated on the FTO back contact substrate revealed a lower open-circuit voltage ( V oc) and fill factor (FF) than the Mo back contact substrate, resulting in lower solar cell efficiencies (6.5% for FTO and 7.4% for Mo). The differences between the behaviors are attributed to the interfacial properties between the CIGSSe film and the back contact electrode.

A new simple colorimetric sensor 1 based on amide-pyrene moiety was designed and synthesized for cyanide (CN -) in aqueous solution. The sensor 1 showed high selectivity toward CN −, which induces an immediate color change from colorless to yellow for cyanide over other anions. Moreover, the sensor 1 could be used efficiently in a wide pH range (7–10) with no interference from other anions. The sensing of CN − was found to be reversible with a proper reagent such as HCl. Additionally, the sensing mechanism for CN − was theoretically supported by density functional theory and time-dependent density functional theory calculations. Therefore, sensor 1 can serve as a practical chemosensor for cyanide in aqueous solution.

Ball-milled and chemically activated pitch-based carbon fibers (PCF) were prepared for use as electrode materials. Ball milling altered the structure of PCF from fibers to micro-sized particles with loss of porosity. In contrast, chemical activation using KOH facilitated the development of pore structures. The supercapacitive behavior of treated PCF was assessed using cyclic voltammetry and galvanostatic charge/discharge experiments in 6 M KOH electrolytic solution. BAPCF900, the sample subjected to combined ball milling and chemical treatment, activated at 900 °C, exhibited a specific capacitance of about 80 F/g at a current density of 0.2 A/g; this good capacitance is attributed to a specific surface area of 803 m2/g and a total pore volume of 0.352 cm3/g, and is related to the appropriate pore structure for electrode application, comprising mesopores and micropores.

A julolidine–nitroaniline conjugate as a new simple colorimetric chemosensor 1 for the detection of both F− and CN − has been developed. This sensor could simultaneously detect two biologically important anions (F− and CN −) through colorimetric methods over most other competitive anions. It exhibited a distinct color change from yellow to orange upon addition of F− through deprotonation process. In addition, the sensor 1 displayed an obvious color change from yellow to colorless upon binding with CN − through a nucleophilic addition mechanism. Thus, this sensor exhibits a new method to simultaneously assay F− and CN − with different color change in the same solvent environment.

Coordination polymers (CPs) and metal–organic frameworks (MOFs) continually gain much attention due to their interesting structures and remarkable applications to a wide range of fields. According to the very recent IUPAC recommendations for the terminology, CPs are coordination compounds with repeating coordination entities extending in 1, 2, or 3 dimensions, and MOFs are coordination networks with organic ligands containing potential voids. IUPAC also recommended the use of the term “coordination networks” to indicate (i) coordination compounds extending, through repeating coordination entities, in 1 dimension, but with cross-links between two or more individual chains, loops, or spiro-links, or (ii) coordination compounds extending through repeating coordination entities in 2 or 3 dimensions. For the successful preparation of such polymeric species, the choice or design of proper linking ligands is essential, and those possessing either pyridyl or carboxylate terminals are typically employed. Several d–f coordination polymers, which contain both dand f-block metals as nodes in their frameworks, were recently constructed from asymmetric linking ligands possessing pyridyl–carboxylate or pyridyl–imidazole terminals. We recently launched a research program that involves the synthesis of novel pyridyl–carboxylate-type linking ligands and their CPs possessing d, f, or d–f metals, and a few linking ligands and their CPs have been prepared. In particular, we became interested in the pyridyl–carboxylate-type ligands containing an amide (–C(O)–NH–) fragment, which might be utilized further for the so-called postsynthetic modification of CPs and MOFs. In this context, our group recently prepared two ligands of this type (HL and HL' in Chart 1), both of which contain a 3-pyridyl and a carboxylate terminals. The ligand HL was employed to prepare a 2D copper coordination polymer with a layer framework, {[CuL2(H2O)]·2H2O}∞. In addition, the ligand HL' was utilized to construct cadmium and nickel coordination polymers: {[Cd(L')2](H2O)}∞ (a 2D layer) and {[Ni(L')2(H2O)2](H2O)}∞ (a 1D double-chain). In order to further examine the linking capability of the ligand HL, we attempted to construct new coordination polymers with it. We herein report the preparation, structure, and thermal behavior of a 2D zinc coordination polymer, [ZnCl(L)]∞. Experimental

Cu2ZnSnSe4 (CZTSe) thin films were synthesized on transparent conducting oxide glass substrates via a simple, non-toxic, and low-cost process using a precursor solution paste. A three-step heating process (oxidation, sulfurization, and selenization) was employed to synthesize a CZTSe thin film as an absorber layer for use in thin-film solar cells. In particular, we focused on the effects of sulfurization conditions on CZTSe film formation. We found that sulfurization at 400 °C involves the formation of secondary phases such as CuSe2 and Cu2SnSe3, but they gradually disappeared when the temperature was increased. The formed CZTSe thin films showed homogenous and good crystallinity with grain sizes of approximately 600 nm. A solar cell device was tentatively fabricated and showed a power conversion efficiency of 2.2% on an active area of 0.44 cm 2 with an open circuit voltage of 365 mV, a short current density of 20.6 mA/cm 2 , and a fill factor of 28.7%.

In this study, carbon aerogel (CA) was synthesized using a soft-template method, and the optimum conditions for the adsorption of carbon dioxide (CO2) by the carbon aerogel were evaluated by controlling the activation temperature. KOH was used as the activation agent at a KOH/CA activation ratio of 4:1. Three types of activated CAs were synthesized at activation temperatures of 800 °C (CA-K-800), 900 °C (CA-K-900), and 1000 °C (CA-K-1000), and their surface and pore characteristics along with the CO2 adsorption characteristics were examined. The results showed that with the increase in activation temperature from 800 to 900 °C, the total pore volume and specific surface area sharply increased from 1.2165 to 1.2500 cm 3 /g and 1281 to 1526 m 2 /g, respectively. However, the values for both these parameters decreased at temperatures above 1000 °C. The best CO2 adsorption capacity of 10.9 wt % was obtained for the CA-K-900 sample at 298 K and 1 bar. This result highlights the importance of the structural and textural characteristics of the carbon aerogel, prepared at different activation temperatures on CO2 adsorption behaviors.

Polyacrylonitrile (PAN)-based ultrafine fibers and carbon fibers were produced by wet-spinning, and the crystal sizes and thermal and mechanical properties of the fibers were investigated. Scanning electron microscopy revealed that the superfine fibrils in the surfaces of the PAN/polyvinyl acetate (PVA) blend fibers increased slightly with increasing PAN content before removal of the PVA. Differential scanning calorimetry indicated that the PAN and PVA in the blend fibers do not mix and, therefore, each maintains their inherent thermal characteristics. The crystal sizes of the blend fibers prepared by removing PVA with water increased at 5 wt % water. The extent of the reaction of the PAN carbon fibers, as calculated from the FT-IR spectra, is maximized at the stepwise temperature of 230 o C, and the density increased significantly above this temperature. The carbon fibers had relatively good mechanical properties, as shown by their tensile strength and modulus values of 2396 MPa and 213 GPa, respectively.

Protein kinases (PKs) are an important source of drug targets, especially in oncology. With 500 or more kinases in the human genome and only few kinase inhibitors approved, kinase inhibitor discovery is becoming more and more valuable. Because the discovery of kinase inhibitors with an increased selectivity is an important therapeutic concept, many researchers have been trying to address this issue with various methodologies. Although many attempts to predict the activity and selectivity of kinase inhibitors have been made, the issue of selectivity has not yet been resolved. Here, we studied kinase selectivity by generating predictive models and analyzing their descriptors by using kinase-profiling data. The 5-fold cross-validation accuracies for the 51 models were between 72.4% and 93.7% and the ROC values for all the 51 models were over 0.7. The phylogenetic tree based on the descriptor distance is quite different from that generated on the basis of sequence alignment.

Chitosan non-woven fabrics were acetylated to improve their antimicrobial properties. The active chlorine content, antimicrobial properties, storage stability, and surface properties of acetylated chitosan non-woven fabrics were investigated. The active chlorine content of the fabrics increased upon reduction of the degree of the acetylation or increase in sodium hypochlorite concentration. Acetylated chitosan non-woven fabrics showed powerful antimicrobial activity by efficiently killing Escherichia coli and forming a growth inhibition zone for Staphylococcus aureus. Furthermore, scanning electron microscopy observations demonstrated that the acetylated chitosan non-woven fabrics were not damaged in sodium hypochlorite solution.

In this work, manganese dioxide (Mn3O4)/carbon black (CB) composites (Mn-CBs) were prepared by an in situ coating method as electrical fillers and the effect of the Mn-CBs on the electrical performance of activated carbon (AC)-based electrodes was investigated. Structural features of Mn-CBs produced via in situ coating using a KMnO4 solution were confirmed by XRD and TEM images. The electrical performances, including cv curves, charge-discharge behaviors, and specific capacitance of the ACs/Mn-CBs, were determined by cyclic voltammograms. It was found that the composites of Mn3O4 and CBs were successfully formed by in situ coating method. ACs/Mn-CBs showed higher electrical performance than that of AC electrodes fabricated with conventional CBs due to the pesudocapacitance reaction of manganese oxides in the aqueous electrolyte. Consequently, it is anticipated that the incorporation of Mn3O4 into CBs could facilitate the utilization of CBs as electrical filler, leading to enhanced electrochemical performance of AC electrodes for supercapacitors.

The thermodynamic parameters for the intercalative interaction of structurally related well known intercalators, 9-aminoacridine (9AA) and proflavine (PF) were determined by means of fluorescence quenching study. The fluorescence intensity of 9AA decreased upon intercalation to DNA, poly[d(A-T)2] and poly[d(G-C)2]. A van’t Hoff plot was constructed from the temperature-dependence of slope of the ratio of the fluorophore in the absence and presence of a quencher molecule with respect to the quencher concentration, which is known as a Stern-Volmer plot. Consequently, the thermodynamic parameters, enthalpy and entropy change, for complex formation was calculated from the slope and y-intercept of the van’t Hoff plot. The detailed thermodynamic profile has been elucidated the exothermic nature of complex formation. The complex formation of 9AA with DNA, poly[d(A-T)2] and poly[d(G-C)2] was energetically favorable with a similar negative Gibb’s free energy. On the other hand, the entropy change appeared to be unfavorable for 9AA-poly[d(G-C)2] complex formation, which was in contrast to that observed with native DNA and poly[d(A-T)2] cases. The equilibrium constant for the intercalation of PF to poly[d(G-C)2] was larger than that to DNA, and was the largest among sets tested despite the most unfavorable entropy change, which was compensated for by the largest favorable enthalpy. The favorable hydrogen bond contribution to the formation of the complexes was revealed from the analyzed thermodynamic data.

Reduced graphene oxide, Electrochemical impedance spectroscopy, Hairpin DNARecent efforts toward the development of electrochemicalbiosensors have emphasized the incorporation of nano-materials, such as carbon nanotubes, metal nanoparticles,and graphene into the electrode. This incorporation, parti-cularly of graphene, significantly improves the sensor sensi-tivity and selectivity.

A novel bioabsorbable suture material, poly(glycolide-caprolactone) (PGLCL) monofilament, was prepared by spinning of the PGLCL copolymer. The physical properties, strength retention, biocompatibility, and organism resolvability of the PGLCL monofilament were investigated. The results showed that the knot pull strength of the monofilament was higher than that stated in European Pharmacopoeia. The in vivo retention strength following implantation was 64%, 23%, 7%, and 0% after one, two, three, and four weeks, respectively. Mortality, clinical signs, validation, and sterility tests indicated that all items had passed. Organism resolvability tests showed that the PGLCL monofilament, as a suture, was absorbed within 91 days.

E-mail: sjpark@inha.ac.krReceived April 5, 2012, Accepted August 23, 2012Nanoporous carbons with a high specific surface area were prepared directly from thermoplastic acrylic resinas carbon precursor and MgO powder as template by carbonization over the temperature range, 500-1000 °C.The effect of the carbonization temperature on the pore structure and CO

Aluminum oxide () nanofibers were treated thermally under an ammonia () gas stream balanced by nitrogen to form a thin aluminum nitride (AlN) layer on the nanofibers, resulting in the enhancement of thermal conductivity of /epoxy nanocomposites. The micro-structural and morphological properties of the -assisted thermally-treated nanofibers were characterized by X-ray diffraction (XRD) and atomic force microscopy (AEM), respectively. The surface characteristics and pore structures were observed by X-ray photoelectron spectroscopy (XPS), Zeta-potential and /77 K isothermal adsorptions. From the results, the formation of AlN on nanofibers was confirmed by XRD and XPS. The thermal conductivity (TC) of the modified nanofibers/epoxy composites increased with increasing treated temperatures. On the other hand, the severely treated /epoxy composites showed a decrease in TC, resulting from a decrease in the probability of heat-transfer networks between the filler and matrix in this system due to the aggregation of nanofiber fillers.

nanoparticles, Epoxidized castor oil, Thermal stabilities, Fracture toughness IntroductionEpoxy resins are used widely in non-structural (coatings,flooring, and painting) and structural (casting, tooling, andmatrices for advanced composites) applications owing totheir outstanding mechanical performance, good chemicaland electrical resistance, and superior dimensional stability.

E-mail: sjpark@inha.ac.krReceived November 26, 2011, Accepted February 3, 2012In this work, we prepared activated multi-walled carbon nanotubes/polyacrylonitrile (A-MWCNTs/C)composites by film casting and activation method. Electrochemical properties of the composites wereinvestigated in terms of serving as MWCNTs-based electrode materials for electric double layer capacitors(EDLCs). As a result, the A-MWCNTs/C composites had much higher BET specific surface area, and porevolume, and lower volume ratio of micropores than those of pristine MWCNTs/PAN ones. Furthermore, somefunctional groups were added on the surface of the A-MWCNTs/C composites. The specific capacitance of theA-MWCNTs/C composites was more than 4.5 times that of the pristine ones at 0.1 V discharging voltageowing to the changes of the structure and surface characteristics of the MWCNTs by activation process.Key Words : Multi-walled carbon nanotubes, Polyacrylonitrile, Composites, Activation, ElectrochemicalpropertiesIntroductionIn recent years, electrochemical capacitors have beenstudied in terms of their practical application as high powerdevices, since they have higher power density than batteriesand higher energy density than ordinary capacitors, as wellas a long cycle life. Electrochemical capacitors can bedivided into two types according to the energy storage mech-anism: electrochemical double-layer capacitors (EDLCs)and redox supercapacitors. EDLCs are being considered fora variety of applications such as the capacitive deionizationof water and as pulse power sources for cellular devices.

Thrombin is a serine protease that catalyzes the conversion of soluble fibrinogen to insoluble fibrin, and thus induces physiological and pathological blood coagulation. Therefore, it is important to detect thrombin in blood serum for purposes of diagnosis. To achieve this goal, it has been suggested that a 15-mer aptamer strongly binds with thrombin to form a G-quartet structure of the aptamer. Generally, 5'-end thiol-functionalized aptamer has been used as an anti-thrombin binder. Herein, we evaluate the possibility of utilizing a 3'-SH aptasensor for thrombin detection using SPR spectroscopy, and compare the enhancement of the electrochemical signal of the thrombin-aptamer bound on a porous gold substrate. Although the two aptamers have similar configurations, in SPR analysis, the 3'-SH aptamer was a effective aptasensor as well as 5'-SH aptamer. Results from electrochemical analysis showed that the porous gold substrate acted as a good substrate for an aptasensor and demonstrated 5-fold enhancement of current change, as compared to gold thin film.

In this work, the amine grafting treated activated carbons were studied for carbon dioxide adsorbent. The surfaces of activated carbon were functionalized by 3-chloropropyltrimethoxysilane, which was subsequently grafted with amine compounds tris-(2-aminoethyl)amine and tri-ethylenetetramine and subjected to comparison. The surface functional groups of the amine grafted activated carbons were characterized using XPS. The textural properties of the amine grafted activated carbons were analyzed by N2/77 K isotherms. Carbon dioxide adsorption behaviors of the amine grafted activated carbons were examined via the amounts of carbon dioxide adsorption at 298 K and 1.0 atm. From the results, tris-(2-aminoethyl)amine grafted activated carbons showed 43.8 cm 3 /g of carbon dioxide adsorption while non-treated activated carbons and triethylenetetramine grafted activated carbons showed less carbon dioxide adsorption. These results were thought to be due to the presence of isolated amine groups in the amine compounds. Tris-(2-aminoethyl)amine grafted activated carbons have basic features that result in the enhancement of adsorption capacity of the carbon dioxide molecules, which have an acidic feature.

In this study, mercury vapor adsorption behaviors for some kinds of porous materials having various pore structures were investigated. The specific surface area and pore structures were studied by BET and D-R plot methods from /77 K adsorption isotherms. It was found that the micropore materials (activated carbons, ACs) showed the highest mercury adsorption capacity. In a comparative study of mesoporous materials (SBA-15 and MCM-41), the adsorption capacity of the SBA-15 was higher than that of MCM-41. From the pore structure analysis, it was found that SBA-15 has a higher micropore fraction compared to MCM-41. This result indicates that the mercury vapor adsorptions can be determined by two factors. The first factor is the specific surface area of the adsorbent, and the second is the micropore fraction when the specific surface areas of the adsorbent are similar.

Agency for Defense Development, Daejeon 305-600, KoreaReceived October 1, 2011, Accepted March 28, 2011Electroless plating of metallic nickel on carbon fiber surfaces was carried out to control specific electricresistivity of the fibers, and the effects of the nickel content and coating thickness on the electric properties werestudied. The structural and surface properties of the carbon fibers were characterized using X-ray diffraction(XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The specificresistivity of the fibers was measured using a four-point probe testing method. From the XPS results, theoxygen and Ni atomic ratio of the fibers was greatly enhanced as the plating time increased. Additionally, itwas observed that the specific electric resistivity decreased considerably in the presence of metallic nickelparticles and with the formation of nickel layers on carbon fibers.Key Words : Metal plating, Specific resistivity, Carbon fibersIntroductionWith the rapid development of the electronics industry,especially as it pertains to personal computers and mobilesphones, the problem of electromagnetic interference (EMI)is increasing. One effective technique to solve the EMI pro-blem is to increase the electrical conductivity (or decreasespecific electric resistivity) of the plastic cages of electricdevices.

Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon 305-764, KoreaReceived September 29, 2010, Accepted February 1, 2011In the present study, the approach of high accuracy mass measurements for phospholipid identifications wasevaluated using a 7 T ESI-FTMS/linear ion trap MS/MS. Experiments were carried out for porcine brain,bovine liver, and soybean total lipid extracts in both positive and negative ion modes. In total, 59, 55, and 18phospholipid species were characterized in the positive ion mode for porcine brain, bovine liver, and soybeanlipid extracts, respectively. Assigned lipid classes were PC, PE, PEt, PS, and SM. In the negative ion mode,PG, PS, PA, PE, and PI classes were observed. In the negative ion mode, for porcine brain, bovine liver, andsoybean lipid extracts, 28, 34, and 29 species were characterized, respectively. Comparison of our results withthose obtained by other groups using derivatization-LC-APCI MS and nano-RP-LC-MS/MS showed that ourapproach can characterize PC species as effectively as those methods could. In conclusion, we demonstratedthat high accuracy mass measurements of total lipid extracts using a high resolution FTMS, particularly, 7TFTMS, plus ion-trap MS/MS are very useful in profiling lipid compositions in biological samples. Abbreviation: PA, phosphatidic acid; PC, phosphatidylcholine; PE, phosphatidylethanolamine; PEt, phosphatid-ylethanol; PG, phosphatidylglycerol; PI, phosphatidylinositol; PS, phosphtidylserine; SM, sphingomyelinKey Words : Lipids, Fourier transform ion cyclotron resonance mass spectrometer, Linear ion trap, Accuratemass measurements, Lipid databaseIntroductionFourier transform-ion cyclotron resonance mass spectro-metry (FT-ICR MS or FTMS) offers an ultrahigh massresolution and extraordinary mass accuracy, which has thusled to its wide applications in protein/peptide analysis.

In this work, the effects of different surface functional groups on the elemental mercury adsorption of porous carbons modified by chemical treatments were investigated. The surface properties of the treated carbons were observed by Boehm’s titration and X-ray photoelectron spectroscopy (XPS). It was found that the textural properties, including specific surface area and pore structures, slightly decreased after the treatments, while the oxygen content of the ACs was predominantly enhanced. Elemental mercury adsorption behaviors of the acidtreated ACs were found to be four or three times better than those of non-treated ACs or base-treated ACs, respectively. This result indicates that the different compositions of surface functional groups can lead to the high elemental mercury adsorption capacity of the ACs. In case of the acid-treated ACs, the RC=O/RC-O and RCOOH/RC-O showed higher values than those of other samples, indicating that there is a considerable relationship between mercury adsorption and surface functional groups on the ACs.

In this study, conjugate fibers were prepared from 1,4-cyclohexanedimethanol-modified polyethylene terephthalate (PET) resin using side by side conjugate spinning, sea-island type conjugate spinning, and split type conjugate spinning methods, and the properties of the conjugate fibers were investigated via several techniques. When viscosity increased, the tenacity of side by side conjugate fibers was increased, whereas elongation decreased. The sea-island conjugate fibers showed lower weight loss and surface color difference (K/S) values relative to that of regular PET fibers at the same conditions. The SEM results indicate that orange type spilt readily produced at a temperature range of 120 - 140.

Colloidal silver nanoparticles (AgNPs) have been commercialized as the typically stabilized form via the addition of a variety of surfactants or polymers. Herein, to examine the effects of stabilizing AgNPs in suspension, we modified the surface of bare AgNPs with four type of surfactants (NaDDBS, SDS, TW80, CTAB) and polymers (PVP, PAA, PAH, CMC). The modified AgNPs was applied to compare suspension stability and nanotoxicity test using Escherichia coli (E. coli) as a model organism. Modification of AgNPs surface using chemical stabilizer may be not related with molecular weight, but chemical structure such as ionic state and functional group of stabilizer. In this study, it is noteworthy that AgNPs modified with a cationic stabilizer (CTAB, PAH) were importantly toxic to E. coli, rather than anionic stabilizers (NaDDBS, SDS). Comparing similar anionic stabilizer, i.e., NaDDBS and SDS, the result showed that lipophilicity of chemical structure can affect on E. coli, because NaDDBS, which contains a lipophilic benzene ring, accelerated the cytotoxicity of AgNPs. Interestingly, none of the stabilizers tested, including biocompatible nonionic stabilizers (i.e., TW80 and cellulose) caused a reduction in AgNP toxicity. This showed that toxicity of AgNPs cannot be reduced using stabilizers.

In this work, poly(methyl methacrylate) (PMMA) was grafted onto amine treated graphite nanosheets (NH2-GNs) and the surface characteristics and physical properties of the NH2-GNs-g-PMMA films were investigated. The graft reaction of NH2-GNs and PMMA was confirmed from the shift of the N1S peak, including amine oxygen and amide oxygen, by X-ray photoelectron spectroscopy (XPS). The surface characteristics of the NH2-GNs-g-PMMA films were measured as a function of the NH2-GN content using the contact angle method. It was revealed that the specific component of the surface free energy (γs) of the films was slightly increased as the NH2-GN content increased. Also, the thermal and mechanical properties of the NH2-GNs-g-PMMA films were enhanced with the addition of NH2-GNs. This can be attributed to the chemical bonding caused by the graft reaction between the NH2-GNs and the PMMA matrix.

Polypropylene (PP) non-woven fabrics have been widely used as filtration membranes in wastewater purification with industrial applications due to their low cost, good mechanical strength, and high thermal and chemical stability. The membrane fouling behavior depends strongly on the physical and mechanical properties of the membrane, including pore size, porosity, morphology, and hydrophilicity. 1-5 In general, PP non-woven fabrics have poor hydrophilicity; this has limited their application in the biomedical field. It is therefore necessary to develop PP non-woven fabrics with improved surface hydrophilicity to increase the scope of their use. Plasma treatment, an environmentally friendly alternative to traditional chemical activation, only changes the uppermost atomic layers of a membrane surface without affecting the bulk properties of the polymer. 6-12 To perform as a functional membrane, the PP non-woven fabrics must have a porosity of ≤ 1 μm, remove > 95% of impurities, and possess a morphology for surface filtration. However, the porosity of traditional membranes prepared from non-woven fabrics is ≥ 5 μm and exhibit a depth filtration mechanism. The fibers prepared by melt-blown spinning have usually 8-15 μm porosity, which is reduced to 1-2 μm after heat treatment. 13-15 In this study, PP nonwoven fabrics were prepared by a melt-blown spinning process. To control the porosity and impart hydrophilicity, the PP non-woven fabrics were treated with heat and plasma processes. The mechanical properties, contact angle, water flux, average pore size, average pore pressure, and particle removal efficiency of these PP nonwoven fabrics were investigated. PP non-woven fabrics were prepared by melt-blown spinning. However, the resulting PP non-woven fabrics have a large pore size and low hydrophilicity, making them unsuitable for use as filtration membranes. The PP non-woven fabrics were subsequently treated with heat and plasma processes to control porosity and impart hydrophilicity. 16,17 Figure 1 shows SEM micrographs of the PP non-woven fabrics before and after heat treatment. Figure 1 shows the increase in the fiber sizes of the PP non-woven fabrics from 2-7 μm to 4-11 μm before and after the heat treatment. This was due to the densification effect. 18,19

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2005-2001287), the Ministry of Knowledge Economy in Korea (09MC3310, Programmable Bio-CMOS Field Effect Transistors), the Korea Research Foundation Grant funded by Korea Government (MOEHRD, Basic Research Promotion Fund) (KRF-2005-075-C00021), and the Nano/Bio Science & Technology Program (M10536090001- 05N3609-00110) of the Ministry of Education, Science and Technology (MEST), Republic of Korea.

‡In this study, the effects of the various parameters of spinning and drawing processes on the properties of polyester full drawn yarn (FDY) prepared by steam processing during high-speed spinning were investigated using several techniques. The wet shrinkage ratio of the FDY was able to be manipulated by controlling the temperature and draw ratio. The FDY made using the steam high speed spinning technique exhibited identical properties (such as tenacity, elongation, and wet shrinkage ratio) to that of regular FDY, made using the spin-draw process. FDY prepared using the steam process during high-speed spinning showed excellent dyeability. The dye pick-up of the polyester yarn spun at high-speed spinning was found to be improved when dyed under an atmospheric pressure of 100 o C. This result was the same as regular FDY dyed under a high pressure of 130 o C.

In this study, the optimal preparation conditions in the polymerization process of poly(ethylene terephthalate) (PET) were studied in detail. As a result, the dispersibility of TiO 2 was significantly improved by the addition of dispersant and steric hinderance additives into TiO 2 /ethylene glycol (EG) slurry during the esterification step. The addition sequence of TiO 2 /EG slurry and stirring also affected the dispersibility of TiO 2 . The SEM results showed that some TiO 2 particles were agglomerated in the PET matrix. The full dull (FD) PET chip and fiber were prepared according to the optimal preparation conditions. The FD PET fiber exhibited a better dispersibility than that of the FD PET chip.