Influence of MgO template on carbon dioxide adsorption of cation exchange resin-based nanoporous carbon

Meng, Long-Yue,Park, Soo-Jin Elsevier 2012 JOURNAL OF COLLOID AND INTERFACE SCIENCE - Vol.366 No.1

<P><B>Abstract</B></P> <P>In this work, porous carbons with well-developed pore structures were directly prepared from a weak acid cation exchange resin (CER) by the carbonization of a mixture with Mg acetate in different ratios. The effect of the Mg acetate-to-CER ratio on the pore structure and CO<SUB>2</SUB> adsorption capacities of the obtained porous carbons was studied. The textural properties and morphologies of the porous carbons were analyzed <I>via</I> N<SUB>2</SUB>/77K adsorption/desorption isotherms, SEM, and TEM, respectively. The CO<SUB>2</SUB> adsorption capacities of the prepared porous carbons were measured at 298K and 1bar and 30bar. By dissolving the MgO template, the porous carbons exhibited high specific surface areas (326–1276m<SUP>2</SUP>/g) and high pore volumes (0.258–0.687cm<SUP>3</SUP>/g). The CO<SUB>2</SUB> adsorption capacities of the porous carbons were enhanced to 164.4mg/g at 1bar and 1045mg/g at 30bar by increasing the Mg acetate-to-CER ratio. This result indicates that CER was one of the carbon precursors to producing the porous structure, as well as for improving the CO<SUB>2</SUB> adsorption capacities of the carbon species.</P> <P><B>Graphical abstract</B></P> <P>The porous carbons were directly prepared from a weak acid cation exchange resin by the carbonization of a mixture with Mg acetate.</P> <P>[DISPLAY OMISSION]</P> <P><B>Highlights</B></P> <P>► The nanoporous carbons were directly prepared from a cation exchange resin and Mg acetate. ► The microstructure of the obtained porous carbons was significantly affected by the Mg acetate-to-resin ratio. ► By dissolving the MgO template, the nanoporous carbons exhibited high specific surface areas and pore volume. ► The CO<SUB>2</SUB> adsorption capacities of the nanoporous carbons were enhanced by increasing the Mg acetate-to-resin ratio.</P>

Effect of nano-silica spheres template on CO2 capture of exchange resin-based nanoporous carbons.

Meng, Long-Yue,Park, Soo-Jin American Scientific Publishers 2013 Journal of Nanoscience and Nanotechnology Vol.13 No.1

<P>In this work, a nanoporous carbon-based adsorbent with a higher specific surface area was directly prepared from polystyrene-based cation exchange resin (PCER) by carbonization of a mixture of nano-silica spheres. The silica/PCER composites were carbonized at 1173 K with different silica/PCER ratios. The effects of nano-silica spheres content on the pore structures of nanoporous carbons were investigated by N2 full isotherms. The CO2 capture capacity was measured by CO2 isothermal adsorption at 298 K and 1 bar. From the results, it was found that the nano-silica spheres/PCER ratio had a major influence on the CO2 capture capacity and the textural properties of the prepared nanoporous carbons. The specific surface area and total pore volume, as well as the pore size of the nanoporous carbons increased with increasing silica/PCER ratio.</P>

Rice Husk as a Food Carrier Forselective Enrichment of Tea Catechins

Meng Shi,Long-Yue Huang,Rong-Rong Han,Qiao Lin, Jian-Hui Ye,Yue-Rong Liang,Jian-Hui Ye 한국차학회 2015 한국차학회지 Vol.- No.S

The potentials of rice husk, oat bran and soya milk cake as food carriers for tea catechins(TC) were studied. Adsorption properties, contact time and temperature effects and the concentration of tea catechins, as well as digestive stability were investigated in this paper. The result showed that the adsorption capacity of rice husk for tea catechins was 32.04 mgg-1 which was 28.1 % and 17.7 % higher than those of oat bran and soya milk cake and no obvious adsorbability to caffeine was observed for these materials. The selectivity coefficient K of EGCg to TC for rice husk was 4.44 in comparison with 1.87 and 1.96 of oat husk and soya milk cake. This guarantees rice husk a selective food carrier to tea catechins with enrichment of EGCg. Also, 20 min contact time and tea extract concentration above 1.75 g L-1 are recommended in order to obtain a high loading amount of tea catechins onto rice husk, and low temperature is favorable for the adsorption processof tea catechins onto rice husk. Digestive study showed that combination of tea catechins with rice husk was propitious to increase the digestive stability of tea catechins in simulated gastrointestinal fluids. Thus, rice husk is a promising food carrier for tea catechins. Further studies would be focusing on the identification and separation of the functional constituent of rice husk and its interaction mechanism with tea catechins.

Investigation of Narrow Pore Size Distribution on Carbon Dioxide Capture of Nanoporous Carbons

Meng, Long-Yue,Park, Soo-Jin Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

Nanoporous carbons with a high specific surface area were prepared directly from thermoplastic acrylic resin as carbon precursor and MgO powder as template by carbonization over the temperature range, $500-1000^{\circ}C$. The effect of the carbonization temperature on the pore structure and $CO_2$ adsorption capacity of the obtained porous carbon was examined. The textural properties and morphology of the porous carbon materials were analyzed by $N_2/-196^{\circ}C$ and $CO_2/0^{\circ}C$ adsorption/desorption isotherms, SEM and TEM. The $CO_2$ adsorption capacity of the prepared porous carbon was measured at $25^{\circ}C$ and 1 bar and 30 bar. The specific surface area increased from 237 to $1251m^2/g$, and the total pore volumes increased from 0.242 to $0.763cm^3/g$ with increasing the carbonization temperature. The carbonization temperature acts mainly by generating large narrow micropores and mesopores with an average pore size dependent on the level of carbonization of the MgO-templated nanoporous carbons. The results showed that the MgO-templated nanoporous carbons at $900^{\circ}C$ exhibited the best $CO_2$ adsorption value of 194 mg/g at 1 bar.

Preparation and Characterization of Reduced Graphene Nanosheets via Pre-exfoliation of Graphite Flakes

Meng, Long-Yue,Park, Soo-Jin Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.1

In this work, the reduced graphene nanosheets were synthesized from pre-exfoliated graphite flakes. The pristine graphite flakes were firstly pre-exfoliated to graphite nanoplatelets in the presence of acetic acid. The obtained graphite nanoplatelets were treated by Hummer's method to produce graphite oxide sheets and were finally exfoliated to graphene nanosheets by ultrasonication and reduction processes. The prepared graphene nanosheets were studied by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), atomic force microscopy (AFM), and transmission electron microscopy (TEM). From the results, it was found that the preexfoliation process showed significant influence on preparation of graphite oxide sheets and graphene nanosheets. The prepared graphene nanosheets were applied to the preparation of conductive materials, which yielded a greatly improved electrical resistance of $200{\Omega}/sq$.

Research and Implementation of a Vertical Search Engine in the Financial Domain

Yue Hou-guang,ZhangLing,Meng Fan-jun,Songhong-hao 보안공학연구지원센터 2014 International Journal of u- and e- Service, Scienc Vol.7 No.5

The exponential growth of the data on the web makes it difficult for web users to locate and obtain the interesting information. The general web search engines, such as Google, Baidu, reduce the degree of difficulty to some extent. The rise of vertical search engine provides a promising approach to address the big challenge. A Chinese vertical search engine is urgently needed to provide professional financial information retrieval service for related financial institutions and government agencies. Therefore, in this paper we investigate, design and implement a vertical search engine in the financial domain. Based onNutch plug-in mechanism, we provide and implement the details of a vertical search engine in the financial domain, especially in the finance domain focused crawler. Experimental results show that, the finance domain focused crawler based on Nutch plug-in mechanism has good performance and can satisfy practical requirements of medium search application, and the system runs well.

Superhydrophobic carbon-based materials: a review of synthesis, structure, and applications

Meng, Long-Yue,Park, Soo-Jin 한국탄소학회 2014 Carbon Letters Vol.15 No.2

Materials with appropriate surface roughness and low surface energy can form superhy-drophobic surfaces, displaying water contact angles greater than 150º. Superhydrophobic carbon-based materials are particularly interesting due to their exceptional physicochemical properties. This review discusses the various techniques used to produce superhydrophobic carbon-based materials such as carbon fibers,carbon nanotubes, graphene, amorphous car-bons, etc. Recent advances in emerging fieldssuch as energy, environmental remediation, and thermal management in relation to these materials are also discussed.

Bioassay-guided Isolation of a Novel Protein with Antitumor Activity from Trachyrhamphus serratus (Syngnathidae)

Meng Yue Wang,Sun Xing Qin,Fen He,Xiaobo Li 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.6

A novel protein with antitumor activity, Hailongin, was purified from the aqueous extract of the whole body of Trachyrhamphus serratus, which is commonly used in traditional Chinese medicine, by bioassay-guided fractionation. Hailongin exhibited strong inhibition of proliferation of the tested human cell lines, such as A549, HeLa, LoVo and CCRF-CEM. The IC_50 values of Hailongin ranged from 5.4 to 25.7 μg/mL. An in vivo study showed that the growth of implanted S-180 solid tumors in mice was significantly inhibited by Hailongin treatment, while the immunological function of the tumor-bearing mice was enhanced. The molecular weight and the isoelectric point of Hailongin were 57.074 kDa (by MALDI-TOF-MS) and 6.2 (by isoelectric focusing-polyacrylamide gel electrophoresis), respectively. Seventeen amino acids were identified in Hailongin. The acidic amino acids accounted for the majority of Hailongin’s amino acid composition. The N-terminal amino acid sequence of Hailongin was determined to be IVPYSHNAGNKGLTQMR and showed no significant homology with known proteins.

Preparation and photocatalytic activity of composite metal oxides derived from Salen-Cu(II) intercalated layered double hydroxides

Yue Meng,Shengjie Xia,Guoxiang Pan,Jilong Xue,Junhui Jiang,Zheming Ni 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.8

Copper(II) Schiff-base Complexes (Salen-Cu(II)) intercalated zinc-chromium layered double hydroxides (ZnSBCuCr-LDHs) were successfully prepared via coprecipitation. Then, a novel photocatalytic material Zn-Cu-Cr composite oxides (ZnSBCuCr-MO) was prepared after calcination at 500 oC with ZnSBCuCr-LDHs as precursor. The structure and properties of the materials were thoroughly characterized by powder X-ray diffraction (XRD), inductively coupled plasma atomic emission spectrometry (ICP-AES), ultraviolet visible diffuse reflectance spectroscopy (UV-Vis DRS), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activities of the materials were investigated by photodegradation of a cationic dye Rhodamin B (RhB), which was hard to adsorb by LDHs. The effects of the photocatalyst dosage, the initial pH and temperature of RhB solution on the photocatalytic efficiency were discussed. The results showed that ZnSBCuCr-MO displayed higher photocatalytic activity for RhB than calcined ZnCr-LDHs (ZnCr-MO) and calcined ZnCuCr-LDHs (ZnCuCr-MO). Meanwhile, ZnSBCuCr- MO exhibited better stability and reusability. In addition, the possible photocatalytic mechanism and degradation pathway for RhB were studied through density functional theory (DFT) calculation of the RhB molecule, UV-vis absorption variation and LC-MS analyses of the RhB solution.

Corticotropin-releasing Factor Changes the Phenotype and Function of Dendritic Cells in Mouse Mesenteric Lymph Nodes

( Li Meng ),( Zhang Lu ),( Wang Xiaoteng ),( Hu Yue ),( Lu Bin ),( Meng Lina ),( Chen Zhe ) 대한소화기기능성질환·운동학회 2015 Journal of Neurogastroenterology and Motility (JNM Vol.21 No.4

Background/Aims Dendritic cells (DCs) are a significant contributor to the pathology of numerous chronic inflammatory autoimmune disorders; however, the effects of Corticotropin-releasing factor (CRF) on intestinal DCs are poorly understood. In this study, we investigated the role of CRF in alterations of intestinal dendritic cell phenotype and function. Methods Mouse mesenteric lymph node dendritic cells (MLNDCs) were obtained using magnetic bead sorting. Surface expression of CRF receptor type 1 (CRF-R1) and CRF-R2 was determined by double-labeling immunofluorescence and quantitative polymerase chain reaction (qPCR) and MLNDCs were subsequently exposed to CRF in the presence or absence of CRF-R1 and CRF-R2 antagonists. Expression of surface molecules (MHC-I and MHC-II) and co-stimulatory molecules (CD80 and CD86) was determined by flow cytometric and western blot analyses, and the T cell stimulatory capacity of MLNDCs was evaluated by mixed lymphocyte reaction. Results Immunofluorescent staining and quatitative polymerase chain reaction indicated that both the CRF receptors (CRF-R1 and CRF-2) are expressed on the surface of MLNDCs. Exposure to CRF increased the expression of MHC-II on MLNDCs as well as their capacity to stimulate T cell proliferation. MLNDCs treated with CRF-R1 antagonist exhibited a phenotype characterized by a less activated state and reduced surface expression of MHC-II, and consequently showed reduced capacity to stimulate T cells. In contrast, treatment of MLNDCs with CRF-R2 antagonist yielded an opposite result. Conclusions CRF can alter the phenotype and function of intestinal DCs through direct action on CRF-R1 and CRF-R2, and activation of the CRF-R1 and CRF-R2 pathways yields opposing outcomes.(J Neurogastroenterol Motil 2015;21:571-580)