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Ansan, South Korea

Han Y.-S.,Nanospace Co. | Lee J.-W.,Korea Institute of Ceramic Engineering And Technology | Park S.-M.,Korea Institute of Ceramic Engineering And Technology
Journal of Ceramic Processing Research | Year: 2010

Nanocrystalline TiO2 particles with a mean particle diameter of 5 nm and a positive surface charge were coagulated with delaminated silicate layers to form a heterocoagulated mesoporous nanocomposite. Nitrogen sorption isotherm analysis revealed the TiO2-montmorillonite nanocomposite to have a specific surface area (SBET) and pore volume (Vtot) of 253m2/g and 0.36mL/g, respectively. Water isotherm measurements also showed that the mesoporous nanocomposite has a large water sorption capacity of 0.37 ml/g and large adsorption-desorption hysteresis, which is suitable for self-humidity control materials. Source

Han Y.-S.,Nanospace Co. | Lee S.-H.,Hanyang University | Choi K.H.,Korea Institute of Industrial Technology | Park I.,Korea Institute of Industrial Technology
Journal of Physics and Chemistry of Solids | Year: 2010

Chitosan-montmorillonite nanocomposites were prepared by an ion exchange reaction between water soluble oligomeric chitosan and a Na+-montmorillonite. The chitosan-montmorillonite nanocomposites were rapidly prepared within 1 h due to the high affinity between the chitosan and the montmorillonite clay host. The basal spacings of the composites were in a range of 14.5-19.6 Å depending on the mixing ratio of chitosan to clay. According to the thermogravimetric analysis (TG) and powder X-ray diffraction analysis the thermal stability of chitosan was remarkably improved in the interlayer space due to the strong electrostatic interaction of cationic chitosan molecules with anionic silicate layers. From the antimicrobial activity test it was found that the nanocomposites showed a synergistic effect in the antimicrobial activity against to Escherichia coli and Staphylococcus aureus. © 2009 Elsevier Ltd. All rights reserved. Source

Yang J.-H.,Nanospace Co. | Lee H.-S.,Seil FA Co. | Paek S.-M.,Kyungpook National University | Han Y.-S.,Nanospace Co.
Chemistry Letters | Year: 2011

New layered inorganicinorganic nanohybrids with highly porous structures were prepared by pillaring SiO2Fe2O3 nanoparticles into montmorillonite via exfoliation and reassembly. Gas removal activity of SiO2Fe2O3- pillared clay is much higher than that of active carbon, suggesting that pillaring strategy could be an effective method for removal of various gases. © 2011 The Chemical Society of Japan. Source

Han Y.-S.,Nanospace Co. | Lee S.-Y.,Nanospace Co. | Yang J.-H.,Nanospace Co. | Soo Hwang H.,Korea Institute of Industrial Technology | Park I.,Korea Institute of Industrial Technology
Journal of Physics and Chemistry of Solids | Year: 2010

A representative herbicide, paraquat (PQ; 1,1′-dimethyl-(4,4′-bipyridium) dichloride) was intercalated into montmorillonite by solution and solid state reaction methods. In a typical solution process paraquat aqueous solution was mixed with montmorillonite (Kunipia-F) aqueous suspension, which resulted in a paraquat-montmorillonite layer complex with a basal spacing of 1.3 nm. A paraquat-montmorillonite complex was also easily prepared by solid state reaction method. The mixture of paraquat and Na-montmorillonite was ground under ambient temperature. The basal spacing of the mixture increased to 1.3 nm after grinding for 30 min. In order to achieve the pH dependent releasing of intercalated PQ molecules, the PQ-montmorillonite complex was coated with cellulose acetate phthalate. The polymer modified PQ-montmorillonite complex exhibited a strongly suppressed PQ releasing in the acidic pH domain, while an enhanced PQ releasing at the neutral pH range, respectively. © 2009 Elsevier Ltd. All rights reserved. Source

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