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Immobilization of lipase on surface modified magnetic nanoparticles using alkyl benzenesulfonate
Kanagasabai Muruganandam Ponvel,Dong-Geun Lee,Eun-Ji Woo,안익성,이창하 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.1
The surface of nano-sized magnetite (NSM) particles synthesized by coprecipitation method was modified by alkyl benzenesulfonate (ABS) as a coating material. ABS on the NSM was expected to form a spacer between the surface of the NSM particles and the enzyme adsorbed and to play a role of strong enzyme adsorption onto a hydrophobic surface. Transmission electron microscopy showed that the NSM particles had an average size of 10 nm. Magnetic measurement revealed that the nanoparticles were superparamagnetic and the saturation magnetization was about 68 emu/g. Porcine pancreas lipase (PPL) was immobilized onto the ABS-NSM, which was to catalyze hydrolysis of olive oil and showed enhanced durability in the reuse after being recovered by magnetic separations.
Adsorption of 2,4-dichlorophenol on metal-nitrate modified activated carbon
Kanagasabai Muruganandam Ponvel,Dhamodaran Kavitha,Kyung-Min Kim,이창하 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.5
To remove 2,4-dichlorophenol (2,4-DCP) from aqueous solution, the surface of the activated carbon was first treated with HCl and then the surface was modified by using various metal ions (Cu, Co, Fe, Ni, Zn, and Mg). Metal doping significantly enhanced the adsorption efficiency of activated carbon, an effect that was further increased by HCl treatment of the modified activated carbons. Of all the preparations, the zinc(Ⅱ)-modified activated carbon with HCl treatment showed the highest adsorption capacity for 2,4-DCP. Analysis of the zinc(Ⅱ)-modified activated carbon by SEM and BET showed a surface area and micropore volume of around 1,154.69 ㎡/g and 0.291 ㎤/g, respectively, values about 20% higher than in the starting material. In the pH range of 2.0-11.0, the maximum uptake of 2,4- DCP from an initial concentration of 1,000 mg/L was 508 mg/g at pH 4.0.
Woo, EunJi,Ponvel, Kanagasabai Muruganandam,Ahn, Ik-Sung,Lee, Chang-Ha Royal Society of Chemistry 2010 Journal of materials chemistry Vol.20 No.8
<P>We synthesized magnetic/silica nanoparticles with a core/shell structure. The average diameter of the spherical particles was approximately 100 nm, and the average thickness of the silica shell was 20 nm. Due to the core of the magnetic clusters, the particles exhibited strong magnetization (21 emu/g). To immobilize His-tagged lipase, copper complexes with three different ligands were anchored to the surfaces of the particles. Up to 70% of the initial activity was obtained after three uses. Differences in the enzymatic activity and ligand-dependent reusability are discussed.</P> <P>Graphic Abstract</P><P>Magnetic/silica nanoparticles with high magnetization were prepared. Particles modified by organosilane ligands with copper complexes showed high activity and reuse efficiency of the lipases. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b918682d'> </P>
변상훈,Dhamodaran Kavitha,Kanagasabai Muruganandam Ponvel,Kyung-min Kim,이창하 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.6
Coal-based granular activated carbon was modified with acetates of sodium, potassium and lithium at concentrations of 10 and 15% and used as adsorbents to explore the adsorption mechanism of nickel ion in aqueous solution. Acetate treatment reduced surface area and pore volume of the activated carbons, but the adsorption amount of Ni(Ⅱ) on the modified activated carbons (MAC) was greater than that on the virgin activated carbon. The adsorption depended on pH of the solution with an optimum at 4.5 and the adsorbed nickel could be fully desorbed by using 0.05 M HCl solution. The maximum adsorption capacity of nickel ion on Li (15 wt%) modified activated carbon was 151.3 mg/g and the adsorption isotherm follows Langmuir, Sips, and Redlich-Peterson isotherm models better than the Freundlich isotherm model. The kinetic data was better fitted by a non-linear form of the pseudo-first order than the pseudo-second order, but the difference between two kinetic models was small.