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Etsushu Kuraoka - One of the best experts on this subject based on the ideXlab platform.

  • Modification of a novel macroporous silica based crown ether impregnated polymeric composite with 1 dodecanol and its adsorption for some fission and non fission products contained in high level liquid waste
    European Polymer Journal, 2008
    Co-Authors: Anyun Zhang, Weihong Wang, Zhifang Chai, Etsushu Kuraoka
    Abstract:

    Abstract A novel macroporous silica-based chelating polymeric composite, DtDo/SiO2–P, was synthesized by Molecular Modification of 4,4′,(5′)-di-(tert-butylcyclohexano)-18-crown-6 (DtBuCH18C6) with a long carbon chain organic compound 1-dodecanol. It was performed through impregnation and immobilization of DtBuCH18C6 and 1-dodecanol molecules into the pores of the SiO2–P particles. The adsorption of a few fission and non-fission product elements Sr(II), Ba(II), Cs(I), Ru(III), Mo(VI), Na(I), K(I), Pd(II), La(III), and Y(III) onto DtDo/SiO2–P was investigated at 323 K. The effects of contact time and the HNO3 concentration in a range of 0.1–4.0 M were investigated. It was found that at the optimum concentration of 2.0 M HNO3, DtDo/SiO2–P exhibited strong adsorption ability and excellent selectivity for Sr(II) over all of the tested elements, which showed very weak or almost no adsorption except Ba(II). The bleeding of total organic carbon (TOC) from DtDo/SiO2–P was evaluated. The quantity of TOC in aqueous phase increased with an increase in HNO3 concentration in terms of a linear equation [TOC] = 35.82[HNO3] + 115.5 with a correlation coefficient of 0.9751. The TOC content leaked from DtDo/SiO2–P modified by 1-dodecanol, 119.0–269.3 ppm, in the range of 1.0–4.0 M HNO3 was significantly lower than that of 424.8–634.6 ppm in the case without Modification. It resulted from the interMolecular interaction force of DtBuCH18C6 and 1-dodecanol through hydrogen bonding. The reduction of DtBuCH18C6 leakage by Molecular Modification was achieved. It is of great benefit to application of DtDo/SiO2–P in partitioning of Sr(II), one of the main heat generators, from high level liquid waste (HLLW) in reprocessing process of nuclear spent fuel in MAREC (Minor Actinides Recovery from HLLW by Extraction Chromatography) process developed.

  • impregnation synthesis of a novel macroporous silica based crown ether polymeric material modified by 1 dodecanol and its adsorption for strontium and some coexistent metals
    Separation and Purification Technology, 2008
    Co-Authors: Anyun Zhang, Etsushu Kuraoka, Chunmei Chen, Mikio Kumagai
    Abstract:

    Abstract 4,4′,(5′)-Di-( tert -butylcyclohexano)-18-crown-6(DtBuCH18C6) is a chelating agent having high selectivity mostly for Sr(II). To significantly reduce its leakage by Molecular Modification, a macroporous silica-based DtBuCH18C6 polymeric composite (DtDo/SiO 2 –P) was synthesized. It was performed by impregnating and immobilizing DtBuCH18C6 and 1-dodecanol molecules into the pores of the SiO 2 –P particles utilizing an advanced vacuum sucking technique. The adsorption of a few fission and non-fission products Sr(II), Ba(II), Cs(I), Ru(III), Mo(VI), Na(I), K(I), Pd(II), La(III), and Y(III) onto DtDo/SiO 2 –P was investigated. It was done by examining the effects of contact time and the HNO 3 concentration in a range of 0.1–5.0 M at 298 K. At the optimum concentration of 2.0 M HNO 3 , DtDo/SiO 2 –P exhibited strong adsorption ability and high selectivity for Sr(II) great over all of the tested elements, which showed very weak or almost no adsorption except Ba(II). Meanwhile, It was found that the quantity of total organic carbon (TOC) leaked from DtDo/SiO 2 –P in 2.0 M HNO 3 , 187.5 ppm, was lower than 658.4 ppm that leaked from DtBuCH18C6/SiO 2 –P, which was not modified. This was ascribed to the effective association of DtBuCH18C6 and 1-dodecanol through interMolecular interaction. The reduction of DtBuCH18C6 leakage by Molecular Modification with 1-dodecanol was achieved. It was of great benefit to application of DtDo/SiO 2 –P in chromatographic partitioning of Sr(II), one of the main heat generators, from high level liquid waste (HLLW) in reprocessing of nuclear spent fuel in the MAREC (Minor Actinides Recovery from HLLW by Extraction Chromatography) process developed recently.

Anyun Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Modification of a novel macroporous silica based crown ether impregnated polymeric composite with 1 dodecanol and its adsorption for some fission and non fission products contained in high level liquid waste
    European Polymer Journal, 2008
    Co-Authors: Anyun Zhang, Weihong Wang, Zhifang Chai, Etsushu Kuraoka
    Abstract:

    Abstract A novel macroporous silica-based chelating polymeric composite, DtDo/SiO2–P, was synthesized by Molecular Modification of 4,4′,(5′)-di-(tert-butylcyclohexano)-18-crown-6 (DtBuCH18C6) with a long carbon chain organic compound 1-dodecanol. It was performed through impregnation and immobilization of DtBuCH18C6 and 1-dodecanol molecules into the pores of the SiO2–P particles. The adsorption of a few fission and non-fission product elements Sr(II), Ba(II), Cs(I), Ru(III), Mo(VI), Na(I), K(I), Pd(II), La(III), and Y(III) onto DtDo/SiO2–P was investigated at 323 K. The effects of contact time and the HNO3 concentration in a range of 0.1–4.0 M were investigated. It was found that at the optimum concentration of 2.0 M HNO3, DtDo/SiO2–P exhibited strong adsorption ability and excellent selectivity for Sr(II) over all of the tested elements, which showed very weak or almost no adsorption except Ba(II). The bleeding of total organic carbon (TOC) from DtDo/SiO2–P was evaluated. The quantity of TOC in aqueous phase increased with an increase in HNO3 concentration in terms of a linear equation [TOC] = 35.82[HNO3] + 115.5 with a correlation coefficient of 0.9751. The TOC content leaked from DtDo/SiO2–P modified by 1-dodecanol, 119.0–269.3 ppm, in the range of 1.0–4.0 M HNO3 was significantly lower than that of 424.8–634.6 ppm in the case without Modification. It resulted from the interMolecular interaction force of DtBuCH18C6 and 1-dodecanol through hydrogen bonding. The reduction of DtBuCH18C6 leakage by Molecular Modification was achieved. It is of great benefit to application of DtDo/SiO2–P in partitioning of Sr(II), one of the main heat generators, from high level liquid waste (HLLW) in reprocessing process of nuclear spent fuel in MAREC (Minor Actinides Recovery from HLLW by Extraction Chromatography) process developed.

  • impregnation synthesis of a novel macroporous silica based crown ether polymeric material modified by 1 dodecanol and its adsorption for strontium and some coexistent metals
    Separation and Purification Technology, 2008
    Co-Authors: Anyun Zhang, Etsushu Kuraoka, Chunmei Chen, Mikio Kumagai
    Abstract:

    Abstract 4,4′,(5′)-Di-( tert -butylcyclohexano)-18-crown-6(DtBuCH18C6) is a chelating agent having high selectivity mostly for Sr(II). To significantly reduce its leakage by Molecular Modification, a macroporous silica-based DtBuCH18C6 polymeric composite (DtDo/SiO 2 –P) was synthesized. It was performed by impregnating and immobilizing DtBuCH18C6 and 1-dodecanol molecules into the pores of the SiO 2 –P particles utilizing an advanced vacuum sucking technique. The adsorption of a few fission and non-fission products Sr(II), Ba(II), Cs(I), Ru(III), Mo(VI), Na(I), K(I), Pd(II), La(III), and Y(III) onto DtDo/SiO 2 –P was investigated. It was done by examining the effects of contact time and the HNO 3 concentration in a range of 0.1–5.0 M at 298 K. At the optimum concentration of 2.0 M HNO 3 , DtDo/SiO 2 –P exhibited strong adsorption ability and high selectivity for Sr(II) great over all of the tested elements, which showed very weak or almost no adsorption except Ba(II). Meanwhile, It was found that the quantity of total organic carbon (TOC) leaked from DtDo/SiO 2 –P in 2.0 M HNO 3 , 187.5 ppm, was lower than 658.4 ppm that leaked from DtBuCH18C6/SiO 2 –P, which was not modified. This was ascribed to the effective association of DtBuCH18C6 and 1-dodecanol through interMolecular interaction. The reduction of DtBuCH18C6 leakage by Molecular Modification with 1-dodecanol was achieved. It was of great benefit to application of DtDo/SiO 2 –P in chromatographic partitioning of Sr(II), one of the main heat generators, from high level liquid waste (HLLW) in reprocessing of nuclear spent fuel in the MAREC (Minor Actinides Recovery from HLLW by Extraction Chromatography) process developed recently.

Mikio Kumagai - One of the best experts on this subject based on the ideXlab platform.

  • impregnation synthesis of a novel macroporous silica based crown ether polymeric material modified by 1 dodecanol and its adsorption for strontium and some coexistent metals
    Separation and Purification Technology, 2008
    Co-Authors: Anyun Zhang, Etsushu Kuraoka, Chunmei Chen, Mikio Kumagai
    Abstract:

    Abstract 4,4′,(5′)-Di-( tert -butylcyclohexano)-18-crown-6(DtBuCH18C6) is a chelating agent having high selectivity mostly for Sr(II). To significantly reduce its leakage by Molecular Modification, a macroporous silica-based DtBuCH18C6 polymeric composite (DtDo/SiO 2 –P) was synthesized. It was performed by impregnating and immobilizing DtBuCH18C6 and 1-dodecanol molecules into the pores of the SiO 2 –P particles utilizing an advanced vacuum sucking technique. The adsorption of a few fission and non-fission products Sr(II), Ba(II), Cs(I), Ru(III), Mo(VI), Na(I), K(I), Pd(II), La(III), and Y(III) onto DtDo/SiO 2 –P was investigated. It was done by examining the effects of contact time and the HNO 3 concentration in a range of 0.1–5.0 M at 298 K. At the optimum concentration of 2.0 M HNO 3 , DtDo/SiO 2 –P exhibited strong adsorption ability and high selectivity for Sr(II) great over all of the tested elements, which showed very weak or almost no adsorption except Ba(II). Meanwhile, It was found that the quantity of total organic carbon (TOC) leaked from DtDo/SiO 2 –P in 2.0 M HNO 3 , 187.5 ppm, was lower than 658.4 ppm that leaked from DtBuCH18C6/SiO 2 –P, which was not modified. This was ascribed to the effective association of DtBuCH18C6 and 1-dodecanol through interMolecular interaction. The reduction of DtBuCH18C6 leakage by Molecular Modification with 1-dodecanol was achieved. It was of great benefit to application of DtDo/SiO 2 –P in chromatographic partitioning of Sr(II), one of the main heat generators, from high level liquid waste (HLLW) in reprocessing of nuclear spent fuel in the MAREC (Minor Actinides Recovery from HLLW by Extraction Chromatography) process developed recently.

Kohjiro Hara - One of the best experts on this subject based on the ideXlab platform.

  • exploitation of ionic liquid electrolyte for dye sensitized solar cells by Molecular Modification of organic dye sensitizers
    Chemistry of Materials, 2009
    Co-Authors: Zhongsheng Wang, Nagatoshi Koumura, Yan Cui, Masanori Miyashita, Shogo Mori, Kohjiro Hara
    Abstract:

    When an alkyl-functionalized metal-free organic dye (MK-2) was employed as a sensitizer, dye-sensitized TiO2 solar cells (DSSCs) fabricated with an ionic liquid (IL) electrolyte showed an energy conversion efficiency of 7.6%, which was comparable to that with a volatile liquid electrolyte. This contrasts with the case of DSSCs employing conventional Ru complex sensitizer (N719), whose efficiency was decreased markedly when the electrolyte was replaced from the volatile to IL. As a result, with the IL electrolyte, the conversion efficiency with MK-2 was higher than that with N719. The result was mainly attributed to longer electron lifetime in the DSSCs with MK-2. The longer electron lifetime is remarkable because with conventional volatile electrolyte, the lifetimes with many organic dyes including MK-2 were shorter than that with N719. This high compatibility of MK-2 with the IL electrolyte shows that the Molecular Modification of organic dyes can overcome the both disadvantages of ILs and organic dyes, ...

Subhani M Okarvi - One of the best experts on this subject based on the ideXlab platform.

  • peptide based radiopharmaceuticals future tools for diagnostic imaging of cancers and other diseases
    Medicinal Research Reviews, 2004
    Co-Authors: Subhani M Okarvi
    Abstract:

    An Erratum has been published for this article in Medicinal Research Reviews 2004;24:685–686. Small synthetic receptor-binding peptides are the agents of choice for diagnostic imaging and radiotherapy of cancers due to their favorable pharmacokinetics. Molecular Modification techniques permit the synthesis of a variety of bioactive peptides with chelating groups, without compromising biological properties. Various techniques have been developed that allow efficient and site-specific labeling of peptides with clinically useful radionuclides such as 99mTc, 123I, 111In, and 18F. Among them, 99mTc is the radionuclide of choice because of its excellent chemical and imaging characteristics. Recently, many 99mTc-labeled peptides have proven to be useful imaging agents. Beside 99mTc-labeled peptides, several peptides radiolabeled with 111In and 123I have been prepared and characterized. In addition, 18F-labeled peptides hold clinical potential due to their ability to quantitatively detect and characterize a variety of human diseases using positron-emission tomography. The availability of this wide range of peptides labeled with different radionuclides offers multiple diagnostic and therapeutic applications. Various receptors are over-expressed in particular tumor types and peptides binding to these receptors can be used to visualize tumor lesions scintigraphically. Thus, radiolabeled peptides have potential use as carriers for the delivery of radionuclides to tumors, infarcts, and infected tissues for diagnostic imaging and radiotherapy. Many radiolabeled peptides are currently under investigation to determine their potential as imaging agents. These peptides are designed mainly for thrombus, tumor, and infection/inflammation imaging. This article presents recent developments in small synthetic peptides for imaging of thrombosis, tumors, and infection/inflammation. © 2004 Wiley Periodicals, Inc. Med Res Rev, 24, No. 3, 357–397, 2004