The Experts below are selected from a list of 1392 Experts worldwide ranked by ideXlab platform

C. W. Won - One of the best experts on this subject based on the ideXlab platform.

  • Combustion of TiO2–Mg and TiO2–Mg–C systems in the presence of NaCl to synthesize nanocrystalline Ti and TiC powders
    Materials Research Bulletin, 2003
    Co-Authors: Hayk H. Nersisyan, Jong-hyeon Lee, C. W. Won
    Abstract:

    Abstract The combustion process of TiO2–Mg and TiO2–Mg–C systems with sodium chloride as an Inert Diluent was investigated. The values of combustion parameters and temperature distribution on a high-temperature wave according to the amount of sodium chloride were obtained by the thermocoupling technique. The leading stages of combustion processes are found and the sizes of reactionary zones were estimated. It is shown that the introduction of NaCl in an initial mixture promotes the formation of a nanocrystalline structure of the final products. As a result, nanosized titanium, and titanium carbide powders have been successfully obtained.

  • Self-propagating high-temperature synthesis of nano-sized titanium carbide powder
    Journal of Materials Research, 2002
    Co-Authors: Hayk H. Nersisyan, Jong-hyeon Lee, C. W. Won
    Abstract:

    The combustion process of a titanium–carbon system with sodium chloride as an Inert Diluent was investigated. The combustion laws and microstructure of final products according to Diluent content were obtained. It was shown that sodium chloride not only decreases combustion temperature but also makes effective protective shells around primary carbide crystals and keeps this ultrafine structure up to the end of combustion. As a result, nano-sized titanium carbide powders were successfully obtained.

Hayk H. Nersisyan - One of the best experts on this subject based on the ideXlab platform.

  • Combustion of TiO2–Mg and TiO2–Mg–C systems in the presence of NaCl to synthesize nanocrystalline Ti and TiC powders
    Materials Research Bulletin, 2003
    Co-Authors: Hayk H. Nersisyan, Jong-hyeon Lee, C. W. Won
    Abstract:

    Abstract The combustion process of TiO2–Mg and TiO2–Mg–C systems with sodium chloride as an Inert Diluent was investigated. The values of combustion parameters and temperature distribution on a high-temperature wave according to the amount of sodium chloride were obtained by the thermocoupling technique. The leading stages of combustion processes are found and the sizes of reactionary zones were estimated. It is shown that the introduction of NaCl in an initial mixture promotes the formation of a nanocrystalline structure of the final products. As a result, nanosized titanium, and titanium carbide powders have been successfully obtained.

  • Self-propagating high-temperature synthesis of nano-sized titanium carbide powder
    Journal of Materials Research, 2002
    Co-Authors: Hayk H. Nersisyan, Jong-hyeon Lee, C. W. Won
    Abstract:

    The combustion process of a titanium–carbon system with sodium chloride as an Inert Diluent was investigated. The combustion laws and microstructure of final products according to Diluent content were obtained. It was shown that sodium chloride not only decreases combustion temperature but also makes effective protective shells around primary carbide crystals and keeps this ultrafine structure up to the end of combustion. As a result, nano-sized titanium carbide powders were successfully obtained.

Fengchih Chang - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Inert Diluent Segment on the Miscibility Behavior of Poly(vinylphenol) with Poly(acetoxystyrene) Blends
    2016
    Co-Authors: Shiao-wei Kuo, Fengchih Chang
    Abstract:

    ABSTRACT: Polymer blends of poly(vinylphenol) (PVPh) and poly(styrene-co-vinylphe-nol) with poly(p-acetoxystyrene) (PAS) were prepared by solution casting from tetra-hydrofuran solution. The thermal properties and hydrogen bonding of the blends were investigated by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy. Although hydrogen bonding existed between the PVPh and PAS seg-ments, the experimental results indicated that PVPh is immiscible with PAS as shown by the existence of two glass-transition temperatures over the entire composition range by DSC. This phenomenon is attributed to the strong self-association of PVPh, intramo-lecular screening, and functional group accessibility effects of the PVPh/PAS blend system. However, the incorporation of an Inert Diluent moiety such as styrene into the PVPh chain renders the modified polymer to be miscible with PAS. Copolymers con-taining between 16 and 51 mol % vinylphenol were fully miscible with PAS according to DSC studies. These observed results were caused by the reduction of the strong self-association of PVPh and the increase of the interassociation between PVPh and PAS segments with the incorporation of styrene on the PVPh chain. According to the Painter–Coleman association model, the interassociation equilibrium constant of PVPh/PAS blends was determined by a model compound and polymer blend. Good correlation between these two methods was obtained after considering the intramolec-ular screening and functional group accessibility effect in the polymer blend. © 200

  • glass transition temperature enhancement of pmma through copolymerization with pmaam and ptcm mediated by hydrogen bonding
    Polymer, 2010
    Co-Authors: Chihfeng Huang, Fengchih Chang
    Abstract:

    Abstract A series of poly(methyl methacrylate- co -methacrylamide- co -tricyclodecyl methacrylate) (PMMA- co -PMAAM- co -PTCM) copolymers possessing high glass transition temperatures and high transparency are prepared. By incorporating the aliphatic tricyclodecyl methacrylate moiety into the PMMA- co -PMAA main chain results in high glass transition temperature and high transparency of PMMA-based polymeric material. The TCM content affects the fraction of hydrogen bonding in these terpolymers, small content of TCM does not sacrifice the fraction of hydrogen-bonded association in and does not cause T g decrease. The extent of free amide group plays the major role in dictating moisture absorption of terpolymers. The incorporation of TCM significantly reduces the moisture absorption of terpolymers due to its hydrophobic and bulky tricyclodecyl group. In addition, the TCM plays the role of Inert Diluent to convert portion of the strong self-associated hydrogen bonded amide groups into inter-associated hydrogen bonding between carbonyl groups of ester units and MAAM.

  • Effects of Inert Diluent Segment and Hydrogen Bonding in Poly(styrene-co-methacrylamide) Copolymers
    Journal of Polymer Research, 2003
    Co-Authors: Hsin-ching Kao, Shiao-wei Kuo, Fengchih Chang
    Abstract:

    A series of random poly(styrene-co-methacrylamide) (PS-co-PMAAM) copolymers were prepared by free radical polymerization of styrene and methacrylamide monomers. The PS and PMAAM units of the copolymer do not have any specific interaction based on the Kwei equation and the infrared spectroscopy result, indicating that the styrene plays strictly as an Inert Diluent segment on the PMAAM main chain. This result offers an opportunity to enhance the miscibility and specific interaction between the amide group of PMAAM and the functional group of second polymer by reducing the strong self-association of the PMAAM.

  • Effect of Inert Diluent segment on the miscibility behavior of poly(vinylphenol) with poly(acetoxystyrene) blends
    Journal of Polymer Science Part B: Polymer Physics, 2002
    Co-Authors: Shiao-wei Kuo, Fengchih Chang
    Abstract:

    Polymer blends of poly(vinylphenol) (PVPh) and poly(styrene-co-vinylphenol) with poly(p-acetoxystyrene) (PAS) were prepared by solution casting from tetrahydrofuran solution. The thermal properties and hydrogen bonding of the blends were investigated by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy. Although hydrogen bonding existed between the PVPh and PAS segments, the experimental results indicated that PVPh is immiscible with PAS as shown by the existence of two glass-transition temperatures over the entire composition range by DSC. This phenomenon is attributed to the strong self-association of PVPh, intramolecular screening, and functional group accessibility effects of the PVPh/PAS blend system. However, the incorporation of an Inert Diluent moiety such as styrene into the PVPh chain renders the modified polymer to be miscible with PAS. Copolymers containing between 16 and 51 mol % vinylphenol were fully miscible with PAS according to DSC studies. These observed results were caused by the reduction of the strong self-association of PVPh and the increase of the interassociation between PVPh and PAS segments with the incorporation of styrene on the PVPh chain. According to the Painter-Coleman association model, the interassociation equilibrium constant of PVPh/PAS blends was determined by a model compound and polymer blend. Good correlation between these two methods was obtained after considering the intramolecular screening and functional group accessibility effect in the polymer blend. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1661–1672, 2002

Jong-hyeon Lee - One of the best experts on this subject based on the ideXlab platform.

  • Combustion of TiO2–Mg and TiO2–Mg–C systems in the presence of NaCl to synthesize nanocrystalline Ti and TiC powders
    Materials Research Bulletin, 2003
    Co-Authors: Hayk H. Nersisyan, Jong-hyeon Lee, C. W. Won
    Abstract:

    Abstract The combustion process of TiO2–Mg and TiO2–Mg–C systems with sodium chloride as an Inert Diluent was investigated. The values of combustion parameters and temperature distribution on a high-temperature wave according to the amount of sodium chloride were obtained by the thermocoupling technique. The leading stages of combustion processes are found and the sizes of reactionary zones were estimated. It is shown that the introduction of NaCl in an initial mixture promotes the formation of a nanocrystalline structure of the final products. As a result, nanosized titanium, and titanium carbide powders have been successfully obtained.

  • Self-propagating high-temperature synthesis of nano-sized titanium carbide powder
    Journal of Materials Research, 2002
    Co-Authors: Hayk H. Nersisyan, Jong-hyeon Lee, C. W. Won
    Abstract:

    The combustion process of a titanium–carbon system with sodium chloride as an Inert Diluent was investigated. The combustion laws and microstructure of final products according to Diluent content were obtained. It was shown that sodium chloride not only decreases combustion temperature but also makes effective protective shells around primary carbide crystals and keeps this ultrafine structure up to the end of combustion. As a result, nano-sized titanium carbide powders were successfully obtained.

William E. Lee - One of the best experts on this subject based on the ideXlab platform.