The Experts below are selected from a list of 102 Experts worldwide ranked by ideXlab platform

Wei Zeng - One of the best experts on this subject based on the ideXlab platform.

  • the drug delivery system of mcm 41 materials via co condensation synthesis
    Materials Chemistry and Physics, 2006
    Co-Authors: Wei Zeng, Xuefeng Qian, Jie Yin, Zikang Zhu
    Abstract:

    Abstract The functional MCM-41 materials were prepared through Co-Condensation Method, as compared postsynthesis and solvothermal processes were also used. The as-functionalized MCM-41 materials have been characterized by XRD, TEM, N2 adsorption and 29Si CP/MAS NMR. The modified materials have been used as drug-controlled delivery system of aspirin. The results showed that the release properties of this system were affected by functionalization degree and the distribution of functional groups on the pore wall surface of mesoporous materials, and the better delivery rate of MCM-41 materials would be obtained via Co-Condensation process.

Mingshu Yang - One of the best experts on this subject based on the ideXlab platform.

  • efficient grafting of polypropylene onto silica nanoparticles and the properties of pp pp g sio2 nanocomposites
    Polymer, 2018
    Co-Authors: Wenjing Yuan, Zheming Chen, Yanfen Ding, Shimin Zhang, Feng Wang, Mingshu Yang
    Abstract:

    Abstract Grafting polyolefin chains onto the surface of silica nanoparticles to form satisfactory polyolefin/silica nanocomposites still remains a challenge, even after the complicated functionalization of the polyolefin chains and surface modification of the silica. In this study, an efficient route for the preparation of polypropylene-grafted nanosilica (PP-g-SiO2) masterbatch was presented through the reactive melt blending of maleic-anhydride-grafted polypropylene (PP-MAH) and amino-functionalized silica (SN-NH2) synthesized by the Co-Condensation Method. The amount of grafted PP chains could achieve to 80.8 wt%. And PP-g-SiO2 exhibited fine dispersion in PP matrix. The shear and extension rheology results of PP/PP-g-SiO2 nanocomposites showed that melt strength of PP could be enhanced remarkably by incorporation of PP-g-SiO2 masterbatch, which revealed the strong interactions between PP-g-SiO2 and PP matrix. These findings provide a facile way to prepare polyolefin-grafted nanosilica, while expanding the potential applications of nanosilica in polyolefin nanocomposites.

A P Singh - One of the best experts on this subject based on the ideXlab platform.

  • sulfonic acid functionalized mesoporous silicas and organosilicas synthesis characterization and catalytic applications
    Journal of Molecular Catalysis A-chemical, 2007
    Co-Authors: Sankaranarayanapillai Shylesh, Prinson P Samuel, Ch Srilakshmi, Renu Parischa, A P Singh
    Abstract:

    Abstract Ethane bridged mesoporous organosilicas and MCM-41 having sulfonic acid groups in the pore channels were prepared by Co-Condensation Method as well as grafting Method, using 3-mercaptopropyltriethoxysilane (3-MPTS) as the sulfur precursor. TEM and N2 sorption isotherm analysis revealed that the mesoporous structural ordering is retained after the functionalization and modifications of organic groups while FT-IR, Raman, XPS and solid-state 13C CP MAS NMR shows the presence of sulfonic acid groups and the stability of the mesoporous framework. The catalytic activity of the developed materials was evaluated in the liquid phase Claisen–Schmidt condensation reaction of acetophenone with benzaldehyde, to probe the effect of mesoporous support surfaces as well as the role of preparation Methods. Results showed that sulfonic acid functionalized ethane–silica samples were more active, selective and stable than the conventional sulfonic acid containing mesoporous catalysts.

K M Parida - One of the best experts on this subject based on the ideXlab platform.

  • copper and nickel modified mcm 41 an efficient catalyst for hydrodehalogenation of chlorobenzene at room temperature
    Industrial & Engineering Chemistry Research, 2011
    Co-Authors: Dharitri Rath, K M Parida
    Abstract:

    The paper reports preparation, surface, and textural characterization of Cu and Ni modified MCM-41 and its application for hydrodehalogenation of chlorobenzene. A series of Cu/Ni modified MCM-41 samples were synthesized by the Co-Condensation Method by varying the amount of Ni and further characterized by various physicochemical Methods. The incorporation of metals in the framework of mesoporous silica matrix was confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies showed the formation of uniform spherical particles on the support surface. The catalytic activity of the samples was evaluated toward the hydrodehalogenation reaction of chlorobenzene at room temperature. Samples containing Si/(Cu + Ni) = 10 showed the highest chlorobenzene (98%) conversion with 100% selectivity for benzene. Among the various solvents studied for the reaction, isopropyl alcohol gave the best results at 2 h ...

  • facile Method for synthesis of polyamine functionalized mesoporous zirconia and its catalytic evaluation toward henry reaction
    Industrial & Engineering Chemistry Research, 2011
    Co-Authors: Surjyakanta Rana, Sujata Mallick, K M Parida
    Abstract:

    Different amine-functionalized mesoporous zirconia were prepared by a Co-Condensation Method using silane [aminopropyltrimethoxysilane (APTES), N-(2 amino ethyl)-3-amino propyl trimethoxy silane (AAPTMS), and 3-[2-(2-amino ethyl amino) ethyl amino] propyl trimethoxy silane (AEPTMS)] and zirconium butoxide. The materials were characterized by X-ray diffraction, BET surface area analysis, 13C magic angle spinning-nuclear magnetic resonance (NMR), Fourier transfer infrared spectroscopy (FTIR), scanning electron micrography (SEM), and thermogravimetric analysis (TGA)−differential thermal analysis (DTA). FTIR and NMR results revealed the successful grafting of organic amines onto the surface of zirconia. The catalytic activities were investigated for liquid phase Henry reaction of aromatic aldehydes with nitro methane.

  • amine functionalized mcm 41 an active and reusable catalyst for knoevenagel condensation reaction
    Journal of Molecular Catalysis A-chemical, 2009
    Co-Authors: K M Parida, Dharitri Rath
    Abstract:

    Abstract This paper reports preparation, characterization of amine modified mesoporous crystalline MCM-41 and its application in Knoevenagel condensation reaction. Amine modified MCM-41 was prepared by Co-Condensation and post-synthesis Methods. The samples were characterized by X-ray powder diffraction, Fourier-transfer infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron micrograph (SEM), 29Si magic-angle spinning (MAS), nuclear magnetic resonance (NMR), diffuse reflectance spectra (DRS), nitrogen adsorption–desorption and CHN analysis. X-ray diffraction patterns indicate that the modified materials retain the standard MCM-41 structure. SEM study exhibits that the arrangement of particles for 12.8% amine modified MCM-41 is well ordered and spherical in nature. CHN analysis supports that complete hydrolysis of ethoxy groups take place in 12.8% amine modified sample. From the NMR study it is confirmed that the surface coverage is 40% in 12.8% amine modified sample. The base catalytic activity of hybrid MCM-41 materials such as amine (post-synthesis and Co-Condensation Methods) and surfactant functionalized materials for condensation reaction between benzaldehyde and diethyl malonate in solvent free, room temperature synthesis of cinnamic acid was evaluated and correlated with the surface and textural properties. Sample containing 12.8 wt% amine loaded by Co-Condensation Method showed highest malonic ester conversion (92%) and selectivity (98%) for cinnamic acid.

Yanli Zhao - One of the best experts on this subject based on the ideXlab platform.