A new method for the synthesis of fine catalyst powders is presented. Catalyst precursors are dissolved in an ethanol-water
mixture which is burned through a nozzle-type burner. As a result, catalyst powders are formed and removed from flue gases
through a filter. LaMnO3 catalysts for the catalytic combustion of methane have been prepared, characterised (TEM, XRD) and compared with a reference
manfacturing method (the citrates one) showing promising, though improvable, results.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
The obvious different aggregation and adsorption behavior of six newly quaternary ammonium surfactants with different lipophilic counterions has been discoverd by measurements of equilibrium and dynamic surface tension, fluorescence and conductivity. Interestingly, the critical micelle concentration (CMC) and its surface tension γCMC decrease with the increasing counterion chain length. However, three methods have confirmed that an exception of CMC increases slightly from C16NC1 to C16NC2. According to experimental results, a balanced mechanism between hydrophobicity and electrostatic of counterion is proposed. Besides, the dynamic surface tension results show the diffusion coefficient increases with the increasing counterion length both at a short time (Dt?→?0) and long time (Dt?→?∞), which indicates a faster adsorption process. Unlike the inorganic counterion, the diffusion coefficient decreases with the increase of hydrophobic chain length. This is attributed to the strong electrostatic interactions between counterions and cationic headgroups. 相似文献
In our photo‐induced immobilization technique for an antibody (IgG) using azopolymers, the introduction of COOH and NMe2 into the azopolymers, which can introduce surface charges, strongly affected the immobilization properties such as the efficiency of immobilization and the activity of the immobilized IgG (i.e., the orientation of the immobilized IgG). The introduction of COOH promoted a more active orientation of the immobilized IgG. The orientation was determined during the adsorption process onto the azopolymer surface in solution before photo‐immobilization, and was maintained during the photo‐immobilization. The surface charge of the azopolymer appears to be an important factor for IgG orientation, which involves electrostatic interactions between its Fab and the azopolymer surface.
DNA condensing agents play a critical role in gene therapy. A tetranuclear nickel(II) complex, [NiII4(L?2H)(H2O)6(CH3CH2OH)2] ? 6NO3 (L=3,3',5,5'‐tetrakis{[(2‐hydroxyethyl)(pyridin‐2‐ylmethyl)amino]methyl}biphenyl‐4,4'‐diol), has been synthesized as a nonviral vector to induce DNA condensation. X‐ray crystallographic data indicate that the complex crystallizes in the monoclinic system with space group P21/n, a=10.291(9), b=24.15(2), c=13.896(11) Å, and β=98.175(13)°. The DNA condensation induced by the complex has been investigated by means of UV/Vis spectroscopy, fluorescence spectroscopy, circular dichroism spectroscopy, dynamic light scattering, atomic force microscopy, gel electrophoresis assay, and zeta potential analysis. The complex interacts strongly with DNA through electrostatic attraction and induces its condensation into globular nanoparticles at low concentration. The release of DNA from its compact state has been achieved using the chelator ethylenediaminetetraacetic acid (EDTA) for the first time. Other essential properties, such as DNA cleavage inactivity and biocompatibility, have also been examined in vitro. In general, the complex satisfies the requirements of a gene vector in all of these respects. 相似文献