Organic Synthesis: Theory and Applications, Volume 5 …

Organic Synthesis: Theory and Applications, Volume 4 [T

Organic Synthesis: Theory and Applications, Volume 5 by T

VI. LIST OF NAMED ORGANIC REACTIONS Bischler-Napieralski Isoquinoline Synthesis.................................................................................... ......................62

Organic Synthesis: Theory and Applications, Volume 4  …

- Organic Synthesis: Theory and Applications, Volume 4

A solvothermal method was also used by Chen [], who prepared nanocrystalline ZnO, free of hydroxyl groups. It was obtained from a reaction of zinc powder with trimethylamine -oxide (Me3N→O) and 4-picoline -oxide (4-pic→NO), carried out in an environment of organic solvents (toluene, ethylenediamine (EDA) and -tetramethylenediamine (TMEDA)), in an autoclave at 180 °C. The process involved the following reactions (11) and (14):

21/08/1998 · Find Organic Synthesis: Theory and Applications, Volume 4 - ..

Poly(methyl methacrylate) was also used as a ZnO surface modifier by Hong []. Nanoparticles of zinc oxide with a diameter of approximately 30 nm were synthesized by means of homogeneous precipitation followed by calcination. In order to introduce reactive groups onto the ZnO surface, a reaction was carried out between the hydroxyl groups and a silane coupling agent (3-methacryloxypropyltrimethoxysilane). Graft polymerization was effected by means of a reaction between the ZnO, containing silanol groups, and the monomer. Tests showed that the polymerization does not alter the crystalline structure of the ZnO nanoparticles. Their dispersion in the organic solvent can greatly improve the graft polymerization of PMMA, and further improvement can be achieved by the addition of other surfactants. Modification of ZnO nanoparticles by grafted PMMA increases the degree of lyophilicity of the inorganic surface and reduces the formation of aggregates. The work of Hong , showed that ZnO nanoparticles grafted with PMMA can increase the thermal stability of polystyrene.

Organic Synthesis Vol 4 Theory And Applications


Organic Synthesis Theory And Applications 2001 - …

Shim [] carried out modification of zinc oxide using poly(methyl methacrylate) (PMMA). A ZnO/PMMA composite was synthesized by means of polymerization . The majority of microspheres of the MO/polymer composite are produced by coupling of existing polymer chains with the inorganic surface or by polymerization on the phase boundary of inorganic particles. Shim , demonstrated that the stability of dispersion of ZnO in a monomer depends strongly on the nature of its surface, since this provides a precondition enabling dispersion of particles of the medium within drops of monomer and consequently their enclosure in PMMA. The most important condition in the production of the composite is the interphase compatibility between the inorganic compound and the polymer. For this purpose the surface of the inorganic system should be treated with a hydrophobic organic substance. The obtained inorganic-polymer composites form persistent microspheres and combine easily into highly processed polymers. Similar studies have been carried out and published by other researchers [,].

Organic Synthesis Vol 3 Theory And Applications - …

Over the past decade much work has been done on developing nanocomposites produced by the action of modified inorganic carriers with polymer matrices. Such procedures make it possible to produce new classes of polymeric materials which combine properties of both inorganic particles and organic polymer matrices (including process ability and elasticity). The MO/polymer composites produced in this way have unique electrical, thermal and optical properties, which enable their range of applications to be extended in many branches of industry [–].

Organic Synthesis Theory and Applications, Volume 5

Change of state of the surface of zinc oxide nanowires through plasma treatment is one of the most promising methods of ZnO modification. Experiments carried out by Ra [] aimed to determine how reactive chemical treatment using oxygen affects electrical transport, gas selectivity and the internal photoelectric effect of ZnO nanowires with a diameter of 80 nm, using a field-effect transistor (FET). A significant increase in the concentration of oxygen was observed, in the form of active oxygen centres (O2− and OH) on the nanowire surface. After treatment the concentration of the carrier and mobility of the ZnO decreased. There was also an improvement in properties relating to the detection of hydrogen by the modified nanowires, and the time of photocurrent amplification in UV radiation. In summarizing their work, Ra , stated that modification of the surface of ZnO using plasma treatment with oxygen opens up new possibilities for the production of electronic devices, catalysts and high-performance sensors.