Ham, Synthesis of manganese oxide particles in supercritical water.

Arai, Hydrothermal synthesis of metal oxide fine particles at supercritical conditions.

Synthesis and characterization of novel ZrO2-SiO2 mixed oxides

Li [] proposed a method of preparing nanometric zinc oxide using a microemulsion which is formed when alcohol is added to an emulsion system consisting of water, oil and emulsifier, until a transparent mixture is obtained. In this case the microemulsion consists of a solution of heptane and hexanol together with a non-ionic surfactant (such as Triton X-100). The growth of nanoparticles involves the exchange of the substrates Zn(NO3)2 and NaOH between the microemulsion drops and the medium (poly(ethylene glycol)—PEG 400), and aggregation of the formed nuclei. Drops of microemulsion act as a microreactor in which the desired reaction takes place. In the synthesis of ZnO, different concentrations of PEG 400 were used (0%–50%). illustrates the process of synthesis in microemulsion and the shape of ZnO nanoparticles as proposed by the aforementioned authors.

Synthesis of phosphine oxides - Organic chemistry

There also exist many other methods of obtaining zinc oxide, including growing from a gas phase, a pyrolysis spray method, a sonochemical method, synthesis using microwaves, and many others.

The hollow spheres which were obtained had diameters of 2–5 μm and contained channels approximately 10 nm in diameter. The thickness of the wall of such a sphere was approximately 1 μm. The system proposed by Zhang may combine the properties of both a solvothermal hybrid and an ionothermal system. It can be expected that a solvothermal hybrid and an ionothermal system may be successfully used to synthesize new materials with interesting properties and morphologies.


A Review on the Synthesis of Manganese Oxide …

In processes of synthesis of nanopowders based on precipitation, it is increasingly common for surfactants to be used to control the growth of particles. The presence of these compounds affects not only nucleation and particle growth, but also coagulation and flocculation of the particles. The surfactant method involves chelation of the metal cations of the precursor by surfactants in an aqueous environment. Wang [] obtained nanometric zinc oxide from ZnCl2 and NH4OH in the presence of the cationic surfactant CTAB (cetyltrimethylammonium bromide). The process was carried out at room temperature, and the resulting powder was calcined at 500 °C to remove residues of the surfactant. The product was highly crystalline ZnO with a wurtzite structure and with small, well-dispersed spherical nanoparticles in size of 50 nm. It was found that CTAB affects the process of nucleation and growth of crystallites during synthesis, and also prevents the formation of agglomerates.

Synthesis of tetrasubstituted pyrazines and pyrazine N -oxides

Lanje [] used the cost competitive and simple precipitation process for the synthesis of zinc oxide. The single step process with the large scale production without unwanted impurities is desirable for the cost-effective preparation of ZnO nanparticles. As a consequence, the low cost precursors such as zinc nitrate and sodium hydroxide to synthesize the ZnO nanoparticles ( 40 nm) were used. In order to reduce the agglomeration among the smaller particles, the starch molecule which contains many O-H functional groups and could bind surface of nanoparticles in initial nucleation stage, was used.

Studies on the Hydrothermal Synthesis of Niobium(V) Oxides

Because of its interesting properties, zinc oxide has been the subject of study by many researchers. This has led to the development of a great variety of techniques for synthesizing the compound. Unfortunately, methods that work in the laboratory cannot always be applied on an industrial scale, where it is important for the process to be economically effective, high yielding and simple to implement.