Metal colloid synthesis synthetic preparation

The synthetic methods which have been used include modern versions of established methods of metal colloid preparation such as the mild chemical reduction of solutions of transition metal salts and complexes and newer methods such as radiolysis and photochemical reduction, metal atom extrusion from labile organometallics. And the use of metal vapor synthesis techniques. Some of these reactions have been in use for many years, and some are the results of research stimulated by the current resurgence in metal colloid chemistry. The list of preparative methods is being extended daily, and, as examples of these methods are described below, the reader will quickly be made aware that almost any organometallic reaction or physical process which results in the deposition of a metal is in fact a resource for the metal colloid chemist. The acquisition of new methods requires only the opportunism of the synthetic chemist in turning a previously negative result into a synthetic possibility. 

Other Metal Magnetic Nanopartides Synthesized by Methods of Colloidal Chemistry In the previous sections, the coUoidal synthesis of Co and CoPts nanocrystals and the great potential of an organometallic approach in the preparation of high-quality magnetic nanoparticles have been discussed. Yet, these synthetic... 

Extending the use of zeolites into larger dimensions, say to catalyse enzymatic reactions and for the purification of colloidal precious metals, was the aim of researchers at Mobil Corporation (USA), who in 1992 discovered a viable and versatile synthetic procedure to prepare mesoporous materials, i.e. materials with ordered porosity in the range between 20 and 500 A (2-50 nm Kresge et al. 1992). Their first material was termed MCM-41 (Mobil Composition of Matter) and the mechanisms involved templating of a silica sol-gel synthesis by an amphiphilic surfactant. 

In fact, other synthetic methods for colloidal metal particles have been developed in the early 20th century, both physical or chemical, until the fundamental work of Turkevitch in 1951 [16]. Interestingly, he started a systematic study of gold nanoparticle (NP) synthesis with various methods by using transmission electron microscopy (TEM) analysis to optimise the preparative conditions until obtaining what is commonly known as the Turkevitch method. 

---