Preparative strategies

Five aspects of the preparation of solids can be distinguished (i) preparation of a series of compounds in order to investigate a specific property, as exemplified by a series of perovskite oxides to examine their electrical properties or by a series of spinel ferrites to screen their magnetic properties (ii) preparation of unknown members of a structurally related class of solids to extend (or extrapolate) structure-property relations, as exemplified by the synthesis of layered chalcogenides and their intercalates or derivatives of TTF-TCNQ to study their superconductivity (iii) synthesis of a new class of compounds (e.g. sialons, (Si, Al)3(0, N)4, or doped polyacetylenes), with novel structural properties (iv) preparation of known solids of prescribed specifications (crystallinity, shape, purity, etc.) as in the case of crystals of Si, III-V compounds and 

Prototype First reported by (year) Subsequent development 

Naj -alumina Stillwell (1926) oxygen sensor Solid electrolyte. 

It is helpful to make a distinction between the preparation of new solids and the 

6Gai 2Fe3 gOi2 Bubble memory devices 

---

Recently, an in-depth review on molecular imprinted membranes has been published by Piletsky et al. [4]. Four preparation strategies for MIP membranes can be distinguished (i) in-situ polymerization by bulk crosslinking (ii) preparation by dry phase inversion with a casting/solvent evaporation process [45-51] (iii) preparation by wet phase inversion with a casting/immersion precipitation [52-54] and (iv) surface imprinting. 

A list of different authors that have been involved in designing new preparative strategies for obtaining this polymer imder controlled conditions is given in Table 2. 

Preparation Strategies Involving Chemical Oxidative Approaches... 

As nitridoborates are known as A3(BN2) for alkaline elements (A = Li, Na) and as AE3(BN2)2 for alkaline-earth elements (AE = Ca, Sr, Ba) it would be interesting to find methods for the synthesis of nitridoborates of transition or lanthanide elements. Can they be made straightforward Hke Ii3(BN2) and AE3(BN2)2 from metal nitrides and layer-like a-BN, or do they require new preparative strategies - if they can be made at all ... 

Principles and Characteristics A sample can contain a great number of compounds, but analysts are usually interested only in the qualitative presence (and the quantitative amount) of a small number of the total compounds. Selectivity is an important parameter in analytical separations. The total analytical process clearly benefits from selectivity enhancement arising from appropriate sample preparation strategies. Selective separation of groups or compound classes can simplify a mixture of analytes before analysis, which in turn enhances analytical precision and sensitivity. Selective fractionation, in some cases, allows easier resolution of the compounds of interest, so analysts can avoid the extreme conditions of high-resolution columns. 

Wang, H., Hanash, S. (2005). Intact-protein based sample preparation strategies for proteome analysis in combination with mass spectrometry. Mass Spectrom. Rev. 24, 413 126. 

The recent trend of decreasing available sample volumes and requiring lower limits of quantitation (LLOQs) means better sample preparation procedures are under consideration. Further improvements MS sensitivity will eventually impact sample preparation strategies and sample throughput. 

DOE (US Department of Energy) (2007b). America s Strategic Unconventional Fuels. Volume I - Preparation Strategy, Plan and Recommendations. Task Force on Strategic Unconventional Fuels, www.unconventionalfuels.org. 

S.F. Willigeroth, K. Beneke, M. Hannig, R. Zimehl, Preparation strategies for phosphate-based mineral biomaterials. Prog. Colloid Polym. Sci. 121 (2002) 1-6. 

When entrapment methods are being used for heterogenization, the size of the metal complex is more important than the specific adsorptive interaction. There are two different preparation strategies. The first is based on building up catalysts in well-defined cages of porous supports. This approach is also called the ship in a bottle method [29]. The other approach is to build up a polymer network around a preformed catalyst. 

---