High-throughput materials, synthesis

High-Throughput Materials Synthesis and Solution Characterization ... 

Electrocatalytic activity of supported metal particles has been investigated on surfaces prepared in an ultrahigh vacuum (UHV) molecular beam epitaxy system (DCA Instruments) modified to allow high throughput (parallel) synthesis of thin-film materials [Guerin and Hayden, 2006]. The system is shown in Fig. 16.1, and consisted of two physical vapor deposition (PVD) chambers, a sputtering chamber, and a surface characterization chamber (CC), all interconnected by a transfer chamber (TC). The entire system was maintained at UHV, with a base pressure of 10 °mbar. Sample access was achieved through a load lock, and samples could be transferred... 

In the same publication, a method for the parallelization of TAP experiments was also indicated. It was stated that ...high-throughput transient kinetics carried out in addition to high-throughput catalyst synthesis and testing both accelerate the search for new catalytic materials and bring fundamental insights into reaction mechanisms. ... 

The combinatorial assembly of isocyanate-decorated dendrimers was reported by Newkome et al. (93) as a method to modulate the solubility, reactivity and viscosity properties of such popular materials. This modulation has an obvious impact for the discovery of high loading, soluble and flexible supports for high throughput organic synthesis. 

D. Dendukuri, D. Pregibon, J. Collins, T. Hatton, and P. Doyle, Continuous-flow lithography for high-throughput microparticle synthesis, Nature Materials, 5, 365-369, 2006. 

Active heterogeneous catalysts have been obtained. Examples include titania-, vanadia-, silica-, and ceria-based catalysts. A survey of catalytic materials prepared in flames can be found in [20]. Recent advances include nanocrystalline Ti02 [24], one-step synthesis of noble metal Ti02 [25], Ru-doped cobalt-zirconia [26], vanadia-titania [27], Rh-Al203 for chemoselective hydrogenations [28], and alumina-supported noble metal particles via high-throughput experimentation [29]. 

Guerin S, Hayden BE. 2006. Physical vapor deposition method for the high-throughput synthesis of solid-state material libraries. J Comb Chem 8 66-73. 

Hahndorf, I., Buyevskaya, O.V., Langpape, M. et al. (2002) Experimental equipment for high-throughput synthesis and testing of catalytic materials. Chem. Eng. J., 89, 119. 

Several articles in the area of microwave-assisted parallel synthesis have described irradiation of 96-well filter-bottom polypropylene plates in conventional household microwave ovens for high-throughput synthesis. While some authors have not reported any difficulties in relation to the use of such equipment (see Scheme 4.24) [77], others have experienced problems in connection with the thermal instability of the polypropylene material itself [89], and with respect to the creation of temperature gradients between individual wells upon microwave heating [89, 90]. Figure 4.5 shows the temperature gradients after irradiation of a conventional 96-well plate for 1 min in a domestic microwave oven. For the particular chemistry involved (Scheme 7.45), the 20 °C difference between the inner and outer wells was, however, not critical. 

Apart from the traditional organic and combinatorial/high-throughput synthesis protocols covered in this book, more recent applications of microwave chemistry include biochemical processes such as high-speed polymerase chain reaction (PCR) [2], rapid enzyme-mediated protein mapping [3], and general enzyme-mediated organic transformations (biocatalysis) [4], Furthermore, microwaves have been used in conjunction with electrochemical [5] and photochemical processes [6], and are also heavily employed in polymer chemistry [7] and material science applications [8], such as in the fabrication and modification of carbon nanotubes or nanowires [9]. 

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