Split and Recombination

The splitting and recombination of the beam is accomplished by means of two rotating sector mirrors which are geared to the same electric motor so that they work in unison (Fig. 17.12). The microprocessor which is used to operate such an instrument will automatically correct for the dark current of the photocell, i.e. the small current which passes even when the cell is not exposed to radiation. 

A chemical library is a precisely defined collection of different chemical compounds. Chemical libraries can be either prepared by parallel synthesis or by split-and-recombine synthesis. 

These conceptual goals are attained by several combinatorial methods and tools. Characteristic for combinatorial chemistry is the synthesis on solid support or by polymer-supported synthesis, allowing for much higher efficiency in library production. Synthesis can be conducted either in automated parallel synthesis or by split-and-recombine synthesis. Centerpieces of combinatorial methods further include specific analytical methods for combinatorial... 

Split-and-Recombine Synthesis for the Preparation of Large Libraries... 

Introduced in the early 1990s, the split-and-recombine concept contributed much to the early success of combinatorial chemistry. Often, all combinatorial methods were identified with this concept. Split-and-recombine synthesis offered easy access to large number of individual compounds in few steps. If conducted on polymer beads, these are easily separated mechanically and can be identified subsequent to a screening step. 

Combinatorial Chemistry. Figure 2 Chemical libraries are prepared either by parallel synthesis or by the split-and-recombine method. In the latter case, coupling m building blocks in m separated reaction flasks through n synthetic cycles on a beaded polymer carrier generates a combinatorial library with nf individual compounds and one compound per bead. 

Neglecting flow nonuniformities, the contributions of molecular diffusion ana turbulent mixing arising from stream splitting and recombination around the sorbent particles can be considered additive [Langer et ah, Int. J. Heat and Mass Transfer, 21, 751 (1978)] thus, the axial dispersion coefficient DL is given by ... 

Figure 4 Micromixers, (a) Interdigital structure of a multilamination micromixer. (b) Principle of split-and-recombine static micromixers. (Source IMM.)...

This approaches the performance of conventional static mixers, closing the gap between this smallest class of industrially used apparatus and micro mixers for analytical purposes [130], Thus, a toolbox of microstructured mixers is available for the whole range of flow rates. This box comprises interdigital multi-laminating with a few ml h 1 capacity and split-and-recombine micro mixers (caterpillar type) up to 1001 h 1 as well as interdigital concentric microstructured mixers (StarLam type) series achieving 300, 1000 and up to 3000 1 h, dependent on the respective sub-version. 

Split-and-recombine Mixing Most Relevant Citations... 

Mixer 56 [M 56] Mdbius-type Split-and-recombine Micro Mixer... 

C., An optimized split-and-recombine micro mixer with uniform chaotic mixing, Lab Chip 2004, 4, 65-69. 

---