SAMIM

In order to reduce the adhesion between a polymeric mold and a silicon/quartz master, the master surface is typically modified with a fluorosilane e.g., CF3(CF2)6(CH2)2SiCl3(g)). In addition, the final removal of the mold may also be carried out in the presence of a liquid with a low viscosity such as methanol (solvent-assisted micromolding (SAMIM)). 

Solvent-Assisted Microcontact Molding (SAMIM) A small amount of solvent (e.g., methanol, ethanol, or acetone) is spread on a patterned PDMS stamp which is placed on a polymer, such as photoresist. The solvent swells the polymer and causes it to expand to fill the surface relief of the stamp. Feature size as small as 60 nm can be reached. 

Yadav A, Lomash V, Samim M, Flora SIS. Curcumin encapsulated in chitosan nanoparticles A novel strategy forthe treatment of arsenic toxicity. Chem Biol Interact 2012 199(1) 49-61. 

The PRINT technique is analogous to micromolding in capillaries (MMIC) or solvent-assisted micromolding (SAMIM), with the use of perfluorinated polymers rather than silicones (Figure 4.72). The use of PFPE instead of PDMS molds offers the following benefits (Figure 4.73) ... 

Figure 4.72. Schematic of soft lithographic procedures for (a) replica molding (REM), (b) microtransfer molding (pTM), (c) micromolding in capillaries (MIMIC), and (d) solvent-assisted micromolding (SAMIM). Reproduced with permission from Angew. Chem. Int. Ed. 1998, 37, 550. Copyright 1998 Wiley-VCH.

Figures 3.2 and 3.3 show SEM images of several 3D structures formed by soft molding or SAMIM. The circular cones shown in Figure 3.2a have a base diameter of approximately 1 pm. Rounded triangular channels with a period of approximately 3 pm are depicted in Figure 3.2b. A three-level structure is shown in Figure 3.2c. These results demonstrate the effectiveness of solvent-assisted molding in fabricating 3D structures. SAMIM can also replicate complex relief structures over large...

Figure 33 Images of polymeric microstructures fabricated by SAMIM. (a-<) SEM images of quasi three-dimensional structures in photoresist (Microposit 1805, Shipley 1.6(im thick) spin-coated on Si/SiOz, polystyrene (PS, Goodfellow 2.0 pm thick), and ABS (Goodfellow 0.85 pm thick), respectively.

H. Kiyani, H.A. Samim, F. Ghorbani, S. EsmaieU, One-pot, four-component synthesis of pyrano[2,3-c]pyrazoles catalyzed by sodium benzoate in aqueous medium, Curr. Chem. Lett. 2 (2013) 197-206. 

In Europe, a small number of large custom smelters (Metaleurop, MetaUgesellschaft and Nuova Samim) are responsible for the majority of lead concentrate purchases, sometimes holding equity interests in supplying mines. Similarly, three Japanese smelters account for almost the entire custom concentrate imports into Japan. Asarco (in the USA) has custom smelted... 

A number of companies in Europe (Metallgeseiischafc, Metaleurop, Nuova Samim, for example) have important secondary interests in addition to primary smelting activities, and have been actively developing these. So too has MIM, through ownership links with Britannia Refined Metals in the UK. In North America, while several primary smelters use lead scrap feed. Doe Run s Buick secondary plant (opened in 1991) was the first example of direct primary producer involvement in recycling facilities. Emissions from this plant are apparently 60 per cent less than at traditional secondary lead facilities. 

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