Polymer chips

Fu et al. [73] used a hybrid device for fabrication and packaging of microchips. This method consisted of a layer of inorganic substrate like silicon wafer and organic elastomer such as PDMS to perform multiple functions on an integrated chip. 

Lagally et al. [74] developed an integrated device for PCR and NCE with electric field control and fluorescence detection. Furthermore, the device had integrated heaters and temperature sensors, as well as PDMS membrane valving to control analyte transport. The PDMS unit was fabricated as membrane valves between a glass PCR chamber and the glass NCE channel, allowing precise control of both process unit operation and analyte transport. 

Zhao et al. [75] described a protocol for creating micron sized structures in the substrate material to design, produce, and fabricate a microfluidic system with 

Pour PDMS over master cure at 70°C for 1 hour 

Zhu et al. [76] designed and fabricated microfluidic devices on polymethylmethacrylate (PMMA) substrates for electrochemical analysis applications using an improved UY-LIGA process. The microchannel structures were transferred from a nickel mold onto the plastic plates by the hot embossing 

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Synthetic Fiber and Plastics Industries. In the synthetic fibers and plastics industries, the substrate itself serves as the solvent, and the whitener is not appHed from solutions as in textiles. Table 6 Hsts the types of FWAs used in the synthetic fibers and plastic industries. In the case of synthetic fibers, such as polyamide and polyester produced by the melt-spinning process, FWAs can be added at the start or during the course of polymerization or polycondensation. However, FWAs can also be powdered onto the polymer chips prior to spinning. The above types of appHcation place severe thermal and chemical demands on FWAs. They must not interfere with the polymerization reaction and must remain stable under spinning conditions. 

The polymer chips comprise two feed micro channels which are connected in a Y-type flow configuration to one elongated micro channel which is folded multiple times for compact design [29]. At the end of this channel a split into two channels is made, again by a Y-type flow configuration. The two-channel flow configuration serves for preparing water-oil parallel (bi-laminated) streams. 

An example of typical equipment used to make PET fibers is shown in this figure. Prior to melting, the polymer chips must be thoroughly dried, typically under vacuum at elevated temperatures for several hours. The equilibrium moisture content of PET under ambient conditions is about 0.4 % [3] and this much moisture would cause unacceptable levels of degradation. The dried polymer chips are fed to an extruder which melts the chips and forwards them to a... 

Fine fibers of PET usually appear white, even though the polymer chips that they are made from may appear grey in color. This is a consequence of the high amount of specular reflection of ambient light, emanating from the large surface area of the fibers. 

To produce the melted polymer, the polymer chips, rods, marbles, or sheets are heated forming a melted pool of material. In order to minimize oxidation, the melted polymer is blanketed by an inert gas such as nitrogen or argon. The fluidity (inverse of viscosity) of the melt increases with increased temperature as does the cost to provide the necessary energy and tendency for unwanted reactions to occur. Thus, the polymer melt is generally assisted to and through the spinneret by means of an extruder, which may also be used to supply some or all of the heating. 

The use of capillaries to run immunoassay reactions was presented in the 1980s and 1990s by Halsall group [8] for the detection of atrazine. The system was based on a flow injection analysis protocol where different solutions (sample, conjugate) were injected and reacted in the capillary itself the affinity-captured enzyme conjugate then reacted with a substrate solution injected in the capillary prior to detection. The reacted substrate solution was then pushed towards an electrode for amperometric detection. The authors showed that the incubation time reached equilibrium after about 20 min, but they worked with a capillary of 360 pm diameter. In order to really reduce the incubation time below lmin, we developed disposable polymer chips with an internal diameter of 40 pm (almost one order of magnitude smaller than... 

Similar to computer technologies, so-called plug and play micro fluidic devices were developed. These devices are composed of a fluid driving unit and a polymer chip containing micro fluidic channels and reservoirs. The one and only connection is an electrical bus system which connects the chip with the external control unit. By filling the reservoirs with reagents, the chip can be used for performing chemical reactions or biochemical analysis [72],... 

Griebel, A., Rund, S., Schonfeld, F., Domer, W., Konrad, R., Hardt, S., Integrated polymer chip for two-dimensional capillary gel electrophoresis. Labchip 2004, 4, 18-23. 

Prest, J.E., Baldock, SJ., Fielden, P.R., Goddard, N.J., Brown, B.J.T., Miniaturised isotachophoretic analysis of inorganic arsenic speciation using a planar polymer chip with integrated conductivity detection. J. Chromatogr. A 2003,990, 325-334. 

Seki, M., Yamada, M., Ezaki, R., Aoyama, R., Hong, J.W., Chromatographic separation of proteins on a PDMS-polymer chip by pressure flow. Micro Total Analysis Systems, Proceedings 5th p7i45 Symposium, Monterey, CA, Oct. 21-25, 2001, 48-50. 

Sample Composition, TGA, and LOI Results of Compounded Polymer Chips, Tapes and Strings, and Effect of Additives on the Fiber and Fabric Properties... 

Sample Composition, TGA, LOI, and Flame Spread Results of Compounded Polymer Chips and Strings of Nylon 6 with/without Clays and Flame Retardants... 

Recycling begins with sorting plastics by type, shredding the plastics into small chips, and washing the chips to remove adhesives and labels. After the chips are dried and any metal caps or rings are removed, the polymer chips are melted and molded for reuse. 

Hong JW, Hosokawa K, Fuji T, Seki M> Endo I. Microfabricated polymer chip for capillary gel electrophoresis. Biotechnol Prog 2001 17 958-62. 

DrobnyJ.G.,"Radiation Technology for Polymers", CHIPS, Weimar, 2002. 

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