Polymer coating method contamination

Although the polymer coating-based TRCS is inexpensive and convenient method as described above, there are some issues related to contamination by (1) the desorption of the coated polymer during cell culture and/or by lowering temperature as mentioned above and (2) difficulty in fabricating cell sheet without a defect. The issues may be problems in cell sheet-based tissue engineering. 

Microspectroscopy applies the identification power of infrared spectroscopy to the microscopic realm. Contaminants on printed circuit boards, blemishes in coatings, and other production defects can be isolated in situ and analyzed (see Electronics, coatings). Analysis of flaws that develop during use illuminates the method of failure. Microscopic samples, such as particulates filtered from air, can be analyzed individually. The forensic applications are many paint chips, single fibers, explosive residues, and inks on currency can all be identified nondestmctively (see Forensic chemistry). The structures of layered materials, such as laminated polymer films, are studied via microspectroscopy by cross-sectioning the materials and examining the individual layers edge on (47). 

The initial alloy coatings deposited on to polymers showed a tendency to exhibit pinhole defects most of which have since been attributed to the presence of dust particles. Polymer films have a propensity to accumulate an electrostatic charge that attracts fine particles. As an alternative, interim method to address the issue of defects in the Pd-Cu alloy membrane films, films were deposited onto smooth, silicon wafers. Particulate and other contaminants can be more readily controlled (i.e., minimized) on a silicon surface, in comparison to plastic, and is considerably smoother than plastic. In experiments using magnetron sputtering, we were able to produce defect-free Pd-Cu films on 12 in. diameter silicon and 4 in. square glass plates. A released film, 4 p.m thick, is shown in Fig. 11.4. Films as thin as 0.7 p.m have been produced in this way. 

Nanocomposites are materials in which nanoparticles (in this case, nanorods) are dispersed in a continuous matrix. The matrix may be a polymer, nanorods, or other nanoparticles. Nanorod composites find applications in diverse areas such as efficient charge storage, removal of contaminants (e.g. surfactant) from water, emissivity control devices, and metallodielectrics, and so on. A number of methods such as electroless deposition, the sol-gel method, the hydrothermal method, solution casting, carbother-mal reduction, the template-based method, the sonochemical method, and electrospinning can be used to prepare composite nanorods. Nanorod composites are different from core-shell nanorods. In core-shell nanorods, the coating is uniform, whereas in the nanorod composite (consisting of a nanorod and a nanoparticle on a surface), fine nanoparticles are dispersed on the surface of the nanorods. Some specific examples of the preparation of nanocomposites consisting of nanorods are described below. 

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