Polymer-coated rods

Table I. Relative Thrombogenicity of Vein Segments Placed on Polymer-Coated Rods...

Stir-Bar Sorptive Extraction This technique was developed to overcome the problems related to the very small amount of fiber coating material that is applied in SPME. Stir-bar sorptive extraction (SBSE) utilizes a magnetic rod coated with polymeric sorbent. Such a concept was introduced by Baltussen [92]. The magnetic stir bars have a length of 1 or 2 cm, and the polymer film a thickness of 500 or 1000 pm. The bar provides a large volume of polymer coating and its sorption capacity is much higher than in the conventional SPME method. In this technique, the sorbent-coated stir-bar is exposed directly to the liquid sample. When equilibrium is reached, the stir-bar is placed in the thermal desorber unit and analytes are released into GC. 

ESR signals [7] observed with LCVD-coated glass rods are shown in Figures 6.5, and 6.6. By removing plasma polymer coating from the surface of a glass rod, it is possible to quantitatively examine both the free spins in the plasma... 

Besides rings, spontaneous formation of nanoparticle strip patterns has been observed on dewetting a dilute film of polymer coated nanoparticles floating on a water surface [577]. Hybridization of branched DNA trimers and Au nanoparticle DNA conjugates have been employed to produce discrete self-assembled nanoparticle dendrimers [578]. Self-assembly of triangular and hexagonal CdS nanocrystals into complex structures such as rods and arrows has been observed [579]. Furthermore, self-assembly of CdSe nanoparticle-copolymer mixtures has been observed wherein the copolymers assemble into cylindrical domains that dictate the distribution of the nanoparticles [580]. 

Laminates or polymer coatings containing dispersed rods or nanoshells could provide a cheap and effective solution for application of spectrally selective coatings of nanoparticles to existing structures. A novel implementation of this is to impart NIR/IR extinction properties of nanoshells to protective eyewear or contact lenses [93]. 

The opacity of plastic foams, and polymers with scratched surfaces, is also governed by Fresnel s law. The n value of the gas which occupies the scratch indentation is much lower than that of the polymer. Light may be directed through rods of transparent polymers, such as PMMA. This effect may be enhanced when the rod or filament is coated with a polymer with a different refractive index, such as polytetrafluoroethylene (ptfe). Optical fibers utilize this principle. 

Polytetrafluoroethylene powders can be extruded but not by the methods applied to conventional thermoplastics. The polymer must not be subjected to excessive mechanical working above the melting point or cracking of the finished piece will result. For this reason, the polymer is worked while it is still cold. The powder is compacted with the aid of a screw or a ram and forced through a hot die in which it is sintered (James). This method is used to fabricate rods or heavy wall tubing or to apply heavy coatings to electrical conductors. 

Glutamate Sensors. The glutamate sensors were constructed using graphite rods (Ultracarbon, Bay City, MI), which were polished to a smooth finish and coated with a small amount of redox polymer (0.033 Mmole of polymer-bound ferrocene) dissolved in chloroform. After evaporation of the solvent, a 5 m1 aliquot of glutamate oxidase (Yamasa Shoyu Co., Japan) solution (100 units/ml in pH 7.0 phosphate buffer) was added to the surface and allowed to dry at room temperature. The electrodes were stored under dry conditions at 5°C. 

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