Polymer coating procedure

The amount of polymer added per quantum dot was standardized with reference to the number of surface atoms on the quantum dot. This relationship was used in order to shed light on the mechanism of interaction between the quantum dots and the polymer, and to simplify the extrapolation of the polymer coating procedure to other nanocrystalline materials, without the need... 

The rqjroducibility of polymer film formation is greatly improved by the spin coating technique where the polymer solution is applied by a microsyringe onto the center of a rapidly rotated disk electrode Rather thick films can be produced by repeated application of small volumes of stock solution. A thorough discussion and detailed experimental description of a reliable spin coating procedure was given recently... 

For Gg (b), a reasonable (although not strictly correct) procedure is to replace the Stern potential in one of the standard equations for Gg by the zeta potential of the polymer-coated particles this assumes that the plane of hydrodynamic shear corresponds to the periphery of the adsorbed layer. 

The OFRR interior surface is then coated with various polymers, such as moderately polar methyl phenyl polysiloxane (OV-17) or highly polar polyethylene glycol (PEG), for the detection of different types of chemical vapors. The coating procedures are adapted from well-developed static coating procedures for GC... 

Polypyrrole readily forms acceptable films under a wide variety of conditions [86] though there are subtle distinctions in behaviour as a result of exact preparation procedure [87]. Ultrasound at 20 kHz at sufficient intensity impedes polypyrrole formation and removes the polymer coating from the electrode [88]. At higher ultrasonic frequencies (e.g. 800 kHz) a free-standing film is produced which can be peeled from the electrode. This film has the interesting feature that the imprint of the wave-... 

The next patent of interest in the current pyrot literature is that of Duguet (Ref 30) which suggests that silicone oil can be used to coat powdered ingredients such as Pb azide as part of a coating compn which may also include either polyesters, polyurethanes or NC. The purpose of the coating is to decrease friction and hot-wire sensitivity. The coating procedure includes soln of the polymer in a ketone (2— 20%), addn of 10—60 wt % of the azide, and finally the addn of 20—60 wt % of the silicone oil. The coated grains are then dried in the open for 2—3 hrs. 

The synthetic polymer Nation is an anionic, inert polymer that has hydrophilic and hydrophobic properties. Nation is composed of perfluorosulfonic acid and has shown to increase the lifetime of sensors and to decrease the inflammatory response in the short term and decrease interferents (believed to be due to the anionic property). Nation can be applied as an outer coating to sensors through a dip coating or spin coating procedure to entrap the enzyme and improve biocompatibility of the... 

Solid-phase microextraction (SPME) — is a procedure originally developed for sample preconcentration in gas chromatography (GC). In this procedure a small-diameter fused silica optical fiber, coated with a liquid polymer phase such as poly(dimethylsiloxane), is immersed in an aqueous sample solution. The -> analytes partition into the polymer phase and are then thermally desorbed in the GC injector on the column. The same polymer coating is used as a stationary phase of capillary GC columns. The extraction is a non-exhaustive liquid-liquid extraction with the convenience that the organic phase is attached to the fiber. This fiber is contained in a syringe, which protects it and simplifies introduction of the fiber into a GC injector. Both uncoated and coated fibers with films of different GC stationary phases can be used. SPME can be successfully applied to the analysis of volatile chlorinated organic compounds, such as chlorinated organic solvents and substituted benzenes as well as nonvolatile chlorinated biphenyls. 

Batch use of imprinted polymers has been applied in the evaluation of polymers by saturation binding tests and in the applications of molecularly imprinted sorbent assays [1,23,24]. In a common procedure, imprinted polymers obtained as blocks were crushed, ground and sieved to prepare sized polymer particles. The resultant particles were then distributed into each vial and recovered by filtration after use. Recently, a new batch-type in situ procedure has been reported. It utilises a polymer coating prepared on an inner surface at the bottom of a vial and allows direct assessment of the polymers. In this section, this type of in situ preparation of imprinted polymers and an application to combinatorial chemistry are described. 

The procedure for correcting the observed retention data involved the following steps. First, the area of the peak from a polymer-coated column was inserted into Equation 8 to determine the support retention corresponding to that particular area. Then the computed VnsuPvalue was subtracted according to Equation 11. This procedure was found to yield high reproducibility for Vg data, which was unattainable otherwise. 

---