Octadecylamine

Filming amines In such situations, one approach is to use the filming type of amine, of which octadecylamine is the most common example. This, and related substances, forms a barrier on the internal surfaces of the feed system offering some protection against corrosive attack. 

Condensate treatments include neutralizing amines such as morpholine and filming amines such as octadecylamine (ODA). 

Octadecylamine (filming amine) 3 ppm maximum in steam, and excluding the use of such steam in milk and milk products. 

Some commonly used filming amines are better at promoting dropwise condensation, whereas others, notably octadecylamine (stearylamine), are better at reducing friction and improving the drop runoff rate. 

Filmers are based on primary, secondary, or tertiary monoamines or diamines and contain alkyl chains with from 8 to 22 carbons. The most prominent material is the 18-carbon-chain aliphatic monoalkylamine, octadecylamine (ODA). 

Amine acetates [R-NH2-CH3COOH]. Examples include hydrogenated tallowalkylamine acetate and octadecylamine actetate. 

Simple Filmer Formulation (a) Materials Octadecylamine 10% emulsion 100.0%... 

FIG. 9 Silver nanoparticles capped by 4-carboxythiophenol electrostatically adsorbed to positively charged octadecylamine monolayers, (a) Mass uptake versus number of layers at subphase pH 12 and pH 9 the inset shows the contact angle of water versus the number of layers, (b) Absorbance spectra as a function of the number of layers transferred (left), with the inset showing the plasmon absorbance at 460 nm versus the number of layers. Thickness versus number of layers as determined by optical interferometry is shown on the right. (Reprinted with permission from Ref. 103. Copyright 1996 American Chemical Society.)... 

DNA solution (25 mg/mL) was used as a subphase. Octadecylamine monolayer was spread at the subphase surface and compressed to the surface-pressnre valne of 15 mN/m. The adsorption of DNA at the amine head groups was performed for 1 hour. Then the layer was compressed to 30 mN/m and the film was transferred onto solid snbstrates. 

Such layer structure does not allow ns to say a priori that hybridization of DNA will be possible, for it is protected by the octadecylamine layer. In order to control for this possibility, fluorescence measurements were performed. The first indication that hybridization was successful is that after the process, the sample surface became wettable, while before it and after cold hybridization it was not wettable at all. The results of the fluorescence measurements are summarized in Table 10. The results of the specific hybridization are three times more with respect to unspecific hybridization and one order of magnitude more with respect to cold hybridization. Thus, it appears that during a normal hybridization (100% homology) some structural changes and redistribution of the layer takes place. As a result, DNA becomes available for the specific reaction. Such a model also explains why the fluorescence level after unspecific hybridization (10% homology) is higher with respect to cold hybridization. Because the molecules have some mobility when the film is warmed, some DNA from the film could be hybridized on itself, while during cold hybridization this is impossible. 

In 1997, a Chinese research group [78] used the colloidal solution of 70-nm-sized carboxylated latex particles as a subphase and spread mixtures of cationic and other surfactants at the air-solution interface. If the pH was sufficiently low (1.5-3.0), the electrostatic interaction between the polar headgroups of the monolayer and the surface groups of the latex particles was strong enough to attract the latex to the surface. A fairly densely packed array of particles could be obtained if a 2 1 mixture of octadecylamine and stearic acid was spread at the interface. The particle films could be transferred onto solid substrates using the LB technique. The structure was studied using transmission electron microscopy. 

The use of ordered supramolecular assemblies, such as micelles, monolayers, vesicles, inverted micelles, and lyotropic liquid crystalline systems, allows for the controlled nucleation of inorganic materials on molecular templates with well-defined structure and surface chemistry. Poly(propyleneimine) dendrimers modified with long aliphatic chains are a new class of amphiphiles which display a variety of aggregation states due to their conformational flexibility [38]. In the presence of octadecylamine, poly(propyleneimine) dendrimers modified with long alkyl chains self-assemble to form remarkably rigid and well-defined aggregates. When the aggregate dispersion was injected into a supersaturated... 

Fig. 12 Cobalt nanorods synthesized in the presence of a mixture of oleic acid and a octylamine b dedecylamine c hexadecylamine d octadecylamine...

HDZ = hydrazine Igepal CO-520 = polyoxyethylene(5)nonylphenyl ether ISO = isooctane LAc = linoleic acid MA = methylamine MST = mesitylene Ni°(cod)2 = bis (r]4-l,5-cyclooctadiene) Ni(0) NMPyr = N-methylpyrrole OA = oleylamine OAc = oleic acid Oc = octane OcA = octylamine ODA = octadecylamine PAA = poly (acrylic add) PD = 2-pyrrolidone Igepal CA-520 = polyoxyethylene(5)isooctylphenyl ether PVP = polyvinylpyrrolidone Pyr = pyrrole RAc = ricinoleic acid ... 

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