Octyltrimethylammonium bromide

Kodak) and cetyltrimethylammonium bromide, gTAB (Sigma) were purchased as indicated and then purified by recrystallization from ethanol. However, hexyltrimethylcunmonium bromide (CgTAB) and octyltrimethylammonium bromide (CgTAB) were synthesized by refluxing either 1-bromohexane or 1-bromooctane (Aldrich) with trimethylamine methanol solution and finally recrystallized twice from benzene.(5) An anionic surfactant, sodium dodecyl sulfate,... 

Let us consider the effect of surfactant on the properties of the polymer boundary layers. Octyltrimethylammonium bromide (OTMAB) integrated into the compound was used as surfactant. Figure 2.23 shows that surfactant that has little effect on the cure rate of the epoxy compound in the bulk does increase the rate and the degree of conversion in the boundary layer on the surface of KRS-5. The adsorption of surfactant on the interface seems to remove the selective sorption of the epoxy resin, which excludes the opportunity for formation of the undercured boundary layer and results in increase of the adhesion strength (Table 2.8). 

CsBr = octyltrimethylammonium bromide, = dodecyltrimethylammonium bromide, C gOH = hexadecyltrimethylammonium hydroxide, C.10CI = hexadecyltrimethylammonium chloride, C gBr = hexadecyltrimethylammonium bromide, CieOH = octadecyitrimethyi-ammonium hydroxide, HEX = hexadecane, TOL = toluene, MES = mesitylene... 

As concerns the concentration of the surfactant, the optimum value equals ca 4.4 molecules per one molecule of AI2O3. With higher concentrations of surfactant (such as 10 molecules per one molecule of AI2O3) the channel structure forms but some problems may arise. With AIMS-63 a greater concentration of the surfactant (octyltrimethylammonium bromide) was needed because of its much higher solubility in comparison with surfactants containing longer alkyl chains. 

FIG. 6 Instrumental response curves (calorimeter signals and refractive index detector signals) of the step-by-step displacement of water (2) by n-octyltrimethylammonium bromide (1) on Vulcan 3G graphitized carbon black at 298.15 K. The adsorption path is followed by the desorption path. The concentration increments are indicated in the figure in mmol/dml... 

Data for many other surfactants have been reported sodium alkylsulfates ° ° sodimn hexylsrdfate and hexylammonium chloride in brine solution i octylam-monium chloride, octyltrimethylammonium chloride and bromide, and sodium and potassium capiylates sodium /j-(l-propylnonyl)benzenesulfonate ii dode-cylp5rridinium chloride and bromide heptylammo-nium chloride nonionic surfactants C ,H2 ,+i (OCHgCHglnOH with various m and n values perfluorinated anionic surfactants and cationic surfactants with a perfluoroalkylcarboxylate counterion. Some of these data must be reanalyzed using Equation 3.9 or, if the required data are available, Equation 3.16, in order to extract meaningful rate constants. 

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