N-dodecylpyridinium

Surfactants greatly improve the performance of trans-cinnamaldehyde as a corrosion inhibitor for steel in HCl [741,1590,1591]. They act by enhancing the adsorption at the surface. Increased solubility or dispersibility of the inhibitor is an incidental effect. N-dodecylpyridinium bromide is effective in this aspect far below its critical micelle concentration, probably as a result of electrostatic adsorption of the monomeric form of N-dodecylpyridinium bromide. This leads to the formation of a hydrophobic monolayer, which attracts the inhibitor. On the other hand, an ethoxylated nonylphenol, a nonionic surfactant, acts by incorporating the inhibitor into micelles, which themselves adsorb on the steel surface and facilitate the adsorption of trans-cinnamaldehyde. 

Mixtures of aldehydes with surfactants are active in preventing corrosion, in particular in the presence of mineral or organic acids [646]. The aldehyde may be trans-cinnamaldehyde. The surfactant may be N-dodecylpyridinium bromide or the reaction product of trimethyl-1-heptanol with ethylene oxide [645]. Such aldehyde and surfactant mixtures provide greater and more reliable corrosion inhibition than the respective compositions containing aldehydes alone. 

Figure 18.11 (a) Osmotic coefficient (b) apparent relative molar enthalpy (c) apparent molar volume and (d) apparent molar heat capacity, at T = 298.15 K and p = 0.1 MPa, for (1) n-decylpyridinium chloride and (2) n-dodecylpyridinium chloride. 

The effect of temperature on the thermodynamic properties and the CMC is shown in Figure 18.13, where 4>L, < >CP and (f>V at three temperatures are graphed as a function of the molality m for n-dodecylpyridinium chloride. We can interpolate the results in Figure 18.13a to determine that L at the CMC is near zero for this surfactant at a temperature near, but just above, 298.15 K. When 4>L = 0, the CMC is at its minimum value. We will better understand why as we consider theories for describing the curves shown in Figures 18.11 and 18.13. 

Figure 18.13 Effect of temperature on (a) apparent relative molar enthalpies (b) apparent molar volumes and (c) apparent molar heat capacities, for n-dodecylpyridinium chloride. The temperatures are (1) 298.15 K (2) 313.15 K and (3) 328.15 K.

The thermodynamic properties at T = 298.15 K shown in Figure 18.11 come from S. Causi, R. De Lisi, and S. Milioto, Thermodynamic properties of N-octyl-, N-decyl- and N-dodecylpyridinium chlorides in water , J. Solution Chem., 20, 1031-1058 (1991). Results at the other two temperatures are courtesy of K. Ballerat-Busserolles, C. Bizzo, L. Pezzimi, K. Sullivan, and E. M. Woolley, Apparent molar volumes and heat capacities at aqueous n-dodecyclpyridium chloride at molalities from 0.003 molkg-1 to 0.15 molkg-1, at temperatures from 283.15 K. to 393.15 K, and at the pressure 0.35 MPa , J. Chem. Thermodyn., 30, 971-983 (1998). 

Cationic counter-ion N-Dodecylpyridinium chloride silanized silicagel... 

The zwitterion, N-dodecylpyridinium-3-carboxylate converted in an acetonitrile suspension with an acetonitrile solution of nitronium tetrafluoroborate to the nitro ester, upon treatment with phenol gave 2-nitrophenol in 95% yield (ref.61). 

Laurylpyridinium chloride CAS 104-74-5 EINECS/ELINCS 203-232-2 Synonyms 1-Dodecylpyridinium chloride N-Dodecylpyridinium chloride ... 

FIG. 5 Cis conformation with respect to the amide bond of sodium IV-lauroylsarcosi-nate upon vesicle formation in an equimolar mixture with N-dodecylpyridinium chloride. 

Before the experiment, it was immersed in a dilute solution of the surfactant, n-dodecylpyridinium chloride (DPyCl) (Tokyo Kasei Co., Ltd.) containing 3x10 M sodium sulphate (Wako Pure Chemicals Industries, Ltd.). The structure of this surfactant is illustrated in Figure A. 1(c). 

Table 25 Ri Values of Indole Derivatives on Silanized Silica Gel Untreated and with 4% N-Dodecylpyridinium Chloride (NDPC) ...

Uchman M et al (2012) Coassembly of poly(ethylene oxide)-block-poly(methacrylic acid) and n-dodecylpyridinium chloride in aqueous solutions leading to ordered micellar assemblies within copolymer aggregates. Macromolecules 45 6471-6480. doi 10.1021/ma301510j... 

Polyelectrolyte gels with strong static potential also adsorb ionic sur ctant with opposite charge. Figure 3 shows the adsorption isotherms of die cationic surfactant, N-dodecylpyridinium chloride (C]2PyCl), on the anionic polymer gel, poly (2-acrylamide-2-methylpropanesulfonic acid) (PAMPS). This figure is compared with the corresponding linear polymer solution [38]. 

N-dodecylpyridinium chloride (Ci2PyCl), 107 Dripping properties of paint, 385 Drug delivery, 142 Drug delivery behavior... 

Dodecylpyridinium chloride N-Dodecylpyridinium chloride Dodecylpyridin-ium chloridel. See Laurylpyridinium chloride Dodecylpyridinium sulfate. See Laurylpyridinium bisulfate 1-Dodecyl-2-pyrrolidinone N-Dodecylpyrrolidinone N-Dodecyl-2-pyrrolidone. See Lauryl pyrrolidone... 

Isothermal titration microcalorimetry has been used to determine directly the enthalpy of micellization (AH ) of l-alkyl-4-n-dodecylpyridinium surfactants with several counterions in aqueous solutions. The values of AH for all these micelle-forming cationic surfactants vary within -1.7 to -22.4 kJ/mol at a constant temperature of 30°C. The increase in temperature from 30 to 50°C decreases AH,n° by nearly 8 to 13 kJ/mol for all surfactants of the study. Recently, the... 

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