NMR spectra of surfactant

Figure 1 Si liquid state NMR spectra of surfactant-silicate mixtures a) waterglass 0.5M Si02 0.1M CTAB 0.9M NaOH, experiment 3, Table 1, b) octameric silicate species (D4R) 0.5M SiC>2 0.1M CTAB 1.0M TMAOH 21vol% MeOH, experiment 11, Table 1 and c) waterglass 0.5M Si02 0.1M CTAB 0.4M NaOH 0.6M TMAOH 21vol% MeOH experiment 4, Table 1 ( external reference)...

Figure 6. 13C, 1II-decoupled NMR spectra of surfactant in chloroform-v concentrations are wt % surfactant (S) S denotes the Conoco sample temperatures are reported in °C T stands for number of transients. 

Figure 7. 13C, 1H-decoupled NMR spectra of surfactant—water samples ( 4), dispersion in aqueous solution, ( 5), transparent sample ( 6), liquid crystal produced by water vapor sorption by crystal ( 7), dry crystal (u stands for unresolved resonances). 

Figure 8. 13C, W-decoupled NMR spectra of surfactant-water samples relative peak heights are not significant.

Figure 9. 13C, II-decoupled NMR spectra of surfactant-decane samples. The sample with 82 wt % surfactant was produced by equilibrating surfactant crys-tallites with decane vapor.

Figure 13. 13C, 1H-decoupled NMR spectra of surfactant (S)-water (W)-decane (D) systems. All samples were translucent to turbid. Sample 20 was gel-like. 

Nuclear magnetic resonance (NMR) spectrometry has seldom been used as a quantitative analytical method but can have some practical importance in the characterization of surfactants [296-298]. 13C-NMR spectrometry has been used for the qualitative and also quantitative analysis of dodecyl, tetradecyl, and cetyl sulfates [299]. H- and, 3C-NMR spectra of sodium dodecyl sulfate are given by Mazumdar [300]. 

Fig. 7.1 shows a typical H-NMR spectrum obtained with the partially purified, microbubble surfactant mixture prior to monolayer formation. For comparison, Table 7.1 gives the chemical-shift data for the proton resonances that can be readily identified in the 1 H-NMR spectra of long-chain acyl lipids (ref. 395-401). 

Incorporation of both functionalities is also confirmed by 13C ll MAS NMR. -CH2-CH2- bridges are represented by the broad resonance at 2-5 ppm, while -CH=CH- units are found at 147 ppm. Importantly, 13C 111 MAS NMR spectra also indicate the template in the BTSE-silica and BTSEY-silica mesophases is in the disordered gauche conformation as the peak attributable to the inner chain methylenes is observed at 31.0ppm. C 1 MAS NMR spectra of the extracted PMOs show only the broad resonances corresponding to -CH2-CH2- or Cl I CI I units proving the removal of surfactant template. 

Showed in Figure 1 are the NMR spectra of the surfactant-collected precursor before and after 150°C steaming. For both samples, there was approximately an equal distribution of and Q silicon environment. TTie steaming produced only a small increase of species, suggesting the hydration of surface silica species. The NMR spectra are very similar to that obtained by Kremer et al. recently. 

The thio-disuccinate 13 aggregates in chloroform/cyclohexane (1 1) to form inverse micelles, which bind and solubilize carbohydrates. H-NMR spectra of nitrophenolates and ESR spectra of TEMPO derivatives indicate that the carbohydrates bind tightly to the surfactant s head group at low water con-tent ". ... 

Fig. 35. C-NMR-spectra of aqueous dispersions of poly- -butylcyanoacrylate nanocapsules after 3 h of annealing at different temperatures (a) 50°C, (b) 100°C, (c) 130°C. The ( H)- C crosspolarization spectra (tcp = 1 ms, left column) indicate the loss of the solid capsule wall at higher temperatures (see also Fig. 36). The narrow signals superimposed on the solid-state spectrum of the polymer derive partially from the adsorption of the triglyceride oil and the surfactant to the capsule surface (compare Section 4.4), partially from the residual cp in the liquid phase. The direct excitation spectra (right column) show the liquid and dissolved components with an increasing indication for traces of the n-butylcyanoacrylate monomer which results from depolymerization of the capsule wall material (arrows, see also Fig. 37). ...

There have been numerous attempts to determine HLB numbers from other fundamental properties of surfactants, e.g., from cloud points of nonionics (Schott, 1969), from CMCs (Lin, 1973), from gas chromatography retention times (Becher, 1964 Petrowski, 1973), from NMR spectra of nonionics (Ben-et, 1972), from partial molal volumes (Marszall, 1973), and from solubility parameters (Hayashi, 1967 McDonald, 1970 Beerbower, 1971). Although relations have been developed between many of these quantities and HLB values calculated from structural groups in the molecule, particularly in the case of nonionic surfactants, there are few or no data showing that the HLB values calculated in these fashions are indicative of actual emulsion behavior. 

Ryoo and co-workers synthesized MFI zeoHtes with varied morphology by means of a surfactant as structure-directing agent [76]. The zeolitic catalysts so fabricated were found to exhibit superior catalytic activities during decalin cracking reactions. To correlate the observed reactivity with acid properties of the catalysts, the P-R3PO NMR approaches with TMPO and TBPO probe molecules were exploited. The P NMR spectra of TMPO and TBPO adsorbed on various MFI zeohtes are compared to a... 

Na MAS NMR spectra of NZ and AZ samples exhibit only one resonance line at <5 s 24 ppm - Fig. 24E,F [03R1]. The intensity of sodium lines, after acid treatment, decreased as a result of the loss of sodium cations. The CP-MAS NMR spectra of NZ-surfactant samples were assigned to the corresponding dmgs. These data... 

Returning to Figure 11.5, let us go through the ID spectrum first, and then we will see why the COSY spectrum is so important in characterising this molecule. The three peaks in the region 0.8-1.8 ppm correspond to the fatty alkyl chain, exactly as they do in Figure 11.4. In fact, this pattern of chemical shifts is characteristic of the H-NMR spectra of all surfactants with a linear fatty alkyl chain. 

Already in early NMR studies of surfactant adsorption layers, 2H investigations had been the method of choice [27-30], and a number of investigations has evolved in the meantime. The disadvantages over IH studies, i.e. lower sensitivity and the necessity of labelling, are overcompensated by the achievement of quantitative results In the case of no isotropic motional mode averaging the quadnipolar interaction, wide line 2H spectra resulted in order parameters, while for surfactants in the isotropically averaged state linewidths and relaxation rates can be evaluated. 

This can be calculated from the splitting of the -H NMR spectra of the same deuterated surfactant in a lamellar or hexagonal phase. 

Figure 2.9 Part of the 400 MHz NMR spectra of gemini surfactants in DgO at 25°C. The signals observed are those of the N+CH2CH2N+ protons (3.92 ppm in the bulk phase and 4.03-4.13 ppm in micelles), (a), (b) and (c) surfactant 14-2-14 at 0.25 mM, 0.167 mM and 0.125 mM (d) surfactant 18-2-8 at 0.5 mM (e) surfactant 12-2-12 at 1.25 mM. Reproduced from Reference 69 with permission of the Royal Society of Chemistry.

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