Effect of N-glycinylmaleamic acid on microstructural characteristics and solubilization properties of sodium dodecyl sulfate micellar assemblies

1H NMR spectroscopic investigations on the conformation of amphiphilic aromatic amino acid derivatives in solution: effect of chemical architecture of amphiphiles and polarity of solvent medium

In this study, the conformation of the amphiphilic lauryl esters of L-tyrosine (LET) and L-phenylalanine (LEP) in water and dimethyl sulfoxide is established. The alkyl chain protons of LEP in D(2)O appear at δ 1.010-1.398 and show an upfield shift and large line width, suggesting the proximity of the phenyl ring to the alkyl chain in contrast to that of LET. Quite interestingly, in DMSO-d(6), the (1)H NMR spectra of LET and LEP show a strong similarity that is suggestive of an orientation that positions the aromatic ring and aliphatic chain away from each other. These results are substantiated with two-dimensional nuclear Overhauser enhancement spectroscopy (2D NOSEY). Theoretical molecular models of the conformation at the interface corroborate the experimental findings. Investigations of the solvent polarity and chemical structure-dependent conformation are discussed.

Glycine Derived Polymerizable Cosurfactant in the Synthesis of Functionalized Poly(butyl acrylate) Nanolatexes

The approach of employing N-glycinylmaleamic acid (NGMA) as an efficient cosurfactant to provide microemulsion polymerization of butyl acrylate using a weight ratio of sodium dodecyl sulfate (SDS)/butyl acrylate (BA) at <or=1.5, which is lower than that employed in previous experiments, has been demonstrated. The narrow polydispersity index at 1.36-1.48 of poly(butyl acrylate) copolymers from investigated microemulsion polymerization reactions evidences the promotion of a controlled polymerization reaction, in contrast to the solution polymerization method generating polymers with higher polydispersity index at 3.15-4.23. The enhanced incorporation of NGMA at approximately 0.35 m in the copolymer demonstrates the merits of the proximity effect enabled in the microemulsion polymerization reaction. The incorporation of NGMA promotes rigidity of the polymer chain as suggested by a higher Tg of -16.8 degrees C for the copolymer in comparison to that of the poly(butyl acrylate) homopolymer.