Acidic microemulsions of dodecane/ p-dodecylbenzenesulfonic acid/water/HCl part 2. structure by proton NMR self-diffusion and relaxation studies

Autor:	P. Albonico, Wallace O. Parker, E. Borgarello, I. Blute
Rok vydání:	1990
Předmět:	chemistry.chemical_compound Monomer chemistry Pulmonary surfactant Dodecane Phase (matter) Relaxation (NMR) General Engineering Proton NMR Analytical chemistry Organic chemistry Microemulsion Nuclear magnetic resonance spectroscopy
Zdroj:	Colloids and Surfaces. 48:21-28
ISSN:	0166-6622
DOI:	10.1016/0166-6622(90)80214-o
Popis:	Two isotropic regions, S (surfactant phase) and L 2 , exist in the ternary phase diagrams for the title system formed with 10 and 11 % (w/w) HCl. The microemulsions present within these regions were investigated by proton Fourier transform pulsed-gradient spin-echo NMR spectroscopy and aromatic linewidth measurements. Self-diffusion coefficients of dodecane and water reveal a constant bicontinous microstructure across the S region with oil effectively diffusing in one dimension. Transverse relaxation rates of surfactant aromatic protons increase significantly with an increase in oil content, which is accompanied by a decrease in HCl content, across the S region. This is discussed in terms of changes in monomer packing. A water droplet-in-oil micro-structure is present in L 2 solutions with low amounts of surfactant while an extended layered structure occurs at higher concentrations of surfactant.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::dbc3bf7f57ea3c958fb6ed69298da042 https://doi.org/10.1016/0166-6622(90)80214-o Zobrazit plný text záznamu