Comparison of Small-Angle Scattering Methods for the Structural Analysis of Octyl-β-maltopyranoside Micelles

Abstract

Small-angle neutron scattering (SANS) and small-angle X-ray scattering (SAXS) experiments were performed to investigate the micelle structure of n-octyl-β-maltopyranoside (OM). Density measurements were carried out to obtain the volumetric characteristics of OM for micelle structure analysis. Both temperature and concentration were varied in scattering experiments to study their effects on micelle size. The scattering data were analyzed by the indirect Fourier transformation method (IFT) and model fitting. The IFT method gave the radius of gyration of the micelles and their pair distance distribution function. It was found that the radii of gyration from SANS data were much smaller than those from SAXS data at similar solution conditions. Moreover, pair distance distribution functions from SANS and SAXS data were also different. Model fitting indicated that a spherical shell model can be used to describe both SANS and SAXS data using similar structure parameters. Comparison of SAXS data in D 2 O and H 2 O shows that the OM micelle has a similar structure in both solvents. The size of the micelle does not increase with increasing concentration up to 188 mM. From 10 to 50 °C, the structure of the micelle is not sensitive to temperature changes. Comparison of the micelle structures of OM with those of its two closely related glycolipids, n-octyl-β-glucopyranoside (OG) and n-dodecyl-β-maltopyranoside (DM), suggests that the hydrophilic force plays an important role in the micelle structure of glycolipids.

Characterization of Microemulsion Systems Formed by a Mixed 1,3‐Dioxolane Ethoxylate/Octyl Glucoside Surfactant System

“…SANS data were reduced using a typical reduction procedure to yield normalized scattering intensities, I(Q) (cm -1 ), as a function of Q (Å -1 ), which consisted of subtracting scattering contributions from the empty cell and background scattering, sorting data collected from the two different detector distances, and subtracting scattering due to the solvents, weighed according to their respective volume fractions. Volume fractions for the surfactants were calculated based on densities for C 8 bG 1 and CK-2,13 of 1.15 g mL -1 [23] and 0.95 g mL -1 (measured in the laboratory), respectively. Data were analyzed using two different approaches.…”

Interfacial dynamics and structure of surfactant layers

“…Small-angle neutron scattering is used in studies on surfactant aggregation for the determination of the structure and composition of micelles or vesicles on length scales of 1 to 1000 nm and for density profiling of polymer and surfactant layers adsorbed to the surfaces of colloidal particles [45][46][47][48][49].…”

The effect of octyl glucoside on the lamellar phase of diluted C12E4 and alcohol systems

“…On the contrary, sugar-based surfactants are less sensitive to temperature. From 10 to 50 • C, the structure of OG micelles is not sensitive to temperature changes [27].…”