Complex, Dynamic Behavior of Extremely Asymmetric Di-n-Alkylphosphate-Anion Aggregates, the Long-Chain Effect and the Role of a Limiting Size: Cryo-TEM, SANS, and X-Ray Diffraction Studies

Abstract

For extremely asymmetric n-hexyl(n-decyl)phosphate (HDeP), n-hexyl(n-dodecyl)phosphate (HDoP), and n-hexyl(n-cetyl)phosphate (HCeP), the effect of the long-chains on the dynamic behavior of their aggregate structures in water was examined by cryo-TEM imaging, SANS, and X-ray diffraction techniques. The cryo-TEM images demonstrated the complex and dynamic behavior of the aggregates, and its dependence on the length of the long-chain. Application of the one-dimensional aggregate theory to the SANS results led to the conclusion that the existence of a limiting size also depended on the length of the main long-hydrocarbon chain and affected strongly the dynamic behavior of the aggregates, causing breakage of thread-like micelles or ribbon-like aggregates. The X-ray diffraction patterns of the lyotropic liquid crystalline samples of HDeP and HCeP were used to estimate the aggregate structures of this limited size.

Applicability of Chlorpromazine.HCl- lyotropic nanosystems into photogalvanic cells

“…Considering the X-ray crystallographic data for CPZHCl in the solid-state [43], this value is indicative of a surfactant bilayer. Following the Bragg equation, it has been suggested that the diffuse, wide-angle feature corresponds to the intraaggregate spacings (d = 4.4 Å) between the alkyl chains attached to the N-X position on individual CPZHCl molecules, as similar values (4.5 Å) have been proposed for the spacings between alkyl chains within XYZ lyotropic liquid crystals [44]. Taken together with reported NMR data [45], this implies that the CPZ.HCl molecules aggregate together in a "cup-stack" arrangement and on top of each other, with the hydrophobic core comprising the aromatic rings, and the alkyl chains penetrating the aqueous pseudo phase enabling the formation of a micellar palisade layer.…”

Phase Behavior of Ester Based Anionic Surfactants: Sodium Alkyl Sulfoacetates

“…About 3.0–3.3 mg of samples were sealed in aluminum sample pans and the heat flow was measured against alumina as a reference. Temperature scans from 25 to 80 °C was performed for each sample at rates of 3 K min –1 . − …”