Spontaneous Vesicle Formation of Single Chain and Double Chain Cationic Surfactant Mixtures

Abstract

The concentration vs composition diagram of aggregate formation of the dodecyltrimethylammonium bromide (DTAB) and didodecyldimethylammonium bromide (DDAB) mixture in aqueous solution at rather dilute region was constructed by analyzing the surface tension, turbidity, and electrical conductivity data and inspected by cryo-TEM images and dynamic light scattering data. Although the aqueous solution of DTAB forms only micelles, the transition from monomer to small aggregates and then to vesicle was found at 0.1 < X2 <or=1, where X2 is the mole fraction of DDAB in the DTAB-DDAB mixture, while vesicle particles were formed directly from monomer solution at 0 < X2 < 0.1. Furthermore, the transition from vesicle to micelle was found at 0 < X2 < 0.4 at higher concentrations. An addition of DTAB to DDAB solution lowered considerably the DDAB concentration of the vesicle formation, which is attributable to asymmetric distribution of DTAB molecules between inner and outer monolayers of the vesicle bilayer. The shape and size of aggregates were obtained from surface tension, cryo-TEM, and light scattering data.

Structural and morphological transition of long-chain phospholipid vesicles induced by mixing with short-chain phospholipid

“…To understand inclusively the structural and morphological transitions by the data from the different experimental sources of DSC and fluorescence performed at the different DMPC concentrations, we constructed the total phospholipids concentration m vs. phospholipids composition X DHPC diagram [32,35,36], where m and X DHPC are defined as…”

Drug‐Induced Micelle‐to‐Vesicle Transition of a Cationic Gemini Surfactant: Potential Applications in Drug Delivery

“…Although biocompatible, niosomes have limitations, including physical instability due to their fusion into larger aggregates and low leakage barrier for the entrapped drugs . More recently, vesicles based on cationic surfactants were investigated as convenient alternatives to niosomes due to the simplicity of their formulation and long‐term stability …”

“…Spontaneous vesicle formation from a mixture of single‐ and double‐chain cationic surfactant mixtures was demonstrated by Aratono et al . The self‐assembly behavior of mixed systems consisting of sodium fatty alcohol ether sulfate and the conventional cationic surfactant cetyltrimethylammonium bromide (CTABr) was preliminarily investigated, and the aggregate structures were characterized by TEM, dynamic light scattering (DLS), and small‐angle XRD .…”

Conductometry and Thermodynamics Study of Metal Dioctylsulfosuccinate in Aqueous Solution

“…[2][3][4] Many techniques have been applied to analyze the process of micellization by measuring changes in physical properties at the CMC. [5][6][7][8] Most commonly, the breaks in the electrical conductivity and surface tension are used for this purpose. Especially the differences in CMC with respect to the nature of the counterions as well as the shape of the micelles and the surface charge density have been investigated, and appear to reflect the degree of binding of the counterions to the micelles.…”