Self-Assembly Study of Polydisperse Ethylene Oxide-Based Nonionic Surfactants

Abstract

The self-assembly behavior of polyethoxylate-based multicomponent nonionic surfactants was studied. Using the dynamic light scattering method, thermodynamical parameters such as the critical micelle concentration (cmc) and hydrophile-lipophile balance (HLB), as well as the micelle size and micelle size distribution, were determined. The number average molecular weight and number average HLB of the samples were determined by MALDI-TOF-MS and 1H NMR techniques, and the data were evaluated. A connection was found between the HLB and the ln(cmc) value of the samples which can be described by a simple equation. Using this equation and plotting ln(cmc) versus the average number of ethylene oxide units, lines were obtained at different temperatures, and their slope allowed the calculation of the contribution of a single ethylene oxide unit to the Gibbs free energy of micellization.

More Fluorous Surface Modifier Makes it Less Oleophobic: Fluorinated Siloxane Copolymer/PDMS Coatings

“…Lower weight percents are associated with lower temperatures for aggregate formation. Considering the relatively low concentrations that result in phase separation, the amphiphilic nature of D5-3, and analogous aggregation phenomena in aqueous solutions,16 for the remainder of the results and discussion we use critical micelle concentration (CMC) to describe aggregation.…”

“…D5-3 is an amphiphile in PDMS, where the immiscibility of fluorocarbons in silicone fluids is well established . Although a large body of information is available on the solubility and aggregation of amphiphiles in water, comparable information does not exist for fluorous silicone amphiphiles. To acquire fundamental knowledge on phase behavior, dynamic light scattering was carried out on a model system.…”

Colloidal soft matter as drug delivery system

“…Several methods can be utilized to determined the CMC and the CMT. The most used are particle size techniques (light scattering)271–273 or other methods such as gel permeation chromatography,274, 275 tensiometry and UV spectroscopy 271, 276–278. In addition, the technique of fluorescent spectroscopy offers considerable sensitivity and precision.…”

α-Acetal, ω-Alkyne Poly(ethylene oxide) as a Versatile Building Block for the Synthesis of Glycoconjugated Graft-Copolymers Suited for Targeted Drug Delivery

“…This low HLB close to 5 was chosen, on purpose for the critical association concentration (cac) to be low, which is a requirement for biomedical application. 28 The acetal end-group of the PEO grafts was hydrolyzed and the released aldehyde was reacted with an amino derivative by reductive amination. This coupling reaction was selected because it can occur in water, a good solvent for sugars, used as pilot molecules in drug targeting, and it is tolerant toward chemical functions of sugars, which does not impose additional protection/deprotection reactions.…”

“…Several copolymers were accordingly prepared, in which the number and length of the PEO grafts were changed in such a manner that the HLB was maintained close to 5. This low HLB close to 5 was chosen, on purpose for the critical association concentration (cac) to be low, which is a requirement for biomedical application …”