Structure of Block Copolymers Adsorbed to Perfluorocarbon Emulsions

Abstract

We have used small-angle neutron scattering (SANS) to study the structure of block copolymers (Poloxamer 188, Poloxamer 407, and Poloxamine 908) adsorbed at the perfluorodecalin−water interface in a submicrometer emulsion system. The data were analyzed using an established transform method to yield the polymer volume fraction profile as a function of distance from the oil−water interface. There was a good correlation between the derived adsorbed amounts of polymer and those measured experimentally, and between the adsorbed layer dimensions from SANS and earlier light scattering measurements. The profiles are consistent with a model in which the poly(propylene oxide) blocks are bound at the interface and the poly(ethylene oxide) blocks are largely present as tails. An electrolyte (sodium chloride at 0.1−0.2 M concentration) was found to significantly reduce the bound fraction of Poloxamer 188, and caused a significant increase in the extension of the adsorbed layer, without affecting the amount of polymer adsorbed.

Polymer-Dispersed Bicontinuous Cubic Glycolipid Nanoparticles

“…The chain size in this case is estimated as 3.9 nm. Consequently, the linear dimension of triblock polymer PL is 8.9 nm, which is comparable to the hydrodynamic size of PL adsorbed onto perflurocarbon droplets (26). The thickness of lipid bilayer, i.e., the twice of the thickness of phytanyl chains, is determined as 2.6 nm (27).…”

Fluorine‐containing nanoemulsions for MRI cell tracking

“…F68 stabilizes the PFC oil droplets in aqueous phase mostly by steric effects 66. Previous structural studies have shown that block polymers adsorb onto the interface between the colloid PFC and the aqueous phase and that this adsorption is dependent on the electrolyte concentration in the solution 67–69…”

Induced micellization and micellar transitions in aqueous solutions of non-linear block copolymer Tetronic® T904

“…These copolymers play an important role in the withdrawing of water and are used in corrosion prevention in well service fluids. There have been very few studies on the surface activity [12,13], micellization, [14][15][16][17], solubilizing [15,17], emulsifying/demulsifying [11,12,[17][18][19], behavior of Tetronic Ò surfactants.…”

“…In contrast, those polymers containing the longer PPO blocks possessed larger areas occupied in the condensed state and enhanced surface activity. Washington et al [12] have determined the structure of Tetronics Ò adsorbed at the perfluorodecalin-water interface in a submicrometer emulsion system from SANS measurements. Tirnaksiz and Kalsin [11] used Tetronic Ò T908 as a hydrophilic surfactant for formulation of water/oil/water multiple emulsions; the concentration of copolymer was an important parameter in the ability to prepare stable emulsions.…”