Self-Assembly of Amphiphilic Statistical Copolymers and Their Aqueous Rheological Properties

Abstract

A range of poly(n-butyl methacrylate-stat-methacrylic acid) [P(BMA-stat-MAA)] statistical copolymers of various compositions and molecular weights ranging from 5 to 30 kDa were prepared using either reversible addition-fragmentation chain transfer (RAFT) solution copolymerization or conventional free radical polymerization in isopropanol (IPA). On dilution with water, these amphiphilic copolymers self-assembled to form spherical nano-objects as confirmed by small-angle X-ray scattering (SAXS) and transmission electron microscopy. Various structural particle models were examined to extract information regarding the mean nano-object size and morphology. It is found that nano-object radii are independent of copolymer molecular weight, but depend on the copolymer composition: the smaller the amount of MAA units in the molecules the larger the nanoobjects are formed. Combined SAXS and aqueous electrophoretic measurements indicated that most of the MAA units are located at the nano-object surface. Furthermore, SAXS and rheology measurements were used to monitor the effect of solvent composition on the copolymer morphology both at a fixed copolymer concentration (either 1 wt% or 25 wt%) and also for a gradual variation in copolymer

The effect of macromolecular structure on the rheology and surface properties of amphiphilic random polystyrene-r-poly(meth)acrylate copolymers prepared by RDRP

“…When dissolved in water, these polymers self-assemble into nano-objects, whose size is independent of the molecular weight, but dependent on the copolymer composition. 24 As shown by the examples reported above, the structure of the polymers and the synthetic method used to prepare them have crucial roles in the final properties of the polymer solutions. In particular, it is important to understand how the different monomers are incorporated in the growing chains during synthesis.…”

Interactions between an Associative Amphiphilic Block Polyelectrolyte and Surfactants in Water: Effect of Charge Type on Solution Properties and Aggregation

“…As the hydrophobicity increases, coil-to-globule transition and aggregation will start occurring (Figure 1d), resulting in complex structures and solution behavior. Highly hydrophobic PE with well-defined polymer architectures have been mostly studied experimentally by DLS, microscopy, rheology and surface tension measurements [19][20][21].…”

Multilayer onion‐like vesicles self‐assembled from amphiphilic hyperbranched multiarm copolymers via simulation

“…Delicate nanostructures can be designed by self‐assembly of amphiphilic molecules and have been successfully applied biomimetic, nanoscale devices, drug, and gene delivery . As an important kind of nanostructures, vesicles with specific structures and functions have attracted more attentions due to the potential applications in biomedicine and nanotechnology .…”