Synthesis and Assembly of Designer Styrenic Diblock Polyelectrolytes

Abstract

Harnessing molecular design principles toward functional applications of ion-containing macromolecules relies on diversifying experimental data sets of well-understood materials. Here, we report a simple, tunable framework for preparing styrenic polyelectrolytes, using aqueous reversible addition−fragmentation chain transfer (RAFT) polymerization in a parallel synthesis approach. A series of diblock polycations and polyanions were RAFT chain-extended from poly-( e t h y l e n e o x i d e ) ( P E O ) u s i n g ( v i n y l b e n z y l )trimethylammonium chloride (PEO-b-PVBTMA) and sodium 4-styrenesulfonate (PEO-b-PSS), with varying neutral PEO block lengths, charged styrenic block lengths, and RAFT endgroup identity. The materials characterization and kinetics study of chain growth exhibited control of the molar mass distribution for both systems. These block polyelectrolytes were also demonstrated to form polyelectrolyte complex (PEC) driven selfassemblies. We present two simple outcomes of micellization to show the importance of polymer selection from a broadened pool of polyelectrolyte candidates: (i) uniform PEC-core micelles comprising PEO-b-PVBTMA and poly(acrylic acid) and (ii) PEC nanoaggregates comprising PEO-b-PVBTMA and PEO-b-PSS. The materials characteristics of these charged assemblies were investigated with dynamic light scattering, small-angle X-ray scattering, and cryogenic-transmission electron microscopy imaging. This model synthetic platform offers a straightforward path to expand the design space of conventional polyelectrolytes into gram-scale block polymer structures, which can ultimately enable the development of more sophisticated ionic materials into technology.

Mechanism of Dissociation Kinetics in Polyelectrolyte Complex Micelles

“…In this article, we aim to make strides toward understanding the mechanism of dis- . 35,36 The subscripts indicate the numbers of repeat units. The PVBTMA block has been demonstrated as an effective cationic vector for DNA encapsulation and delivery, while the PAA block has been extensively studied as a proxy for weakly charged biomacromolecules.…”

“…PEO-b-PVBTMA was synthesized by aqueous reversible additionfragmentation chain transfer (RAFT) polymerization. The details have been previously reported by us previously 35. The poly(acrylic acid sodium salt) (PAA 158 , M w = 14,800 g mol -1 ) was purchased from Polymer Source Inc. with confirmed molecular weight and chemical structures.Micelle Preparation.…”

Assembly and Characterization of Polyelectrolyte Complex Micelles

“…We hope that these protocols will enable more researchers to effectively explore the capabilities of these interesting nanoparticles. generated in a high throughput manner 28 . The choice of charged group strongly affects the stability of ion pairing and shape of micelles 26 , and PCM size has been shown to increase with the length of the charged block 5,7,26 (Figure 2), thus allowing PCM properties to be tuned for the requirements of a desired application.…”

Effect of mixed solvents on polyelectrolyte complexes with salt

“…PSS 100 was used as received (purchased from Polymer Standards Service). PVBTMA 100 was synthesized with aqueous reversible addition-fragmentation chain transfer (RAFT) polymerization to be approximately symmetric to PSS, based on previous work in our group [29]. Desired amount of VA-044 initiator, VBTMA monomer, and CPhPA chain transfer agent (molar equivalence of 1 to 1000 to 10, respectively) were added to the acetate buffer solution in a dried 25-mL round bottom flask.…”