Syntheses of Amphiphilic Diblock Copolymers Containing a Conjugated Block and Their Self-Assembling Properties

Abstract

An efficient approach to the syntheses of amphiphilic rod-coil diblock and coil-rod-coil triblock copolymers was developed. Each diblock copolymer consists of a perfectly monodispersed oligo(phenylene vinylene) covalently bonded to a poly(ethylene glycol) block with a very low polydispersity (<1.05). The structure and basic physical properties of these copolymers were characterized by various spectroscopic techniques such as NMR, MALDI-TOF, GPC, DSC, UV/vis, and the fluorescence study. These diblock copolymers were shown to possess remarkable self-assembling abilities, and long cylindrical micelles (>1 µm) were formed. TEM, SANS, and AFM studies showed that the core of the micelles has a diameter of ∼8-10 nm and was composed of an OPV block. TEM and SANS studies revealed that these OPV-PEG micelles have a cylindrical OPV core surrounded by a PEG corona. Cryo-TEM and SANS studies indicate that fibers were formed even in very dilute THF/H 2 O solutions. Since the conjugated OPV blocks exhibit liquid crystallinity and electric and optical properties, these micelles are interesting for studying the electroactive effect in a nanometer scale.

Supramolecular self-assembly and opto-electronic properties of semiconducting block copolymers

“…In an environment that preferentially dissolves one of the blocks, we expect aggregation of the other block to give rise to the formation of micelles or even more complex mesophases [85]. In the DOO-PPV-based diblock copolymers described in this study, the PPV blocks could form the core of the micelles, and in view of their stiffness and restricted length, they might well form lyotropic nematic domains in speci®c solvents.…”

Self-Assembly of Poly(diethylhexyloxy-p-phenylenevinylene)-b- poly(4-vinylpyridine) Rod−Coil Block Copolymer Systems

“…12 An increasing number of experimental studies have been carried out during the past 10 years, enabled by remarkable advances in the synthesis of rod-coil block copolymers. Two main approaches for the synthesis of π-conjugated rod-coil block copolymers have been developed: the divergent path consists of the living polymerization of the coil block started from a rod macroinitiator, [13][14][15] whereas in the convergent way the coil block obtained by living polymerization is linked, either quenched [16][17][18] or condensated, [19][20][21][22][23] with the end-functionalized rod. An alternative route, however, restricted to some particular polymers, consists of successively polymerizing by living anionic polymerization two coil blocks where one is a precursor for the rod.…”

Self-assembly of rod-coil block copolymers from weakly to moderately segregated regimes

“…Finally, the strong anisotropy of rod-like blocks introduces large conformational asymmetry effects in rod-coil block copolymers which can have a considerable impact on the perturb self-assembled morphologies compared to coil-coil block copolymers [19]. The steadily increasing number of experimental and theoretical studies devoted to rod-coil block copolymers, has been triggered by the considerable advances in the synthetic 380 The European Physical Journal E routes followed to control their synthesis [5,[20][21][22][23][24][25][26][27]. In the present study we have taken advantage of the progress made on synthetic strategies to design rod-coil block copolymers, to synthesize two homologue series of rodcoil block copolymers having, respectively, i) the same π-conjugated rod block, ii) different coil polymers of variable molecular weight.…”