Combination of Cationic and Radical RAFT Polymerizations: A Versatile Route to Well-Defined Poly(ethyl vinyl ether)-block-poly(vinylidene fluoride) Block Copolymers

Poly(vinylidene fluoride)-containing block copolymers are difficult to prepare and still very rare in spite of their potential use in high added value applications. This communication describes in detail the synthesis of unprecedented poly(ethyl vinyl ether)-block-poly(vinylidene fluoride) (PEVE-b-PVDF) block copolymers (BCP) via the sequential combination of cationic RAFT polymerization of vinyl ethers and radical RAFT polymerization of vinylidene fluoride (VDF). Dithiocarbamate chain transfer agents were found to efficiently control the radical RAFT polymerization of VDF and to be suitable for the preparation of PEVE-b-PVDF BCP. These new block copolymers composed of incompatible polymer segments may find applications owing to their phase segregation and self-assembly behavior.

Well-defined poly(vinylidene fluoride) (PVDF) based-dendrimers synthesized by click chemistry: enhanced crystallinity of PVDF and increased hydrophobicity of PVDF films

This study reports the preparation of a novel fluorinated dendrimer bearing PVDF branches by click chemistry and its characterization by several analytical methods.

“One-pot” aminolysis/thia-Michael addition preparation of well-defined amphiphilic PVDF-b-PEG-b-PVDF triblock copolymers: self-assembly behaviour in mixed solvents

Novel amphiphilic PVDF-based triblock copolymer (PVDF₅₀-b-PEG₁₃₆-b-PVDF₅₀) is synthesized using RAFT polymerization and a one-pot thia-Michael addition. Self-assembly of this ABA copolymer resulted in formation of original crystalline structures.

π-Stacking Interactions of Graphene-Coated Cobalt Magnetic Nanoparticles with Pyrene-Tagged Dendritic Poly(Vinylidene Fluoride)

This study investigates the non-covalent coating of cobalt magnetic nanoparticles (MNPs) involving a graphene surface with pyrene-tagged dendritic poly(vinylidene fluoride) (PVDF). Dendrimers bearing a pyrene moiety were selected to play the role of spacers between the graphene surface of the MNPs and the PVDF chains, the pyrene unit being expected to interact with the surface of the MNPs. The pyrene-tagged dendritic spacer 11 decorated with ten acetylenic units was prepared and fully characterized. Azido-functionalized PVDF chains were then grafted onto each branch of the dendrimer using Huisgen's [3+2] cycloaddition reaction. Next, the association of the resulting pyrene-tagged dendritic PVDF 13 with commercially available Co/C MNPs by π-stacking interactions was studied by fluorescence spectroscopy. Evaluated were the stability of the π-stacking interactions when the temperature increased and the reversibility of the process when the temperature decreased. Also, hybrid MNPs were prepared from pyrene-tagged dendrimers decorated either with acetylenic functions (11) or with PVDF branches (13), and they were characterized by transmission electron microscopy and comparative elemental analysis was carried out with naked MNPs.

Preparation of well-defined 2D-lenticular aggregates by self-assembly of PNIPAM-b-PVDF amphiphilic diblock copolymers in solution

PNIPAM-b-PVDF amphiphilic block copolymers were synthesized via RAFT polymerization in dimethyl carbonate. These block copolymers were able to self-assemble into various morphologies such as spherical, crumpled, lamellar and lenticular 2D aggregates.

Evaluation of Self-Assembly Pathways to Control Crystallization-Driven Self-Assembly of a Semicrystalline P(VDF-co-HFP)-b-PEG-b-P(VDF-co-HFP) Triblock Copolymer

To date, amphiphilic block copolymers (BCPs) containing poly(vinylidene fluoride-co-hexafluoropropene) (P(VDF-co-HFP)) copolymers are rare. At moderate content of HFP, this fluorocopolymer remains semicrystalline and is able to crystallize. Amphiphilic BCPs, containing a P(VDF-co-HFP) segment could, thus be appealing for the preparation of self-assembled block copolymer morphologies through crystallization-driven self-assembly (CDSA) in selective solvents. Here the synthesis, characterization by 1H and 19F NMR spectroscopies, GPC, TGA, DSC, and XRD; and the self-assembly behavior of a P(VDF-co-HFP)-b-PEG-b-P(VDF-co-HFP) triblock copolymer were studied. The well-defined ABA amphiphilic fluorinated triblock copolymer was self-assembled into nano-objects by varying a series of key parameters such as the solvent and the non -solvent, the self-assembly protocols, and the temperature. A large range of morphologies such as spherical, square, rectangular, fiber-like, and platelet structures with sizes ranging from a few nanometers to micrometers was obtained depending on the self-assembly protocols and solvents systems used. The temperature-induced crystallization-driven self-assembly (TI-CDSA) protocol allowed some control over the shape and size of some of the morphologies.

Fluorinated nanotubes: synthesis and self-assembly of cyclic peptide-poly(vinylidene fluoride) conjugates

The synthesis of cyclic peptide-poly(vinylidene fluoride) (CP-PVDF) conjugates comprising (d-alt-l)-cyclopeptides as building blocks and their self-assembly into tube-like structures is described. By growing two PVDF polymeric chains from opposite sides of a preassembled cyclic-peptide macro-chain transfer agent, a PVDF-CP-PVDF conjugate was prepared. This "grafting-from" strategy, allowed the synthesis of the conjugate with high purity and using facile purification steps. The controlled self-assembly of the conjugate from DMF or DMSO solutions was carried out by addition of THF. This triggered the aggregation process that led to formation of tube-like structures. The mean length and width of the PVDF-CP-PVDF tubes were measured using atomic force microscopy (AFM) and transmission electron microscopy (TEM). Surprisingly, the self-assembly of the CP-PVDF conjugates in DMF/THF allowed the preparation of long (up to 25 μm) tube-like structures. The formation of such long tubular peptide-polymer aggregates, based on the stacking of cyclopeptides, is unprecedented and is believed to rely on synergetic effects between the stacking of the cyclic peptide and the interactions of the fluoropolymer-peptide conjugates.

Correction: Preparation of well-defined 2D-lenticular aggregates by self-assembly of PNIPAM-b-PVDF amphiphilic diblock copolymers in solution

Correction for ‘Preparation of well-defined 2D-lenticular aggregates by self-assembly of PNIPAM-b-PVDF amphiphilic diblock copolymers in solution’ by Enrique Folgado et al., Polym. Chem., 2021, 12, 1465–1475, DOI: 10.1039/D0PY01193B.