Macromolecules最新文献

Biomimetic synthesis represents a cutting-edge topic in chemistry/materials science. Herein, we demonstrate poly(ethylene glycol) (PEG) short side-chain-assisted monomer complex coacervation and reaction-induced polyion complex compartmentalization that lead to oxygen-tolerant polymerization-induced electrostatic self-assembly (PIESA). This is achieved by the one-pot synthesis of a PEGylated anionic polyelectrolyte and heterogeneous iterative polymerization of a cationic monomer under ecofriendly ambient, in-air aqueous photo-RAFT conditions. Simultaneous reversible all-segment-participating ternary complex coacervation and Coulombic interdomain interactions lead to coacervate nanoreactors that are capable of immediate initiation and fast reversible addition–fragmentation chain transfer reactions. Approximately 2 nm monomer complex nanoclusters act as building blocks to drive liquid–liquid phase separation. Polymerization induces hierarchical self-assembly in a droplet nucleation–fusion–fission mechanism together with PEG-crowded polyion complex compartmentalization, using nanoclusters as building blocks, mechanistically similar to liquid–liquid phase separation through supramolecular polymerization. Consequently, protein-like, one-component multicompartment coacervate nanoreactors with oxygen-tolerant well-controlled fast reactions are achieved. This work provides important implications for the efficient precise synthesis of biomimetic coacervate nanodevices of increasing complexity.

Molecular recognition is of crucial importance in several healthcare applications, such as sensing, drug delivery, and therapeutics. Molecularly imprinted polymers (MIPs) present an interesting alternative to biological receptors (e.g., antibodies, enzymes) for this purpose since synthetic receptors overcome the limited robustness, flexibility, high-cost, and potential for inhibition that comes with natural recognition elements. However, off the shelf MIP products remain limited, which is likely due to the lack of a scalable production approach that can manufacture these materials in high yields and narrow and defined size distributions to have full control over their properties. In this Perspective, we will confer how breakthroughs in the automation of MIP design, manufacturing, and evaluation of performance will accelerate the (commercial) implementation of MIPs in healthcare technology. In addition, we will discuss how prediction of the in vivo behavior of MIPs with animal-free technologies (e.g., 3D tissue models) will be critical to assess their clinical potential.

Sulfone bonding refers to dipole–dipole interactions between sulfone groups, which have been long overlooked. Herein, sulfone bonding was employed for the first time as the driving force for the self-assembly of block copolymers via a polymerization-induced sulfone-bond-driven self-assembly (PI-SDSA) strategy. The presence of sulfone bonding in a sulfone-functionalized monomer was first confirmed by scanning tunneling microscopy break junction measurements at the single-molecule level. Successful PI-SDSA was achieved in toluene, and the polymerization kinetics confirmed the polymerization-enhanced sulfone bonding as the driving force. The PI-SDSA was demonstrated to possess a peculiar monomer/solvent library by the successful PI-SDSA of a series of sulfone-containing monomers in solvents with varying dipole moments. The as-prepared sulfone-functionalized polymer assemblies manifested unique salt-responsiveness because of the competitive ion–dipole interactions between the ions and sulfone groups, enabling the salt-responsive payload release. The use of sulfone bonding as the driving force for self-assembly has provided a new perspective for both the polymerization-induced self-assembly and the self-assembly of block copolymers and will inspire the design of stimuli-responsive supramolecular materials.

Topological modification of block copolymer (BCP) conformations offers a promising approach for developing self-assembled periodic nanostructured materials with smaller domain sizes, which are essential for a range of technological applications. Cyclic polymers, with their inherently more compact conformations, present an effective strategy for achieving this miniaturization. In this work, through a combination of analytical theory and coarse-grained molecular dynamics simulations, we establish a relationship between different nonlinear topologies and the corresponding domain size of lamella-forming BCPs. Our investigations includes BCP architectures with one or two cyclic segments such as tadpoles, diblock and triblock 8-shaped polymers, and diblock nonconcatenated and concatenated rings. We demonstrate that the primary reduction in lamellar domain size is driven by the more compact arrangement of monomers in the cyclic architectures, with an additional contribution from the nonconcatenation of cyclic segments. This is corroborated by theoretical predictions for both domain size reduction and BCP conformations across different architectures. Moreover, consistent with theoretical expectations, the nonconcatenation of rings reduces the interpenetration of opposing brushes, thereby lowering friction between lamellae.

Charge transfer in alternating donor–acceptor (D–A) conjugated polymers plays a crucial role in the development of organic electronics and spintronics. However, the contribution of intrachain charge transfer to the optoelectronic properties remains poorly understood due to the interference of interchain aggregation. Here, we report an approach to rational control of the interchain interaction of an open-shell D–A polymer through segregation of strongly interactive backbones, from which polymeric side chains are grafted so that the intrachain interaction between donors and acceptors becomes dominant. The grafted bottlebrush polymers are still open-shell, owing to the presence of unpaired conduction electrons along the π-conjugated backbones, resulting in asymmetric electron spin resonance. Meanwhile, the minimized interchain aggregation leads to near-infrared photoluminescence despite the narrow optical band gap. Surprisingly, the intrachain dominating D–A charge transfer and delocalization, together with the long-range structural ordering of these bottlebrush polymers in solid states, enables ferromagnetism both at and below room temperature. The effects of the chain length and the grafting density of the polymeric side chains on the optical and magnetic properties have been studied in detail.