Controlled Polymerization of Multivinyl Monomers: Formation of Cyclized/Knotted Single‐Chain Polymer Architectures

Seventy years ago, Flory and Stockmayer predicted that the polymerization of multivinyl monomers (MVMs) would inevitably lead to insoluble cross‐linked gel networks. Since then, the use of MVMs has largely been limited to as cross‐linking agents. More recently, however, polymerization strategies such as reversible deactivation radical polymerization (RDRP) have paved the way for the exploration of new possibilities in terms of both polymer architectures and functional capabilities. This Minireview provides historical context to the problem of polymerizing MVMs, before highlighting how RDRP has led to the formation of new cyclized/knotted polymer structures. Although the potential of such cyclized/knot polymer architectures is far from being fulfilled, some emerging applications are discussed.     

Localized Surface Plasmon Resonance Meets Controlled/Living Radical Polymerization: An Adaptable Strategy for Broadband Light‐Regulated Macromolecular Synthesis

The photophysical process of localized surface plasmon resonance (LSPR) is, for the first time, exploited for broadband photon harvesting in photo‐regulated controlled/living radical polymerization. Efficient macromolecular synthesis was achieved under illumination with light wavelengths extending from the visible to the near‐infrared regions. Plasmonic Ag nanostructures were in situ generated on Ag₃PO₄ photocatalysts in a reversible addition‐fragmentation chain transfer (RAFT) system, thereby promoting polymerization of various monomers following a LSPR‐mediated electron transfer mechanism. Owing to the LSPR‐enhanced broadband photon harvesting, high monomer conversion (>99 %) was achieved under natural sunlight within 0.8 h. The deep penetration of NIR light enabled successful polymerization with reaction vessels screened by opaque barriers. Moreover, by trapping active oxygen species generated in the photocatalytic process, polymerization could be implemented without pre‐deoxygenation.     

Bacteria‐Assisted Activation of Antimicrobial Polypeptides by a Random‐Coil to Helix Transition

The application of antimicrobial peptides (AMPs) is largely hindered by their non‐specific toxicity against mammalian cells, which is usually associated with helical structure, hydrophobicity, and charge density. A random coil‐to‐helix transition mechanism has now been introduced into the design of AMPs, minimizing the toxicity against mammalian cells while maintaining high antimicrobial activity. By incorporating anionic phosphorylated tyrosine into the cationic polypeptide, the helical structure of AMPs was distorted owing to the side‐chain charge interaction. Together with the decreased charge density, the AMPs exhibited inhibited toxicity against mammalian cells. At the infectious site, the AMPs can be activated by bacterial phosphatase to restore the helical structure, thus contributing to strong membrane disruptive capability and potent antimicrobial activity. This bacteria‐activated system is an effective strategy to enhance the therapeutic selectivity of AMPs.     

Peristome‐Mimetic Curved Surface for Spontaneous and Directional Separation of Micro Water‐in‐Oil Drops

Separation of micro‐scaled water‐in‐oil droplets is important in environmental protection, bioassays, and saving functional inks. So far, bulk oil–water separation has been achieved by membrane separation and sponge absorption, but micro‐drop separation still remains a challenge. Herein we report that instead of the “plug‐and‐go” separation model, tiny water‐in‐oil droplets can be separated into pure water and oil droplets through “go‐in‐opposite ways” on curved peristome‐mimetic surfaces, in milliseconds, without energy input. More importantly, this overflow controlled method can be applied to handle oil‐in‐oil droplets with surface tension differences as low as 14.7 mN m⁻¹ and viscous liquids with viscosities as high as hundreds centipoises, which markedly increases the range of applicable liquids for micro‐scaled separation. Furthermore, the curved peristome‐mimetic surface guides the separated drops in different directions with high efficiency.     

Fluorogel Elastomers with Tunable Transparency,Elasticity, Shape‐Memory,and Antifouling Properties

Omniphobic fluorogel elastomers were prepared by photocuring perfluorinated acrylates and a perfluoropolyether crosslinker. By tuning either the chemical composition or the temperature that control the crystallinity of the resulting polymer chains, a broad range of optical and mechanical properties of the fluorogel can be achieved. After infusing with fluorinated lubricants, the fluorogels showed excellent resistance to wetting by various liquids and anti‐biofouling behavior, while maintaining cytocompatiblity.