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A diversity of pyridine-containing polymeric nanomaterials with controllable structures and multiple responses were developed through complementary hydrogen-bonding directed polymerization-induced self-assembly in aqueous solution.

We report well-defined double-bond-containing diblock copolymers via RAFT polymerization.

Polyallenes containing internal double bonds directly attached to the backbone have attracted considerable attention due to their reactive structure and direct access to diverse functional polymers. Herein, we report the first example of controlled synthesis of polyallene-based diblock copolymers with tunable structure and low polydispersities via reversible addition–fragmentation chain transfer (RAFT) polymerization. RAFT homopolymerization of phenoxyallene (POA) was firstly conducted as a model reaction to explore the polymerization conditions. The preservation of end groups of the chain transfer agent (CTA) throughout the polymerization confirmed the livingness of poly(phenoxyallene) (PPOA). Next, well-defined poly(N-isopropyl acrylamide)-b-poly(phenoxyallene) (PNIPAM-b-PPOA) diblock copolymers were synthesized by RAFT block copolymerization of POA mediated by PNIPAM-based macroCTA. We demonstrate the in situ formation of unique nanofibers based on PNIPAM-b-PPOA diblock copolymer via polymerization-induced self-assembly (PISA) at high solid concentration in methanol. This work opens a new avenue to synthesize well-defined polyallene-based copolymers via living/controlled radical polymerization and nanoparticles for broad applications.

New-generation smart surfaces responsive to external stimuli with a controllable wettability have garnered increasing attention in recent years. Notably, a smart surface with a switchable wettability that manifests the facile transition between water-adhesive, rolling isotropic, and rolling anisotropic forms has yet to be explored. Herein, we report the crafting of a superhydrophobic surface with both tunable microstructures and wettability by capitalizing on the azobenzene-containing memory polymer as the substrate. Intriguingly, through photo-manipulation, the azo-polymer film is reversibly and reliably transformed among three wetting states, that is, rose-petal-like water-adhesion, lotus-leaf-like rolling isotropy, and rice-leaf-like rolling anisotropy. Furthermore, the smart superhydrophobic surface is employed as a rewritable platform for droplet transportation. As such, our study expands the category of responsive bio-inspired superhydrophobicity and provides a new strategy to design and access superwetting materials.

In this work, a novel alternating amphiphilic copolymer (AAC) P(EG4-a-NAzoOMe) with azobenzene pendants was synthesized through the azide–alkyne click reaction. This proposed AAC exhibits unusual photo- and pH-responsive behaviors by taking advantage of a special alternating amphiphilic topology to prevent the azobenzene pendants from ordered aggregation. P(EG4-a-NAzoOMe) could self-assemble into different sized homogeneous large compound micelles (LCMs) by tuning the initial concentration. The LCMs responded to UV stimuli almost as fast as the P(EG4-a-NAzoOMe) polymer, and the size of LCMs enlarged with the acidity of the solution together with the color change from yellow to violet. Moreover, the LCMs featured acidity-enhanced aggregation induced emission (AIE) similarly because of the special alternating amphiphilic topology. The first reported stimuli-responsive AAC could not only serve as a promising tunable delivery carrier or sensor, but also be inspirational for developing azobenzene AIE materials.

A novel approach for preparing self-cleaning anti-fouling surfaces with compositional heterogeneous polymer brushes at a molecular-length scale was developed. This approach exploits three critical elements including hydrophilic poly(ethylene glycol) (PEG) brushes with non-fouling functionalities, self-cleaning fouling-release hydrophobic poly(2,2,3,3,3-pentafluoropropyl acrylate) (PPFA) brushes and catechol moieties, an important component of mussel adhesive proteins (MAPs), to anchor asymmetric polymer brushes onto surfaces. Well-defined PtBBPMA-co-PPEGMEMA-co-PDOMA macroinitiators were first prepared by RAFT copolymerization of tert-butyl 2-((2-bromopropanoyloxy)methyl)acrylate (tBBPMA) bearing a Br-containing ATRP initiating group, poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) macromonomer and N-(3,4-dihydroxy-phenethyl) methacrylamide (DOMA) with an adhesive anchoring group of catechol moieties. The target asymmetric polymer brushes were obtained by ATRP of PFA initiated by the macroinitiator via the grafting-from strategy. By using the drop coating method, the asymmetric polymer brush surface could form a layer of amphiphilic brushes onto the substrate with the assistance of adhesive anchoring groups. With a dense heterogeneous brush conformation at a molecular-length scale, (PtBA-co-PPEGMEMA-co-PDOMA)-g-PPFA-based surface shows considerable self-cleaning anti-fouling performance with less protein adsorption (up to 93% off) and cell adhesion (up to 88% off) compared to the bare surface.

A fluorine-containing anti-fouling surface was developed at a molecular-length scale by using a compositional heterogeneous polymer brush, which involves hydrophilic poly(ethylene glycol) (PEG) brushes with non-fouling functionality, fouling-release hydrophobic poly(2,2,3,3,3-pentafluoropropyl acrylate) (PPFA) brushes and catechol moieties, an important component of mussel adhesive proteins (MAPs), to anchor asymmetric polymer brushes onto surfaces. A well-defined PtBBPMA-co-PPEGMEMA-co-PDOMA macroinitiator was firstly prepared by RAFT copolymerization of tert-butyl 2-((2-bromopropanoyloxy)methyl)acrylate (tBBPMA) consisting of a Br-containing ATRP initiating group, poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) macromonomer and N-(3,4-dihydroxyphenethyl) methacrylamide (DOMA) bearing an adhesive anchoring group of the catechol moiety. ATRP of PFA was then directly initiated by PtBBPMA-co-PPEGMEMA-co-PDOMA to afford (PtBA-co-PPEGMEMA-co-PDOMA)-g-PPFA asymmetric polymer brush via the grafting-from strategy. The asymmetric polymer brush surface could form a layer of amphiphilic brushes on the substrate with the assistance of adhesive anchoring groups through the drop coating technology. With dense heterogeneous brush conformation at a molecular-length scale, (PtBA-co-PPEGMEMA-co-PDOMA)-g-PPFA-based surface shows considerable anti-fouling performance with less protein adsorption (81.9% off) and cell adhesion (83.6% off) in comparison with bare surface.

A series of well-defined amphiphilic asymmetric polymer brushes containing hetero side chains, hydrophobic polystyrene (PS) and hydrophilic poly(ethylene glycol) (PEG), was synthesized by sequential reversible addition–fragmentation chain transfer (RAFT) polymerization and atom transfer radical polymerization (ATRP). The well-defined polyacrylate-based backbones (Mw/Mn ≤ 1.22), PtBBPMA-co-PPEGMEMA, were first prepared by RAFT copolymerization of tert-butyl 2-((2-bromopropanoyloxy)methyl)acrylate (tBBPMA), which bears a Br-containing ATRP initiating group and a poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) macromonomer. The reactivity ratios determined by Fineman–Ross and Kelen–Tudos methods showed that both monomers tended to form random copolymers. The density of the Br-containing ATRP initiating group could be well tuned by the feeding ratio of comonomers. ATRP of styrene was directly initiated by PtBBPMA-co-PPEGMEMA without polymeric functionality transformation to afford well-defined (PtBA-g-PS)-co-PPEGMEMA polymer brushes (Mw/Mn ≤ 1.26) via the grafting-from strategy. The pendant tert-butoxycarbonyls in the backbone were selectively hydrolyzed to carboxyls for providing (PAA-g-PS)-co-PPEGMEMA polymer brushes. Both polymer brushes with the exact same side chains, but different backbones, self-assembled into large compound micelles and bowl-shaped micelles in aqueous media, respectively. This is a direct and strong example to address the importance of the properties of the backbone of a graft copolymer on its self-assembly behavior. Interestingly, different from common spherical micelles, which can just solubilize hydrophobic compounds within their core, the large compound micelles formed by (PtBA-g-PS)-co-PPEGMEMA polymer brushes can encapsulate hydrophilic Rhodamine 6G and hydrophobic pyrene separately or simultaneously.