Host-guest complexation modulated aqueous polymerization-induced self-assembly for monodisperse hierarchical nanoflowers

This work presents a one-step synthesis of monodisperse nanoflowers by aqueous polymerization-induced self-assembly (PISA), modulated by host-guest interactions. Owing to the low monomer swelling of nanoparticles restricted by host-guest complexation, hierarchical surficial micellar structures were generated at the outer surface of the vesicles, forming fractal nanoflowers with a diameter polydispersity as low as 1.01. Our method allows the straightforward synthesis of monodisperse hierarchical nanoparticles for a wide range of applications.

pH-Controlled Stereoregular Polymerization of Poly(methyl methacrylate) in Vesicle Membranes

Here, we report a pH-controlled stereoregular polymerization of methyl methacrylate (MMA) inside the membrane of H20-COOH hyperbranched polymer vesicles using a common radical polymerization process. The vesicle size decreases from 745 to 214 nm with an increase of solution pH from 2.60 to 7.26, and the isotacticity of the obtained polymethyl methacrylates (PMMAs) is accordingly elevated from 9 to 35%. The obtained isotactic-rich PMMAs show a lower glass transition temperature depending on the isotacticity than the commercial random PMMAs. A mechanism study according to the in situ Fourier transform infrared measurements indicates that the control of polymer isotacticity results from the monomer conformation confined effect inside the thin vesicle membranes. The present study provides a new method to realize the preparation of isotactic polymers with the characteristics of facile synthesis, pH controllability, and a green polymerization process in aqueous solution as well as under mild reaction conditions of ambient temperature and pressure.

Polymer Vesicle Sensor for Visual and Sensitive Detection of SO2 in Water

This study reports the first polymer vesicle sensor for the visual detection of SO₂ and its derivatives in water. A strong binding ability between tertiary alkanolamines and SO₂ has been used as the driving force for the detection by the graft of tertiary amine alcohol (TAA) groups onto an amphiphilic hyperbranched multiarm polymer, which can self-assemble into vesicles with enriched TAA groups on the surface. The polymer vesicles will undergo proton exchange with cresol red (CR) to produce CR-immobilized vesicles (CR@vesicles). Subsequently, through competitive binding with the TAA groups between CR and SO₂ or HSO₃^-, the CR@vesicles (purple) can quickly change into SO₂@vesicles (colorless) with the release of protonated CR (yellow). Such a fast purple to yellow transition in the solution allows the visual detection of SO₂ or its derivatives in water by the naked eye. A visual test paper for SO₂ gas has also been demonstrated by the adsorption of CR@vesicles onto paper. Meanwhile, the detection limit of CR@vesicles for HSO₃^- is approximately 25 nM, which is improved by approximately 30 times when compared with that of small molecule-based sensors with a similar structure (0.83 μM). Such an enhanced detection sensitivity should be related to the enrichment of TAA groups as well as the CR in CR@vesicles. In addition, the CR@vesicle sensors also show selectivity and specificity for the detection of SO₂ or HSO₃^- among anions such as F^-, Br^-, Cl^-, SO₄^2-, NO₂^-, C₂O₄^2-, S₂O₃^2-, SCN^-, AcO^-, SO₃^2-, S^2-, and HCO₃^-.

Self-assembly and functionalization of alternating copolymer vesicles

This work reports novel alternating copolymer vesicles and their facile functionalization with carboxyl and amino groups through click copolymerization.

Hybrid Vesicles with Alterable Fully Covered Armors of Nanoparticles: Fabrication, Catalysis, and Surface-Enhanced Raman Scattering

This work reports on the facile preparation of hybrid polymer vesicles with alterable armors of metal nanoparticles by using a novel hyperbranched polymer vesicle as the templates. The vesicles were prepared through the aqueous self-assembly of a hyperbranched multiarm copolymers with many tertiary amino groups on the surface, which can electrostatically complexed or coordinated with metal ions like AuCl4(-), PtCl6(2-), and Ag(+) ions. Subsequently, the vesicles coated with metal ions can be in situ reduced into metal nanoparticles, through which a series of surface-engineered vesicles (Au@vesicles, Ag@vesicles, Pt@vesicles) with an advantage of fully covered metal nanoparticles on the surface could be readily prepared. The morphologies, structures, and formation mechanism of the as-prepared hybrid vesicles were carefully characterized, and the obtained hybrid vesicles also showed great potentials in catalysis and surface-enhanced Raman scattering (SERS) applications.

Fluorescent vesicles formed by simple surfactants induced by oppositely-charged carbon quantum dots

Fluorescent vesicles can be constructed by mixing oppositely-charged CQDs and simple surfactants in water.

Hyperbranched polymer vesicles: from self-assembly, characterization, mechanisms, and properties to applications

This tutorial review summarizes the first 10 years of work on hyperbranched polymer vesicles from syntheses, self-assembly, and properties to applications.