A novel high-performance magnetorheological material, named as magnetorheological plastomer (MRP), was developed by dispersing iron particles into a plastic polyurethane (PU) matrix. The dynamic properties (including storage modulus and loss factor) of the MRP material were systematically tested and the influences of the iron particle content and magnetic field were analyzed. It is found that the anisotropic MRP product with 80% iron particle weight fraction (A-MRP-80), shows a high dynamic property: the maximum magneto-induced storage modulus is 6.54 MPa; the relative MR effect reaches as high as 532%; the loss factor can be reduced to 0.03 by adjusting magnetic field. This kind of MRP shows a much higher magnetorheological performance than the previously reported magnetorhelogical elastomer (MRE). The mechanism for its high MR performance was proposed and the influence of the iron particle distribution and temperature on the dynamic properties were discussed.

To improve the mechanical properties of the natural rubber based magnetorheological elastomers (MREs), rosin glycerin ester was added into the carrier matrix to enhance wettability and dispersibility of CI particles. Dynamic performance, including shear modulus, loss factor and viscosity of non-vulcanized matrix was measured by rheometer. In comparison to the natural rubber based MREs, the MR effect of these hybrid matrix MREs were higher and they can reach to 112% when the mass fraction of CI particles is only 60%. The contact angle was tested by drop shape analysis system (DSA) and it was found that the compatibility between the iron particles and matrix was improved. In combination of the microstructure and mechanical property analysis, a possible mechanism was proposed. Finally, the loss factor and tensile strength were studied.

Fluorescent polymersomes are interesting systems for cell/tissue imaging and in vivo study of drug distribution and delivery. We report on bright fluorescent polymersomes with aggregation-induced emission self-assembled by a series of tetraphenylethylene (TPE)-containing amphiphilic biodegradable block copolymers, where the hydrophilic block is a polyethylene glycol and hydrophobic block is a TPE-substituted trimethylenecarbonate polymer P(TPE-TMC). Their self-assemblies in water were prepared by nanoprecipitation using dioxane or tetrahydrofuran as co-solvent, and the self-assembling processes were studied in detail by cryo-electron microscopy, dynamic light scattering, and spectrofluorometer. The polymersomes are formed via the closure of bilayer lamellae self-assembled first by amphiphilic block copolymers. The polymersome membrane affords a nanosize bright fluorescent system with self-assembly induced emission in the thickness scale of 10-15 nm. The control of the whole size of polymersome is achieved by the choice of co-solvent for self-assembling and by the design of a suitable hydrophilic/hydrophobic ratio of block copolymers. These polymersomes can be potentially used as a stable fluorescent tool to monitor the transportation and distribution of drugs and bioconjugates in living cells.

Physically cross-linked isotropic and anisotropic poly(vinyl alcohol) (PVA) hydrogels containing micron-sized carbonyl iron particles were prepared through a cyclic freezing-thawing process. The PVA hydrogel can respond to a magnetic field and shows a magnetorheological (MR) effect, i.e., the modulus of the PVA hydrogel can be adjusted under a magnetic field. The chain-like structures of carbonyl iron are formed in the PVA hydrogel after orientation under a magnetic field of 1.5 T. Also some magnetic field induced oriented pores with a tunable diameter are observed in the dried PVA gel. The MR effect can be adjusted by changing the carbonyl iron content, the initial concentration of PVA solution and test frequency. The formation of aligned chain-like structures of carbonyl iron in the anisotropic PVA MR hydrogel improves the compression properties and the MR effect. At a carbonyl iron content of 70 wt%, the maximum absolute and relative MR effect of anisotropic PVA MR hydrogels are $1.24 MPa and $230%, respectively. The PVA hydrogels with good MR effects and moderate mechanical strength have potential applications in artificial muscle, soft actuators and drug release.

A dandelion‐like supramolecular polymer (DSP) with a “sphere‐star‐parachute” topological structure consisting of a spherical hyperbranched core and many parachute‐like arms is constructed by the non‐covalent host–guest coupling between a cyclodextrin‐endcapped hyperbranched multi‐arm copolymer (host) and many functionalized adamantanes with each having three alkyl chain arms (guests). The obtained DSPs can further self‐assemble into nanotubes in water in a hierarchical way from vesicles to nanotubes through sequential vesicle aggregation and fusion steps. The nanotubes have a bilayer structure consisting of multiple “hydrophobic‐hyperbranched‐hydrophilic” layers. Such a structure is very useful for constructing a chlorosome‐like artificial aqueous light‐harvesting system, as demonstrated here, via the incorporation of hydrophobic 4‐(2‐hydroxyethylamino)‐7‐nitro‐2,1,3‐benzoxadiazole as donors inside the hyperbranched cores of the nanotubes and the hydrophilic Rhodamine B as the acceptors immobilized on the nanotube surfaces. This as‐prepared nanotube light harvesting system demonstrates unexpectedly high energy transfer efficiency (above 90%) in water. This extends supramolecular polymers with more complex topological structure, special self‐assembly behavior, and new functionality.

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We report here a zwitterionic copolymer based non-covalently cross-linked hydrogel with intrinsic self-healing nature for potential use in enhanced oil recovery.

In this study, the interfacial friction damping properties of magnetorheological elastomers (MREs) were investigated experimentally. Two kinds of carbonyl iron particles, with sizes of 1.1 μm and 9.0 μm, were used to fabricate four MRE samples, whose particle weight fractions were 10%, 30%, 60% and 80%, respectively. Their microstructures were observed using an environmental scanning electron microscope (SEM). The dynamic performances of these samples, including shear storage modulus and loss factor were measured with a modified dynamic mechanical analyzer (DMA). The experimental results indicate that MRE samples fabricated with 1.1 μm carbonyl iron particles have obvious particle agglomeration, which results in the fluctuation of loss factor compared with other MRE samples fabricated with large particle sizes. The analysis implies that the interfacial friction damping mainly comes from the frictional sliding at the interfaces between the free rubber and the particles.