Compared with traditional thermosets, malleable thermosets have more applications in aerospace, biotechnology, and construction. Here we report a one-step, solvent-free, catalyst-free polycondensation method between diamine and formaldehyde to prepare a series of malleable hemiaminal dynamic covalent networks (HDCNs). The materials have excellent malleability and reprocessability by hot pressing. The Young's modulus and breaking strength of HDCNs obtained by the polycondensation of formaldehyde and 4,4-diaminodiphenylmethane (MDA) are as high as 1.6 GPa and 60 MPa, respectively, which can be facilely adjusted through the introduction of polyetheramine-400 (PEDA). Moreover, the HDCNs feature the shape memory ability with a recovery ratio above 93.5% and can be recycled by the addition of different monomers. This promising HDCN, prepared from economical raw materials, may have vast applications in industries.

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The development of inexpensive and highly efficient enzyme-responsive polymers has significantly contributed to targeted drug delivery systems. Here, a superamphiphile with a capability of fluorescent dissociation sensing is designed. It is constructed with negatively charged adenosine 5'-triphosphate (ATP) and negatively charged fluorescein diphosphate (FDP), which are used as fluorescence detection, and a cationic diblock copolymer methoxy-poly(ethylene glycol) -b-poly(2-dimethyl-aminoethyl methacrylate) . Upon addition of calf intestinal alkaline phosphatase, the superamphiphile disintegrates, presumably due to the enzymatic hydrolysis of ATP. This process is accompanied by an increase in the fluorescence emission intensity of fluorescein owing to the hydrolysis of FDP. The in vitro application of the superamphiphile is also proven. Thus, the "turn-on" fluorescence of the superamphiphile serves as a real-time module for detection of the disintegration of superamphiphile.

The fabrication of block copolymer (BCP) vesicles with controlled membrane permeability and promising stability remains a considerable challenge. Herein, a new type of pH‐responsive and self‐crosslinked vesicle based on a hydrolytically hindered urea bond is reported. This kind of vesicle is formed by the self‐assembly of a pH‐responsive and hydrolytically self‐crosslinkable copolymer poly(ethylene glycol)‐block‐poly[2‐(3‐(tert‐butyl)‐3‐ethylureido)ethyl methacrylate‐co‐2‐(diethylamino)ethyl methacrylate] (PEG‐b‐P(TBEU‐co‐DEA)). The BCP can be easily synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization of 2‐(3‐(tert‐butyl)‐3‐ethylureido)ethyl methacrylate (TBEU) and 2‐(diethylamino)ethyl methacrylate (DEA) using PEG‐based macro‐chain transfer agent. The copolymer could self‐assemble into stable vesicles by the hydrophobic interaction and in situ cross‐linking between amines and isocyanates after the hydrolysis of the hindered urea bonds without any catalyst. Dynamic light scattering (DLS) studies show that the vesicles exhibit enhanced stability against the dilution of organic solvent, and the size can be adjusted through the change of pH values. Moreover, the alkaline phosphatase‐loaded vesicles can act as nano‐reactor and enable free diffusion of small molecules into the vesicles, followed by the significantly improved fluorescence intensity of phosphate‐caged fluorescein. This self‐crosslinking and pH‐sensitive vesicles may serve as a smart platform in controlled drug delivery and molecular reactor.