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The development of 1D stimuli‐responsive ultrathin organic nanomaterials (UTONMs)‐based hybrid nanocomposites with tailored functions is necessitated to construct hybrid catalysts with adjustable catalytic performance. Herein, the self‐assembly of ternary amphiphilic alternating azopeptoids into micron‐scaled ultrathin peptoid nanobelts (PNBs) is reported with a thickness of ≈2.2 nm. The pendants hydrophobic conjugate stacking mechanism is accountable for the formation of 1D long‐ranged‐ordered nanostructure, whose thickness is highly dependent on the length of the suspended side‐chains. The photo‐triggered reversible transition from PNBs to nanospheres (≈92 nm) is rendered by the photo‐isomerization of azobenzene moiety upon alternating irradiation with UV and visible lights. Moreover, the carboxyl‐modified aggregates are employed as supports to load Pd nanoparticles, successfully preparing hybrid nanocomposites. As a proof‐of‐concept experiment, the catalytic activity of both control and these hybrid nanocomposites are evaluated toward chemo‐enzymatic cascade catalysis for 3,3′,5,5′‐tetramethylbenzidine oxidation with in situ UV–vis spectroscopic monitor. Compared to nanospheres‐based systems, PNBs‐based nanocomposites exhibited larger catalytic performance, attributable to the ultrathin nanostructures and subsequent ultrahigh specific surface area. The photo‐controllable recyclable catalytic activity is effectively modulated using the alternative irradiation with UV and visible lights for three cycles. The work paves an appealing avenue to prepare UTONMs‐based stimuli‐responsive hybrid nanocomposites with controllable performance. [ABSTRACT FROM AUTHOR]

Due to the intrinsic porosity and photo‐regulated pore environment, azobenzene (Azo) functionalized covalent organic frameworks (COFs) show great potential for contaminant removal. However, the stability and degree of functionality of the COFs greatly affect the porosity and subsequent adsorption capacity and selectivity. Herein, a highly stable thiazole‐linked COF containing phenolic hydroxyl groups (OH‐COF) is constructed by using 4,4′,4′‐(1,3,5‐triazine‐2,4,6‐triyl)trianiline and 2,5‐dihydroxyterephthalaldehyde in the presence of sulfur, which shows high crystallinity and specific surface. Azo‐functionalized COFs ((Azo)x‐COFs) are prepared by grafting different amounts azobenzene groups onto OH‐COF through post‐modification, whose aperture is conveniently tuned by the grafted azobenzene amount. The pore size of (Azo)x‐COFs also can be reversibly adjusted under UV and visible light irradiation without affecting the crystallinity. Appropriate amount of Azo‐grafted (Azo)0.1‐COF possessed a high adsorption capacity (1216.93 mg g−1) to Congo red (CR). While the adsorption capacity of (Azo)1.0‐COF to CR significantly increased 2.9 times to reach 1489.96 mg g−1 after UV irradiation. (Azo)1.0‐COF also can selectively separate dye molecules with different sizes based on photo‐regulated pore size, showing excellent reversibility and reusability. As such, the ability to photo‐regulate the adsorption and interception of (Azo)x‐COFs highlights their significance in functioning as smart porous nanomaterials for pollutant removal and water purification. [ABSTRACT FROM AUTHOR]

Stimuli‐responsive photonic crystals (PCs) have attracted increasing attentions owing to the unique optical feature in regulating the propagation of light and tunable structural colors in response to external stimuli, emerging application potential on diverse fields. However, the development of stimuli‐responsive PCs with wide visible light range, broad shift of bandgaps, and adjustable responsive rates for counterfeiting remains challenging. Herein, a simple strategy for the preparation of photo‐responsive azobenzene‐containing inverse opal (AzoIO) films is reported. First, azobenzene‐containing composites are generated by filling functional monomers into voids of silica colloids crystals. Followed by the thermal polymerization and subsequent etching, a series of AzoIO films are successfully fabricated with adjustable structural colors in wide visible wavelength. Upon irradiation with linearly polarized visible light (LPVL), a slowly broad blueshift of bandgaps (≈138 nm, 3200 s) is observed due to the anisotropic shrinkage of the periodic PC structures. However, UV light irradiation contributed to a fast broad blueshift of bandgaps (≈131 nm, 10 s), owing to the photoisomerization merit of azobenzene moiety. The proof‐of‐concept study on the applications in light‐modulated multicolored writable paper, encryption films, and fast writing/erasing demonstrated the potential for information security. This work paves an avenue for developing promising optical anti‐counterfeiting materials. [ABSTRACT FROM AUTHOR]

Amphiphilic rigid backbone polymers are traditionally seemed as one-dimensional (1D) rods and show distinct self-assembly behavior to flexible polymers, but they could hardly adapt morphology-tunable self-assembly by changing their holistic conformation upon external stimuli. In this study, we synthesized a series of amphiphilic homopolymers poly(acetylene azobenzene oligoethylene glycol) (P(AAzo-EGx)) containing conjugated polyacetylene mainchain, azobenzene pendants and oligo ethylene glycol tails in each unit. This comb-like amphiphilic polymer could be treated as two-dimensional (2D) nanoribbons with tunable holistic conformation via meticulous tailoring intrastrand repulsion and interchain π-π interaction of azobenzene pendants by light, temperature, and solvent swelling. P(AAzo-EG2) could self-assemble into large vesicles in ambient, whereas transformed to supramolecular helix bundles (SHBs) at 65 °C as well as depicted by dissipative particle dynamics (DPD) simulation, and then turned into grass leaf-like micelles upon sequential ultraviolet (UV) and blue light irradiation. The three assemblies featured different stacking mode of PAAzo skeletons although showed similar aggregate induce emission (AIE) effect. In this holistic macromolecular chain conformation-induced self-assembly and morphology transformation, temperature influenced the stacking of hydrophobic parts mainly by tuning the torsion of PAAzo skeleton. Certain amount of good solvent played a vital role by swelling of hydrophobic PAAzo skeleton, and helping the movement and rearrangement of azobenzene pendants and polyacetylene mainchains like a lubricant. The length and diameter of SHBs could be tuned by changing EGx tails. This work uncovered a facile strategy to tailor the self-assembly of rigid backbone polymers for fabrication of functional nanodevices. [ABSTRACT FROM AUTHOR]