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A novel supra-amphiphilic metallogelator [Cu12](OTf)2 having functional dibenzo-24-Crown-8 as hydrophilic part and complexed Cu2+/terpyridine as hydrophobic part was prepared from an amphiphilic precursor. The supra-amphiphilic metallogelator was found to be able to gel in toluene/CH3CN or THF/CH3CN. The self-assembly mechanism of [Cu12](OTf)2 into supramolecular gel was extensively studied by FT-IR, UV-Vis, fluorescence, PXRD spectroscopic techniques, and theoretical calculations, revealing that the intermolecular π-π interaction plays a vital role in the gel formation. Due to the presence of dibenzo-24-Crown-8 and coordinating terpyridine motif within the supra-amphiphilic metallogelator, the reversible gel-sol transition can be induced by several stimulus, including temperature, pH, mechanical force, and metal ion/competitive host molecule, making this supramolecular gel highly adaptive to the external environment. The work reported here offers prospects for designing more metal-based supra-amphiphilic self-assembly building blocks by integrating the functions from both ligands and metal ions, opening new avenues for preparing multiple stimuli-responsive and adaptive materials.

Multicomponent lanthanide-based metallogel offers unique prospects to access versatile, dynamic supramolecular soft materials with hierarchical stimuli-responsiveness and tunable functions, particularly for applications in the optical display field. In this work, a novel ligand L bearing classical coordinating terpyridine (tpy) and hosting 24-Crown-8 (24C8) moieties was synthesized with a function-oriented design principle, which further allowed the complexation between L and a series of lanthanide ions (Ln). Interestingly, several L-Ln complexes with 1:1 stoichiometry were found to be able to gel the solvent toluene/CH3CN (1:1), and thus lanthanide-based metallogels were successfully prepared. The L-Eu and L-Tb gel was found to be emissive and further utilized to produce a white light emitter through fine adjustment of stoichiometry among Eu, Tb, and L. Importantly, the multicomponent gel strategy was employed, and additional non-coordinating chromophores were introduced into the metallogel system. Thus a broad-spectrum of emission was achieved, and these multicomponent emissive gels were successfully applied as a photo printer. The metallogels also showed multiple stimuli-responsiveness such as pH, guest molecules thanks to the anchoring of predesigned functional moieties such as tpy and 24C8 on the ligand L. It is assumed that our multicomponent metallogel research shown here may open new avenues towards the design and preparation of intelligent and tunable hybrid lanthanide-based optical materials.

In this study, a thermo-responsive temporary plugging agent was developed with the property of solution (sol)–gel–sol transition behavior at different temperatures. At low temperature, the material is in the sol state, while increasing temperature led to a stable gel formation, but the gel can transform to sol again upon further heating. This unique behavior was characterized by a series of SEM, FT-IR, XRD, rheology, and viscoelasticity measurements. All scientific results showed noncovalent interactions between the components, which play an important role for the supramolecular gel formation. These findings provide that this system can be applied as a temporary plugging agent by the idea of temperature-induced smart material with the advantages of cross-linker and gel-breaker free. Physical simulation experiment results showed that the material is a solid free fluid with good fluidity at room temperature. After injecting to formation, the fluid gradually transformed to a hard gel around 90 °C with suffic...

Acrylamide copolymers are often used as acidizing diverting and thickening agents for their advantageous thickening, flocculation, adhesion and resistance reduction properties. Experimental results indicate that the acid concentration greatly affects the properties of acrylamide polymers, which varies from results reported by other researchers. Considering the theoretical and field application value of the present study, four comparable acrylamide-based polymers were synthesized, and their macro- and micro-changes as well as the related changes in viscosity and molecular weight were studied in high-concentration hydrochloric acid. A proposed mechanism of acrylamide copolymer stability and degradation is provided, and further suggestions are made for the modification of acrylamide copolymers.

International audience; Mechanically interlocked molecules (MIMs) have emerged as intriguing building blocks for the construction of stimuli-responsive devices and materials. A particularly interesting and well-implemented subclass of MIMs is composed of symmetric bistable [c2]daisy chain rotaxanes. Topologically, they consist in the double thread of two symmetric macrocycles that are covalently linked to an axle bearing two switchable stations and a bulky stopper to avoid unthreading. Here we report the synthesis and characterization of a series of unsymmetric bistable [c2]daisy chain rotaxanes that present two different electroactive units as stoppers (an electron donor triarylamine and an electron acceptor perylene bisimide unit). Using a combination of 1D and 2D NMR along with cyclic voltammetry, we demonstrate that the pH actuation of the mechanical bond can be used to modulate the electrochemical properties of the bistable [c2]daisy chain rotaxanes when switching between the contracted and extended forms. pH-Switchable [c2]daisy chain rotaxanes that present two different electroactive units as stoppers have been synthesized and fully characterized. Their actuation between the contracted and extended forms leads to a modification of their electrochemical properties.