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Adhesive hydrogels have gained great interest for biomedical applications, because of their great adhesion, tunable structure, high water content, and biocompatibility. However, it is still challenging to engineer hydrogel materials combining tissue repairs and strain sensors. In this work, poly­(thioctic acid) (PTA) is used as a skeleton structure and mixed with polydopamine (PDA), resulting in hydrogels with excellent stretchability, resilience, and adhesion, which can adhere to various organic (porcine skin) and inorganic materials (ceramic, wood, glass, etc.) in both dry and wet environments. The hydrogels also exhibit antiswelling behavior, self-healing, and repeatable adhesion capacity (seven times), which are meaningful for bioapplications and show satisfactory biocompatibility, biodegradation, cell affinity, and ability to limit apoptosis in both in vitro and in vivo experiments. In the full-thickness skin defect model, the hydrogels can accelerate the wound healing process. The introduction of Fe3+ can significantly enhance the conductivity of the hydrogels, making it possible for the hydrogels to be used as strain sensors. This functional hydrogel may find an appealing application as an antiswelling and durability adhesive for strain sensors.

Development of stimuli-responsive hydrogels with improving mechanical strength is highly important for widening the practical applications of the smart soft hydrogel materials. In this paper, the metal−ligand coordinated hydrogels with tunable strength and thermosensitivity were fabricated by a facile two-step method including polymerization and post crosslinking. Compressive tests indicate that the covalent cross-linking degree, coordinated cross-linking degree and the type of coordinated metal ions largely impact the mechanical properties. Four types of the first transition metal ions including Zn 2+ , Cu 2+ , Co 2+ , and Ni 2+ were used for coordination, which enhanced the mechanical properties of the hydrogels to different extents. In particular, the compressive strength of Zn 2+ coordinated hydrogel is significantly improved compared with other ions coordinated hydrogels. The deswelling tests and differential scanning calorimetry (DSC) characterizations proved that the type of metal ions has great influence on the lower critical solution temperature (LCST) of the hydrogels. Herein, we attribute the different mechanical strength and phase transition behavior to the relaxation times as well as the divers spatial cross-linking density of the hydrogels, which may provide a avenue for the design of high-strength and fast-response hydrogels.

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A novel modified polyaspartic acid polymer, polyaspartic acid/4‐(2‐aminoethyl) morpholine graft copolymer (PASP/AEM), was prepared through a ring‐opening reaction of polysuccinimide and 4‐(2‐aminoethyl) morpholine and characterized by 1H NMR. The scale inhibition performance of this copolymer and its ability to disperse Fe2O3 were investigated in static tests. Scanning electron microscopy and X‐ray powder diffraction were used to analyze the effects of PASP/AEM on scale formation. The performance and mechanism of corrosion inhibition by the synthesized copolymer were studied via weight loss measurements and electrochemical measurements. The results showed that PASP/AEM possessed outstanding scale and corrosion inhibition efficiencies and had potential for use as a green scale and pickling inhibitor.

To improve the corrosion inhibition efficiency of eco-friendly polyaspartic acid (PASP) for mild steel in acidic solutions, PASP/N-(3-aminopropyl)imidazole (PD-1) and PASP/N-(3-aminopropyl)-imidazole-co-ndodecylamine (PD-2) were chemically synthesized by the facile ring-opening reaction of polysuccinimide. Inhibition efficiencies of PD-1 and PD-2 for mild steel in a 0.5 M H 2 SO 4 solution were investigated by electrochemical measurements (electrochemical impedance and polarization) and the weight loss method. In comparison with PASP, PD-1 and PD-2 show improved inhibition efficiencies due to the functional groups. In particular, PD-2 shows superior corrosion inhibition capacity, and the efficiency is up to 94% at a relatively low concentration of 100 mg L À1 at 298 K, as determined by potentiodynamic polarization measurements. Surface analysis of mild steel with PD-2 as an inhibitor clearly indicates that the inhibitor molecules adsorb on the steel surface and efficiently inhibit the corrosion of mild steel. The present work provides very meaningful results in designing and preparing new polymer inhibitors with high inhibition efficiency.

Ionic surfactants can be combined with various functional groups through electrostatic interaction, resulting in a series of thermotropic liquid crystals (TLCs).

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