Nylon 6 fabrics were chemically modified via reduction with BH 3 for being functionalized as heterogeneous base organocatalysts for Knoevenagel condensation. The results of FTIR, XPS, and SEM indicated the successful modification of nylon 6 fabrics. With a low catalytic dosage of 6.6 mol % and a short reaction time (2 h), the fabric catalysts were well applicable to Knoevenagel condensation of a wide range of substrates and up to 98% yield could be obtained. In addition, the fabric catalysts have some beneficial advantages in terms of easy separation, good reusability, and recyclability (up to 10 times).

Mechanochromic elastomers play an important role in stain sensing, materials damage alarming and stress detecting, etc. Low activation strain and stress, high toughness and resilience, and self-recovery ability are essential...

Designing artificial systems to mimic chiral superstructures and exploring how achiral molecules precisely modulate their chirality is crucial to understand the origin of homochirality in nature. Herein, the tunability nature of supramolecular chirality is subtly applied to fabricate robust chiral covalent polymers with controlled macroscopic helicity. When using conventional supramolecular transcription methods to prepare chiral poly(m-phenylenediamine), simply introducing various small amounts of achiral diaminopyridines (DAPs) to copolymerize with m-phenylenediamine (MPD) enables the resulting chiral copolymers with adjustable helical configurations and chiroptical activities in an enantiopure template system. The strong hydrogen bonds between DAPs and the template molecules ((S)/(R)-PhgC 16 ) proved to be the driving force for guiding the chiral polymerization mode of MPD. Impressively, the exquisite self-sorting phenomenon is observed by tuning the stoichiometric ratio of DAP and (R)-PhgC 16 , where the as-prepared copolymers with opposite helicity can exist simultaneously to form a double network structure and their chiroptical activity can be well regulated. In addition, based on such a copolymerization strategy, a conceptual library of helical functional copolymers is built with editable polymer types including conducting polymers and designable amine-aldehyde condensation-based polymers. This copolymerization-mediated synthetic strategy may facilitate the development of chiral polymers with controlled morphologies and dynamic compositions.

Triboelectric nanogenerator (TENG) and its self-powered sensor based on the principles of contact electricity generation and electrostatic induction have important application prospects in the fields of new energy and internet of things (IoT). In the contact separation process of polymer materials with different electronegativity values, due to the transfer of electrons, a changing electrostatic field will be generated in the space around the polymer. In the existing TENG research, the field strength perpendicular to the plane of the friction layer and the electrode layer is mainly used to generate electrostatic induction, and the electric field effect around the polymer is ignored. According to the principle of electrostatic induction, the internal charge of the conductor in the electric field will be redistributed, which provides a way for the conductor to generate an induced electrical signal on the surface of the conductor without contacting the friction material. In this paper, we design a non-contact triboelectric nanogenerator (NC-TENG) based on changing electrostatic field. The influence of the distance between the conductor and the friction material, the induction area of the conductor and the position of the conductor relative to the friction material on the induced electrical output performance are studied when silicone rubber and nitrile rubber are used as a friction material. The results show that the NC-TENG can produce a stable electrical signal output when the conductor is completely separated from the friction material. The induced voltage of NC-TENG decreases with the increase of the distance between the conductor and the friction material, and gradually increases with the increase of the conductor's induction area. For the friction material with a size of 30 mm × 30 mm, the electrical output of NC-TENG tends to be stable when its conductor area is 60 mm × 45 mm. In addition, the different orientation of the conductor relative to the friction material also has a significant effect on the induced electrical output. The NC-TENG designed in this paper provides a novel electrical output generation mode, which provides a higher possibility for the subsequent research on TENG and the application of self-powered sensors.

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