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Liquid-free ionic conductors (LFICs) have promising applications in flexible electronics because most ionic conductors currently suffer from ionic liquid leakage or water evaporation issues. However, it has been a formidable challenge for LFICs to achieve long-term repeated self-adhesion on different substrates, especially on soft biological tissues. Based on the double-network design concept, we first fabricate a series of repeatable self-adhesive liquid-free double-network ionic conductors (SALFDNICs), consisting of stretchable first poly(AA-ChCl)-type supramolecular deep eutectic polymer networks and stiff second polydopamine (PDA) networks, which can maintain sufficient dynamic hydrogen bonds and catechol groups in the ionic conductors by preventing the overoxidation of dopamine, thus balancing the contradiction between adhesion and cohesion in liquid-free ionic conductors. Therefore, SALFDNICs can instantly form various interface interaction forces with multiple substrates (adhesion strength up to 757 N/m) and firmly adhere to various substrates for 20 detachment-reattachment cycles with a reduction in adhesion strength of less than 15%. Furthermore, SALFDNICs also have other comprehensive properties, such as optimum self-healing properties (self-healing efficiency of 90%), good stretchability (strain at break of 1200%), and promising conductivity (2.31 × 10

Ionic skin with a high performance has been extensively explored due to its ability to convert external stimuli into obvious electrical signals for wearable electronics and intelligent detection. H...

Ionic conductors are normally prepared from water-based materials in the solid form and feature a combination of intrinsic transparency and stretchability. The sensitivity toward humidity inevitably leads to dehydration or deliquescence issues, which will limit the long-term use of ionic conductors. Here, a novel ionic conductor based on natural bacterial cellulose (BC) and polymerizable deep eutectic solvents (PDESs) is developed for addressing the abovementioned drawbacks. The superstrong three-dimensional nanofiber network and strong interfacial interaction endow the BC-PDES ionic conductor with significantly enhanced mechanical properties (tensile strength of 8 × 105 Pa and compressive strength of 6.68 × 106 Pa). Furthermore, compared to deliquescent PDESs, BC-PDES composites showed obvious mechanical stability, which maintain good mechanical properties even when exposed to high humidity for 120 days. These materials were demonstrated to possess multiple sensitivity to external stimulus, such as strain, pressure, bend, and temperature. Thus, they can easily serve as supersensitive sensors to recognize physical activity of humans such as limb movements, throat vibrations, and handwriting. Moreover, the BC-PDES ionic conductors can be used in flexible, patterned electroluminescent devices. This work provides an efficient strategy for making cellulose-based sustainable and functional ionic conductors which have broad application in artificial flexible electronics and other products.

It is a challenge to synthesize all-in-one molecular networks that are autonomously self-healable over a wide temperature range (from subzero to high), transparent, stretchable, and conductive. Her...

Stretchable and antifreezing conductive hydrogels, especially prepared from natural polymers, are beneficial for important and rapidly growing stretchable electronic devices. Unfortunately, the pot...

Natural hydrogels have attracted extensive research interest and shown great potential for many biomedical applications. In this study, a series of biocompatible hydrogels was reported based on the self-assembly of positively charged partially deacetylated α-chitin nanofibers (α-DECHN) and negatively charged 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibers (TOCNF) for anticancer drug delivery. The formation mechanisms of the α-DECHN/TOCNF hydrogels with different mixing proportions were studied, and their morphological, mechanical, and swelling properties were comprehensively investigated. Additionally, the drug delivery performance of the hydrogels was compared via sustained release test of an anticancer drug (5-fluorouracil). The results showed that the hydrogel with higher physical cross-linking degree exhibited a higher drug loading efficiency and drug release percentage.

A simple triphenylphosphine-ligated cobalt catalyst is reported for the direct ortho-C-H methylation and ethylation of aromatic, heteroaromatic, alkenyl, and even aliphatic carboxamides with inexpensive organoaluminum reagents in the presence of a cheap alkyl chloride as oxidant. This reaction shows monoselectivity in contrast with previously established C-H methylation methodologies.

Phototriggered base proliferation as a highly efficient domino reaction is presented for creating functionally photo-screened materials, providing a strategy for the photopolymerization of shadow areas via chemically diffuse amines toward the nonirradiated areas during polymerization. By integrating proliferated amines with a peroxide initiator (dibenzoyl peroxide, BPO), phototriggered self-propagating polymerization of acrylate monomers in three-dimensional space was achieved. The advantages of this approach lie in its enhanced photosensitivity, increased propagating velocity, and elevated double-bond conversion (90%) while reducing the local high temperature and the minimum BPO concentration that sustain a traveling front. Astonishingly, the propagating velocity and local maximum temperature can be well-modulated by varied BPO concentration and the appropriate amount of BA-BPD (1-(9-fluorenylmethoxycarbonyl)-4-benzylpiperidine) concentration, respectively. Finally, functionally photo-screened material c...