Many load-bearing tissues in nature obtain high toughness by fabricating anisotropic structures with spatially regulated composition and modulus at the macroscale. This inspires a toughening strategy for hydrogels based on the controlling of modulus heterogeneity. Herein, a facile approach to realize light-regulated spatial modulus heterogeneity with large contrast in hydrogels is proposed. Ferric citric acid complex (Fe /CA-complex) is used as a light-responsive ionic cross-linker, which can first stiffen an alginate/polyacrylamide (Alg/PAAm) hydrogel by coordinating with the Alg to form another network, then realize light-triggered softening through photoreduction of ferric ions (Fe ). Based on this, a stripe-patterned hydrogel with alternating stiff and soft segments can be fabricated through photopatterning. The modulus contrast between the stiff and soft phases can be adjusted by control of several influence factors and the maximum modulus contrast can reach up to 87 times. As a result, the toughness of the stripe-patterned hydrogel is enhanced by 3.5 times comparing to that hydrogel without a pattern. This approach shows great potential in the synthesis of smart hydrogels with light-programmable mechanical performances, and may be widely applicable for the hydrogels with functional groups that can coordinate with metal ions.
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http://dx.doi.org/10.1002/marc.202200077 | DOI Listing |
Angew Chem Int Ed Engl
March 2025
Nankai University, College of Chemistry, No.94 Weijin Road, 300071, Tianjin, CHINA.
Covalent organic frameworks (COFs) have been regarded as promising cathode materials for lithium batteries. However, they generally show low practical capacity. Here we report the design, preparation, and battery application of a highly crystalline two-dimensional truxenone-based COF (TRO-BT-COF) with rich redox active sites, realizing a high practical capacity.
View Article and Find Full Text PDFMolecules
February 2025
Graduate School of Science and Engineering, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan.
Nitrite is a health and environmental hazard and pollutes water sources globally, but sensitive, rapid, and facile quantification methods are lacking. Herein, we report a method for extracting and quantifying low-concentration nitrite in surface water using minimal sample and solvent volumes. The nitrite reacted with sulfanilamide and -1-naphthylethylenediammonium dichloride (NED), yielding an azo dye for extraction into an organic ion-associate liquid phase (IALP) formed in situ using ethylhexyloxypropylammonium and dodecyl sulfate ions.
View Article and Find Full Text PDFPolymers (Basel)
February 2025
Dipartimento di Fisica and Centro di Ricerca Interdipartimentale in Materiali Avanzati e Dispositivi (MADE), Università degli Studi di Pavia, Via A. Bassi 6, 27100 Pavia, Italy.
Dielectric elastomer generators (DEGs) are electrostatic transducers capable of harvesting electrical energy from oscillating mechanical parts and storing it in a battery or supercapacitor. The energy conversion element typically consists of a flexible capacitor with a variable capacitance that depends on the applied stress cycle and requires an external voltage source (bias voltage). In designing an energy harvesting device from human gait, we propose integrating two components: a dielectric elastomer fabricated using a nanocomposite polyurethane (TPU-CaCuTiO) and an electret serving as a bias voltage source.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
March 2025
Central South University, School of Metallurgy and Environment, Lushan South Road 932, 410083, Changsha, CHINA.
Organic perylene has been heralded as a promising candidate due to abundant structural diversity and tunability. However, its practical application is severely plagued by facile solubility, scarce redox-active sites, and andante kinetics behaviors. Herein, the perylene derivative (DPL), i.
View Article and Find Full Text PDFACS Nano
March 2025
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.
To surmount the shortcomings of powder-based catalysts and small electrode sizes, the development of meter-scale integrated electrode materials is essential for practical electrocatalytic applications, which requires fine control over the effective surface grafting of catalytic active sites on large-size electrodes as well as addressing the challenge of balancing cost-effective and large-scale manufacturing with highly active and stable operation. Herein, we report a low-cost, facile, and scalable method for directly constructing meter-scale single-molecule-integrated catalytic electrodes using commercially available, flexible, and size-tailored conductive carbon textiles (e.g.
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