Smart materials for light control of droplets.

Droplet manipulation plays a critical role in both fundamental research and practical applications, especially when combined with smart materials and external fields to achieve multifunctional droplet manipulation. Light control of droplets has emerged as a significant and widely used strategy, driven primarily by photochemistry, photomechanics, light-induced Marangoni effects, and light-induced electric effects. This approach allowing for droplet manipulation with high spatial and temporal resolution, all while maintaining a remote and non-contact mode of operation.

Self-Destructive Structural Color Liquids for Time-Temperature Indicating.

Vaccines are undoubtedly a powerful weapon in our fight against global pandemics, as demonstrated in the recent COVID-19 case, yet they often face significant challenges in reliable cold chain transport. Despite extensive efforts to monitor their time-temperature history, current time-temperature indicators (TTIs) suffer from limited reliability and stability, such as difficulty in avoiding human intervention, inapplicable to subzero temperatures, narrow tracking temperature ranges, or susceptibility to photobleaching. Herein, we develop a class of structural color materials that harnesses dual merits of fluidic nature and structural color, enabling thermal-triggered visible color destruction based on triggering agent-diffusion-induced irreversible disassembly of liquid colloidal photonic crystals for indicating the time-temperature history of the cold chain transport.

Self-Healable and Super-Tough Double-Network Hydrogel Fibers from Dynamic Acylhydrazone Bonding and Supramolecular Interactions.

Macroscopic hydrogel fibers are highly desirable for smart textiles, but the fabrication of self-healable and super-tough covalent/physical double-network hydrogels is rarely reported. Herein, copolymers containing ketone groups were synthesized and prepared into a dynamic covalent hydrogel via acylhydrazone chemistry. Double-network hydrogels were constructed via the dynamic covalent crosslinking of copolymers and the supramolecular interactions of iota-carrageenan.

Bioinspired Photo-Cross-Linking of Stretched Solid Silks for Enhanced Strength.

In this study, solid fibroin fibers (FFs) were directly cross-linked by employing a ruthenium-mediated redox pair under visible light at room temperature for the first time. The chemical cross-link through dityrosine connection was confirmed by Fourier-transform infrared (FTIR) spectroscopy, fluorescence spectra, and a solubility test. The resultant cross-link density of fibers was calculated based on their swelling ratio evaluation in LiBr solution.

Bacterial cellulose reinforced double-network hydrogels for shape memory strand.

Tough hydrogels with shape memory property are highly desirable for actuators and smart engineering materials. Herein, super-tough polyacrylamide/iota-carrageenan double-network hydrogels were synthesized via a one-pot radical polymerization and strengthened by incorporating bacterial cellulose microclusters, through the intermolecular hydrogen bonds and topological interlock between microclusters and polymer network. Such hydrogels were able to withstand over 200 kPa of tensile stress, or be stretched over 27 times of initial length, and reached a high toughness of ∼2000 kJ/m.

Novel Biological Hydrogel: Swelling Behaviors Study in Salt Solutions with Different Ionic Valence Number.

In this paper, poly γ-glutamic acid/ε-polylysine (γ-PGA/ε-PL) hydrogels were successful prepared. The γ-PGA/ε-PL hydrogels could be used to remove Na⁺, Ca, and Cr from aqueous solution and were characterized by scanning electron microscopy. The performance of hydrogels were estimated under different ionic concentration, temperature, and pH.

Preparation and properties of EDC/NHS mediated crosslinking poly (gamma-glutamic acid)/epsilon-polylysine hydrogels.

In this paper, a novel pH-sensitive poly (amino acid) hydrogel based on poly γ-glutamic acid (γ-PGA) and ε-polylysine (ε-PL) was prepared by carbodiimide (EDC) and N-hydroxysuccinimide (NHS) mediated polymerization. The influence of PGA/PL molar ratio and EDC/NHS concentration on the structure and properties was studied. Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) proved that hydrogels were crosslinked through amide bond linkage, and the conversion rate of a carboxyl group could reach 96%.

Production of nano bacterial cellulose from waste water of candied jujube-processing industry using Acetobacter xylinum.

The work is aimed to investigate the suitability of waste water of candied jujube-processing industry for the production of bacterial cellulose (BC) by Gluconacetobacter xylinum CGMCC No.2955 and to study the structure properties of bacterial cellulose membranes. After acid pretreatment, the glucose of hydrolysate was higher than that of waste water of candied jujube.