Inorganic Salts Induce Thermally Reversible and Anti‐Freezing Cellulose Hydrogels

Abstract

Inspired by the anti‐freezing mechanisms found in nature, ionic compounds (ZnCl2/CaCl2) are integrated into cellulose hydrogel networks to enhance the freezing resistance. In this work, cotton cellulose is dissolved by a specially designed ZnCl2/CaCl2 system, which endows the cellulose hydrogels specific properties such as excellent freeze‐tolerance, good ion conductivity, and superior thermal reversibility. Interestingly, the rate of cellulose coagulation could be promoted by the addition of extra water or glycerol. This new type of cellulose‐based hydrogel may be suitable for the construction of flexible devices used at temperature as low as −70 °C.

Anisotropic Protein Organofibers Encoded With Extraordinary Mechanical Behavior for Cellular Mechanobiology Applications

“…Compared to conventional isotropic organohydrogel systems, the structured ELP‐surfactant organofibers show extraordinary mechanical performance. For example, synthesized polymer gel networks have limited tensile strength at the scale of kiloPascal level, [28–31] and show tenuous modulus property [32–35] . In our system, the strength of anisotropic ELP‐surfactant organofibers is at least one order of magnitude higher than the isotropic counterparts aforementioned, highlighting their robustness in term of mechanical properties (Table 1).…”

Anisotropic Protein Organofibers Encoded With Extraordinary Mechanical Behavior for Cellular Mechanobiology Applications

“…Compared to conventional isotropic organohydrogel systems, the structured ELP‐surfactant organofibers show extraordinary mechanical performance. For example, synthesized polymer gel networks have limited tensile strength at the scale of kiloPascal level, [28–31] and show tenuous modulus property [32–35] . In our system, the strength of anisotropic ELP‐surfactant organofibers is at least one order of magnitude higher than the isotropic counterparts aforementioned, highlighting their robustness in term of mechanical properties (Table 1).…”

Redox‐Active Iron‐Citrate Complex Regulated Robust Coating‐Free Hydrogel Microfiber Net with High Environmental Tolerance and Sensitivity

“…It is observed that the hydrogel microfiber maintains good elasticity at −40 °C with almost coincident tensile curve to that at 25 °C, and the fiber becomes brittle lower than −50 °C. The frost resistance of hydrogel microfiber is attributed to the presence of glycerol, which is known to significantly inhibit ice crystallization in hydrogel systems 32,33…”