Highly Stretchable, Shape Memory Organohydrogels Using Phase‐Transition Microinclusions

Abstract

Shape memory effect in polymer materials has attracted considerable attention due to its promising applications in a variety of fields. However, shape memory polymers prepared by conventional strategy suffer from a common problem, in which high strain capacity and excellent shape memory behavior cannot be simultaneously achieved. This study reports a general and synergistic strategy to fabricate high-strain and tough shape memory organohydrogels that feature binary cooperative phase. The phase- transition micro-organogels and elastic hydrogel framework act synergistically to provide excellent thermomechanical performance and shape memory effect. During shape memory process, the organohydrogels exhibit high strain capacity, featuring fully recoverable stretching deformation by up to 2600% and compression by up to 85% beneath a load ≈20 times the organohydrogel's weight. Furthermore, owing to the micro-organogel and hydrogel heterostructures, the interfacial tension derived from heterophases dominates the shape recovery of the organohydrogel material. Simple processing and smart surface patterning of the shape memory behavior and multiple shape memory effects can also be realized. Meanwhile, these organohydrogels are also nonswellable in water and oil, which is important for multimedia applications.

Template-free formation of spindle-like α-Fe2O3 microstructures by hydrothermal reduction

“…And that, different types of anisotropy have a significant effect on the saturation values of magnetic materials [7]. Therefore, compared to our previous work, the relatively higher Ms in this work may be attributed to crystalline structure, crystal anisotropy and shape anisotropy [13].…”

“…Until now, several methods have been developed to fabricate α-Fe 2 O 3 micro/nanostructures with tunable shapes and size because it is widely accepted that the physical and chemical properties of micro/nano-structural materials are closely related to their size, size distribution, and morphology. During the past years, various hematite structures, such as rods [7], needle-like [8], nano-rings [9], scaffolds [10], hollow quasi-cubics [11], porous [12], flowers [13], and polyhedron [14] have been successfully prepared by various methods and applied various fields. However, most of the above-mentioned structures need expensive instruments, hard template, and complex post-processing.…”

Nanofiber‐Based Hydrogels: Controllable Synthesis and Multifunctional Applications

“…In recent years, the requirement and development speed of soft intelligent materials are increasing with each passing day. Among these smart materials, flexible actuators triggered by various external stimulus such as electrical stimulation, light magnetic field, temperature, pH value, and humidity, have attracted a lot of attention due to their promising applications in many fields . Although some progresses have been obtained in the past few years, the preparation of flexible actuator with controllable moving direction and rapid shape recovery property is still a great difficulty .…”

Effect of solvent–matrix interactions on structures and mechanical properties of micelle‐crosslinked gels

“…Recently, nonaqueous solvents are introduced into hydrogels and play an important role in adjusting the mechanical properties. Liu and coworkers prepared organogels by using an oil‐in‐water emulsion comprised of oil phase (molten paraffin and lauryl methacrylate) and water phase containing N , N ‐dimethyl acrylamide (DMA). The obtained organohydrogels exhibited high stretchability, and a full recovery from more than 2500% strain.…”