Adaptive and freeze-tolerant heteronetwork organohydrogels with enhanced mechanical stability over a wide temperature range

Hainan Gao,Lie Chen,Ziguang Zhao,Li Wang,Jianqi Zhang,Yudong Cai,Dong Han,Jiajia Zhou,Lei Jiang,Wenda Hua,Mingjie Liu

doi:10.1038/ncomms15911

Abstract

Many biological organisms with exceptional freezing tolerance can resist the damages to cells from extra-/intracellular ice crystals and thus maintain their mechanical stability at subzero temperatures. Inspired by the freezing tolerance mechanisms found in nature, here we report a strategy of combining hydrophilic/oleophilic heteronetworks to produce self-adaptive, freeze-tolerant and mechanically stable organohydrogels. The organohydrogels can simultaneously use water and oil as a dispersion medium, and quickly switch between hydrogel- and organogel-like behaviours in response to the nature of the surrounding phase. Accordingly, their surfaces display unusual adaptive dual superlyophobic in oil/water system (that is, they are superhydrophobic under oil and superoleophobic under water). Moreover, the organogel component can inhibit the ice crystallization of the hydrogel component, thus enhancing the mechanical stability of organohydrogel over a wide temperature range (−78 to 80 °C). The organohydrogels may have promising applications in complex and harsh environments.

Highlights

Many biological organisms with exceptional freezing tolerance can resist the damages to cells from extra-/intracellular ice crystals and maintain their mechanical stability at subzero temperatures
Inspired by the freezing tolerance mechanisms found in nature, here we report a heteronetwork organohydrogel with stable elasticity over a wide temperature range ( À 78 to 80 °C)
After adequately dehydrating the material with acetone, the hydrophilic polymer network (HPN) were swollen in an ethanol solution containing lauryl methacrylate (LMA; 34.1 wt%), n-butyl methacrylate (BMA; 35.0 wt%), ethylene glycol dimethacrylate (0.62 wt%) as a crosslinker and 2,2-diethoxyacetophenone (0.41 wt%) as a photoinitiator (Fig. 1a)

Summary

Introduction

Many biological organisms with exceptional freezing tolerance can resist the damages to cells from extra-/intracellular ice crystals and maintain their mechanical stability at subzero temperatures. Many biological organisms, such as plants and animals living at high latitudes and altitudes, can survive subzero temperatures and resist the damages to cells from extra-/intracellular ice crystals[1,2] This exceptional freezing tolerance originates from increased quantities of fatty species (for example, membrane lipids), which allow cell membranes to inhibit growth of ice and maintain their mechanical stability[3–5]. The organogel component can inhibit the ice crystallization in hydrogel, enhancing the mechanical stability of organohydrogel at subzero temperatures This concept of complementary heteronetworks within a gel matrix will inspire researchers to design soft materials with complex and unusual functions

Methods

Results

Conclusion