Adaptive Superamphiphilic Organohydrogels with Reconfigurable Surface Topography for Programming Unidirectional Liquid Transport

Abstract

Adaptive materials with reconfigurable surface topography in response to external environments have attracted considerable attention in various fields. Here, adaptive superamphiphilic organohydrogels with reconfigurable surface topography are reported, featuring a high degree of freedom. The organohydrogels can simultaneously adapt to different surrounding mediums and reversibly switch between hydrogel-and organogeldominated surface reconfigurations to realize adaptive superhydrophilic and superoleophilic transitions. Meanwhile, these adaptive organohydrogels possess a heteronetwork complementary effect to elicit surface self-healing capacity. Importantly, owing to these organohydrogels' reversible wettability transition, excellent surface morphing performance and bioinspired strategy, various geometrically complex biomimetic topographies can be programmed, offering unique unidirectional transport for opposite-featured liquids in multimedia environments. Smart organohydrogel-based microfluidic devices are also developed for on-demand remote programming of liquid transport. Therefore, the organohydrogels suggest a reconfigurable surface topography design strategy, and would act as adaptive programmable materials for smart surface applications.

Self‐Hydrophobization in a Dynamic Hydrogel for Creating Nonspecific Repeatable Underwater Adhesion

“…For a hydrophilic adherent, we hypothesized that the surfactants (SDS/FDS) from the hydrogels were attached to the hydrophilic surfaces at first and converted the surface properties to hydrophobic to achieve adhesion (Figure S8, Supporting Information). To confirm this self‐regulation process, we measured the WCA of the substrates and hydrogel samples before and after adhesion . As anticipated, the hydrophobic PE substrate becomes hydrophilic with a WCA of ≈30° after detaching from the hydrogel, while the Fe‐PAM‐C‐M hydrogel retained hydrophobicity with the WCA of ≈100°.…”

Recent Advances in Bioinspired Gel Surfaces with Superwettability and Special Adhesion

“…Inspired by such functionality, Gao et al developed an organohydrogel through in situ polymerization of oleophilic polymer (butyl methacrylate (BMA) and lauryl methacrylate (LMA)) within a cross-linked hydrophilic network (N,N-dimethylacrylamide: DMA) swollen with amphiphilic solvents (ethanol) (Figure 5e). [57] Such adaptive wettability demonstrated excellent reversibility after alternately immersing the organohydrogel in water and oil. In water, the organohydrogel performed like a hydrogel due to the swelling of the hydrophilic network.…”

Directional liquid dynamics of interfaces with superwettability

“…The overlapping structured peristome of pitcher plants (11) shows super-slippery and microdrop directional spreading properties. These breakthrough findings have also led to disruptive changes in human research (12)(13)(14)(15).…”

“…With this background, research on the directional liquid dynamics of interfaces with superwettability has experienced explosive growth during the past decade and is expected to continue (12)(13)(14)(15)(16)(17). At the present time, it is most important to determine the relationship between fundamental research and practical applications (1,2).…”

“…At present, it is a common method to en-hance the directional dynamics of a liquid on a superwetting surface by an external field stimulation (18)(19)(20)(21). Different external fields have their own (dis)advantages and applicable environments (13)(14)(15)(16)(17)(18)(19)(20)(21). Developing new responsive materials or optimizing the structure/ composition of the existing materials is the way forward.…”