Recently, smart liquid permeation has aroused much attention. However, existing strategies to achieve such a goal are often based on reversibly controlling hydrophobicity/hydrophilicity on static porous structures, which are unsuitable for oils with low surface tension, and meanwhile they cannot realize tunable permeation flux since the pore sizes are constant. Herein, we report a superlyophilic shape memory porous sponge (SSMS) that can demonstrate tunable pore size from about 28 nm to 900 μm as the material’s shape is changed. Based on the controllability in pore size, not only ON/OFF penetration but also precisely tunable permeation flux can be obtained for both water and oil. Furthermore, by using the SSMS, an application in accurate release of small-molecule rhodamine B was also demonstrated. This work reports a material with tunable pore size for controllable liquid permeation, which provides some ideas for designing smart superwetting permeation materials.
The separation of surfactant-stabilized oil-in-water emulsions is a challenging issue as such state-of-art technologies usually suffer from energy-intensive, time-consuming, and inefficient processes. Here, we constructed a series of superphilic cryogels of regular, ordered, and oriented porous structures that are similar to that of lotus root. Using dimethyl sulfoxide as a solvent and its crystals as porogens, monolithic cryogels were obtained by polymerization of polyethylene glycol diacrylate (PEGDA) embedded with polydivinylbenzene (PDVB) particles at the nondeeply frozen condition. The as-prepared cryogels were of interconnected micrometer-sized porous structure in the range of several micrometers to several tens of micrometers in pore diameter. The pristine polyPEGDA cryogels displayed superphilicity in air, superhydrophilicity under oil, and oleophobicity underwater, and the addition of PDVB particles into the matrix increased the surface roughness and thus led to a higher oleophobicity underwater as well as an enhancement in mechanical strength. The composite cryogels showed a rapid separation of the surfactant-stabilized oil-in-water emulsion with high separation efficacy up to 99.9% driven solely by gravity, and they exhibited a good recyclability after eight time treatments. Owing to the combination of the special interfacial interactions and pore-size effect, the three-dimensional supermacroporous monoliths with superwettability are a potential alternative for separation of oil-in-water emulsion with high separation efficacy and low cost.
危险品化学品经营许可证（带存储）