open access

https://hdl.handle.net/2115/78650

Hydrophobic Hydrogels with Fruit-Like Structure and Functions

英語

semipermeable skin

2019-06-20

Wiley-Blackwell

Advanced Materials

31(25)

1900702

Normally, a polymer network swells in a good solvent to form a gel but the gel shrinks in a poor solvent. Here, an abnormal phenomenon is reported: some hydrophobic gels significantly swell in water, reaching water content as high as 99.6 wt%. Such abnormal swelling behaviors in the nonsolvent water are observed universally for various hydrophobic organogels containing omniphilic organic solvents that have a higher affinity to water than to the hydrophobic polymers. The formation of a semipermeable skin layer due to rapid phase separation, and the asymmetric diffusion of water molecules into the gel driven by the high osmotic pressure of the organic solvent-water mixing, are found to be the reasons. As a result, the hydrophobic hydrogels have a fruit-like structure, consisting of hydrophobic skin and water-trapped micropores, to display various unique properties, such as significantly enhanced strength, surface hydrophobicity, and antidrying, despite their extremely high water content. Furthermore, the hydrophobic hydrogels exhibit selective water absorption from concentrated saline solutions and rapid water release at a small pressure like squeezing juices from fruits. These novel functions of hydrophobic hydrogels will find promising applications, e.g., as materials that can automatically take the fresh water from seawater.

学術雑誌論文

Accepted Manuscript

This is the peer reviewed version of the following article: https://onlinelibrary.wiley.com/doi/full/10.1002/adma.201900702 , which has been published in final form at 10.1002/adma.201900702. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.

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