From Fragility to Flexibility: Construction of Hydrogel Bridges toward a Flexible Multifunctional Free‐Standing CaCO3 Film

• Published in: Advanced functional materials Vol. 28; no. 5
• Main Authors: Yuan, Xue, Nie, Wu‐Cheng, Xu, Chen, Wang, Xiao‐Hui, Xiao, Qian, Song, Fei, Wang, Xiu‐Li, Wang, Yu‐Zhong
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 31.01.2018
• Subjects: Bridge construction; CaCO3 films; Calcium carbonate; Construction methods; Crustaceans; Fragility; free‐standing films; Heavy metals; Hydrogels; Materials science; Microparticles; Nacre; oil/water separation; Self-similarity; self‐cleaning films; Separation; Underwater
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201704956

Free‐standing CaCO3 materials are an important member in biological systems because of their existence in many natural organisms such as nacre, shell, and crustacean cuticle. However, toughness of those artificial mineral films is sacrificed once their inorganic content is up to 90%, thus free‐standing characteristics have seldom been achieved for CaCO3 films, let alone their real applications. Herein a fast and simple method for constructing hydrogel “bridges” for CaCO3 microparticles is presented, developing highly flexible free‐standing CaCO3 films with only 5% organic content. Such integrated films have underwater superoleophobicity and self‐cleaning function, which guarantee their repeated application in oil/water separation. Furthermore, heavy metal ions can be efficiently removed by simple filtration with the films. Because of the self‐similar structure, the films are able to resist mechanical abrasion without losing the anti‐wetting property and separation efficiency. The free‐standing CaCO3 films are put forward for the first time to practical application, demonstrating the strategy can bring a brilliant prospect to artificial biomineral materials. A highly flexible free‐standing CaCO3 film with multiple functions is fabricated by constructing spider web‐simulated hydrogel bridges to connect fragile CaCO3 microparticles together. Owing to underwater superoleophobicity and their self‐cleaning function, allow to apply such films for the first time in oil/water separation and heavy metal removal. A self‐similar structure of the film guarantees good mechanical abrasion resistance without losing functions.