Cheng Yiren, Hirano Eiji, Wang Hao, Kuwayama Motonobu, Meijer E W, Huang Hubiao, Aida Takuzo
Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
RIKEN Center for Emergent Matter Science, Wako, Saitama, Japan.
Science. 2024 Nov 22;386(6724):875-881. doi: 10.1126/science.ado1782. Epub 2024 Nov 21.
Plastics that can metabolize in oceans are highly sought for a sustainable future. In this work, we report the noncovalent synthesis of unprecedented plastics that are mechanically strong yet metabolizable under biologically relevant conditions owing to their dissociative nature with electrolytes. Salt-bridging sodium hexametaphosphate with di- or tritopic guanidinium sulfate in water forms a cross-linked supramolecular network, which is stable unless electrolytes are resupplied. This unusual stability is caused by a liquid-liquid phase separation that expels sodium sulfate, generated upon salt bridging, into a water-rich phase. Drying the remaining condensed liquid phase yields glassy plastics that are thermally reshapable, such as thermoplastics, and usable even in aqueous media with hydrophobic parylene C coating. This approach can be extended to polysaccharide-based supramolecular plastics that are applicable for three-dimensional printing.
能够在海洋中代谢的塑料对于可持续发展的未来至关重要。在这项工作中，我们报道了前所未有的塑料的非共价合成，这些塑料机械强度高，且由于其与电解质的解离性质，在生物相关条件下可代谢。在水中，六偏磷酸钠与二价或三价硫酸胍通过盐桥作用形成交联超分子网络，该网络除非重新补充电解质否则是稳定的。这种不寻常的稳定性是由液-液相分离引起的，它将盐桥作用产生的硫酸钠排到富水相中。干燥剩余的浓缩液相可得到热可重塑的玻璃状塑料，如热塑性塑料，甚至在带有疏水性聚对二甲苯C涂层的水性介质中也可使用。这种方法可以扩展到适用于三维打印的基于多糖的超分子塑料。
