title: Biologically formed mesoporous amorphous silica.
abstract: Mesoporous crystalline silica has attracted the attention of scientists due to its extraordinary functionalities. In particular, substantial progress has been made in the synthesis of mesoporous crystalline silica using biomimetic approaches under ambient conditions. However, the biomimetic synthesis of mesoporous amorphous silica has not been well studied so far. Here we show that amorphous silica can be synthesized in aqueous solution under ambient conditions via biological catalysis. The high purity amorphous silica is obtained as spicules (average diameter: 15.6 microm) that are cemented through junctions, thereby forming the skeleton of the freshwater sponge Cauxi. We discover that such amorphous spicules themselves contain mesopores. This opens a potential avenue to develop highly durable mesoporous membranes at room temperature. We also describe the macro- and microstructural features, the mechanism of biological precipitation, and the properties of the Cauxi skeleton.
authors.affiliation: Section of Chemistry, Aalborg University, DK-9000 Aalborg, Denmark.
authors.forename: Martin
authors.initials: M
authors.lastname: Jensen
authors.forename: Ralf
authors.initials: R
authors.lastname: Keding
authors.forename: Thomas
authors.initials: T
authors.lastname: Höche
authors.forename: Yuanzheng
authors.initials: Y
authors.lastname: Yue
mesh_terms: D000818:Animals; D040761:Biomimetic Materials / Q000138:chemical synthesis / Q000737:chemistry; D011161:Porifera / Q000737:chemistry* / Q000378:metabolism; D012822:Silicon Dioxide / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism
chemical_list: D012822:Silicon Dioxide