Lin, H.-P.H.-P.LinCHUNG-YUAN MOU2018-09-102018-09-101996http://www.scopus.com/inward/record.url?eid=2-s2.0-0029783547&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/321919The recently discovered mesoporous aluminosilicate MCM-41 consists of hexagonal arrays of nanometer-sized cylindrical pores. It is shown that this material can be synthesized by cooperative condensation of silicate and cylindrical cationic micelles. Careful control of the surfactant-water content and the rate of condensation of silica at high alkalinity resulted in hollow tubules 0.3 to 3 micrometers in diameter. The wall of the tubules consisted of coaxial cylindrical pores, nanometers in size, that are characteristic of those of MCM-41. The formation of this higher order structure may take place through a liquid crystal phase transformation mechanism involving an anisotropic membrane-to-tubule phase change. The hierarchical organization of this 'tubules-within-a-tubule' particle texture is similar to that of the frustules of marine diatoms.[SDGs]SDG14aluminum; silicon dioxide; surfactant; anisotropy; article; chemical structure; crystal structure; phase transition; polymerization; priority journal; scanning electron microscopy; transmission electron microscopy; water content; X ray diffraction; Bacillariophyta; Nitzschia alba'Tubules-within-a-tubule' hierarchical order of mesoporous molecular sieves in MCM-41journal article10.1126/science.273.5276.7652-s2.0-0029783547