title: Spontaneous formation and characterization of silica mesoporous crystal spheres with reverse multiply twinned polyhedral hollows.
abstract: A crystal is an object with translational symmetry. Basic research into and production of new materials necessitates the preparation of crystals of a particular morphology and with well-defined crystal defects. In this work, we found novel silica mesoporous crystal spheres with polyhedral hollows (icosahedral, such as those observed for proteins of virus capsids, decahedral, Wulff polyhedral, etc.) formed by the reverse multiply twinned bicontinuous double diamond mesostructure. Vesicles with a low-curvature lamellar structure were first formed by the self-assembly of amphiphilic carboxylic acid molecules in the presence of a nonionic surfactant and then underwent a structural transformation process that gave a reverse multiply twinned mesoporous shell while maintaining the hollow shape. These polyhedral hollow crystals showed an enhanced contrast of backscattering signatures relative to the incident acoustic signals and thus could be used as a potential contrast agent in medical ultrasonography with drug loadings in the mesopores.
authors.affiliation: School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P. R. China.
authors.forename: Lu
authors.initials: L
authors.lastname: Han
authors.forename: Ping
authors.initials: P
authors.lastname: Xiong
authors.forename: Jingfeng
authors.initials: J
authors.lastname: Bai
authors.forename: Shunai
authors.initials: S
authors.lastname: Che
mesh_terms: D003460:Crystallization; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D012822:Silicon Dioxide