Low temperature effect on the morphological control of mesoporous silica nanofibers at near-neutral pH: A biomimetic strategy

Silica biominerals with elaborate skeletons can be fabricated at mild conditions of near-neutral pH and low temperature through biosilicification. In this paper, a biomimetic way was reported by which hexagonally ordered mesoporous silica fibers were facilely synthesized. Scanning electron microscope (SEM) and transmission electron microscope (TEM) observations reveal high yield of the mesoporous silica fibers with diameter varying from 200 to 400 nm and mesopore channels parallel to the axes of the fibers. At near-neutral pH, low temperature of 283 K was proved to be essential to control the morphogenesis of the surfactant liquid crystal templated silica. X-ray diffraction (XRD) and nitrogen sorption measurements indicate that the silica nanofibers possess ordered hexagonal mesostructure and narrow pore size distribution. Both the structure and morphology are sensitive to the synthesis temperature. Synthesis at the temperature of 293 K led to decreasing of mesostructure regularity, as well as a transformation of morphology from nanofibers to particle aggregates.