Synthesis Of The Silica Nanofiber Within Anodic Alumina Membrane

Nanotechnology is a new rising subject in 21 st century which has provoked significant interest in physics, chemistry, biology, materials and other fields. With the development of nanotechnology, researchers can synthesis nanomaterials with different morphologies via different ways. Typical one-dimensional nanomaterials include nanotube, nanowire, nanorod, nanoribbon and so on. Because of its unique structure and excellent performance, silica nanofiber is widely used in catalyst, sensor, drug delivery,environmental governance and other fields. Silica nanofiber is one perfect material for the separation of metal ions due to the abounding hydroxyls on its large BET surface.One-dimensional nanoscaled silica was synthesized within anodic alumina membrane pores under using organic compounds as template or organic-free templating conditions. We used pressure-induced infiltration approach during synthesis process and silica nanofiber was produced in anodic alumina membrane by employing the sol-gel method. The effect of the ratio of chemical reagent and the hydrolysis time on the morphography was also investigated by N2 adsorption-desorption, scanning electron microscope（SEM） and transmission electron microscope（TEM）. The resulting hybrid membrane could be used for separation of meta lion Fe（II） and effect on pH and the flow speed of aqueous solution was also detected.（1）One-dimensional nanoscaled silica was synthesized within anodic alumina membrane pores using small organic molecules as template. The resulting silica nanofiber could be used for separation of meta lion Fe（II）.Silica nanofiber was synthesized in anodic alumina membrane by using the glucose as template. The result of the N2 adsorption-desorption data show that, when the crystallization time was 24 h, the specific surface area was 7.1874 m2/g, the pore volume was 0.0394 mL/g. We can see the pores with the same size on the surface of the new-prepared silica nanofiber by using TEM.Using DBTA as template, silica nanofiber was synthesized in anodic alumina membrane. when the crystallization time was 24 h, the specific surface area was12.0531 m2/g, the pore volume was 0.0384 mL/g. Porous structure of nanofiber was observed by using TEM.The resulting hybrid membrane could be applied to adsorb and separate Fe²⁺. The result demonstrated that the optimum experimental conditions as follow:the concentration of Fe²⁺, solution pH value, flow rate of solution and volume of sample were 1.0 μg/mL, 5.0, 1.5 mL/min, 2 mL respectively.（2）Silica nanofiber was synthesized in anodic alumina membrane without using organic templates. The resulting silica nanofiber could be used for separation of metal ion Fe（II）.The effect of the molarities of TEOS and reaction time on morphology was investigated. When the concentration of TEOS was 0.4 M, solution pH value was 5.0and the crystallization time was 48 h, we synthesized the resulting nanofiber which the length was 60 μm and the diameter was 100 nm.The resulting hybrid membrane was successful applied to adsorb and separate Fe²⁺.It explored the influence of the pH, flow rate and volume of the solution on Fe²⁺’s adsorption and separation. The result demonstrated that the optimum experimental conditions as follow: the concentration of Fe²⁺, solution pH value, flow rate of solution and volume of sample were 1.0 μg/mL, 5.0, 2.0 mL/min and 2 mL respectively.