Effects of Synthetic Conditions on the Morphology and Structure of Silica Hollow Submicrospheres with Radially Oriented Mesochannels

doi:10.7517/j.issn.1674-0475.2010.06.442

Abstract

Abstract: In this work,a dual-templating method using polystyrene submicrospheres(PS) as core template and cetyltrimethylammonium bromide(CTAB) as co-template(porogen) was developed to fabricate hollow silica submicrospheres with radially oriented mesochannels.The fabricated hollow submicrospheres were nearly monodisperse and well separated.The amounts of CTAB and tetraethoxysilane(TEOS) and the kinds of catalyst were shown to have large effects on the morphology,shell thickness and purity of the fabricated hollow submicrospheres.When the amount of CTAB was 0.077 g,severe coalescence of hollow submicrospheres occurred.When the amount of CTAB increased to 0.110 g,the obtained hollow submicrospheres were well dispersed.When the amount of CTAB further increased to 0.143 g,however,impurity of silica nanoparticles increased.When the amount of TEOS was 0.175 mL,the morphology of hollow submicrospheres was less spherical and the shell thickness was not uniform.When the amount of TEOS was 0.250 mL,hollow submicrospheres of good integrity and uniform shell thickness were obtained.When the amount of TEOS further increased to 0.325 mL,the shell thickness of hollow submicrospheres increased significantly and a small amount of silica nanoparticles appeared simultaneously as impurity.The morphology of hollow submicrospheres was also largely affected by the kinds of catalyst.When the amount of NaOH(concentration: 1 mol/L) was 0.05-0.10 mL,spherical aggregates of small silica nanoparticles formed.With increase of the NaOH amount to 0.10-0.20 mL,the small silica nanoparticles gradually fused together and the surface of spherical aggregate became smooth.When the NaOH amount further increased to 0.20-0.30 mL,smaller silica nanoparticles appeared simultaneously as impurity.On the basis of our experimental results and other reports,a tentative mechanism was proposed for the formation of silica hollow submicrospheres with radially oriented mesochannels.

Key words: radially oriented mesochannel, silica, hollow submicrosphere, monodisperse

CLC Number:

TQ174

LIU Zhi-xin, DU Xin, HE Jun-hui, HE Yong, ZHANG Lin. Effects of Synthetic Conditions on the Morphology and Structure of Silica Hollow Submicrospheres with Radially Oriented Mesochannels[J]. Imaging Science and Photochemistry, 2010, 28(6): 442-456.

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