Mesoporous Silica Hollow Spheres with Ordered Radial Mesochannels by a Spontaneous Self-Transformation Approach

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• 作者：Zhaogang Teng ; Xiaodan Su ; Yuanyi Zheng ; Jing Sun ; Guotao Chen ; Congcong Tian ; Jiandong Wang ; Hao Li ; Yane Zhao ; Guangming Lu
• 刊名：Chemistry of Materials
• 出版年：2013
• 出版时间：January 8, 2013
• 年：2013
• 卷：25
• 期：1
• 页码：98-105
• 全文大小：470K
• 年卷期：v.25,no.1(January 8, 2013)
• ISSN：1520-5002

文摘

We demonstrate a self-transformation approach for the synthesis of ordered mesoporous silica hollow spheres with radially oriented mesochannels. The method is simple and facile, in which mesostructured silica spheres synthesized in a St枚ber solution can spontaneously transform to hollow structure when they are incubated with water. The formation of the hollow structure does not require any sacrificial templates, emulsion droplets, or surface protective agents. The obtained mesoporous silica hollow spheres possess controllable diameter, tunable shell thickness, high specific surface area, and uniform mesopore. Transmission electron microscopy (TEM) observations show that the formation of the hollow spheres undergoes a selective etching process in the inner section. ²⁹Si NMR spectra and detailed reactions demonstrate that the solid-to-hollow transformation of the St枚ber silica spheres in water is attributed to the difference in the degree of condensation of silica between their outer layer and inner section. Cytotoxicity and histological assays confirm that the obtained mesoporous silica hollow spheres possess good biocompatibility. Besides, the capability of the hollow spheres as contrast agents for untrasound imaging is conducted in vitro. Moreover, yolk鈥搒hell microspheres with a Fe₃O₄@nSiO₂ core and a mesoporous silica shell are successfully prepared based on the facile self-transformation strategy, which provides a general method to create various yolk鈥搒hell structured multifunctional composites for different applications.

Keywords:

hollow spheres; mesoporous; silica; self-transformation; yolk鈭抯hell