刘晓辉文献综述汇报.ppt

1、报告人：刘晓辉报告人：刘晓辉 2013 年年 4 月月 21日日 本综述主要内容本综述主要内容：本综述是郑南峰课题组刚刚在本综述是郑南峰课题组刚刚在Nanoscale上发表题为上发表题为Self-templating synthesis of hollow mesoporous silica and their applications in catalysis and drug delivery 的综述的综述文章文章 综述了空心介孔二氧化硅（包括综述了空心介孔二氧化硅（包括yolk/shell结构）的合成及应用。合成方面着重强调结构）的合成及应用。合成方面着重强调了了自身模板法自身模板法，包

2、括，包括表面保护表面保护-腐蚀法、基于结构差异的选择性腐蚀法以及阳离子表面腐蚀法、基于结构差异的选择性腐蚀法以及阳离子表面活性剂辅助自模板法活性剂辅助自模板法等三大类。应用方面则主要介绍了等三大类。应用方面则主要介绍了催化和药物传输方面催化和药物传输方面的应用。的应用。Hollow mesoporous silica materials have been intensively pursued because of their unique properties for various applications.Yolk/shell structured hollow mesoporous

3、silica with functional cores inside their hollow interior can further broaden the applications of hollow mesoporous silica.Self-templating stra-tegy has been developed as one of the most important strategies to effectively fabricate hollow mesoporous silica and their yolk/shell counterparts.In this

4、feature article,we provide an overview of advances in self-templating synthesis of hollow mesoporous silica based on the following three strategies:surface-protected etching,structural difference-based selective etching,and cationic surfac-tant assisted self-templating.We then discuss some important

5、 app-lications of these self-templating strategies derived hollow mesoporous silica,such as nanoreactors for confined catalysis and multifunctional platform for combined therapy.Finally,some perspectives for the future development of this active research field are provided.AbstractAbstract1.Introduc

6、tion1.Hollow structures are highly attractive in both fundamental research and practical applications.2.Up to date,templating method is probably the most effective and general route to prepare HMS.In comparison,as an evident advantage of hard-templating methods,the shape andcavity sizes of HMS can b

7、e easily and precisely controlled by the prefabricated templates.3.it has been well demonstrated that the encapsulation of functional nanoparticles in hollow materials not only effectively enhances the stability of these nanoparticles,but also introducenew functionalities for hollow materials.yolk/s

8、hell HMS,has thus attracted tremendous interest inrecent years.However,the synthesis and applications of yolk/shell HMS are still faced with challenges.4.In order to obtain yolk/shell HMS with more compositional diversity,several other methods have thus been exploited,including ship-in-bottle method

9、s,partial etching core of core/shell coresilica,multiple nanocasting,and soft-templating method.Howeverintrinsic disadvantages of these methods,such as poor control of the growth or etching of core,time-consuming and cumbersome synthetic procedures,andlow efficiency .To overcome these disadvantages.

10、“self-template”.5.In this feature article,we focus on the recent research progress in the synthesis and applications of HMS based on self-templating methods.2.Self-templating strategies for synthesis of HMSSchematic illustrations for surface-protected etching strategy(a)and structural difference-bas

11、ed selective etching strategy(b,c)for thesynthesis of HMS from sSiO2.C18TMS:n-octadecyltrimethoxysilane,TSD:N-3-(trimethoxysilyl)-propylethylene-diamine.Fig.12.1.Surface-protected etchingTEM images showing the morphology of PVP coated sSiO2after etching by NaOH for(a)0 h;(b)1 h;(c)2 h 45 min;and(d)3

12、 h.All scalebars are 200 nm.Fig.22.2.Structural difference-based selective etchingTEM images:sSiO2C18/SiO2(a,b)and HMS obtained by treating sSiO2C18/SiO2in 0.6 M Na2CO3solution at 80 C for 0.5 h(c,d).Fig.3又如：又如：AuAPTES/SiO2SiO2(a)TEM image of sSiO2TSD/SiO2sSiO2,TEM image(b)andSEM images(c,d)of yolk/

13、shell SiO2HMS obtained by HF etching ofsSiO2TSD/SiO2sSiO2,(e)TEM image of HMS obtained by HFetching of TSD/SiO2sSiO2.内层内层sSiO22.3.Cationic surfactant assisted self-templatinghighly dispersible HMS particles are desired in some applications,such as biomedicine.Since cationic surfactants in MCM-41-typ

14、e OMS are readily removed by a mild extraction operation,using cationic surfactants to direct theformation of ordered mesoporous silica shell is expected to provide an opportunity to prepare highly dispersible HMSIn order to obtain HMS with ordered mesoporous shell,chosen quaternary ammonium cationi

15、c surfactants as the structure-directing agents,due to their following properties:(1)the excellent solubility,(2)high critical micelle temperature(CMT),and(3)the strong electrostatic interaction with negatively charged silica species in basic conditions.（4）after-treatment2.3.1.Cationic surfactant as

16、sisted selective etching （strategy 1）目标：目标：prepare highly dispersible HMS、ordered mesoporous silica shell.TEM images of silica spheres sSiO2-250(a)and HMSS-W-250(b),(c,d)N2sorption isotherms and the pore size distribution of sSiO2-250and25 HMSS-W-250.HMSS-W-250 has a rather narrow size distribution centered at 2.5 nm(Fig.6d),similar to that of MCM-41-type OMS obtained by using CTAB as the structure-directing agentTEM images show the effect of CTAB concentration on the conversion of sSiO2 to HMSS