Molina Emilie, Mathonnat Mélody, Richard Jason, Lacroix-Desmazes Patrick, In Martin, Dieudonné Philippe, Cacciaguerra Thomas, Gérardin Corine, Marcotte Nathalie
ICGM UMR 5253 CNRS - Université de Montpellier - ENSCM, ENSCM 240 Av Pr E. Jeanbrau, 34296 Montpellier cedex 5, France.
Laboratoire Charles Coulomb, UMR 5221 CNRS - Université de Montpellier, 34095 Montpellier, France.
Beilstein J Nanotechnol. 2019 Jan 11;10:144-156. doi: 10.3762/bjnano.10.14. eCollection 2019.
Ordered mesoporous silica materials were prepared under different pH conditions by using a silicon alkoxide as a silica source and polyion complex (PIC) micelles as the structure-directing agents. PIC micelles were formed by complexation between a weak polyacid-containing double-hydrophilic block copolymer, poly(ethylene oxide)--poly(acrylic acid) (PEO--PAA), and a weak polybase, oligochitosan-type polyamine. As both the micellization process and the rate of silica condensation are highly dependent on pH, the properties of silica mesostructures can be modulated by changing the pH of the reaction medium. Varying the materials synthesis pH from 4.5 to 7.9 led to 2D-hexagonal, wormlike or lamellar mesostructures, with a varying degree of order. The chemical composition of the as-synthesized hybrid organic/inorganic materials was also found to vary with pH. The structure variations were discussed based on the extent of electrostatic complexing bonds between acrylate and amino functions and on the silica condensation rate as a function of pH.
以硅醇盐为硅源、聚离子复合物(PIC)胶束为结构导向剂,在不同pH条件下制备了有序介孔二氧化硅材料。PIC胶束由含弱多元酸的双亲水嵌段共聚物聚(环氧乙烷)-聚(丙烯酸)(PEO-PAA)与弱多元碱低聚壳聚糖型多胺络合形成。由于胶束化过程和二氧化硅缩合速率都高度依赖于pH值,因此可以通过改变反应介质的pH值来调节二氧化硅介观结构的性质。将材料合成pH值从4.5变化到7.9会导致二维六方、蠕虫状或层状介观结构,且有序程度不同。还发现合成的有机/无机杂化材料的化学组成随pH值变化。基于丙烯酸酯和氨基官能团之间静电络合键的程度以及作为pH值函数的二氧化硅缩合速率,对结构变化进行了讨论。