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首页> 外文期刊>Microporous and mesoporous materials: The offical journal of the International Zeolite Association >Protocol optimization for the mild detemplation of mesoporous silica nanoparticles resulting in enhanced texture and colloidal stability
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Protocol optimization for the mild detemplation of mesoporous silica nanoparticles resulting in enhanced texture and colloidal stability

机译：介孔二氧化硅纳米粒子温和脱色的方案优化，可增强质地和胶体稳定性

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Porosity development of mesostructured colloidal silica nanoparticles is related to the removal of the organic templates and co-templates which is often carried out by calcination at high temperatures, 500 -600 degrees C. In this study a mild detemplation method based on the oxidative Fenton chemistry has been investigated. The Fenton reaction involves the generation of OH center dot radicals following a redox Fe3+/Fe2+ cycle that is used as catalyst and H2O2 as oxidant source. Improved material properties are anticipated since the Fenton chemistry comprises milder conditions than calcination. However, the general application of this methodology is not straightforward due to limitations in the hydrothermal stability of the particular system under study. The objective of this work is three-fold: 1) reducing the residual Fe in the resulting solid as this can be detrimental for the application of the material, 2) shortening the reaction time by optimizing the reaction temperature to minimize possible particle agglomeration, and finally 3) investigating the structural and textural properties of the resulting material in comparison to the calcined counterparts. It appears that the Fenton detemplation can be optimized by shortening the reaction time significantly at low Fe concentration. The milder conditions of detemplation give rise to enhanced properties in terms of surface area, pore volume, structural preservation, low Fe residue and high degree of surface hydroxylation; the colloidal particles are stable during storage. A relative particle size increase, expressed as 0.11%.h(-1), has been determined. (C) 2015 Elsevier Inc. All rights reserved.
机译：介孔结构的胶体二氧化硅纳米颗粒的孔隙度发展与有机模板和共模板的去除有关，这通常是通过在500 -600摄氏度的高温下煅烧来完成的。在这项研究中，基于氧化Fenton化学方法的温和的脱模板方法已被调查。 Fenton反应包括在氧化还原Fe3 + / Fe2 +循环后生成OH中心点自由基，该循环用作催化剂，H2O2作为氧化剂。由于Fenton化学比煅烧具有更温和的条件，因此有望改善材料的性能。然而，由于所研究的特定系统在水热稳定性方面的局限性，该方法的一般应用并不简单。这项工作的目的是三方面的：1）减少生成的固体中的残留铁，因为这对材料的应用可能有害; 2）通过优化反应温度以最小化可能的颗粒团聚来缩短反应时间，以及最后3）与煅烧后的对应物相比，研究所得材料的结构和质地特性。似乎可以通过显着缩短低铁浓度下的反应时间来优化Fenton脱模板。较温和的去离子条件在表面积，孔体积，结构保留，低铁残留和高表面羟基化方面具有增强的性能;胶体颗粒在储存过程中是稳定的。确定了相对粒径的增加，表示为0.11％.h（-1）。 （C）2015 Elsevier Inc.保留所有权利。

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