Controlled Etching of Internal and External Structures of SiO2 Nanoparticles Using Hydrogen Bond of Polyelectrolytes
Controlled Etching of Internal and External Structures of SiO2 Nanoparticles Using Hydrogen Bond of Polyelectrolytes
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DOI：
10.1021/am501941c
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发表时间：
2014-06-25
影响因子：
9.5
通讯作者：
Lee, Ha-Jin
中科院分区：
文献类型：
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作者：
Islam, Md. Shahinul;Choi, Won San;Lee, Ha-Jin
我们已经证明了一种新的策略，在环境条件下使用无表面活性剂的方法合成介孔二氧化硅纳米粒子（MSNPs）。通过简单地将具有高分子量的基于胺的聚合物（聚乙烯亚胺; PEI）添加到二氧化硅纳米颗粒（SNP）溶液中，产生两种类型的MSNP，包括红丹样MSNP（R-MSNP）和中空MSNP（H-MSNP）。通过改变反应条件（反应时间、PEI的摩尔比和分子量等），系统地研究了MSNPs的结构变化。并使用电子显微镜技术进行观察。使用XPS、拉曼和红外光谱仔细研究了这两种MSNPs的形成机制。由于合成的MSNPs是高度多孔的材料，包含内部的有机/无机网络，我们研究了这些MSNPs的去除/吸附性能相对于污染物对未来可能使用的环境修复应用。相对于R-MSNPs，H-MSNPs表现出环境修复能力，因为PEI存在于H-MSNPs的蛛网状内部结构之间，从而为污染物的吸附提供了大量的反应位点。这里提出的方法也可以作为一种直接的方法，用于制备内部连接的网络内的子结构。
We have demonstrated a novel strategy for the synthesis of mesoporous silica nanoparticles (MSNPs) using a surfactant-free method under ambient conditions. By the simple addition of an amine-based polymer (polyethylenimine; PEI) with a high molecular weight to a silica nanoparticle (SNP) solution, two types of MSNPs, including rambutan-like MSNPs (R-MSNPs) and hollow MSNPs (H-MSNPs), were produced. The structural changes of the MSNPs were systematically studied using various reaction conditions (reaction time, molar ratio and molecular weight of PEI, etc.) and were observed using electron microscopic techniques. The formation mechanisms of both MSNPs were carefully investigated using XPS, Raman, and IR spectroscopies. Because the synthesized MSNPs are highly porous materials that contain internal organic/inorganic networks, we investigated the removal/adsorption properties of these MSNPs with respect to pollutants toward possible future use in environmental remediation applications. The H-MSNPs exhibited environmental remediation capabilities relative to the R-MSNPs because PEI is present between the cobweb-like internal structures of the H-MSNPs, thereby providing a significant number of reaction sites for the adsorption of pollutants. The approach presented here can also be used as a direct method for the preparation of intraconnected networks within the substructures.