Effect of Surface Charge and Elemental Composition on the Swelling and Delamination of Montmorillonite Nanoclays Using Sedimentation Field-flow Fractionation and Mass Spectroscopy
Effect of Surface Charge and Elemental Composition on the Swelling and Delamination of Montmorillonite Nanoclays Using Sedimentation Field-flow Fractionation and Mass Spectroscopy
复制标题
使用沉降场流分级和质谱法研究表面电荷和元素组成对蒙脱土纳米粘土膨胀和分层的影响
DOI：
10.1346/ccmn.2015.0630604
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发表时间：
2015
影响因子：
2.2
通讯作者：
Jan D. Miller
中科院分区：
文献类型：
--
作者：
S. Assemi;Sugandha B. Sharma;S. Tadjiki;K. Prisbrey;J. Ranville;Jan D. Miller
蒙脱石型粘土颗粒（包括蒙脱石）的溶胀性质在各种工业中是令人感兴趣的。在亚微米级的蒙皂石颗粒的表面性质的基本理解将有助于调查的分布特性，如电荷和元素组成的影响。采用沉降场流分级法（SdFFF）研究了钠基蒙脱土（Na-Mnt）纳米粘土（SWy-2）的溶胀和分层行为。通过电子显微镜和电感耦合发射光谱（ICP-OES）检查馏分。在SWy-2 Na-Mnt颗粒的尺寸分布中观察到两个不同的群体（双峰尺寸分布），平均等效球径分别为约60 nm和250 nm。相比之下，STx-1钙蒙脱石（Ca-Mnt）颗粒的粒径分布仅显示出一个峰值，平均等效球径约为410 nm，水合4天后变为440 nm。通过ICP-OES对沿着Na-Mnt的尺寸分布获得的级分进行分析，显示在低于250 nm的级分中富含Ca和Mg，并证实存在Fe和Mg作为同晶取代基。从Na-Mnt粒度分布获得的级分的电子显微照片用于计算粘土颗粒的厚度。用半经验方法计算了纯蒙脱石和Mg取代蒙脱石与Ca ~（2+）或Na ~+之间的架桥力。结果表明，Na-Mnt粘土颗粒的溶胀和脱层由沿着尺寸分布的元素组成和表面电荷等性质决定。
The swelling properties of smectite-type clay particles (including montmorillonite) are of interest in various industries. A fundamental understanding of the surface properties of smectite particles at the sub-micron level would facilitate investigation of the effect of distributed properties such as charge and elemental composition. Swelling and delamination of SWy-2 Na-montmorillonite (Na-Mnt) nano-clay particles were studied here using size distributions obtained by sedimentation field-flow fractionation (SdFFF). Fractions were examined by electron microscopy and inductively-coupled optical emission spectroscopy (ICP-OES). Two distinct populations were observed in the size distribution of SWy-2 Na-Mnt particles (bimodal size distribution), with mean equivalent spherical diameters of ~60 nm and 250 nm, respectively. In contrast, the size distribution of STx-1 Ca-montmorillonite (Ca-Mnt) particles showed only one peak with a mean equivalent spherical diameter of ~410 nm, which changed to 440 nm after 4 days of hydration. Analyses of the fractions by ICP-OES obtained along the size distribution of Na-Mnt showed an abundance of Ca and Mg in the fractions below 250 nm, and confirmed the presence of Fe and Mg as isomorphous substituents. Electron micrographs of the fractions obtained from Na-Mnt size distributions were used to calculate the thickness of the clay particles. Bridging forces between pure orMgsubstituted montmorillonite and either Ca2+ or Na+ were calculated using semi-empirical methods. The results demonstrated that swelling and delamination of Na-Mnt clay particles are dictated by properties such as elemental composition and surface charge which are distributed along the size distribution.
用于编程场流分级的数据分析算法。
影响因子：
7.4
作者：
Williams,PS;Giddings,MC;Giddings,JC
通讯作者：
Giddings,JC