Influence of organic dyes on potassium sulfate crystal growth: a joint morphological and atomic force microscopy analysis
Influence of organic dyes on potassium sulfate crystal growth: a joint morphological and atomic force microscopy analysis
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有机染料对硫酸钾晶体生长的影响：形态学和原子力显微镜联合分析
DOI：
10.1016/s0254-0584(00)00335-7
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发表时间：
2000
影响因子：
4.6
通讯作者：
M. Moret
中科院分区：
文献类型：
--
作者：
M. Moret
原位原子力显微镜 (AFM) 用于研究酸性品红和吡喃存在下硫酸钾晶体的生长。这些多磺化染料能够吸附到 {110} 和 {010}（仅限吡喃）晶面上，产生强烈的惯习修改。使用 AFM，我们分析了添加剂在 {110} 和 {010} 表面的前进步骤中引起的表面微形貌的变化。微形态随时间的演变表明，在低过饱和度下，通过在台阶边缘添加生长单元，层在预先存在的台阶处逐步流动生长。在生长过程中，吡喃和酸性品红的染料分子浓度分别低至～2×10−6 和～4×10−4M，会导致台阶形态和生长速率发生显着变化。事实上，添加剂分子附着在平台上，固定着生长的前沿；结果，生长台阶的边缘变得锯齿状。在临界染料浓度下，晶体生长沿某些晶体方向受到严重阻碍甚至受阻。同时，在宏观层面上观察到强烈的习惯改变。我们的原位 AFM 实验与之前的习性改变研究的比较表明，酸性品红也能够进入 {010} 表面，这是一种以前未被注意到的现象。
In situ atomic force microscopy (AFM) was used to study potassium sulfate crystal growth in the presence of acid fuchsin and pyranine. These polysulfonated dyes are able to adsorb onto the {110} and {010} (pyranine only) crystal faces producing strong habit modifications. Using AFM, we analyzed the changes in surface micromorphology induced by the additives on advancing steps for the {110} and {010} surfaces. Evolution of micromorphology with time showed that at low supersaturations, layers grow by step flow at preexisting steps by the addition of growth units at the step edges. During growth, the presence of dye molecules at concentrations as low as ∼2×10−6and ∼4×10−4M for pyranine and acid fuchsin, respectively, produces significant changes in the step morphology and growth rates. Indeed, the additive molecules attach to the terraces pinning the growing front; as a consequence, the edges of the growing steps become jagged. At critical dye concentrations, crystal growth is heavily encumbered or even blocked along certain crystallographic directions. Concurrently, on a macroscopic scale strong habit modifications are observed. Comparison of our in situ AFM experiments with previous habit modification studies showed that acid fuchsin is also able to enter the {010} surfaces, a previously unnoticed phenomenon.