[论文解读] Development of gold particles at varying precursor concentration

Mubarak Ali, I‐Nan Lin|arXiv (Cornell University)|Apr 26, 2016

Gold and Silver Nanoparticles Synthesis and Applications参考文献 48被引用 30

一句话总结

本研究探讨了金纳米颗粒在基于脉冲的电子-光子-溶液界面工艺下形成及其自组装为更大各向异性结构的过程。通过改变金前驱体浓度（0.05–1.20 mM），研究发现0.30 mM与0.60 mM时产生最大量的微小三角形颗粒，这些颗粒通过光子驱动的自组织过程聚结为更大的几何形状，而定制能量-形状光子可精确控制颗粒尺寸、形状及结构光滑度。

ABSTRACT

Coalescence of tiny particles into extended shapes has been an overlooked phenomenon since long. Present study discusses the formation of tiny shaped particles and their packing into large-sized particles under varying concentration of gold precursor in homemade built pulse-based electronphoton-solution interface process. Under fixed ratio of bipolar pulse OFF to ON time, the amount of precursor decides tiny shaped particles. At air-solution interface, tailored energy-shape photons cropped atoms of monolayer assembly into tiny particles of connecting equilateral triangles in each case. For precursor concentration between 0.07 mM to 0.90 mM, a large number of tiny particles are made in two connecting equilateral triangles, maximum at 0.30 mM and 0.60 mM. On division into triangular-shaped tiny particles while self-bearing field force elongated at electron-solution interface followed by packing under uniform drive into various geometric anisotropic shaped particles at center of photon-solution interface. In the course of packing, travelling photons of hard X-rays modified elongated structure into smooth elements at photon solution interface. At 0.05 mM and 1.20 mM, tiny particles rarely observed are made in tiny shaped particles, their non-uniform drives resulting into pack where distorted particles were developed. Changing argon gas flow rate does not influence the shape of particles but structure at minute level, apparently. Reflected photons patterns at the surface of various geometric anisotropic shaped particles validate formation of smooth elements and in case of distorted ones, it does not. This study purely determines that under what concentration of gold precursor a certain size and shape of tiny-sized particle and large-sized particle is required while utilizing tailored energy-shape photons.

研究动机与目标

• 理解改变金前驱体浓度如何影响微小形状纳米颗粒的形成及其随后聚结为更大颗粒的过程。
• 研究定制能量-形状光子在引导纳米颗粒自组装为几何各向异性结构中的作用。
• 确定最优前驱体浓度，以最大化均匀三角形形状纳米颗粒及光滑、大尺寸颗粒的产率。
• 分析氩气流量对微米级颗粒形态与纳米结构的影响。
• 通过不同颗粒形状的反射光子图案验证结构结果。

提出的方法

• 采用自制的基于脉冲的电子-光子-溶液界面工艺，保持固定的双极脉冲关/开比。
• 系统地改变金前驱体浓度，从0.05 mM至1.20 mM，以研究其对颗粒成核与生长的影响。
• 在气-液界面施加定制能量-形状光子，将单层组装体中的原子裁剪为微小的等边三角形颗粒。
• 电子-溶液界面处的自支撑场力引起颗粒伸长，随后均匀驱动力促进其聚集成各向异性形状。
• 在堆积阶段使用硬X射线光子，将伸长结构在光子-溶液界面处改造成光滑元件。
• 分析反射光子图案以验证光滑与畸变颗粒结构的形成。

实验结果

研究问题

• RQ1 在何种金前驱体浓度下可实现微小三角形颗粒的最大产率？
• RQ2 定制能量-形状光子如何影响微小颗粒自组装为更大各向异性结构？
• RQ3 改变氩气流量对最终颗粒的纳米结构与形状有何影响？
• RQ4 反射光子图案如何与最终颗粒的结构质量（光滑 vs. 畸变）相关联？
• RQ5 电子-溶液界面在纳米颗粒伸长及后续堆积过程中起何作用？

主要发现

• 在0.30 mM与0.60 mM金前驱体浓度下，微小三角形颗粒的产率最高。
• 在0.05 mM与1.20 mM前驱体浓度下，由于驱动力不均匀，极少观察到微小颗粒。
• 低浓度与高浓度下的非均匀驱动力导致畸变颗粒簇的形成。
• 硬X射线光子在堆积阶段成功将伸长颗粒结构改造成光滑的几何元件。
• 反射光子图案证实了有序颗粒中光滑元件的形成，但未能验证畸变结构。
• 氩气流量未改变颗粒形状，但影响了微米级的结构细节。