Shen Yi, Roberge Adam, Tan Rui, Gee Megan Y, Gary Dylan C, Huang Yucheng, Blom Douglas A, Benicewicz Brian C, Cossairt Brandi M, Greytak Andrew B
Department of Chemistry and Biochemistry , University of South Carolina , Columbia , SC 29208 , USA . Email:
Department of Chemistry , University of Washington , Seattle , WA 98195 , USA.
Chem Sci. 2016 Sep 1;7(9):5671-5679. doi: 10.1039/c6sc01301e. Epub 2016 May 25.
This article illustrates the use of gel permeation chromatography (GPC, organic-phase size exclusion chromatography) to separate nanocrystals from weakly-bound small molecules, including solvent, on the basis of size. A variety of colloidal inorganic nanocrystals of different size, shape, composition, and surface termination are shown to yield purified samples with greatly reduced impurity concentrations. Additionally, the method is shown to be useful in achieving a change of solvent without requiring precipitation of the nanocrystals. By taking advantage of the different rates at which small molecules and nanoparticles travel through the column, we show that it is furthermore possible to use the GPC column as a multi-functional flow reactor that can accomplish in sequence the steps of initial purification, ligand exchange with controlled reactant concentration and interaction time, and subsequent cleanup without requiring a change of phase. This example of process intensification GPC is shown to yield nearly complete displacement of the initial surface ligand population upon reaction with small molecule and macromolecular reactants to form ligand-exchanged nanocrystal products.
本文阐述了凝胶渗透色谱法（GPC，有机相尺寸排阻色谱法）基于尺寸从包括溶剂在内的弱结合小分子中分离纳米晶体的应用。不同尺寸、形状、组成和表面端基的多种胶体无机纳米晶体都能得到杂质浓度大幅降低的纯化样品。此外，该方法还被证明在无需纳米晶体沉淀的情况下实现溶剂更换方面很有用。通过利用小分子和纳米颗粒在柱中移动的不同速率，我们表明还可以将GPC柱用作多功能流动反应器，它可以依次完成初始纯化、以受控的反应物浓度和相互作用时间进行配体交换以及随后的净化步骤，而无需改变相。这种过程强化的GPC示例表明，与小分子和大分子反应物反应形成配体交换纳米晶体产物时，初始表面配体群体几乎能被完全取代。
