van Embden Joel, Mulvaney Paul
Chemistry School, University of Melbourne, Parkville, 3010, Victoria, Australia.
Langmuir. 2005 Oct 25;21(22):10226-33. doi: 10.1021/la051081l.
The competing effects of two ligands, oleic acid (OA) and bis-(2,2,4-trimethylpentyl) phosphinic acid (TMPPA), on the nucleation rate and growth of CdSe nanocrystals in octadecene are reported. It is found that TMPPA acts as a high boiling point "nonsolvent" or "nucleating agent". Addition of TMPPA leads to higher initial particle yields and smaller particle diameters. Conversely, oleic acid inhibits nucleation and results in a drastic increase in "early time ripening" (ETR), a phenomenon that causes a rapid reduction in the number of particles within the first minutes of reaction. By controlling the number of nuclei formed with TMPPA and tuning the rate of ETR with oleic acid, high yields of particles can be obtained with sizes between 3 and 7 nm. Furthermore, in the absence of OA, the preparation of very small nanocrystals with diameters approximately 2 nm is facilitated.
报道了两种配体油酸（OA）和双（2,2,4-三甲基戊基）次膦酸（TMPPA）对十八烯中CdSe纳米晶体成核速率和生长的竞争效应。发现TMPPA作为高沸点的“非溶剂”或“成核剂”。添加TMPPA会导致更高的初始颗粒产率和更小的颗粒直径。相反，油酸抑制成核并导致“早期熟化”（ETR）急剧增加，这种现象会在反应的最初几分钟内导致颗粒数量迅速减少。通过控制TMPPA形成的核数量并调节油酸的ETR速率，可以获得高产率的3至7纳米尺寸的颗粒。此外，在没有OA的情况下，有助于制备直径约为2纳米的非常小的纳米晶体。
