Harris Richard Anthony, Shumbula Poslet Morgan, van der Walt Hendriëtte
DST/Mintek Nanotechnology Innovation Centre, Advanced Materials Division, Mintek, Private Bag X3015,Randburg, Johannesburg 2125, South Africa.
Langmuir. 2015 Apr 7;31(13):3934-43. doi: 10.1021/acs.langmuir.5b00671. Epub 2015 Mar 26.
The interface interactions between surfactants oleic acid and oleylamine and magnetic nanoparticles are studied via molecular mechanics and dynamics. Mixtures of these two surfactants are widely advocated in the chemical synthesis of nanoparticles. However, the exact dynamic mechanism remains unclear. Here we report, for the first time, a comprehensive qualitative model showing the importance of acid-base complex formation between oleic acid and oleylamine as well as the presence of free protons in the engineering of nanoparticles of specific shapes and sizes. We show why critical parameters such as surfactant concentration may modify iron oxide nanoparticle shape and size and how this can be understood in the light of acid-base complex pair formation. We report on the influence these parameters have on both the in situ nanoparticle surface charge and zeta potential. Transmission electron microscopy (TEM), FTIR, and pH studies are used to confirm the validity of the calculated binding energies and number of acid-base pairs.
通过分子力学和动力学研究了表面活性剂油酸和油胺与磁性纳米颗粒之间的界面相互作用。这两种表面活性剂的混合物在纳米颗粒的化学合成中得到广泛提倡。然而，确切的动力学机制仍不清楚。在此，我们首次报告了一个全面的定性模型，该模型显示了油酸和油胺之间形成酸碱络合物的重要性以及游离质子在特定形状和尺寸的纳米颗粒工程中的存在。我们展示了为什么诸如表面活性剂浓度等关键参数可能会改变氧化铁纳米颗粒的形状和尺寸，以及如何根据酸碱络合物对的形成来理解这一点。我们报告了这些参数对原位纳米颗粒表面电荷和zeta电位的影响。使用透射电子显微镜（TEM）、傅里叶变换红外光谱（FTIR）和pH研究来确认计算出的结合能和酸碱对数量的有效性。
