Daicel Corporation, 1239, Shinzaike, Aboshi-ku, Himeji, Hyogo 671-1283, Japan.
Electron Microscope Unit, Mark Wainwright Analytical Centre and School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052, Australia.
Langmuir. 2022 Jan 18;38(2):661-669. doi: 10.1021/acs.langmuir.1c02283. Epub 2022 Jan 5.
Detonation nanodiamonds have found numerous potential applications in a diverse array of fields such as biomedical imaging and drug delivery. Here, we systematically characterized non-functionalized and polyglycerol-functionalized detonation nanodiamond particles (DNPs) dispersed in aqueous suspensions at different ionic strengths (∼1.0 × 10 to 1.0 × 10 M) via dynamic light scattering and cryogenic transmission electron microscopy. For these colloidal suspensions, the total potential energies of interactions between a pair of DNPs were theoretically calculated using the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory plus the fitting of the Boltzmann distribution to the interparticle spacing distribution of the colloidal DNPs. These investigations revealed that the non-functionalized DNPs are dispersed in aqueous media through the long-range (>10 nm) and weak (<7 ) electrical double-layer repulsive interaction, while the driving force on dispersion of polyglycerol-functionalized DNPs is mostly derived from the short-range (<2 nm) and strong (∼55 ) steric repulsive potential barrier generated by the polyglycerol. Moreover, our results show that the truly monodispersed and individually dispersed DNP colloids, forming no aggregates in aqueous suspensions, are available by both functionalizing DNPs by polyglycerol and increasing ionic strength of suspending media to ≳1.0 × 10 M.
爆轰纳米金刚石在生物医学成像和药物输送等多个领域有着广泛的潜在应用。在这里，我们通过动态光散射和低温透射电子显微镜系统地研究了在不同离子强度（约 1.0×10^-1.0×10^M）下分散在水悬浮液中的非功能化和聚甘油功能化爆轰纳米金刚石颗粒（DNP）。对于这些胶体悬浮液，使用德加古因-朗道-维尔韦尔-奥弗贝克（DLVO）理论加上对胶体 DNP 间的粒子间距分布的玻尔兹曼分布拟合，理论计算了一对 DNP 之间的总相互作用势能。这些研究表明，非功能化的 DNP 通过长程（>10nm）和弱（<7）的电双层排斥相互作用分散在水介质中，而聚甘油功能化的 DNP 的分散驱动力主要来自于聚甘油产生的短程（<2nm）和强（~55）的空间位阻排斥势垒。此外，我们的结果表明，通过聚甘油功能化和增加悬浮介质的离子强度至≥1.0×10^M，可以获得真正单分散且在水悬浮液中无聚集的单个分散的 DNP 胶体。
