Abraham Leggins, Thomas Tiju, Pichumani Moorthi
Department of Nanoscience and Technology, Sri Ramakrishna Engineering College, Coimbatore, Tamil Nadu, India.
Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Adyar, Chennai 600036, Tamil Nadu, India; Indian Solar Energy Harnessing Center - An Energy Consortium, Indian Institute of Technology Madras, Adyar, Chennai 600036, Tamil Nadu, India.
J Colloid Interface Sci. 2019 Jul 1;547:234-244. doi: 10.1016/j.jcis.2019.04.003. Epub 2019 Apr 2.
The physico-chemical mechanisms associated reverse micelle based encapsulation processes deserve investigation owing to the direct correlation between stability of micellar structure and nano encapsulation. The presence of core nanoparticles is expected to influence the stability of micellar structure when the concentrations of surfactant and particle concentration are varied. Hence, it should be possible to define the micellar aggregation - complexation regimes and systematic measurements have robust implications for nano encapsulation.
Reverse micelle systems stabilized by non-ionic surfactant are formulated with the presence of core nanoparticles. Micellar aggregation and complexation processes are analyzed in two different oil phase (n-hexane and n-butanol). The regimes are probed by measuring average hydrodynamic diameter of reverse micelle, optical transmittance and specific conductivity. Shell encapsulation experiments are performed in aggregation and complexation regimes.
When the concentration of surfactant increases, reverse micelle size increases (to dia ∼ 200 nm). This is a reversal of the otherwise reported trend wherein the core is absent. Breakdown of stable reverse micellar structure obstructs shell coating and this is a first attempt to analyze micellar aggregation - complexation regimes with the presence of core. Reverse micelle breakage or complexation is to be completely avoided to achieve core@shell nanoparticles.
由于胶束结构稳定性与纳米封装之间存在直接关联，与基于反胶束的封装过程相关的物理化学机制值得研究。当表面活性剂浓度和颗粒浓度发生变化时，核心纳米颗粒的存在预计会影响胶束结构的稳定性。因此，应该能够定义胶束聚集 - 络合机制，并且系统测量对纳米封装具有重要意义。
在存在核心纳米颗粒的情况下，配制由非离子表面活性剂稳定的反胶束体系。在两种不同的油相（正己烷和正丁醇）中分析胶束聚集和络合过程。通过测量反胶束的平均流体动力学直径、透光率和电导率来探究这些机制。在聚集和络合机制下进行壳层封装实验。
当表面活性剂浓度增加时，反胶束尺寸增大（直径约为200 nm）。这与其他报道的无核心时的趋势相反。稳定的反胶束结构的破坏阻碍了壳层包覆，这是首次尝试在有核心存在的情况下分析胶束聚集 - 络合机制。为了获得核壳纳米颗粒，必须完全避免反胶束破裂或络合。
