Department of Chemistry, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany.
Institute of Inorganic Chemistry, Leibniz-University Hannover, Callinstrasse 9, 30167, Hannover, Germany.
Angew Chem Int Ed Engl. 2020 Jun 2;59(23):8902-8906. doi: 10.1002/anie.202001423. Epub 2020 Mar 25.
Amphiphiles alter the energy of surfaces, but the extent of this feature is typically constant. Smart systems with amphiphilicity as a function of an external, physical trigger are desirable. As a trigger, the exposure to a magnetic field, in particular, is attractive because it is not shielded in water. Amphiphiles like surfactants are well known, but the magnetic response of molecules is typically weak. Vice-versa, magnetic particles with strong response to magnetic triggers are fully established in nanoscience, but they are not amphiphilic. In this work colloids with Janus architecture and ultra-small dimensions (25 nm) have been prepared by spatial control over the thiol-yne click modification of organosilica-magnetite core-shell nanoparticles. The amphiphilic properties of these anisotropically modified particles are proven. Finally, a pronounced and reversible change in interfacial stabilization results from the application of a weak (<1 T) magnetic field.
两亲物会改变表面的能量，但这种特性的程度通常是恒定的。具有两亲性作为外部物理触发功能的智能系统是理想的。磁场暴露是一种特别有吸引力的触发方式，因为它在水中不会被屏蔽。表面活性剂等两亲物是众所周知的，但分子的磁响应通常很弱。反之，对磁触发有强响应的磁性颗粒在纳米科学中已得到充分确立，但它们不是两亲的。在这项工作中，通过对有机硅-磁铁矿核壳纳米粒子的硫醇-炔点击修饰进行空间控制，制备了具有 Janus 结构和超小尺寸（25nm）的胶体。证明了这些各向异性修饰粒子具有两亲性。最后，施加弱（<1T）磁场会导致界面稳定发生明显且可恢复的变化。
