Heijnen Sandrine M F, van Vliet Patrick, Kuipers Bonny W M, Philipse Albert P, Petukhov Andrei V, Ouhajji Samia
Van't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute for Nanomaterials Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
Materials (Basel). 2021 Jan 21;14(3):507. doi: 10.3390/ma14030507.
Experimental evidence is presented for the spontaneous formation of chiral configurations in bulk dispersions of magnetized colloids that interact by a combination of anisotropic dipolar interactions and isotropic depletion attractions. The colloids are superparamagnetic silica spheres, magnetized and aligned by a carefully tuned uniform external magnetic field; isotropic attractions are induced by using poly(ethylene oxide) polymers as depleting agents. At specific polymer concentrations, sphere chains wind around each other to form helical structures-of the type that previously have only been observed in simulations on small sets of unconfined dipolar spheres with additional isotropic interactions.
实验证据表明，在通过各向异性偶极相互作用和各向同性耗尽吸引相结合而相互作用的磁化胶体的体相分散体中，会自发形成手性构型。这些胶体是超顺磁性二氧化硅球体，通过精心调整的均匀外部磁场进行磁化和排列；使用聚环氧乙烷聚合物作为耗尽剂来诱导各向同性吸引。在特定的聚合物浓度下，球体链相互缠绕形成螺旋结构，这种结构以前仅在对少量无约束偶极球体并具有额外各向同性相互作用的模拟中观察到。
