Jang Hyunwoo, Song Chaeyeon, Kim Byungsoo, Lee Chunghyeong, Lee Juncheol, Han Youngkyu, An Ilsin, Kim Joon Heon, Nam Jin, Choi Myung Chul
Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea.
AMOREPACIFIC R&I Center, Yongin 17074, South Korea.
ACS Macro Lett. 2023 Oct 17;12(10):1298-1305. doi: 10.1021/acsmacrolett.3c00339. Epub 2023 Sep 11.
Nanoparticles exhibiting geometrical and chemical anisotropies hold promise for environmentally responsive materials with tunable mechanical properties. However, a comprehensive understanding of their interfacial behaviors remains elusive. In this paper, we control the interfacial anchoring orientation of polystyrene nanodumbbells by adjusting interparticle forces. The film nanostructure is characterized by the orientation angle analysis of individual dumbbells from cross-sectional EM data: dumbbells undergo orientation transitions from a distinctive horizontal bilayer to an isotropic anchoring when electrostatic repulsion is suppressed by either an ionic strength increase or surface amine-modification. This anchoring orientation influences the film's mechanical properties and foam stability, as investigated by a 2D isotherm and dark/bright-field microscopy measurements. Our findings highlight the potential for precise control of supra-colloidal structures by modulating particle alignment, paving the way for smart delivery systems.
呈现几何和化学各向异性的纳米颗粒有望成为具有可调机械性能的环境响应材料。然而，对其界面行为的全面理解仍然难以捉摸。在本文中，我们通过调整粒子间作用力来控制聚苯乙烯纳米哑铃的界面锚定取向。薄膜纳米结构通过对横截面电子显微镜数据中单个哑铃的取向角分析来表征：当通过增加离子强度或表面胺修饰抑制静电排斥时，哑铃经历从独特的水平双层到各向同性锚定的取向转变。通过二维等温线和暗场/亮场显微镜测量研究发现，这种锚定取向会影响薄膜的机械性能和泡沫稳定性。我们的研究结果突出了通过调节粒子排列精确控制超胶体结构的潜力，为智能输送系统铺平了道路。
