Nanowerk September 25, 2023
In a typical approach for creating nanostructures ligands are grafted onto the surfaces of nanoparticles to improve the dispersion stability and control interparticle interactions. Ligands remain secondary and usually are not expected to order significantly during superstructure formation. Researchers in Germany investigated how ligands can play a more decisive role in the formation of anisotropic inorganic–organic hybrid materials. They grafted poly(2-iso-propyl-2-oxazoline) (PiPrOx) as a crystallizable shell onto SiO2 nanoparticles. By varying the PiPrOx grafting density, both solution stability and nanoparticle aggregation behavior could be controlled. Upon prolonged heating, anisotropic nanostructures formed in conjunction with the crystallization of the ligands. Self-assembly of hybrid PiPrOx@SiO2 (shell@core) nanoparticles first, formed amorphous aggregates via gelation, mediated by the interaction between nanoparticles through grafted polymer chains. As a second step, slow radial growth of fibers was observed via directional crystallization, governed by the incorporation of crystalline ribbons formed from free polymeric ligands in combination with crystallization of the covalently attached ligand shell. According to the researchers their work revealed how crystallization-driven self-assembly of ligands can create intricate hybrid nanostructures… read more. TECHNICAL ARTICLEÂ
