1 research outputs found
Self-Assembling Halloysite Nanotubes into Concentric Ring Patterns in a Sphere-on-Flat Geometry
Highly ordered and
concentric ring patterns consisting of halloysite
nanotubes (HNTs) with hierarchical cholesteric architectures are prepared
by evaporation-induced self-assembly in a sphere-on-flat geometry.
The structure and properties of HNTs are investigated. HNTs show a
perfect tubular morphology on the nanoscale with high dispersion stability
in water. Upon drying the HNTs aqueous suspension in a sphere-on-flat
confined space, regular concentric HNTs rings are formed on the substrate
via a self-assembly process. The widths of the inner and outer rings
and the spacing between the adjacent rings increase with an increase
in the concentration of the HNTs suspension. The highly ordered and
concentric HNTs rings show a pronounced Maltese cross-like pattern
under crossed polarizers, which suggests the formation of hierarchical
cholesteric architectures. Scanning electron microscopy and atomic
force microscopy observations show a disclination alignment of HNTs
in the ring strips, especially with a high concentration of the HNTs
suspension. The patterned rough surfaces of the HNTs show low cytotoxicity
and can be used as a cell-supporting scaffold. The HNTs rings can
guide the growth and orientation of C2C12 myoblast cells perpendicular
to the rings. This work provides a simple, repeatable, mild, and high-efficiency
method for obtaining HNTs with hierarchical architectures, which show
potential for a large variety of applications, for example, in vascular
grafts and skin regeneration