INTERLAYER SELF-ASSEMBLY OF 2D NANOCOMPOSITES BASED ON LAYERED PRECURSOR
DOI:
https://doi.org/10.17308/kcmf.2017.19/213Keywords:
composite, self-assembly, layered precursor, colloidal solution, ultrasound, hydrodynamics, instability, electrostaticsAbstract
The purpose of this work is to study the conditions of formation of the composite structures in colloidal solutions of layered precursors (antimony, graphite).
Two-dimensional (2D) allotropes can be considered as building blocks in colloidal solutions of layered precursors. To study the possible interactions of the mono- and multilayers in a colloidal solution of antimony, we carried out quantum-chemical modeling based on the density functional theory (DFT). With a consecutive increase in the number of layers in the structure of antimony, a qualitative change in the distribution of the electron density occurs and it induces an excess positive charge on the outer faces of the layers. The inside layers are neutral as in a single-layer antimonene.
Thus, the presence of charge in the layers is the basis for developing methods and technology of the self-assembly of planar 2D structures of layered precursors and composites based on them.
The formation of the planar 2D structures of antimony and graphite and composites based on them occurs as a result of many hours of ultrasonic exposure to a solution of isopropyl alcohol and water and a finely dispersed single crystal of antimony or highly oriented pyrolytic graphite. The occurrences of self-activated colloidal solutions are determined. The self-activated colloidal solutions are characterized by the presence of long-term nonlinear hydrodynamic effects in a colloidal solution of the antimony, correlated with periodic changes in the particle size in the solution. The experimentally observed processes indicate the presence of 2D structures with a different number of layers in the volume of the solution, differing in the type and magnitude of the charge.
The electrostatically active environment of the colloidal solution creates conditions for the self-assembly of the planar structures of the original precursors and composite structures based on them.
As a result, multilayered 2D allotropes of antimony, graphite and two types of composite structures: a multilayer multigrahene / antimony structure and a polymorphic – multigrafene/nanofiber were obtained.
ACKNOWLEDGMENTS
The reported study was funded by RFBR according to the research(project No. 16-43-360281 р_а)
The research results were obtained with equipment of Voronezh State University Centre for Collective Use of Scientific Equipment.
