MSE9: Non-equilibrium self-assembly of nano-structures: theory and applications
| Researcher: | Dr Victor Burlakov |
| Team Leader(s): | Prof. Alain Goriely |
| Collaborators: | Prof. Osman Bakr, KAUST |
| Prof. Sahraoui Chaieb, KAUST | |
| Michael Terekhov, Metallurg Engineering |
Background
Structures on the nanoscale possess many useful properties and are capable of self-assembly. In this project, we will develop theory for the kinetics of out-of-equilibrium self-assembly of alumina nanofibres (ANFs), which have a high ultimate tensile strength and a large specific surface area. In parallel, we consider two examples of self-assembly of nanoclusters (NCs) and nanoparticles (NPs) under action of a continuous supply of particles with the aim of developing fabrication principles for monodisperse nanoparticulate arrays. This has applications in optoelectronics and quantum information theory.
Techniques and Challenges
The steady-state growth process of ANFs and steady-state energy analysis for NCs and NPs are studied analytically and are described by nonlinear differential equations. The processes are also examined numerically to study the processes’ kinetics, which involves numerical solutions of simultaneous differential equations describing ensembles of ANFs or NPs and NCs to take into account statistical fluctuations in the systems. Obtaining numerical solutions of large (104-105) arrays of simultaneous nonlinear equations is challenging and computationally expensive.
Results
We have developed a theory for the steady-state growth of ANFs in the mean field approximation. This theory contains several parameters, which are determined by comparing the theory’s predictions with experimental data. Our preliminary analysis indicates that surfactants can be used to help obtain monodisperse arrays of NPs, which is in qualitative agreement with experimental data. We found that a narrow size distribution of NCs on a surface can be obtained under highly nonequilibrium conditions, for example in continuous deposition and desorption of atoms.
The Future
For ANFs we will develop a self-consistent growth theory, where the growth rate will be calculated from an initial distribution of the fibre sizes. We may also consider developing a master equation description of the growth process to reduce computational time. For NPs, we plan to analyse various routes of fabrication taking into consideration the flow reactors. For NCs, we will analyse the impact of fluctuations on size distribution.