Visualizing Nanoscale Formation Dynamics of Turing Nanoparticle Patterns
Abstract
Cells utilize dynamic reaction-diffusion processes for critical cellular tasks like reproduction, motility, and morphogenesis. Patterns in tissue and pigmentation, termed Turing patterns, emerge spontaneously via competing reactions and diffusion of signaling biomolecules. Reaction-diffusion phenomena have been underutilized as a tool for assembling synthetic matter due to the complex interplay of autocatalytic reactions and differential diffusion of reactants required to establish reaction diffusion instability under very specific experimental conditions. The overall goal of this work is to establish reaction diffusion instability as a novel method for nanoparticle assembly utilizing a system discovered in our lab consisting of simultaneous polymerization and diffusion of nanoparticles into spatial patterns. The experimental system consists of a ~10 nanometer thick siloxane oligomer film decorated with nanoparticles, which is irradiated with high energy electrons causing the film to undergo radical polymerization and depolymerization reactions. The polymers and nanoparticles diffuse across the surface while undergoing chemical reactions and spontaneously arrange into diverse spatial patterns like stripes, labyrinths, and spots. Importantly, spatial patterns and directed energy inputs are not imposed on the system to form the patterns, i.e., no lithographic techniques are utilized. Instead, patterns emerge spontaneously due to reaction-diffusion instability. This system differs significantly from conventional self-assembly and lithographic methods for generating patterns and larger structures from nanomaterials. The proposed work aims to accomplish three objectives- (1) establish the chemical reactions and reactants involved in nanoparticle Turing pattern formation, (2) develop a mathematical reaction-diffusion model for nanoparticle pattern formation, and (3) investigate effects of concentration and diffusion gradients on pattern formation to rationally control pattern anisotropy and directionality. The expected outcome of this work is to harness the ability of biologically inspired reaction-diffusion systems to controllably assemble nanoparticles into spatial patterns, which will establish a new mechanism for nanoparticle assembly.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 06, 2025
- Source ID
- FA95502410275
Entities
People
- Taylor J Woehl
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Maryland