The growth simulation of pine-needle like structure with diffusion-limited aggregation and oriented attachment.

Area of Science:

• Materials Science
• Computational Modeling
• Physics

Background:

• Understanding the growth mechanisms of anisotropic structures is crucial in materials science.
• Existing models often struggle to capture the transition from random aggregation to ordered growth.
• Pine-needle-like structures exhibit unique properties influenced by their formation process.

Purpose of the Study:

• To develop a quantitative growth model for pine-needle-like structures.
• To investigate the combined effects of diffusion-limited aggregation (DLA) and oriented attachment (OA).
• To analyze the relationship between particle number and needle length.

Main Methods:

• A computational growth model integrating DLA and OA was developed.
• Realistic Brownian motion parameters were defined for DLA.
• The model was applied to growth simulations on various surfaces (line, plane, sphere).

Main Results:

• The introduction of OA transformed random DLA clusters into regular needle-like structures.
• The DLA-OA cluster exhibited a consistent fractal dimensionality of approximately 1.0.
• Maximum needle length (Lmax) showed a power-law relationship with the number of particles (Np): Lmax = aNp^b.

Conclusions:

• The combined DLA-OA model effectively simulates the formation of ordered, needle-like structures.
• Steric hindrance significantly influences needle growth, especially on planar surfaces.
• The model provides a quantitative framework for understanding anisotropic growth phenomena.