Introduction
To get precipitates of CdS, we’ve used protein CysDes which could react with Cysteine to manufacture S2-. In the whole system, there were lots of Cd2+. As we all know, we can get molecules of CdS. Subsequently, these molecules would aggregate as a crystal. In this part, we wanted to know the precise structure of the crystal to get the actual reaction area.
What were we modeling:
In reference [1], [2], [3], [4], we know a method that called DLA simulation which can help us to achieve our goal. DLA means diffusion-limited aggregation. Feasibility and more details in these paper.
Firstly, we assumed that there was a core of a crystal. Every molecule would aggregate to the heart. If a molecule combined with the core, it would become a part of the heart. The molecule and the heart would become a new core for the next molecule.
As a molecule, it would walk randomly in the solution. In our system, we ignored the interaction force between molecules. Because of this approximation, we could use a DLA model to describe the structure of a CdS crystal.
We regarded every molecule of CdS as a particle in our model and considered the size of the particle equal to 1. With time went by, every particle could move randomly in a 2D/3D spatial area. Every step of these particles was considered as 1 too.
At the beginning, we considered a simple question--what would happen if the particles just moved in a 2D flat plane? As you can see, in