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Results

Figure 1 represents initially randomly placed spherical particles that are subjected to Brownian motion and molecular interactions. Figure 2 shows the agglomerates formed by colliding particles during the simulation.

 

 

 

 

 

Figure 3: Plot of log(N) vs log(Rg) for the aggregate containing 191 primary particles.The movie below shows the nanoparticle agglomeration of initially randomly placed 250 primary particles. The particles move according to the Brownian Motion (friction coefficient between particles and surrounding fluid Ɣ = 1.64*10-12 kg/ms and the system temperature T=300K). As the particles collide, they stick to each other and form irregular clusters. Each clusters can then be quantified by the fractal dimension Df.

For this agglomerate Df is calculated as 1.92 by using a power law relationship between the number of particles and the radius of gyration of the cluster (Figure 3).Formation and growth of nanoparticle agglomerates by the collision of single particles, single particles with clusters and clusters with clusters that are subjected to Brownian Motion and intermolecular interactions.

Formation and growth of nanoparticle agglomerates by the collision of single particles, single particles with clusters and clusters with clusters that are subjected to Brownian Motion and intermolecular interactions.

 

 

 

 

 

 

 

 

 Results of the third funding period

In the third funding period of the project the aggregation dynamics between similar aggregates is analyzed with the coarse-graining (CG) method. It foots on the collision probability of the aggregates, a function of the interval between the aggregates and their fractale profile.

Figure 3 indicates the collision probalitity of aggregates from 9 different groups, which are figured by the use of ballistic methods. In form of tables they were further used in coarse-grained ESPResSo simualtions.

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Fig. 3: Collision probability for CG simulation
 
Fig. 4: Collision amount of detailed LD simulations

Figure 4 indicates the results of detailed LD simulations, while in figure 5 the comparishon of the results between collision amount in a detailed and a coarse-grained simualation is visible.

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Fig. 5: Comparison of detailed LD and CG simulation results for the aggregate with Rg=3, Df=1.6