Modelling of Aggregation of Nanoparticles and its effect on their Structural and Biological Functions

Abstract

Nanoparticles have applications such as drug delivery and cancer treatments, reinforcement of the polymer or metal matrix, consumer products and environment. This work concentrates on how aggregated nanoparticles might realistically effect performance of the intended structural or biological function. As a conceptual basis, primary aggregation is assumed to produce the backbone of micro-structures which then cluster, covering a large portion of the material. This process is assumed to be chaotic and to occur rapidly. Molecular dynamic analysis of this aggregated model is difficult because the problem is not clearly bound and regions not spatially defined. Moreover the modulus of the micron-sized aggregate within the cluster is also difficult to measure directly. Instead an indirect method is developed of the polymer/particle interface in the aggregate which can be verified by bulk modulus experiments on nano-composite samples produced specifically for this work. A computer program equates minimum free-energy of the absorbed polymer molecule to dipolar interaction energies having a Boltzmann’s Distribution. Fractal numbers are used to characterise the molecular/particle interface and configuration of the aggregate backbone. After the principle has been established it is extended to other applications for example how aggregation might effect the probability of release of artificial DNA from silica nano-particles within the body