Interactions between nanofibers in fiber-surfactant suspensions: Theory of corresponding distances

We present the theory of corresponding distances for the interactions mediated by soft nano- structures in fibrous materials. These fibre-soft-fibre interactions are important for the design of fibrous materials as well as for the critical problem of stable fibre suspensions. Unfortunately, they are time-consuming to determine computationally as system sizes are large, their evolution is often slow and the interactions depend on several parameters, such as fibre distance and angle. The theory is developed based on an understanding of the mechanisms that govern the internal structure of the soft component and describes the distance and angle dependence theoretically. The remaining system specific information needed to derive the entire forcefield can be obtained from a single computer simulation or a single experiment. Thus, the theory can be used in conjunction with simulations as well as with experiments.
For simulations it represents an enormous efficiency increase, replacing hundreds of simulations by only one. This enables the routine computation of complete fibre-soft-fibre forcefields by high-level methods, such as atomistic simulation and provides a simple representation of the forcefield.The theory also paves the way to the experimental determination of such forcefields. This amounts to a step-advancement for soft nanotechnology as it enables the efficient rational design of the soft component to fulfil a target function.