The rigid-rod model is capable of predicting several rheological features of rodlike polymers in the nematic phase. The model is formulated in terms of a nonlinear partial differential equation that describes the evolution of an orientational distribution function. The morphological properties and the rheological response of the sample can be determined once the distribution function is known. In this article the rigid-rod model is thoroughly analyzed with tools typical of bifurcation analysis for the case of shear flows. New flow regimes, both stationary and periodic, are found and illustrated. The detailed description of the model bifurcation structure allows some considerations about up to date closure approximations.

A rheological model for rodlike polymers in the nematic liquid-crystalline phase is analyzed to characterize irregular dynamical response under pure shear flows. The model is studied with a continuation approach, and a period doubling scenario is detected. Time series generated via simulation are studied with nonlinear analysis tools to prove the existence of chaotic regimes.

A stochastic approach to describe the crystal size distribution dynamics in antisolvent based crystal growth processes is here introduced. Fluctuations in the process dynamics are taken into account by embedding a deterministic model into a Fokker-Planck equation, which describes the evolution in time of the particle size distribution. The deterministic model used in this application is based on the logistic model, which shows to be adequate to suit the dynamics characteristic of the growth process. Validations against experimental data are presented for the NaCl-water-ethanol antisolvent crystallization system in a bench-scale fed-batch crystallization unit. \u

Morphological characterization of polymer blends is important for tailoring final properties of plastic products based on these systems. A novel technique to estimate the characteristic dimension and size distribution of a polymer blend is proposed and tested. The procedure is based on Fourier transform rheology (FTR) and large-amplitude oscillatory shear experiments and exploits their sensitivity to microstructural properties. The inference protocol requires that the experimental data are analyzed with a model capable of describing the blend dynamics. This novel technique is applicable to immiscible polymer blends of practical industrial interest. The procedure is successfully tested on a model system (an immiscible polymer blend of PDMS in PIB) by treating the polymer blends with the Maffettone-Minale model coupled with the Batchelor theory