Morphology is the decisive factor controlling practical properties such as impact strength or transparency in multiphase polymeric materials. The co-continuous structure formed by polymers has been of great interest to material scientists because of their superiority over those with random morphology. Although a number of efforts--including forcibly freezing the spinodal structure of polymer blends--have been made to produce materials with co-continuous structures, an efficient method for controlling their regularity is still lacking. Here, we demonstrate a novel method using periodic photo-crosslinking to control the length-scale distribution of the spinodal structure in binary polymer blends. It was found that the period distribution of the resulting co-continuous structure became significantly narrow under this periodic forcing. Also, there exists a particular irradiation frequency at which the periodic structure exhibits a minimum, indicating the existence of an ordering process driven by the external modulation frequency. Our findings reveal an easy way to produce polymer materials that is not only useful for optical applications, but also promising for biological separation, such as hemodialysis.

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Numerical models of impact on aramid composite plates and combat helmet were developed. • Experimental tests were carried out ac cording to standards used by manufac turers. • Good accuracy between predictions and experiments was observed proving the ability of the models developed as a de sign tool

The exigent requirements for personal protections in terms of energy absorption and ergonomics have led to increasing interest in bioinspired protections. This work focuses on the numerical analysis of ballistic behavior of different bioinspired geometries under impact loadings. Ceramic armors based on ganoid fish scales (the type exhibited by gars, bichirs and reedfishes), placoid fish scales (characterizing sharks and rays) and armadillo natural protection have been considered. Different impact conditions are studied, including perpendicular and oblique impacts to surface protection, different yaw angle, and multiple impacts. Main conclusion is related to the improved efficiency of modular armors against multiple shots exhibiting more localized damage and crack arrest properties. Moreover, its potential ergonomic is a promising characteristic justifying a deeper study.

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