SURFI

Ballistic Testing of Composites

The research team from the Military Institute of Engineering in Rio de Janeiro (Brazil), led by Prof. Sergio N. Monteiro, published in collaboration with Dr. Drelich a review entitled “Natural Fibers Reinforced Polymer Composites Applied in Ballistic Multilayered Armor for Personal Protection – an Overview.” The review was published in a book entitled Green Materials Engineering by TMS and Springer.

Abstract: Natural fibers have been investigated as composites reinforcement for technological applications. Several natural fiber composites were found to present similar ballistic performance as synthetic materials, such as KevlarTM in multilayered systems (MASs) against high-impact energy projectiles. MASs with a front ceramic followed by natural fibers, natural fabrics or natural non-woven mat such as curaua, jute, sisal, ramie, coir, piassava, fique, and sugarcane bagasse reinforcing polymer matrix composites attend the standards for personal ballistic protection against the threat of 7.62 mm ammunition. These natural fibers or fabrics or non-woven mats composites, as second MAS layer, succeed to capture the cloud of fragments resulting from the projectile impact on the ceramic layer with comparable ballistic efficiency as conventional synthetic aramid fiber composites with same thickness. In this work, the development of research dedicated to these natural fiber-based composites in MASs are overviewed and their advantages over synthetic materials are emphasized, especially the much lower cost.

Surface Innovations, the journal

We are glad to share with you the content of the second issue of 2019 of Surface Innovations with seven papers on variety of topics related to surfaces of biomaterials, bioactivity, antifouling, wetting, and surface modifications.

Rodent

Our new paper entitled “Preclinical In-Vivo Evaluation and Screening of Zinc Based Degradable Metals for Endovascular Stents” has been published in the JOM journal. Roger Guillory, PhD candidate, and Prof. Jeremy Goldman from Biomedical Engineering led this project, in which a metal wire implantation model in rats that our collaborative team introduced in 2012, is refined and described in details. This is a cost effective and realistic model for the biocompatibility evaluation of degradable materials in the vascular environment. In this new publication, metrics routinely used for evaluating stents to quantitatively characterize the long-term progression of the neointima that forms around zinc based wire implants were adapted. Histological cross-sections were used to measure the length of neointimal protrusion from the wire into the lumen (denoted wire to lumen thickness), the base neointimal length (describing the breadth of neointimal activation), and the neointimal area. These metrics were used to provide in depth characterization details for neointimal responses to Zn-Mg and Zn-Li alloys and may be used to compare different materials

Strider and Ant Colony

Georgia published her paper entitled Water-Repellency of Hierarchical-Structured Legs of Water-Walking Striders and Fire Ants in Surface Innovations that summarizes her M.S. program. The following is the abstract of her publication:

“Some insects have the ability to walk on water surface due to hierarchical leg structure and wax coating. In this study, resistance forces of water strider and fire ant legs to submersion in water, under their various orientations, were quantified using a high-sensitivity microbalance. Legs oriented parallel to water surface could support up to ten times as much force before immersion, compared to legs in a perpendicular orientation. Water pressure affected the setae structure differently at parallel and perpendicular approaches, and complete wetting was more difficult in the structure observed during parallel immersion. The wax coating on water strider legs was found to decrease adhesion force with little effect on immersion force. Overall, wax-coated strider legs, having conical setae with nanogrooves to facilitate removal of water, that are oriented parallel to the water surface, coated with wax, and have coned setae with nanogrooves to facilitate removal of water, are natural models for legs of a biomimetic aquatic robot when oriented parallel to the water surface.”

Surface Innovations, the journal

We are glad to share with you the content of the first issue of 2019 of Surface Innovations with eight papers on variety of topics related to surfaces, interfaces, coatings and nanotechnology. Beside regular summary of the issue content, our Editorial also reports ceremony of Doctor Honoris Cause by Poznan University of Technology and International Symposium on Advanced Materials and Sustainable Technologies that was sponsored by ICE Publishing, with poster awards provided by Surface Innovations. Hope you will enjoy reading it.