Vol. 111 No. 2 (2015)

The segmented structure of polyurethane elastomers (PU) is an interesting feature to desing super-tough energy absorbing materials. Understanding the role of segment architecture on the morphology of oriented PU specimens is important to understand the reinforcing mechanism within the material. In this work we present different methodologies employed in the structural characterization of segmented polyurethanes with different macromolecular architecture. It is discussed the type of information obtained with each technique as function of the nature of the different PUs constituent blocks.

Keywords: segmented polyurethanes, structural characterization, macromolecular orientation, structure-properties relationship, spider silk biomimicry

François Joseph Jérôme Nicklès (1820-1869), a French chemist and pharmacist, carried on extensive research in the areas of crystallography, isomorphism, polymorphism, electromagnetism, physiology, fermentation, the theory of odor and smell, fluorine and its derivatives, etc. His results confirmed bismuth belongs to the nitrogen group, the formation of propionic acid during the fermentation of tartaric acid, and fluorine is present in most parts of the organism. His work on fluorine and derivatives led to his death at an early age.

In this second article we analyze the scientific contribution of François Joseph Jérôme Nicklès (1820-1869) and present the results he obtained regarding the theory of odors and smells, sugar pyrolysis, liquid fires based on phosphorus, the presence of fluorine in animal organs and fluids, the analysis and synthesis of a variety of fluorinated compounds, and electromagnetism.

A collection of paintings by MAXAM (formerly Unión Española de Explosivos, UEE), with allusions to the world of explosives, is described as a tool for teaching and outreach of chemistry. This collection has been formed with an annual picture to illustrate (since 1900) the calendar of the company. After outlining the history of UEE (whose pioneer firm was founded by Alfred Nobel), we present some of the most representative pieces of the collection (including the painting by Isabel Quintanilla, entitled Alfred Nobel’s Landscape, to illustrate the calendar for 2015). Its use is proposed to discuss topics such as: industrial chemistry, history and ethics of science, chemistry of explosives, and chemistry and environment, among others.

Keywords: explosives, MAXAM, science and art, science-technology-society

The study of the scientific method as a research method is a good starting point to teach our students how the sciences have developed his way through the knowledge. In chemistry there are quite a few examples to show this methodology in a didactic manner such as, the atomic theories and the development of a systematic classification of the known elements in a table: the periodic table of the elements.

Keywords: elements, discovery, classification, periodic table, periodic properties

El libro "Atomic Absorption Sectrometry: An Introduction" de los autores Alfredo Sanz-Medel y Rosario Pereiro es una segunda edición monográfica sobre la técnica de Espectrometría de Absorción Atómica (AAS), disponible en la mayoría de los laboratorios de análisis de muy diferentes áreas. La obra consta de ocho capítulos organizados para ofrecer al lector una visión actualizada de esta técnica. A lo largo del libro se realiza un recorrido a través de los conceptos básicos, metodologías, técnicas especiales, aplicaciones recientes y  últimos avances en instrumentación y técnicas de análisis. Cada capítulo concluye con ejemplos prácticos sobre la aplicación de la técnica.