RESUMEN
In this work, energetic coordination compounds (ECCs) of transition metals (Fe, Ni, Cu, Zn) containing aliphatic amines as ligands were synthesized: ethylenediamine; 1,3-diaminopropane; tris(2-aminoethyl)amine; tris(3-aminopropyl)amine. The compounds were investigated in terms of ignition/explosion temperature, friction and impact sensitivity. For selected compounds, structural characterisation was presented (IR-ATR spectroscopy, Raman spectroscopy) and their morphology was determined (SEM, powder XRD). They were also investigated by differential scanning calorimetry (DSC). In order to assess the potential application of selected ECCs in detonators, underwater explosion tests were carried out, determining energetic performance. The results achieved for detonators containing ECCs were compared with those for reference detonators (containing pentaerythritol tetranitrate, PETN), indicating their potential use as a "green" alternative to nitric acid esters.
Asunto(s)
Complejos de Coordinación , Sustancias Explosivas , Ligandos , Complejos de Coordinación/química , Complejos de Coordinación/síntesis química , Sustancias Explosivas/química , Aminas/química , Elementos de Transición/química , Rastreo Diferencial de Calorimetría , Espectrometría RamanRESUMEN
The aim of this article is to compare rocket propellants containing a traditional binder (hydroxyl-terminated polybutadiene) and an energetic binder (glycidyl azide polymer), as well as a perchlorate oxidising agent and a "green" one, i.e., ammonium perchlorate and phase-stabilised ammonium nitrate. We have outlined the effects of individual substances on the sensitivity parameters and decomposition temperature of the produced solid propellants. The linear combustion velocity was determined using electrical methods. Heats of combustion for the propellant samples and the thermal decomposition features of the utilised binders were investigated via differential scanning calorimetry (DSC). Activation energy values for the energetic decomposition of the propellants were determined via the Kissinger method, based on DSC measurements at varied heating rates.
RESUMEN
This study investigates a supramolecular approach to elucidate the interaction between an organic semiconducting molecule, specifically butyric acid-functionalized perylene diimide, and a block copolymer comprising poly-3-hexyl thiophene-b-polyethylene glycol. This interaction results in the formation of a precisely structured nanoarchitecture within the supramolecular block copolymer, driven by the ionic interplay between the block copolymer and small organic molecules. The optical properties of the synthesized supramolecular block copolymer were characterized by using ellipsometry. Additionally, further characterization employing atomic force microscopy, differential scanning calorimetry, and X-ray diffraction provided detailed insights into the crystallinity and morphology of the nanostructure. The characterization data showed that this approach significantly influenced the tuning of morphology, crystallinity, and optical and electronic properties of the resulting nanostructure. The demonstrated methodology holds considerable promise as a strategic tool for broadening the spectrum of attainable nanomorphologies in semiconducting polymers, particularly for applications in electronics or photovoltaics.
RESUMEN
A series of thermoresponsive glycomicrogels with trehalose in the cross-links or with trehalose in the cross-links and as pending moieties was synthesized. These materials were obtained by surfactant-free precipitation copolymerization of N-isopropylacrylamide and various amounts of trehalose monomers. The resultant particles showed a spherical shape and a submicrometer hydrodynamic size with a narrow size distribution. At 25 °C, glycomicrogels in solutions with physiological ionic strength formed stable colloids, which further gelled upon heating to physiological temperature forming a macroscopic hydrogel with an interconnected porous structure. These extremely soft matrices with dynamic storage modulus in the range of 9-70 Pa were examined in 3D culture systems for HeLa cell culture in comparison to traditional 2D mode. They showed relatively low syneresis over time, especially when glycomicrogels with a high content of hydrophilic trehalose were used as building blocks. An incorporated pending trehalose composed of two α,α'-1,1'-linked d-glucose moieties was used with the intention of providing multivalent interactions with glucose transporters (GLUTs) expressed on the cell surface. A better cell viability was observed when a soft hydrogel with the highest content of trehalose and the lowest syneresis was used as a matrix compared to a 2D control assay.