Spectroscopic (IR, Raman, NMR), thermal and theoretical (DFT) study of alkali metal dipicolinates (2,6) and quinolinates (2,3)

AbstractIn the presented work the thermal, theoretical (DFT) and spectroscopic (IR, Raman, NMR) properties of alkali metal complexes with quinolinic acid (2,3-pyridinedicarboxylic acid) and dipicolinic acid (2,6-pyridinedicarboxylic acid) were studied. The IR and Raman spectra were registered and analyzed in the range of 400–4000cm−1. 1H NMR and 13C NMR spectra of analyzed compounds have been registered and assigned. The electronic charge distribution for the studied acids and their salts with lithium, sodium and potassium was calculated. All the calculations were done in the frame of density functional theory (DFT) using 6-311++G(d,p) basis set. The thermal decomposition of the analyzed compounds was done

Are nanohedgehogs thirsty? Toward new superhydrophobic and anti-icing carbon nanohorn-polymer hybrid surfaces

85% of the world’s polymers production is made up of thermoplastics, and among them, one can find: polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET). In this study, these three polymers were applied for the first time as supports for superhydrophobic and anti-icing surfaces created using single walled carbon nanohorns (SWCNH). A facile method of thermal “feathering” was used and the obtained materials were deeply characterized using thermal (thermogravimetry, differential scanning calorimetry) and microscopic (scanning electron microscopy, atomic force microscopy, confocal microscopy) methods as well as tribological and nanoindentation tests. We show that, depending on the polymer, the process of thermal “bulk” or “surface feathering” occurs. The results supported by Hansen Solubility Parameters calculation combined with Molecular Dynamics Simulations allow to explain the stability of surfaces as well as the wetting behavior revealing that all new materials are superhydrophobic. Moreover, some of them exhibit ice-phobic properties, while droplet freezing process is well described by the dynamic growth angle model. Finally, by discussing the mechanical stability, superhydrophobic and anti-icing properties two optimal surfaces (PP + SWCNH 5 min, PE + SWCNH 10 min) are chosen. Both of them possess intermediate values of Young’s modulus and show intermediate values of static contact angle hysteresis. Since the PE-based solids show enhanced tribological performance, tests, PE + SWCNH 10 min sample emerges as the most perspective in practical hydrophobic and anti-icing applications