9 research outputs found

    The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts

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    The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts. June 4-7, 2019, Szczyrk, Polan

    Nanoscale Phenomena Occurring during Pyrolysis of Salix viminalis Wood

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    Selective utilisation of unique properties of Salix viminalis wood enables preparation of materials of nanotechnologic properties. Thermal decomposition of lignin-cellulose organic matter results in the formation of a nanostructured porous carbon matrix (charcoal). Narrowed pore size distribution (PSD) in the subnanometer range allows to consider the charcoals as carbon molecular sieves (CMSs), which are capable of separating even chemically inert gases like neon, krypton, and nitrogen. High tolerance of Salix viminalis to heavy metal ions enables enriching living plant tissues with metal ions like lanthanum and manganese. Such ions may later form LaMnO3 with parallel transformation of plant tissues (organic matter) to carbon matrix using a heat treatment. In this way, one gets a hybrid material: a porous carbon matrix with uniformly suspended nanocrystallites of LaMoO3. The crystallites are in the catalytically active phase during the conversion of n-butanol to heptanone-4 with high yield and selectivity

    Chemical Activation of Nitrogen-doped Carbon Derived from Chitosan with ZnCl2 to Produce a High-performance Gas Diffusion-type Oxygen Electrode

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    In this study, we fabricated nitrogen-doped carbons (NDCs) derived from chitosan using a new synthesis method that combines the thermal decomposition of chitosan and chemical activation with ZnCl2. Then, the effect of the activation temperature on the microstructure of NDCs was investigated. The performance of a gas diffusion-type oxygen electrode (GDE) using the obtained NDCs was evaluated using an oxygen reduction reaction in an alkaline solution. Finally, the relationship between the microstructure of NDCs and electrode performance was discussed. The surface area and total pore volume of the fabricated NDCs tended to increase with activation temperature, despite decreasing nitrogen content. Additionally, we found that the overpotential of GDE decreases with an increase in specific surface area and total pore volume. The microstructure of the NDCs was found to play a key role in improving the performance of GDEs. Furthermore, the GDE composed of fabricated NDCs with a high surface area and high pore volume exhibited a reduced activation overpotential than that of conventional Pt-loaded carbon black

    Evaluating Gelatin-Based Films with Graphene Nanoparticles for Wound Healing Applications

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    In this study, gelatin-based films containing graphene nanoparticles were obtained. Nanoparticles were taken from four chosen commercial graphene nanoplatelets with different surface areas, such as 150 m2/g, 300 m2/g, 500 m2/g, and 750 m2/g, obtained in different conditions. Their morphology was observed using SEM with STEM mode; porosity, Raman spectra and elemental analysis were checked; and biological properties, such as hemolysis and cytotoxicity, were evaluated. Then, the selected biocompatible nanoparticles were used as the gelatin film modification with 10% concentration. As a result of solvent evaporation, homogeneous thin films were obtained. The surface’s properties, mechanical strength, antioxidant activity, and water vapor permeation rate were examined to select the appropriate film for biomedical applications. We found that the addition of graphene nanoplatelets had a significant effect on the properties of materials, improving surface roughness, surface free energy, antioxidant activity, tensile strength, and Young’s modulus. For the most favorable candidate for wound dressing applications, we chose a gelatin film containing nanoparticles with a surface area of 500 m2/g
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