Nanoscale Phenomena Occurring during Pyrolysis of Salix viminalis Wood

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

Effect of Salix viminalis Pyrolysis Derived Antioxidants on Oxidative Stability of Diesters and Diester–Poly-α-olefin Mixtures

The fabrication of molecular sieves and carbon-based adsorbents by pyrolysis of lignocellulosic material, such as Salix viminalis wood, generates a considerable amount of pyrolysis oil which has no specific application. In the present paper, we investigate phenolic components of S. viminalis derived pyrolysis oil with regard to their potential application to the oxidative stabilization of synthetic lubricating oils. Two phenolic fractions were isolated through solvent extraction (extract A was ether soluble; extract B was methylene chloride soluble) and characterized by chromatographic analysis. High levels of 2,6-dimethoxyphenol and its para-substituted derivatives were attributed to a rather atypical composition of S. viminalis lignin. The antioxidative effect of pyrolysis-derived polyphenols on diesters and their blends with poly-α-olefins was studied by means of a high temperature oxidation test combined with spectroscopic (NMR and FT-IR) product analysis. The test proved that the antioxidant capacity of each extract is high, at the level of ca. 1000 ppm. Extract A had the highest increase in the induction period (170 h), and compared with the commercial BHT antioxidant, it prolonged the lag phase ca. 3.3 times. The effect of the <i>o</i>-methoxy and para substituents, intramolecular hydrogen bonding of the hydroxyl H atom, and synergetic interactions on the antioxidant activity is discussed

The Origin of Amphipathic Nature of Short and Thin Pristine Carbon Nanotubes—Fully Recyclable 1D Water‐in‐Oil Emulsion Stabilizers

Abstract Short and thin pristine carbon nanotubes (CNTs) emerge as 1D emulsion stabilizers capable of replacing aquatoxic low‐molecular surfactants. However, inconsistencies in understanding of water–solid interfaces for realistic CNTs hamper their individualization‐driven functionalities, processability in benign media, and compatibility with a broad‐scale of matrices. Pristine CNT processing based on water and inexpensive n‐alkanes within a low energy regime would constitute an important step toward greener technologies. Therefore, structural CNT components are quantitatively assessed, placing various CNTs on the scale from hydrophobicity to hydrophilicity. This structural interweave can lead to amphipathicity enabling the formation of water‐in‐oil emulsions. Combining experiments with theoretical studies, CNTs and CNT emulsions are comprehensively characterized establishing descriptors of the emulsifying behavior of pristine and purified CNTs. They emerge as having hydrophilic open‐ends, small number of oxygen–functionalized/vacancy surface areas, and hydrophobic sidewalls and full caps. The interplay of these regions allows short and thin CNTs to be utilized as fully recyclable 1D surfactants stabilizing water/oil emulsions which, as demonstrated, can be applied as paints for flexible conductive coatings. It is also shown how the amphipathic strength depends on CNT size, the pristine‐to‐oxidized/vacancy domains and the oil‐to‐water ratios