Integration of wood-based components - Cellulose nanofibrils and tannic acid - into a poly(vinyl alcohol) matrix to improve functional properties.

Poly(vinyl alcohol) (PVA) biocomposite films reinforced with cellulose nanofibrils (CNF) and biologically active tannic acid (TA) were prepared. The influence of different concentrations of CNF and TA in the PVA polymer matrix was investigated in terms of mechanical properties, thermal properties and hydrophobicity improvement of the prepared films. The results showed that in all cases the addition of CNF and TA improved the values of tensile strength and elastic modulus.

Pyrithione metal (Cu, Ni, Ru) complexes as photo-catalysts for styrene oxide production.

Selective photochemical oxidation of styrene was performed in an active acetonitrile medium, using HO with or without ultraviolet (UV) light radiation. Pyrithione metal complexes (M-Pth: M = Cu(II), Ni(II), Ru(II); Pth = 2-mercaptopyridine-N-oxide) were used as catalysts. Catalytic testing measurements were done by varying the time, chemical reaction temperature and HO concentration with or without UV energy.

Highly active and efficient Cu-based hydrotalcite-like structured materials as reusable heterogeneous catalysts used for transcarbonation reaction.

A series of robust and efficient Cu-Al hydrotalcite-like compounds (HTLc) as catalysts were prepared by the simple precipitation method with different Cu/Al molar ratios and investigated for the transcarbonation of glycerol with dimethyl carbonate (DMC) for glycerol carbonate (GC) synthesis in a batch reactor. The structural and textural properties of the Cu-Al (HTLc) catalysts were analyzed by several methods like N-sorption, SEM-EDX/TEM, XRD, FTIR, CO-TPD, TGA/DTA and ICP-OES. It was found that the transcarbonation of glycerol is directly dependent on the strong basic sites of the catalysts.

Acrylate-Based Hybrid Sol-Gel Coating for Corrosion Protection of AA7075-T6 in Aircraft Applications: The Effect of Copolymerization Time.

Pre-hydrolysed/condensed tetraethyl orthosilicate (TEOS) was added to a solution of methyl methacrylate (MMA) and 3-methacryloxypropyltrimethoxysilane (MAPTMS), and then copolymerised for various times to study the influence of the latter on the structure of hybrid sol-gel coatings as corrosion protection of aluminium alloy 7075-T6. The reactions taking place during preparation were characterised using real-time Fourier transform infrared spectroscopy, dynamic light scattering and gel permeation chromatography. The solution characteristics were evaluated, using viscosimetry, followed by measurements of thermal stability determined by thermogravimetric analysis.

Molecular dynamics of 1-ethyl-3-methylimidazolium triflate ionic liquid studied by H and F nuclear magnetic resonances.

The molecular dynamics of an ionic liquid (IL) composed of a 1-ethyl-3-methylimidazolium cation and a triflate (trifluoromethanesulfonate) anion, abbreviated as [Emim][TfO], were studied by NMR spectroscopy. By measuring the temperature-dependent high-field 1H and F spin-lattice relaxation (SLR) rates, the frequency-dependent H and F SLR dispersion curves using fast-field-cycling relaxometry, and the temperature-dependent 1H and F diffusion constants, and by utilizing the fact that the primary NMR-active nucleus on the Emim cation is H, whereas on the TfO anion it is F, the cationic and anionic dynamics were studied separately. A single theoretical relaxation model successfully reproduced all the experimental data of both types of resonant nuclei by fitting all the data simultaneously with the same set of fit parameters.

Crystal structures and emission properties of the BF₂ complex 1-phenyl-3-(3,5-dimethoxyphenyl)-propane-1,3-dione: multiple chromisms, aggregation- or crystallization-induced emission, and the self-assembly effect.

It is known that electron donating groups have quite a different effect on the π-delocalization of a conjugate system when bonded at ortho and para as compared to meta positions in the phenyl ring. In the present work, the BF2 complex of 1-phenyl-3-(3,5-dimethoxyphenyl)-propane-1,3-dione (1), a molecule with two methoxy groups in one of the phenyl rings at meta positions, was prepared. Compound 1 exists as two polymorphs having different mutual orientations of the two methoxy groups: in polymorph A away from each other (termed anti), while in polymorph B one methoxy group is oriented toward the other (syn-anti).

Hydroxyl radical scavenging-based method for evaluation of TiO₂ photocatalytic activity.

A novel hydroxyl radical scavenging method was developed to establish the photocatalytic activity of TiO₂ thin films. Transparent TiO₂ thin films were prepared on soda-lime glass substrates using the sol-gel method and characterized using X-ray diffraction. During photoirradiation in aqueous buffered solutions, activity of the films was followed using the substituted nitrobenzene N,N'-(5-nitro-1,3-phenylene)bisglutaramide as a hydroxyl radical scavenger and its hydroxylated products were quantified using HPLC.

The influence of the reaction temperature on the morphology of sodium titanate 1D nanostructures and their thermal stability.

We have synthesized large quantities of sodium-titanate-based nanotubes and nanoribbons with high yields under hydrothermal conditions from anatase powder in an aqueous NaOH solution. The reaction temperatures were from 95 to 195 degrees C, in steps of 20 degrees C. We observed that the morphology of the nanomaterials, which is reflected in their specific surface areas, depends strongly on the reaction temperature.