Promotive Selectivity to C2-C3 Polyols From Alkaline Cellulose Hydrogenated by Ionic Liquid-stablized Ru Nanoparticles

Alkaline cellulose hydrogenolysis on metal catalyst was an effective way to get C2~C3 polyols. The alkaline cellulose was obtained by treating cellulose with 4 wt% NaOH solution. Ionic liquid-stablized Ru nanoparticles were prepared by reducing metal salt in ionic liquid. The SEM results indicate that the amorphous part of alkaline cellulose is helpful for getting the catalyst into the cavities to have a further hydrogenation reaction. When hydrogenolysis of alkaline cellulose over Ru/[Bmim]BF4 nanoparticles was conducted at 433 K, 63.78% of the substrate was converted with glycerol, 1,2-propanediol and ethylene glycol as main products of which selectivity was up to 58.91 %, whereas the conversion rate over Ru/C catalyst of alkaline cellulose was 59.23 % and only 26.11 % C2~C3 polyols were detected. Moreover, if the ionic liquid-stablized Ru nanoparticles were doped with 53.7 % Ni, the selectivity of C2~C3 polyols was promoted to 65.07 %. These results suggested the advantages of the ionic liquid-stablized Ru nanoparticles, especially doping with Ni, have potentials for promotive selectivity to C2~C3 alcohols. Put forward the plausible mechanism finally.

Effect of Phosphorus on Crystallization of Alkaline Molybdenum-Containing Borosilicate Glasses

The effect of additives of P2O5 on the solubility of molybdenum in the amorphous part of glass and on the phase composition of the crystallized part of the highly alkaline glasses of the Li2O–(Na2O–K2O)–B2O3-SiO2 system was studied. The comparison of the phase composition of samples with or without phosphorus prior and after annealing allowed to determine the change of solubility of molybdenum in the amorphous part of the samples and to evaluate the thermal stability of the synthesized glass-ceramic materials. It was found, that for the compositions without phosphorus and the samples without lithium, when molybdenum is added at the synthesis stage, almost all of the molybdenum is included only in the crystalline molybdates. The study has shown an increase in the solubility of molybdenum only in the structure of lithium-containing glasses with phosphorus.

Research activation energy in thermal modification of wood

The analysis of the process of thermal modification of wood, which was modified by a controlled process of pyrolysis of wood heating (> 180 ° C) in the absence of oxygen, which causes some chemical changes in the chemical structures of cell wall components (lignin, cellulose and hemicellulose), durability. It is proved that in the process of thermal modification the decomposition of hemicelluloses and the amorphous part of cellulose occurs, and therefore the amount of substances that are the environment for the development of fungi in wood significantly decreases. In addition, lignin and the formed pseudolignin undergo a process of polymerization and redistribution of cell volume and give cell walls greater density, hardness, increase hydrophobicity (water repellency), thereby reducing their ability to absorb moisture and edema. Polymerized lignin fills the inner cavity of the cell, forming a closed porous structure with a low ability to bind water. It was found that the most effective parameter for reducing such substances is the temperature and exposure time. The results of thermogravimetric researches are given, the dependence of weight loss on temperature of researches on the basis of which activation energy is calculated is defined. The results of determining the activation energy show that for hardwood species this value exceeds more than 1.5 times compared to softwood.

Effect of gamma radiation on the structural, thermal and optical properties of PMMA/Sn0.75Fe0.25S2 nanocomposite

Nanocomposite films of polymethylmethacrylate PMMA with Sn0.75Fe0.25S2 nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Changes in PMMA/Sn0.75Fe0.25S2 nanocomposite (NCP) due to gamma irradiation have been measured. XRD results indicate that the gamma doses of 10–80 kGy cause intermolecular crosslinking that reduces the ordered portion in the NPs. Bonding between the NPs and the host PMMA was confirmed by FTIR. TGA results indicate an enhancement in thermal stability in the NCP films irradiated with doses 20–80 kGy. The optical band gap was reduced from 3.23 to 2.47 eV upon gamma irradiation up to 80 kGy due bonding between the NPs and PMMA which enhanced the amorphous part of the NPs. Finally, the color variation between the blank and irradiated films (ΔE) was determined. Color changes immensely when the PMMA/Sn0.75Fe0.25S2 NCP films are gamma irradiated. Values of ΔE were as much as 31.6 which is an acceptable match in commercial reproduction on printing presses.

Phase Transformations in Fly Ash-Based Solids

The presented article describes the phase transformations in solid bodies based on fluid fly ash (FFA) over eight years from the initial to the final phases. FFA has been selected as a type of industrial waste whose amount has been growing in recent years. This type of ash has self-hardening properties when watered because of the conditions of its origin. The specific temperature of fluid burning and the addition of calcium carbonate into the burning zone create a mixture of phases which are, even when solidified, ready to form new crystal phases, especially alumina-silicates, relicts of coal clay minerals. For experiments, bricks from the mixture of FFA and quartz sand were industrially produced and left outside. Subsequent mineralogical analyses of samples of various ages confirmed differences in phase compositions. It is supposed that the main role in the presented changes is played by the content of the roentgen-amorphous part of alumina-silicates because they are likely to be transformed into a stable form of feldspar. In addition to that, this article presents the hypothesis of a moving agent, which could explain the transformations in the final bodies.

Synthesis of Hierarchical Zeolites with Morphology Control: Plain and Hollow Spherical Beads of Silicalite-1 Nanosheets

Binderless pure silica zeolites (zeosils) spheres and hollow spheres with a diameter of 20 µm composed of silicalite-1 nanosheets particles were prepared by pseudomorphic transformation of spherical silica beads using different temperatures (110, 130, and 150 °C) and treatment times (1–5 days) in order to adapt the local dissolution rate of silica to the crystallization rate of silicalite-1 nanosheets allowing to preserve the initial morphology of the silica beads. Fully crystalline beads of 20 µm were obtained at 110 °C for 5 days, whereas hollow spheres similar in size were synthesized at higher temperatures. The crystallization process seems to begin at the outer surface of the amorphous silica beads and spreads with the time in the interior of the beads leading to a dissolution of the inner amorphous part of the beads to create zeosil hollow spheres for the highest treatment temperatures (130 and 150 °C). The dissolution rate of the inner amorphous part of the beads increases by increasing the hydrothermal treatment temperature from 130 to 150 °C. The silicalite-1 beads synthesized at 110 °C for 5 days showed to be promising for rapid molecular decontamination by adsorbing n-hexane in larger amount than the silicalite-1 conventional big crystals in powder forms.

Crystallization Pathway for Crystallization of FeB Nanoparticles

The FeB nanoparticle consisting of 5000 particles (4500 Fe atoms and 500 B atoms) have been investigated by means of molecular dynamics (MD) simulation. When the amorphous FeB nanoparticle is annealed at temperature of 900 K for a long time, it is crystallized into bcc crystalline structure. The simulation shows that the sample undergoes crystallization via the nucleation mechanism. During the crystallization, B atoms diffuse to the boundary region of Fe crystal. The crystal growth proceeds when this boundary region attains specific properties which are defined by the fraction of B atoms and the energies of AB-atoms and CB-atoms. Further our study indicates that the crystalline and mixed FeB nanoparticles consists of three distinct parts including Fe crystalline and two FeB amorphous parts (B-poor and B-rich amorphous part). The different polymorphs of FeB nanoparticle differs in the local structure, size of Fe crystal and energies of different type atoms.

The New Generation from Biomembrane with Green Technologies for Wastewater Treatment

A biopolymer of polylactic acid (PLLA)/polypropylene carbonate (PPC)/poly (3-hydroxybutrate) (PHB)/triethyl citrate (TEC) blends was prepared by the solution-casting method at different proportions. The thermal characteristics were studied by differential scanning calorimetry (DSC) and thermogravimetry (TG). PHB and TEC were added to improve the interfacial adhesion, crystallization behavior, and mechanical properties of the immiscible blend from PLLA and PPC (20%). The addition of more than 20% of PPC as an amorphous part hindered the crystallization of PLLA. PPC, PHB, and TEC also interacted with the PLLA matrix, which reduced the glass transition temperature (Tg), the cold crystallization temperature (Tcc), and the melting point (Tm) to about 53, 57 and 15 °C, respectively. The Tg shifted from 60 to 7 °C; therefore, the elongation at break improved from 6% (pure PLLA) to 285% (PLLA blends). In this article, biomembranes of PLLA with additives were developed and made by an electrospinning process. The new generation from biopolymer membranes can be used to absorb suspended pollutants in the water, which helps in the purification of drinking water in the household.

Composition and

Principles of three component Iron-Cobalt-Tungsten alloys electrodeposition from complex Fe (III) based citrate electrolytes are discussed. It is shown, that deposition of ternary alloys proceeds through competitive reduction of cobalt and tungsten with iron. With increasing ligand concentration coatings are enriched with a refractory component; however, increasing current density favors a reverse trend. The effect of both current density and pulse on/off time on the quality, content of alloying metals and surface topography of electrolytic coatings were determined. The application of pulsed electrolysis provides increasing tungsten content up to 13 at.%, at current efficiency of 70–75%. Globular relief of Fe-Co-W coatings is caused by refractory metals incorporation, and crystalline and amorphous parts of structure are visualized by X-ray spectroscopy, including inter-metallic phases Co7W6, Fe7W6 along with α-Fe and Fe3C. The crystallite size of the amorphous part is near 7–8 nm. Corrosion resistance of the coatings is 1.3–2.0 orders of magnitude higher than the substrate parameters as follows from data of polarization resistance method and electrode impedance spectroscopy.

Influence of Chemical Treatments Sequence on Morphology and Crystallinity of Sorghum Fibers

Micro-fibrillated cellulose (MFC) derived from natural fibre is continuously gaining interest to produce an environmentally-friendly material, due to economic and ecological reasons. In consequence, sorghum is one of the most-cultivated crops that usually remain the waste as by product of bioethanol production. Indeed, it will be a promising area to utilize sorghum waste to produce MFC for enhancing polymer performance, especially in terms of crystallinity. The objective of this study is to investigate the effect of a sequence of chemical modification was applied to sorghum fibres, i.e. alkalization using 4% sodium hydroxide followed by bleaching using 1.7% sodium chlorite plus acetic acid as a buffer. The treatment was purposed to unbundle the lignocellulose networks into microfibrils cellulose with less amorphous part and lower hydrophilic properties. Evaluation of the chemical treatments effect on internal microstructure, crystallinity index and chemical composition of sorghum fibre was measured via Field-Emission Scanning Electron microscope (FE-SEM), X-ray Diffraction (XRD) and Fourier Transformation Infra-Red (FTIR) Spectroscopy. The experiments show that treatments led to a removal of binding materials, such as amorphous parts hemicellulose and lignin, from the sorghum fibres, resulting MFC of sorghum fibres and enhanced crystallinity index from 41.12 % to 75.73%.