scholarly journals In Situ Wood Fiber Dyeing Through Laccase Catalysis for Fiberboard Production

2021 ◽  
Vol 9 ◽  
Author(s):  
Alberto Colella ◽  
Addolorata De Chiaro ◽  
Vincenzo Lettera
Keyword(s):  
Aromatic Compounds ◽  
Medium Density Fiberboard ◽  
Wood Fiber ◽  
Alkaline Conditions ◽  
One Step ◽  
Reduce Energy Consumption ◽  
Environmentally Friendly Process ◽  
Coloring Agents ◽  
First Time

The aim of the present work was to develop an innovative and environmentally friendly process for wood fiber dyeing and to produce 3-dimensionally fully colored medium-density fiberboard (MDF). The potential of laccase-catalyzed polymerization of selected precursors to form dyes useful in fiberboard manufacturing, a technique used for the first time in this field, was demonstrated. Some of the 7 aromatic compounds tested yielded colored products after laccase treatment under both acid and alkaline conditions, and a good variety of colors was attained by using mixtures of two different monomers. To demonstrate the coloration and design potential of laccase conversion of aromatic compounds, MDFs were enzymatically dyed using an in situ one-step laccase-catalyzed coloration process, and the results were compared against commercial MDFs obtained by using organic coloring agents. Important advantages over conventional processing methods include good color fastness and, in some cases, new hydrophobic properties, allowing designers and woodworkers to explore the beauty of textures and the use of simpler and milder processing conditions that eliminate harsh chemical use and reduce energy consumption.

scholarly journals One-step ultra-rapid fabrication and thermoelectric properties of Cu2Se bulk thermoelectric material

RSC Advances ◽  
2019 ◽  
Vol 9 (19) ◽  
pp. 10508-10519 ◽  
Author(s):  
Tiezheng Hu ◽  
Yonggao Yan ◽  
Si Wang ◽  
Xianli Su ◽  
Wei Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermoelectric Properties ◽  
Single Phase ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Thermoelectric Energy ◽  
Rapid Fabrication ◽  
One Step ◽  
First Time

Cu2Se is a promising material for thermoelectric energy conversion. Fully dense single-phase bulk Cu2Se was prepared by the combination of self-propagating high-temperature synthesis with in situ quick pressing for the first time.

scholarly journals Hybrid Geopolymeric Foams for the Removal of Metallic Ions from Aqueous Waste Solutions

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4091 ◽  
Author(s):  
Giuseppina Roviello ◽  
Elena Chianese ◽  
Claudio Ferone ◽  
Laura Ricciotti ◽  
Valentina Roviello ◽  
...  
Keyword(s):  
Metal Ions ◽  
Metallic Ions ◽  
Ultrapure Water ◽  
Experimental Procedure ◽  
Strength Tests ◽  
Before And After ◽  
Long Time ◽  
Alkaline Conditions ◽  
First Time

For the first time, hybrid organic–inorganic geopolymeric foams were successfully used as monolithic adsorbents for the removal of metallic ions pollutants from wastewaters. The foams were realized by the in situ foaming of a hybrid geopolymer obtained by a reaction of metakaolin and polysiloxane oligomers under strong alkaline conditions and then cured at room temperature. In this way, porous materials with densities ranging from 0.4 to 0.7 g/cm3 and showing good mechanical properties were produced. With the aim of producing self-standing monolithic adsorbents for the removal of metallic ions pollutants from wastewaters, these porous hybrid geopolymers were subjected to a washing pretreatment with ultrapure water, dried, and then used for absorption tests by dipping them into an aqueous solution with an initial concentration of 20 ppm of Pb2+, Cd2+, Cu2+, and Zn2+ ions. Preliminary results indicated that all the tested materials are effective in the adsorption of the tested metal ions and do not release the removed metal ions upon sinking in ultrapure water, even for a very long time. Interestingly, compressive strength tests performed before and after the washing treatments show that the foamed samples remain intact and maintain their physical–mechanical characteristics, suggesting that these kinds of materials are promising candidates for the production of self-standing, monolithic adsorbent substrates that can be easily collected when exhausted, which is a major advantage in comparison with the use of powdered adsorbents. Moreover, since these materials can be obtained by a simple and versatile experimental procedure, they could be easily shaped or directly foamed into precast molds to be used in packed beds as membranes.

Superhydrophobic nickel/carbon core–shell nanocomposites for the hydrogen transfer reactions of nitrobenzene and N-heterocycles

2020 ◽  
Vol 22 (6) ◽  
pp. 1996-2010 ◽  
Author(s):  
Shaofeng Pang ◽  
Yujing Zhang ◽  
Qiong Su ◽  
Fangfang Liu ◽  
Xin Xie ◽  
...  
Keyword(s):  
Aromatic Compounds ◽  
Hydrogen Transfer ◽  
Transfer Reactions ◽  
Core Shell ◽  
Catalytic Hydrogen ◽  
One Step ◽  
Carbon Core ◽  
Catalytic Hydrogen Transfer ◽  
First Time ◽  
Hydrogen Transfer Reactions

In this work, catalytic hydrogen transfer as an effective, green, convenient and economical strategy is for the first time used to synthesize anilines and N-heterocyclic aromatic compounds from nitrobenzene and N-heterocycles in one step.

scholarly journals Новый тип углеродной наноструктуры на вицинальной поверхности SiС(111)-8-=SUP=-o-=/SUP=-

2019 ◽  
Vol 45 (5) ◽  
pp. 17
Author(s):  
Г.В. Бенеманская ◽  
П.А. Дементьев ◽  
С.А. Кукушкин ◽  
А.В. Осипов ◽  
С.Н. Тимошнев
Keyword(s):  
Synchrotron Radiation ◽  
Electronic Properties ◽  
Photoelectron Spectroscopy ◽  
Aromatic Compounds ◽  
Chemical Bonds ◽  
Carbon Nanostructure ◽  
Vicinal Surfaces ◽  
Metal Atoms ◽  
First Time

AbstractThe electronic properties of the Ba/SiC/Si(111)-8° nanointerface have been studied for the first time by photoelectron spectroscopy using synchrotron radiation. The experiments are conducted in situ in superhigh vacuum on submonolayer Ba coatings of SiC/Si(111)-8° samples grown by the method of substitution of atoms. It is found that the adsorption of Ba causes strong changes in the spectrum of the C 1 s core level. It is shown that the effect is due to the formation of a new, previously unknown carbon nanostructure. It is found that the nanostructure is formed exclusively on the SiC vicinal surfaces in the presence of stabilizing adsorbed Ba metal atoms and consists of carbon rings, in which the chemical bonds are close in nature to the bonds characteristic of aromatic compounds.

Mild and Regioselective Oxidative Bromination of Aromatic Compounds Using Ammonium Bromide and Oxone®

2003 ◽  
Vol 2003 (9) ◽  
pp. 597-598 ◽  
Author(s):  
N. Narender ◽  
K.V.V. Krishna Mohan ◽  
S.J. Kulkarni ◽  
K.V. Raghavan
Keyword(s):  
Aromatic Compounds ◽  
Ammonium Bromide ◽  
Oxidative Bromination ◽  
First Time

The selective mono-bromination of various activated aromatic compounds is reported using in situ generated bromine from NH4Br as a bromine source and oxone® as an oxidant for the first time.

scholarly journals Stretchable Supercapacitor at -30 oC

2020 ◽  
Author(s):  
Xuting Jin ◽  
Li Song ◽  
Hongsheng Yang ◽  
Chunlong Dai ◽  
Yukun xiao ◽  
...  
Keyword(s):  
Room Temperature ◽  
Elastic Fiber ◽  
Real Life ◽  
Cold Intolerance ◽  
Strong Adhesion ◽  
Highly Stretchable ◽  
One Step ◽  
First Time ◽  
Current Device

Abstract At relatively low temperature (e.g, -30 oC), most flexible supercapacitors that work well at room temperature will lose their stretchability due to the poor cold intolerance of conventional electrolytes and the absence of intrinsically stretchable electrodes. Herein, an anti-freezing and highly stretchable supercapacitor (AF-SSC) was fabricated for the first time by one-step in-situ growth of polyaniline onto an organohydrogel polyelectrolyte from cross-linked polyacrylamide networks soaked by ethylene glycol/water/H2SO4. As no extra stretchable substrates (e.g. elastic fiber, polydimethylsiloxane, rubber, etc.) or predefining stretchable structures (e.g. helical, spring, wrinkle, honeycombed structures etc.) are needed in such a design, the prepared AF-SSC shows a high mechanical stretchability of 200% under -30 oC and can be repeatedly stretched for 100 cycles without significant capacitance loss. Besides, an impressive capacitance retention of 73.1% at -30 oC is achieved when the current density increases by 20 times, which is much higher than those of stretchable supercapacitors based on pseudocapacitive materials that operated at room temperature. Furthermore, the device shows an ultralong lifespan with 91.7% capacitance retention after 100000 cycles at -30 oC, outperforming all stretchable supercapacitors reported previously. With other merits of high compressibility, strong adhesion, good processability and excellent anti-drying ability, the current device is an ideal power source to drive multi-functional electronic components in real-life scenarios.

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

The Total Synthesis of Rhabdastrellic Acid A

2018 ◽  
Author(s):  
Yaroslav Boyko ◽  
Christopher Huck ◽  
David Sarlah
Keyword(s):  
Total Synthesis ◽  
Late Stage ◽  
Cross Coupling ◽  
Side Chains ◽  
General Strategy ◽  
Modular Approach ◽  
Linear Sequence ◽  
Generating Sequence ◽  
First Time

<div>The first total synthesis of rhabdastrellic acid A, a highly cytotoxic isomalabaricane triterpenoid, has been accomplished in a linear sequence of 14 steps from commercial geranylacetone. The prominently strained <i>trans-syn-trans</i>-perhydrobenz[<i>e</i>]indene core characteristic of the isomalabaricanes is efficiently accessed in a selective manner for the first time through a rapid, complexity-generating sequence incorporating a reductive radical polyene cyclization, an unprecedented oxidative Rautenstrauch cycloisomerization, and umpolung 𝛼-substitution of a <i>p</i>-toluenesulfonylhydrazone with in situ reductive transposition. A late-stage cross-coupling in concert with a modular approach to polyunsaturated side chains renders this a general strategy for the synthesis of numerous family members of these synthetically challenging and hitherto inaccessible marine triterpenoids.</div>

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