scholarly journals In-situ penetration of ionic liquids during surface densification of Scots pine

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Benedikt Neyses ◽  
Kelly Peeters ◽  
Dietrich Buck ◽  
Lauri Rautkari ◽  
Dick Sandberg

AbstractThe moisture-induced recovery of compressed wood is one of the major problems of wood densification technology. Achieving a cost-efficient surface densification process without the need for additional resins to eliminate the set-recovery may lead to an increase in value of low-density wood species. A previous study has shown that a pre-treatment with ionic liquids (ILs) can nearly eliminate the set-recovery. It was however observed that during the pre-treatment process the IL did not penetrate sufficiently deep into the wood to explain the achieved reduction in set-recovery. Based on these findings, the hypothesis was posed that further penetration of the IL into the wood occurs during the densification stage as a consequence of the applied heat and pressure. Thermo-gravimetric analysis (TGA) and gas-chromatography mass-selective-detection (GC-MSD) showed that the depth of penetration of the IL was greater after the densification process than before. Digital image correlation (DIC) showed that in regions with a high IL concentration, there was almost no set-recovery, and it gradually increased with a decrease in the IL concentration, as observed with TGA and GC-MSD analysis.

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2388 ◽  
Author(s):  
Faiz Ullah Shah ◽  
Inayat Ali Khan ◽  
Patrik Johansson

Here we focus on the thermal and variable temperature electrochemical stabilities of two ionic liquids (ILs) having a common tributyloctyl phosphonium cation [P4,4,4,8]+ and two different orthoborate anions: bis(mandelato)borate [BMB]− and bis(salicylato)borate [BScB]−. The thermo-gravimetric analysis data suggest that [P4,4,4,8][BScB] is thermally more stable than [P4,4,4,8][BMB] in both nitrogen atmosphere and air, while the impedance spectroscopy reveals that [P4,4,4,8][BScB] has higher ionic conductivity than [P4,4,4,8][BMB] over the whole studied temperature range. In contrast, the electrochemical studies confirm that [P4,4,4,8][BMB] is more stable and exhibits a wider electrochemical stability window (ESW) on a glassy carbon electrode surface as compared to [P4,4,4,8][BScB]. A continuous decrease in the ESWs of both ILs is observed as a function of operation temperature.


2015 ◽  
Vol 10 (4) ◽  
pp. 221-228 ◽  
Author(s):  
Syed Nasir Shah ◽  
Kallidanthiyil Chellappan Lethesh ◽  
M. I. Abdul Mutalib ◽  
Rashidah Binti Mohd Pilus

Abstract In this study, functionalized silica supported ionic liquids phases (SILPs) were synthesized and characterized using Fourier Transform infrared (FTIR) spectroscopy, CHNS elemental analysis, thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM). The adsorption of model naphthenic acid such as hexanoic acid, benzoic acid and commercial naphthenic acid from dodecane/kerosene was also investigated. The silica supported ionic liquids are good adsorbent for the removal of naphthenic acid from highly acidic model oil. The regeneration of supported ionic liquid phases as well as recovery of naphthenic acids from the supported ionic liquid phases (SILPs) was investigated.


2018 ◽  
Vol 90 (6) ◽  
pp. 1019-1034 ◽  
Author(s):  
Fatima Javed ◽  
Faheem Ullah ◽  
Hazizan Md. Akil

Abstract Green synthesis of room temperature ionic liquids (RTILs), are presented as friendly and challenging solvents for the effective dissolution of oil palm-lignocellulosic biomass. A series of Bronsted acidic-ionic liquids were prepared by the direct neutralization of diethyl dimethyl ammonium hydroxide with several (economical and environmental friendly) Bronsted acids as RTILs. The structural and physicochemical characterization was performed by applying various techniques as Fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), zeta-nanosizer and dynamic light scattering (DLS) respectively, to state the effect of anion on the extended cellulose dissolution capabilities of the synthesized RTILs under mild conditions. As a polysaccharide solvent, diethyl dimethyl ammonium phosphate (A1P) showed the extreme capability to extract 65 % of cellulose from biomass without any pretreatment for 30 min. The present study could be a significant step toward the synthesis of efficient RTILs and generating upgraded cellulose for Hi-tech engineered composites and energy concerns.


2012 ◽  
Vol 730-732 ◽  
pp. 745-750
Author(s):  
Rute I. Fontinha ◽  
Manuela M. Salta ◽  
Mikhail L. Zheludkevich ◽  
Mário G.S. Ferreira

The organic-inorganic hybrid sol-gel films have been reported as an effective anti-corrosion and environmentally friendly alternative to Cr(VI) pre-treatment for aluminium alloys. The sol-gel process used to obtain these coatings allows the variation of the different synthesis parameters to achieve coatings with optimized properties. In this work, hybrid films with different Zr/Si ratios were synthesized from glycidoxypropyltrimethoxysilane (GPTMS) and zirconium n-propoxide (TPOZ) precursors. Electrochemical Impedance Spectroscopy (EIS) was used to evaluate the corrosion behaviour of coated aluminium specimens in 0.5 M NaCl solution. The morphology and chemical structure of the hybrid coatings prepared were studied by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS), Fourier Transformed Infrared Spectroscopy (FTIR) and Thermo Gravimetric Analysis (TGA). It was found that increasing Zr/Si ratio leads to a more cross linked inorganic network, resulting in higher initial coatings resistance, but may turn coatings more hydrophilic, prone to rapid degradation in water, due to a less connected organic network. Consequently, the best anticorrosive performance derives from the balance between the two opposite trends and it was achieved with Zr/Si molar ratio of 0.25.


2003 ◽  
Vol 775 ◽  
Author(s):  
G.V.Rama Rao ◽  
Qiang Fu ◽  
Linnea K. Ista ◽  
Huifang Xu ◽  
S. Balamurugan ◽  
...  

AbstractThis study details development of hybrid mesoporous materials in which molecular transport through mesopores can be precisely controlled and reversibly modulated. Mesoporous silica materials formed by surfactant templating were modified by surface initiated atom transfer radical polymerization of poly(N-isopropyl acrylamide) (PNIPAAm) a stimuli responsive polymer (SRP) within the porous network. Thermo gravimetric analysis and FTIR spectroscopy were used to confirm the presence of PNIPAAm on the silica surface. Nitrogen porosimetry, transmission electron microscopy and X-ray diffraction analyses confirmed that polymerization occurred uniformly within the porous network. Uptake and release of fluorescent dyes from the particles was monitored by spectrofluorimetry and scanning laser confocal microscopy. Results suggest that the presence of PNIPAAm, a SRP, in the porous network can be used to modulate the transport of aqueous solutes. At low temperature, (e.g., room temperature) the PNIPAAm is hydrated and extended and inhibits transport of analytes; at higher temperatures (e.g., 50°C) it is hydrophobic and is collapsed within the pore network, thus allowing solute diffusion into or out of the mesoporous silica. The transition form hydrophilic to hydrophobic state on polymer grafted mesoporous membranes was determined by contact angle measurements. This work has implications for the development of materials for the selective control of transport of molecular solutes in a variety of applications.


2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Madalina Angelusiu ◽  
Maria Negoiu ◽  
Stefania-Felicia Barbuceanu ◽  
Tudor Rosu

The paper presents the synthesis and characterization of Cu(II), Co(II), Ni(II), Cd(II), Zn(II) and Hg(II) complexes with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)-thiosemicarbazide. The new compounds were characterized by IR, EPR, electronic spectroscopy, magnetic moments, thermo-gravimetric analysis and elemental analysis.


2020 ◽  
Vol 13 ◽  
Author(s):  
Inbasekaran S. ◽  
G. Thiyagarajan ◽  
Ramesh C. Panda ◽  
S. Sankar

Background:: Chrome shavings, a bioactive material, are generated from tannery as waste material. These chrome shaving can be used for the preparation of many value-added products. Objective:: One such attempt is made to use these chrome shaving wastes as a composite bio-battery to produce DC voltage, an alternate green energy source and cleaner technology. Methods:: Chrome shavings are hydrolyzed to make collagen paste and mixed with the ferrous nanoparticles of Moringa oleifera leaves and Carbon nanoparticles of Onion peels to form electrolyte paste as base. Then, the electrolyte base was added to the aluminum paste and conducting gel, and mixed well to form composite material for bio-battery. Results:: The composite material of bio-battery has been characterized using Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analysis (TGA). Series and parallel circuit testing were done using Copper and Zinc electrodes or Carbon and Zinc electrodes as the battery terminals in the electrolyte paste. The surface area of these electrodes needs standardization from bench to pilot scale. The power generated, for an AA battery size, using a single bio-battery cell has produced a DC voltage of 1.5 V; current of 900 mA. Circuit testing on 1 ml of 80 well-cells connected in series has produced DC output of 18 V and 1100 mA whereas 48 V and 1500 mA were obtained from a series-parallel connection. Conclusion:: The glass transition temperature (Tg) of electrolyte of the bio-battery at 53°C indicates that, at this temperature, all the substances present in the bio-battery are well spread and contributing consistently to the electrolyte activity where Fe-C-Nano-Particles were able to form strong chemical bonds on the flanking hydroxyl group sites of the Collagen leading to reduced mobility of polymers and increase Tg. The results instigate promising trends for commercial exploitation of this composite for bio-battery production.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Luqman Ali Shah ◽  
Rida Javed ◽  
Mohammad Siddiq ◽  
Iram BiBi ◽  
Ishrat Jamil ◽  
...  

AbstractThe in-situ stabilization of Ag nanoparticles is carried out by the use of reducing agent and synthesized three different types of hydrogen (anionic, cationic, and neutral) template. The morphology, constitution and thermal stability of the synthesized pure and Ag-entrapped hybrid hydrogels were efficiently confirmed using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermo gravimetric analysis (TGA). The prepared hybrid hydrogels were used in the decolorization of methylene blue (MB) and azo dyes congo red (CR), methyl Orange (MO), and reduction of 4-nitrophenol (4-NP) and nitrobenzene (NB) by an electron donor NaBH4. The kinetics of the reduction reaction was also assessed to determine the activation parameters. The hybrid hydrogen catalysts were recovered by filtration and used continuously up to six times with 98% conversion of pollutants without substantial loss in catalytic activity. It was observed that these types of hydrogel systems can be used for the conversion of pollutants from waste water into useful products.


BMC Chemistry ◽  
2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Arefeh Dehghani Tafti ◽  
Bi Bi Fatemeh Mirjalili ◽  
Abdolhamid Bamoniri ◽  
Naeimeh Salehi

AbstractNano-eggshell/Ti(IV) as a novel naturally based catalyst was prepared, characterized and applied for the synthesis of dihydropyrano[2,3-c]pyrazole derivatives. The characterization of nano-eggshell/Ti(IV) was performed using Fourier Transform Infrared spectroscopy, X-ray Diffraction, Field Emission Scanning Electron Microscopy, Energy-Dispersive X-ray Spectroscopy, and Thermo Gravimetric Analysis. Dihydropyrano[2,3-c]pyrazoles were synthesized in the presence of nano-eggshell/Ti(IV) via a four component reaction of aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate at room temperature under solvent free conditions. The principal affairs of this procedure are mild condition, short reaction times, easy work-up, high yields, reusability of the catalyst and the absence of toxic organic solvents.


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