scholarly journals Conversion of rice husk biomass into reducing sugars: influence of pretreatment with water and [C16MIM][Br-] ionic liquid

2021 ◽  
Author(s):  
Patrícia D. Bohn ◽  
Chayene G. Anchieta ◽  
Kátia R. Kuhn ◽  
Edson I. Muller ◽  
Flávio Mayer ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Rice Husk ◽  
Reducing Sugars ◽  
Biomass Pretreatment ◽  
X Ray Diffraction ◽  
Imidazolium Ionic Liquid ◽  
Higher Temperature ◽  
First Time ◽  
Lower Water Content ◽  
Second Generation Ethanol

Abstract Rice husk is an agricultural lignocellulosic-rich waste which can be used in the production of second-generation ethanol. A biomass pretreatment is necessary to release structural sugars because of the recalcitrance-related properties of lignin and silicon. The use of a long chain imidazolium ionic liquid (IL), 1-hexadecyl-3-methylimidazolium bromide ([C16MIM][Br−]), for rice husk pretreatment is reported for the first time. The influence of the [C16MIM][Br−]:water ratio and temperature on reducing sugars yield was investigated using an experimental design. Structural, chemical, and morphological modifications were observed by Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). Higher temperature (160°C) and lower water content (1:5, IL:water) improved sugar yield. The validation assay (180°C, 1:20 IL:water ratio, 10% (w/v) of biomass, 12 h) resulted in 38% yield of reducing sugars and 60% dissolution of biomass, whereas untreated biomass showed only 0.18% yield of reducing sugars. The characterization analysis confirmed the changes in rice husk structure and morphology after pretreatment with IL. Rice husk pretreatment with [C16MIM][Br−] resulted in a higher concentration of reducing sugars compared to untreated biomass. Therefore, solid ionic liquids combined with water could be used as an alternative solvent for lignocellulosic biomass pretreatment.

scholarly journals One-pot synthesis of polyaniline/Fe3O4 nanocomposite in ionicliquid: electrical conductivity and magnetic studies

2019 ◽  
Vol 118 ◽  
pp. 01059
Author(s):  
Xiaoyang Li ◽  
Genwang Zhang ◽  
Binwei Wang ◽  
Tan Lin ◽  
Guo Wang ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Oxidative Polymerization ◽  
X Ray Diffraction ◽  
Magnetic Studies ◽  
Imidazolium Chloride ◽  
One Pot ◽  
One Pot Synthesis ◽  
Transmission Electron ◽  
First Time

One-pot synthesis of polyaniline/Fe3O4 nanocomposite in 1-methyl-3-alkylcarboxylic acid imidazolium chloride ([CMMIm]Cl) ionic liquid (IL) was introduced for the first time in this work. Transmission electron microscopy (TEM), X-ray diffraction (XRD), four probes method and vibrating sample magnetometer (VSM) were used to explore the influence of IL on the structure, conductivity and magnetic properties of polyaniline/Fe3O4 composite. Compared with Fe3O4 particles prepared in water, the results show that Fe3O4 particles prepare in imidazolium-based ionic liquid were more regular in shape and dispersed uniformly. So the Fe3O4 nanoparticles prepared in IL can easier serve as cores to form the polyaniline/Fe3O4 nanocomposite via in situ chemical oxidative polymerization of aniline molecule. The saturation magnetization of polyaniline/Fe3O4 nanocomposite prepared in ionic liquid shows about 2 times higher than polyaniline/Fe3O4 composite prepared in water. And the conductivities of PANI/Fe3O4 composite prepared in IL decreased and the saturated magnetization increased with the increasing amount of Fe3O4.

scholarly journals Effect of various pretreatment methods on sugar and ethanol production from cellulosic water hyacinth

BioResources ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. 592-606
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ionic Liquid ◽  
Ethanol Production ◽  
Water Hyacinth ◽  
Reducing Sugars ◽  
Ethanol Yield ◽  
Sugar Content ◽  
The Other ◽  
Total Reducing Sugars ◽  
First Time

Effects of acid, alkali, ionic liquid (IL), and microwave-alkali pretreatments on cellulosic water hyacinth (WH) were investigated based on the total reducing sugars (TRS) and ethanol production. For the first time, IL pretreatment with (1-Ethyl-3-methylimidazolium acetate ([EMIM][Ac]) was used for WH, and the efficiency was compared with the other methods. Cellulase and Saccharomyces cerevisiae were fermented together for 72 h. Based on the results, all pretreatment methods effectively increased the sugar content as well as the ethanol yield. Untreated WH had 25 ± 1.5 mg/g of TRS, which was increased to 157 ± 8.2 mg/g, 95 ± 3.1 mg/g, 51 ± 4.2 mg/g, and 45 ± 2.6 mg/g via alkali, microwave-alkali, acid, and IL pretreatments, respectively. The highest TRS level of 402 mg/g was obtained in 24 h and 6.2 ± 0.4 g/L of ethanol in 48 h of fermentation with the alkali-treated WH. The ethanol production was followed by other treatment methods of WH in the order of microwave-alkali, acid, and IL. The results indicated that the ethanol production from WH was related to the type of pretreatment as well as the TRS production.

Mapping the “Extra Solvent Power, ESP” of Ionic Liquids for Monomers, Polymers and Globular Nanoparticles

2017 ◽  
Author(s):  
Jose A. Pomposo
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Linear Polymers ◽  
Green Solvents ◽  
Ionic Polymers ◽  
First Time ◽  
Solvent Power

Understanding the miscibility behavior of ionic liquid (IL) / monomer, IL / polymer and IL / nanoparticle mixtures is critical for the use of ILs as green solvents in polymerization processes, and to rationalize recent observations concerning the superior solubility of some proteins in ILs when compared to standard solvents. In this work, the most relevant results obtained in terms of a three-component Flory-Huggins theory concerning the “Extra Solvent Power, ESP” of ILs when compared to traditional non-ionic solvents for monomeric solutes (case I), linear polymers (case II) and globular nanoparticles (case III) are presented. Moreover, useful ESP maps are drawn for the first time for IL mixtures corresponding to case I, II and III. Finally, a potential pathway to improve the miscibility of non-ionic polymers in ILs is also proposed.

scholarly journals Quartz Crystallite Size and Moganite Content as Indicators of the Mineralogical Maturity of the Carboniferous Chert: The Case of Cherts from Eastern Asturias (Spain)

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Celia Marcos ◽  
María de Uribe-Zorita ◽  
Pedro Álvarez-Lloret ◽  
Alaa Adawy ◽  
Patricia Fernández ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Crystallite Size ◽  
Archaeological Sites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Infrared And Raman Spectroscopy ◽  
First Time ◽  
Geological Formations

Chert samples from different coastal and inland outcrops in the Eastern Asturias (Spain) were mineralogically investigated for the first time for archaeological purposes. X-ray diffraction, X-ray fluorescence, transmission electron microscopy, infrared and Raman spectroscopy and total organic carbon techniques were used. The low content of moganite, since its detection by X-ray diffraction is practically imperceptible, and the crystallite size (over 1000 Å) of the quartz in these cherts would be indicative of its maturity and could potentially be used for dating chert-tools recovered from archaeological sites. Also, this information can constitute essential data to differentiate the cherts and compare them with those used in archaeological tools. However, neither composition nor crystallite size would allow distinguishing between coastal and inland chert outcrops belonging to the same geological formations.

scholarly journals First Report on the Geologic Occurrence of Natural Na–A Zeolite and Associated Minerals in Cretaceous Mudstones of the Paja Formation of Vélez (Santander), Colombia

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 218
Author(s):  
Carlos Alberto Ríos-Reyes ◽  
German Alfonso Reyes-Mendoza ◽  
José Antonio Henao-Martínez ◽  
Craig Williams ◽  
Alan Dyer
Keyword(s):  
Natural Zeolite ◽  
Scanning Electron Micrographs ◽  
Total Sulfur ◽  
Zeolite A ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Phases ◽  
The World ◽  
Porosity And Permeability ◽  
First Time

This study reports for the first time the geologic occurrence of natural zeolite A and associated minerals in mudstones from the Cretaceous Paja Formation in the urban area of the municipality of Vélez (Santander), Colombia. These rocks are mainly composed of quartz, muscovite, pyrophyllite, kaolinite and chlorite group minerals, framboidal and cubic pyrite, as well as marcasite, with minor feldspar, sulphates, and phosphates. Total organic carbon (TOC), total sulfur (TS), and millimeter fragments of algae are high, whereas few centimeters and not biodiverse small ammonite fossils, and other allochemical components are subordinated. Na–A zeolite and associated mineral phases as sodalite occur just beside the interparticle micropores (honeycomb from framboidal, cube molds, and amorphous cavities). It is facilitated by petrophysical properties alterations, due to processes of high diagenesis, temperatures up to 80–100 °C, with weathering contributions, which increase the porosity and permeability, as well as the transmissivity (fluid flow), allowing the geochemistry remobilization and/or recrystallization of pre-existing silica, muscovite, kaolinite minerals group, salts, carbonates, oxides and peroxides. X-ray diffraction analyses reveal the mineral composition of the mudstones and scanning electron micrographs show the typical cubic morphology of Na–A zeolite of approximately 0.45 mμ in particle size. Our data show that the sequence of the transformation of phases is: Poorly crystalline aluminosilicate → sodalite → Na–A zeolite. A literature review shows that this is an unusual example of the occurrence of natural zeolites in sedimentary marine rocks recognized around the world.

scholarly journals The Effect of Surfactant-Modified Montmorillonite on the Cross-Linking Efficiency of Polysiloxanes

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2623
Author(s):  
Monika Wójcik-Bania ◽  
Jakub Matusik
Keyword(s):  
Total Pore Volume ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Cross ◽  
Chain Lengths ◽  
First Time ◽  
Substituent Influence ◽  
Benzyl Substituent

Polymer–clay mineral composites are an important class of materials with various applications in the industry. Despite interesting properties of polysiloxanes, such matrices were rarely used in combination with clay minerals. Thus, for the first time, a systematic study was designed to investigate the cross-linking efficiency of polysiloxane networks in the presence of 2 wt % of organo-montmorillonite. Montmorillonite (Mt) was intercalated with six quaternary ammonium salts of the cation structure [(CH3)2R’NR]+, where R = C12, C14, C16, and R’ = methyl or benzyl substituent. The intercalation efficiency was examined by X-ray diffraction, CHN elemental analysis, and Fourier transform infrared (FTIR) spectroscopy. Textural studies have shown that the application of freezing in liquid nitrogen and freeze-drying after the intercalation increases the specific surface area and the total pore volume of organo-Mt. The polymer matrix was a poly(methylhydrosiloxane) cross-linked with two linear vinylsiloxanes of different siloxane chain lengths between end functional groups. X-ray diffraction and transmission electron microscopy studies have shown that the increase in d-spacing of organo-Mt and the benzyl substituent influence the degree of nanofillers’ exfoliation in the nanocomposites. The increase in the degree of organo-Mt exfoliation reduces the efficiency of hydrosilylation reaction monitored by FTIR. This was due to physical hindrance induced by exfoliated Mt particles.

scholarly journals One-step synthesis of nitrogen-grafted copper-gallic acid for enhanced methylene blue removal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shella Permatasari Santoso ◽  
Vania Bundjaja ◽  
Artik Elisa Angkawijaya ◽  
Chintya Gunarto ◽  
Alchris Woo Go ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Gallic Acid ◽  
Synthesis Method ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
One Step ◽  
Detailed Assessment ◽  
Higher Temperature

AbstractNitrogen-grafting through the addition of glycine (Gly) was performed on a metal- phenolic network (MPN) of copper (Cu2+) and gallic acid (GA) to increase its adsorption capacity. Herein, we reported a one-step synthesis method of MPN, which was developed according to the metal–ligand complexation principle. The nitrogen grafted CuGA (Ng-CuGA) MPN was obtained by reacting Cu2+, GA, and Gly in an aqueous solution at a molar ratio of 1:1:1 and a pH of 8. Several physicochemical measurements, such as Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), N2 sorption, X-ray diffraction (XRD), and thermal gravimetry analysis (TGA), were done on Ng-CuGA to elucidate its characteristics. The analysis revealed that the Ng-CuGA has non-uniform spherical shaped morphology with a pore volume of 0.56 cc/g, a pore size of 23.25 nm, and thermal stability up to 205 °C. The applicational potential of the Ng-CuGA was determined based on its adsorption capacity against methylene blue (MB). The Ng-CuGA was able to adsorb 190.81 mg MB per g adsorbent at a pH of 6 and temperature of 30 °C, which is 1.53 times higher than the non-grafted CuGA. Detailed assessment of Ng-CuGA adsorption properties revealed their pH- and temperature-dependent nature. The adsorption capacity and affinity were found to decrease at a higher temperature, demonstrating the exothermic adsorption behavior.

scholarly journals Impact of high temperatures on aluminoceladonite studied by Mössbauer, Raman, X-ray diffraction and X-ray photoelectron spectroscopy

2021 ◽  
Author(s):  
Mariola Kądziołka-Gaweł ◽  
Maria Czaja ◽  
Mateusz Dulski ◽  
Tomasz Krzykawski ◽  
Magdalena Szubka
Keyword(s):  
Photoelectron Spectroscopy ◽  
Integral Intensity ◽  
Photoelectron Spectra ◽  
X Ray Diffraction ◽  
Structural Reorganization ◽  
Oh Groups ◽  
X Ray ◽  
Al Content ◽  
Integral Intensity Ratio ◽  
Higher Temperature

AbstractMössbauer, Raman, X-ray diffraction and X-ray photoelectron spectroscopies were used to examine the effects of temperature on the structure of two aluminoceladonite samples. The process of oxidation of Fe2+ to Fe3+ ions started at about 350 °C for the sample richer in Al and at 300 °C for the sample somewhat lower Al-content. Mössbauer results show that this process may be associated with dehydroxylation or even initiate it. The first stage of dehydroxylation takes place at a temperature > 350 °C when the adjacent OH groups are replaced with a single residual oxygen atom. Up to ~500 °C, Fe ions do not migrate from cis-octahedra to trans-octahedra sites, but the coordination number of polyhedra changes from six to five. This temperature can be treated as the second stage of dehydroxylation. The temperature dependence on the integral intensity ratio between bands centered at ~590 and 705 cm−1 (I590/I705) clearly reflects the temperature at which six-coordinated polyhedra are transformed into five-coordinated polyhedra. X-ray photoelectron spectra obtained in the region of the Si2p, Al2p, Fe2p, K2p and O1s core levels, highlighted a route to identify the position of Si, Al, K and Fe cations in a structure of layered silicates with temperature. All the measurements show that the sample with a higher aluminum content and a lower iron content in octahedral sites starts to undergo a structural reorganization at a relatively higher temperature than the less aluminum-rich sample does. This suggests that iron may perform an important role in the initiation of the dehydroxylation of aluminoceladonites.

scholarly journals A novel and potentially scalable CVD-based route towards SnO2:Mo thin films as transparent conducting oxides

2021 ◽  
Author(s):  
Tianlei Ma ◽  
Marek Nikiel ◽  
Andrew G. Thomas ◽  
Mohamed Missous ◽  
David J. Lewis
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Mixed Valence ◽  
Chemical Vapour ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conducting Oxides ◽  
Valence States ◽  
3 Omega ◽  
First Time

AbstractIn this report, we prepared transparent and conducting undoped and molybdenum-doped tin oxide (Mo–SnO2) thin films by aerosol-assisted chemical vapour deposition (AACVD). The relationship between the precursor concentration in the feed and in the resulting films was studied by energy-dispersive X-ray spectroscopy, suggesting that the efficiency of doping is quantitative and that this method could potentially impart exquisite control over dopant levels. All SnO2 films were in tetragonal structure as confirmed by powder X-ray diffraction measurements. X-ray photoelectron spectroscopy characterisation indicated for the first time that Mo ions were in mixed valence states of Mo(VI) and Mo(V) on the surface. Incorporation of Mo6+ resulted in the lowest resistivity of $$7.3 \times 10^{{ - 3}} \Omega \,{\text{cm}}$$ 7.3 × 10 - 3 Ω cm , compared to pure SnO2 films with resistivities of $$4.3\left( 0 \right) \times 10^{{ - 2}} \Omega \,{\text{cm}}$$ 4.3 0 × 10 - 2 Ω cm . Meanwhile, a high transmittance of 83% in the visible light range was also acquired. This work presents a comprehensive investigation into impact of Mo doping on SnO2 films synthesised by AACVD for the first time and establishes the potential for scalable deposition of SnO2:Mo thin films in TCO manufacturing. Graphical abstract

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