scholarly journals Preparation of cellulose-rich membranes from wood: effect of wood pretreatment process on membrane performance

Cellulose ◽  
2020 ◽  
Vol 27 (16) ◽  
pp. 9505-9523
Author(s):  
Anastasiia Lopatina ◽  
Ikenna Anugwom ◽  
Mohammadamin Esmaeili ◽  
Liisa Puro ◽  
Tiina Virtanen ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Pure Water ◽  
Deep Eutectic Solvent ◽  
Untreated Wood ◽  
Alkaline Treatment ◽  
Sodium Chlorite ◽  
Wood Biomass ◽  
Wood Treatment ◽  
Complex Chemical Composition ◽  
Treatment Step

AbstractIn this study cellulose-rich membranes were fabricated from untreated and treated hardwood biomass solutions in 1-ethyl-3-methylimidazolium acetate ([Emim][OAc])—dimetylsulfoxide (DMSO) system via wet phase separation. Wood treatment methods aimed to get purified cellulose fraction of wood. Treatment sequence was as followed: deep eutectic solvent pretreatment, sodium chlorite bleaching, and alkaline treatment. Resulted biomass after each treatment step was characterized by chemical composition and crystalline fraction content. Flat-sheet membranes were produced from biomass samples after each treatment step. Characterization of membranes included measurements of pure water permeability and (poly)ethyleneglycol 35 kDa retention, Fourier-transform infrared and Raman spectroscopy, X-ray diffraction measurements and thermogravimetric analysis. The study revealed that it was possible to fabricate membrane from untreated wood as well as from wood biomass after each of treatment steps. The resulted membranes differed in chemical composition and filtration performance. Membrane prepared directly from untreated wood had the highest permeability, the lowest retention; and the most complex chemical composition among others. As treatment steps removed lignin and hemicelluloses from the wood biomass, the corresponding membranes became chemically more homogeneous and showed increased retention and decreased permeability values.

scholarly journals Structural FTIR analysis of cellulose functional groups isolated from Leucaena leucocephala pods using different bleaching agents.

2020 ◽  
Author(s):  
Aida Safina Aridi ◽  
Chin Nyuk Ling ◽  
Nur Akmal Ishak ◽  
Mohammad Yusof Nor Nadiah ◽  
Mohamed Fikry Mohamed Ahmed ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Leucaena Leucocephala ◽  
Functional Group ◽  
Alkaline Treatment ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Sodium Chlorite ◽  
Ftir Analysis ◽  
Cellulose Fibres ◽  
Whiteness Index

Abstract In this study, extracted cellulose fibres were successfully isolated from Leucaena leucocephala pods through an efficient alkaline treatment and bleaching method using different bleaching agents such as 5 wt.% of sodium chlorite (NaClO2), 5 wt.% of oxalic acid (C2H2O4), 5 wt.% of potassium permanganate (KMnO4) and 5 wt.% of sodium hypochlorite (NaClO), respectively. The functional group of the cellulose fibres were analysed by using attenuated total reflection infrared (ATR-IR) spectroscopy. The ATR-IR spectra reported that the Leucaena leucocephala fibres after being given chemical treatment with 5%w/w of NaClO lead the similar functional group with the commercial cellulose due to removal hemicellulose and lignin. The content cellulose of final product was 89.4% was measured by the chemical composition test. Meanwhile, the whiteness index of Leucaena leucocephala fibres treated with 5 wt.% NaClO was 78.5%, which was the highest. The results of ATR-IR, chemical composition test and whiteness index were indicated that the sample of Leucaena leucocephala pods presents the structure of cellulose.

Behavior of Some Varieties in the Kernel Group to the Attack of the Main Pathogens

2018 ◽  
Vol 12 (2) ◽  
pp. 1-7
Author(s):  
Sînziana Venera Morărița
Keyword(s):  
Chemical Composition ◽  
Climatic Conditions ◽  
Complex Chemical ◽  
Complex Chemical Composition ◽  
Large Production ◽  
Special Quality

Abstract Although relatively recent, peach culture has grown great in our country due to the special quality of the fruit, its very complex chemical composition and the large production that can be obtained without much effort. Peach is a species slightly adapted to our climatic conditions, suffers from winter frost, but can provide productive and long productions of 10-15 years.

scholarly journals On the contribution of Aitken mode particles to cloud droplet populations at continental background areas – a parametric sensitivity study

2007 ◽  
Vol 7 (3) ◽  
pp. 6077-6112
Author(s):  
T. Anttila ◽  
V.-M. Kerminen
Keyword(s):  
Surface Tension ◽  
Particle Size ◽  
Chemical Composition ◽  
Pure Water ◽  
Particle Surface ◽  
Chemical Properties ◽  
Sensitivity Study ◽  
Geometric Standard Deviation ◽  
Cloud Droplets ◽  
Aitken Mode

Abstract. Aitken mode particles are potentially an important source of cloud droplets in continental background areas. In order to find out which physico-chemical properties of Aitken mode particles are most important regarding their cloud-nucleating ability, we applied a global sensitivity method to an adiabatic air parcel model simulating the number of cloud droplets formed on Aitken mode particles, CD2. The technique propagates uncertainties in the parameters describing the properties of Aitken mode to CD2. The results show that if the Aitken mode particles do not contain molecules that are able to reduce the particle surface tension more than 30% and/or decrease the mass accommodation coefficient of water, α, below 10−2, the chemical composition and modal properties may have roughly an equal importance at low updraft velocities characterized by maximum supersaturations <0.1%. For larger updraft velocities, however, the particle size distribution is clearly more important than the chemical composition. In general, CD2 exhibits largest sensitivity to the particle number concentration, followed by the particle size. Also the shape of the particle mode, characterized by the geometric standard deviation (GSD), can be as important as the mode mean size at low updraft velocities. Finally, the performed sensitivity analysis revealed also that the chemistry may dominate the total sensitivity of CD2 to the considered parameters if: 1) the value of α varies at least one order of magnitude more than what is expected for pure water surfaces (10−2–1), or 2) the particle surface tension varies more than roughly 30% under conditions close to reaching supersaturation.

Beans (Phaseolus vulgaris L.): whole seeds with complex chemical composition

2018 ◽  
Vol 19 ◽  
pp. 63-71 ◽  
Author(s):  
Francine Gomes Basso Los ◽  
Acácio Antonio Ferreira Zielinski ◽  
José Pedro Wojeicchowski ◽  
Alessandro Nogueira ◽  
Ivo Mottin Demiate
Keyword(s):  
Chemical Composition ◽  
Phaseolus Vulgaris ◽  
Phaseolus Vulgaris L ◽  
Complex Chemical ◽  
Complex Chemical Composition

Calorimetry, chemical composition and in vitro digestibility of sugarcane treated with calcium hydroxide

2018 ◽  
Vol 69 (4) ◽  
pp. 406
Author(s):  
Alexandre M. Dias ◽  
Luís C. V. Ítavo ◽  
Júlio C. Damasceno ◽  
Camila C. B. F. Ítavo ◽  
Geraldo T. Santos ◽  
...  
Keyword(s):  
Weight Loss ◽  
Chemical Composition ◽  
Calcium Hydroxide ◽  
Nutritive Value ◽  
Low Cost ◽  
Alkaline Treatment ◽  
In Vitro Digestibility ◽  
Cellulose Structure ◽  
High Dry Matter

Sugarcane is a source of roughage in animal feeding. It presents high production per unit of cultivated area, relatively easy cultivation and low cost of production per hectare, and better quality and a high dry matter (DM) yield in periods when forage is scarce. This study aimed to evaluate the effect of increasing levels of calcium hydroxide (Ca(OH)2) in sugarcane forage on chemical composition, in vitro digestibility values of DM, neutral detergent fibre (NDF) and acid detergent fibre (ADF), and kinetics of thermal decomposition processes of weight loss and heat flow. Sugarcane was collected close to the ground and 50-kg heaps of the fresh material were formed and mixed with four doses of Ca(OH)2 (0, 8, 16 and 24 g kg–1 sugarcane). Concentrations of NDF and ADF decreased linearly with increasing amount of Ca(OH)2, whereas concentration of hemicellulose increased linearly. In vitro digestibilities of DM, NDF and ADF were enhanced in a quadratic manner with increasing amounts of Ca(OH)2. The release of heat, measured by ΔH, increased linearly with increased Ca(OH)2 levels, likely due to enhanced digestibility of the fibre components. Weight loss decreased linearly between 272.2°C and 397.7°C with increased amounts of Ca(OH)2 added to sugarcane, likely due to changes in cellulose structure, which became denser and thermodynamically more stable than native cellulose following the alkaline treatment. Calcium hydroxide changed chemical composition and digestibility of the fibrous fraction of sugarcane, resulting in better nutritional value. The greatest release of heat and highest in vitro digestibility of fibre were observed when adding 15.2 g Ca(OH)2 kg–1 sugarcane; therefore, this dose is recommended to enhance the nutritive value of sugarcane as ruminant feed.

scholarly journals Calorific Power Improvement of Wood by Heat Treatment and Its Relation to Chemical Composition

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5322
Author(s):  
Idalina Domingos ◽  
Umit Ayata ◽  
José Ferreira ◽  
Luisa Cruz-Lopes ◽  
Ali Sen ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Chemical Composition ◽  
Lignin Content ◽  
Treated Wood ◽  
Untreated Wood ◽  
High Heating Value ◽  
Heat Treated ◽  
Positive Linear Correlation ◽  
Total Extractives ◽  
Calorific Power

Chemical composition influences the calorific power of wood, mainly due to the calorific power of structural compounds and extractives. Heat treatment changes the chemical composition of treated wood. This work studies the relationship between chemical composition and calorific power improvement by heat treatment. Samples were heat-treated by the ThermoWood process ® for 1 h and 2 h. High heating value (HHV) and chemical composition; lignin, cellulose, hemicelluloses and extractives in dichloromethane, ethanol, and water were determined. The HHV of untreated wood ranged between 18.54–19.92 MJ/kg and increased with heat treatment for all the tested species. A positive linear correlation was found between HHV and Klason lignin (R2 = 0.60). A negative trend was observed for holocellulose, cellulose, and hemicelluloses content against HHV, but with low determination coefficients for linear regression. The best adjust for polysaccharides was found for hemicelluloses content. A positive correlation could be found for dichloromethane extractives (R2 = 0.04). The same was obtained in relation to ethanol extractives with R2 = 0.20. For water and total extractives, no clear positive or negative trends could be achieved. The results showed that the HHV of wood increased with heat treatment and that this increase was mainly due to the increase in lignin content.

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