X-ray diffraction methods in the study of the effect of microwave heating on the transformation of cellulose I into cellulose II during mercerization

2007 ◽  
Vol 105 (5) ◽  
pp. 2978-2983 ◽  
Author(s):  
M. A. Moharram ◽  
Osama M. Mahmoud
Keyword(s):  
Microwave Heating ◽  
Cellulose Ii ◽  
X Ray Diffraction ◽  
Cellulose I ◽  
X Ray

scholarly journals CELLULOSE NANOCRYSTALS FROM UNDERUTILIZED POLYTHIA LONGIFOLIA SEED

2017 ◽  
Vol 14 (27) ◽  
pp. 10-18
Author(s):  
Adewale ADEWUYI ◽  
Fabiano Vargas PEREIRA
Keyword(s):  
Adsorption Capacity ◽  
Cellulose Nanocrystals ◽  
Cellulose Ii ◽  
X Ray Diffraction ◽  
Cellulose I ◽  
Sem Images ◽  
X Ray ◽  
Potential Source ◽  
Swelling Capacity ◽  
Water Holding

Polythia longifolia seed (PL), an underutilized seed in Nigeria was used as a starting material to prepare Polythia longifolia cellulose nanocrystals (PLN). Polythia longifolia cellulose (PLC) was first isolated and subjected to sulfuric acid hydrolysis followed by ultrasonication and homogenization. PL, PLC and PLN were characterized using Fourier transformed infrared (FTIR), x-ray diffraction (XRD), thermogravimetric analysis (TG) and scanning electron microscopy (SEM). PLC and PLN were evaluated for their heavy metal adsorption capacity, swelling capacity, water holding capacity and oil holding capacity. SEM images reveal elliptical granules of PLN while XRD shows a mixture of polymorphs of cellulose I and cellulose II. PLN displayed a better water holding, oil holding and swelling capacities. PLN also exhibited a higher adsorption capacity towards Cu2+ and Pb2+ ions than PLC. The results showed that Polythia longifolia seed can serve as a potential source of cellulose nanocrystals which might be useful in other applications.

scholarly journals Dissolution of cotton by 1-ethyl-3-methylimidazolium acetate studied with time–temperature superposition for three different fibre arrangements

Cellulose ◽  
2020 ◽  
Author(s):  
Yunhao Liang ◽  
James E. Hawkins ◽  
Michael E. Ries ◽  
Peter J. Hine
Keyword(s):  
Crystal Structure ◽  
Activation Energy ◽  
Cellulose Ii ◽  
X Ray Diffraction ◽  
Master Curves ◽  
Cellulose I ◽  
X Ray ◽  
Cotton Fibres ◽  
Temperature Superposition ◽  
Time Temperature Superposition

Abstract This study has investigated the dissolution of cotton fibres in the ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) for three fibre arrangements. Dissolution was carried out with excess [C2mim][OAc] at various temperatures and times followed by coagulation with water. Optical microscopy (OM) of the resulting processed and dried cotton fibres indicated that this procedure produced a coagulated fraction surrounding the original fibres. X-ray diffraction (XRD) showed that the crystal structure of this coagulated fraction was predominantly cellulose II, as opposed to the original fibres—mostly cellulose I. The OM and XRD results showed that growth of the coagulated fraction obeyed time–temperature superposition (TTS) and displayed an Arrhenius behaviour allowing a dissolution activation energy to be determined. Although the growth of the coagulated fraction with time were different for these distinct three arrangements, all could be individually shifted to form master curves using TTS, leading to very similar activation energies, 96 ± 3 kJ/mol (23 ± 1 kcal/mol). Graphic abstract

scholarly journals Stable, metastable and unstable cellulose solutions

2017 ◽  
Vol 4 (8) ◽  
pp. 170487 ◽  
Author(s):  
Marta Gubitosi ◽  
Pegah Nosrati ◽  
Mona Koder Hamid ◽  
Stefan Kuczera ◽  
Manja A. Behrens ◽  
...  
Keyword(s):  
Microcrystalline Cellulose ◽  
Small Angle ◽  
Supersaturated Solution ◽  
Cellulose Ii ◽  
Cellulose I ◽  
Tetrabutylammonium Hydroxide ◽  
X Ray ◽  
Stable Regime ◽  
X Ray Scattering ◽  
A Minor

We have characterized the dissolution state of microcrystalline cellulose (MCC) in aqueous tetrabutylammonium hydroxide, TBAH(aq), at different concentrations of TBAH, by means of turbidity and small-angle X-ray scattering. The solubility of cellulose increases with increasing TBAH concentration, which is consistent with solubilization driven by neutralization. When comparing the two polymorphs, the solubility of cellulose I is higher than that of cellulose II. This has the consequence that the dissolution of MCC (cellulose I) may create a supersaturated solution with respect to cellulose II. As for the dissolution state of cellulose, we identify three different regimes. (i) In the stable regime, corresponding to concentrations below the solubility of cellulose II, cellulose is molecularly dissolved and the solutions are thermodynamically stable. (ii) In the metastable regime, corresponding to lower supersaturations with respect to cellulose II, a minor aggregation of cellulose occurs and the solutions are kinetically stable. (iii) In the unstable regime, corresponding to larger supersaturations, there is macroscopic precipitation of cellulose II from solution. Finally, we also discuss strong alkali solvents in general and compare TBAH(aq) with the classical NaOH(aq) solvent.

Eco-Friendly Preparation of Nanofibrillated Cellulose from Water Hyacinth Using NaOH/Urea Pretreatment

2020 ◽  
Vol 990 ◽  
pp. 225-230
Author(s):  
Kraiwit Pakutsah ◽  
Duangdao Aht-Ong
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Water Hyacinth ◽  
Aqueous Suspension ◽  
Nanofibrillated Cellulose ◽  
Cellulose Ii ◽  
Cellulose I ◽  
X Ray ◽  
Transmission Electron ◽  
Water Hyacinth Fiber

In this work, we described an effective approach to prepare nanofibrillated cellulose (NFC) with cellulose II structure under mild condition. Firstly, the water hyacinth (WH) was subjected to a series of a two-step chemical treatment, NaOH/urea pretreatment, and mechanical defibrillation at different defibrillation times. After that, raw water hyacinth fiber (RWF), bleached water hyacinth fiber (BWF), NaOH/urea pretreated water hyacinth fiber (PWF), and the resulting NFC were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD) as well as rheological measurements. It was found that RWF and BWF exhibited cellulose I crystal structure, whereas PWF and the obtained NFC possessed cellulose II crystal structure. FTIR analysis confirmed the evidence that no other chemical reactions preferentially occurred during both NaOH/urea pretreatment and mechanical defibrillation. As evidenced by rheological properties analysis, the NFC aqueous suspension with a gel-like structure demonstrated a shear-thinning behavior. The obtained NFC could potentially be utilized as a reinforcement for polymeric composites.

Comparative Analysis of Crystallinity Changes in Cellulose I Polymers Using ATR-FTIR, X-ray Diffraction, and Carbohydrate-Binding Module Probes

2011 ◽  
Vol 12 (11) ◽  
pp. 4121-4126 ◽  
Author(s):  
Alenka Kljun ◽  
Thomas A. S. Benians ◽  
Florence Goubet ◽  
Frank Meulewaeter ◽  
J. Paul Knox ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
X Ray Diffraction ◽  
Cellulose I ◽  
X Ray ◽  
Crystallinity Changes

Converse Piezoelectric Effect in Cellulose I Revealed by Wide-Angle X-ray Diffraction

2010 ◽  
Vol 11 (5) ◽  
pp. 1281-1285 ◽  
Author(s):  
Wolfgang Gindl ◽  
Gerhard Emsenhuber ◽  
Johannes Plackner ◽  
Johannes Konnerth ◽  
Jozef Keckes
Keyword(s):  
Piezoelectric Effect ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Cellulose I ◽  
X Ray ◽  
Converse Piezoelectric Effect

Synthesis of Alpha Alumina Using Microwave Energy

2014 ◽  
Vol 805 ◽  
pp. 504-507
Author(s):  
Juliana Melo Cartaxo ◽  
M.N. Galdino ◽  
Liszandra Fernanda Araújo Campos ◽  
H.S. Ferreira ◽  
R.H.G.A. Kiminami ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Analysis ◽  
Acid Solution ◽  
Microwave Heating ◽  
Microwave Energy ◽  
Aluminum Nitrate ◽  
X Ray Diffraction ◽  
Treatment Results ◽  
X Ray ◽  
Alpha Alumina

This work investigated the synthesis of α-alumina using dissolution and re-precipitation of aluminum nitrate and microwave heating. The synthesized powders were characterized by X-ray diffraction, thermal analysis (TGA and DTA) and surface are by BET. The dissolution process was carried out using acid solution and heat treatment. Results depicted the efficiency of the process to accelerating the synthesis of alpha alumina. The results showed that the powders have the microwave structure of α-alumina with specific areas ranging between 3 and 15m2/g and pore diameters between 190 to 485nm.

Fine structure in the red algae III. A general survey of cell-wall structure in the red algae

1959 ◽  
Vol 150 (941) ◽  
pp. 456-459 ◽  
Keyword(s):  
Cell Wall ◽  
Red Algae ◽  
Amorphous Matrix ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
X Ray Diffraction ◽  
Cellulose I ◽  
General Survey ◽  
X Ray ◽  
Floridean Starch

A general survey of cell-wall structure in the red algae has been carried out using the methods of X -ray diffraction analysis and electron microscopy. The fifteen species all show a similar wall structure consisting of numerous lamellae each of which is made up of random micro-fibrils embedded in an amorphous matrix. The X -ray diagrams obtained from several species are complicated by the existence of crystalline floridean starch, but nevertheless reveal the absence of cellulose I.

Preparation of Perovskite Type SrNiO3 Photocatalyst Material by Microwave Heating Method

2013 ◽  
Vol 826 ◽  
pp. 211-214 ◽  
Author(s):  
Xin Wang
Keyword(s):  
Microwave Heating ◽  
Heating Time ◽  
X Ray Diffraction ◽  
Calcination Time ◽  
Heating Method ◽  
X Ray ◽  
Preparation Conditions ◽  
Simulated Fuel ◽  
Photocatalytic Material ◽  
Perovskite Type

A new microwave heating method for reparation of SrNiO3 photocatalyst material was described. The optimum preparation conditions are that the microwave power is 560W, the microwave heating time is 30min, the calcination temperature is 700°C and the calcination time is 5h.The compound was measured by X-ray diffraction. In visible light and under the conditions of simulated fuel waste water, the photocatalytic properties of the catalyst material have been studied. The results showed the photocatalytic material prepared by that microwave heating have a high photocatalytic performance of degradation, and the degeneration rate of the dye may reach 98%.

Dissolution and Regeneration of Reed Leaf Fibers in Imidazole-Based Ionic Liquids

2013 ◽  
Vol 652-654 ◽  
pp. 1539-1542
Author(s):  
Hou Jie Zhao ◽  
Chun Yan Wei ◽  
Yong Zhu Cui ◽  
Li Hua Lv ◽  
Xiao Wang
Keyword(s):  
Fourier Transform ◽  
Ionic Liquids ◽  
Infrared Spectroscopy ◽  
Chloride Solution ◽  
X Ray Diffraction ◽  
Cellulose I ◽  
X Ray ◽  
High Temperature And Pressure ◽  
Ft Ir ◽  
Temperature And Pressure

In this paper, regeneration of reed leaf fibers that have been degummed pretreatment in high temperature and pressure dissolved in 1-butyl-3-methylimidazolium chloride ionic liquids was studied. The samples containing 5% or 10%(wt/wt)reed leaf fibers in the ionic liquids, at 90°C for 7h.The dissolution process was viewed by polarizing microscope. Fourier-transform infrared spectroscopy(FT-IR) and X-ray diffraction were used to visualize the crystalline of reed leaf fiber transformed completely from cellulose I to cellulose Ⅱ after regenerated directly from 1-butyl-3-methylimidazolium chloride solution.

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