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Vinogradov, Vladimir V.; Mizerovskii, L. N.; Akaev, O. P.

doi:10.1023/a:1020558829106

Cited by 13 publications

(3 citation statements)

References 8 publications

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“…Cellulose is readily swollen and degraded by H 3 PO 4 ; at sufficiently high concentrations, the extent of swelling can be so high that the crystalline regions become solvated by the acid and the polymer becomes amorphous, 30 if the H 3 PO 4 concentration is reduced below 30%, the cellulose crystal structures can reform. 31 It is likely from this understanding that the granular regions are the product resulting from treatment of the cellulose with phosphoric acid, the carbonisation is due to dehydration of the cellulose hydroxyl groups leaving chromophoric conjugated unsaturated structures, some of which are likely to have graphitic character.…”

Section: Hydrochar Morphologymentioning

confidence: 99%

The physicochemical investigation of hydrothermally reduced textile waste and application within carbon-based electrodes

et al. 2019

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Section: Hydrochar Morphologymentioning

confidence: 99%

The physicochemical investigation of hydrothermally reduced textile waste and application within carbon-based electrodes

et al. 2019

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“…The formation of membranes from cellulose is challenging due to a limited number of solvents for its processing [3][4][5][6]. Most of the cellulose solvents are two-and three-component systems, such as dimethylacetamide/LiCl [7,8], N-methyl-2-pyrrolidone/LiCl [9], dimethyl sulfoxide/paraformaldehyde [10,11], aqueous solutions of H 3 PO 4 [12], and so on. The multi-component composition of these solvents leads to the complexity of dissolution, their instability, and frequently high toxicity.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Non-Solvent Nature on the Rheological Properties of Cellulose Solution in Diluted Ionic Liquid and Performance of Nanofiltration Membranes

Ilyin

Kostyuk

Anokhina

et al. 2023

IJMS

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The weak point of ionic liquids is their high viscosity, limiting the maximum polymer concentration in the forming solutions. A low-viscous co-solvent can reduce viscosity, but cellulose has none. This study demonstrates that dimethyl sulfoxide (DMSO), being non-solvent for cellulose, can act as a nominal co-solvent to improve its processing into a nanofiltration membrane by phase inversion. A study of the rheology of cellulose solutions in diluted ionic liquids ([EMIM]Ac, [EMIM]Cl, and [BMIM]Ac) containing up to 75% DMSO showed the possibility of decreasing the viscosity by up to 50 times while keeping the same cellulose concentration. Surprisingly, typical cellulose non-solvents (water, methanol, ethanol, and isopropanol) behave similarly, reducing the viscosity at low doses but causing structuring of the cellulose solution and its phase separation at high concentrations. According to laser interferometry, the nature of these non-solvents affects the mass transfer direction relative to the forming membrane and the substance interdiffusion rate, which increases by four-fold when passing from isopropanol to methanol or water. Examination of the nanofiltration characteristics of the obtained membranes showed that the dilution of ionic liquid enhances the rejection without changing the permeability, while the transition to alcohols increases the permeability while maintaining the rejection.

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“…This 334 assumption is safe, given the negligible amount of 335 lignin after bleaching, the most probable dissolution of 336 the remaining hemicellulose in the preliminar NaOH/ 337 urea treatment and the fact that cationic groups are 338 also incorporated into anhydropentose units 339 (Deutschle et al 2014). 340 For C1, BEKP was depolymerized with orthophos-341 phoric acid (H 3 PO 4 ), since this compound works both 342 as a hydrolysis agent, as long as its concentration is 343 higher than 30% (w/w), and as a cellulose activator, 344 causing total amorphization if its concentration is 345 superior to 79 wt% (Vinogradov et al 2002). 346 For C2 and C3, a precooled NaOH/urea solution 347 was used as solvent due to the influence of urea on 348 hydrophobic interactions of low-DP cellulose (Zang 349 et al 2002).…”

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Cationic cellulosic derivatives as flocculants in papermaking

et al. 2017

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7 Abstract Water-soluble cationic cellulose deriva-8 tives were synthesized by three different procedures, 9 cationizing bleached hardwood kraft pulp with (3-10 chloro-2-hydroxypropyl) trimethylammonium chlo-11 ride. The first procedure involved a previous depoly-12 merization step with orthophosphoric acid. The 13 second one consisted on dissolving cellulose in 14 NaOH/urea before cationization. For the third proce-15 dure, the reaction medium was heterogeneous since it 16 was carried out with a part of cellulose with high 17 degree of polymerization. Oppositely to the common 18 methods, cationization occurred under mild condi-19 tions. Differences among the three derivatives are 20 illustrated by X-ray diffraction patterns of pretreated 21 samples, infrared spectra, and determinations of the 22 degree of substitution, the zeta potential, the charge 23 density and the molecular weight. The performance of 24 these polyelectrolytes for the flocculation of mineral 25 fillers used in papermaking was tested by laser 26 diffraction spectrometry. The flocculant with the 27 highest degree of polymerization and charge origi-28 nated the best results, particularly when the filler used 29 was kaolin, proving that water-soluble cationic cellu-30 lose derivatives can aid in the flocculation of fillers 31 used in papermaking. On the contrary, the shortest-32 chained derivative was not effective. The results were 33 interpreted in terms of the characteristics of the 34 cellulose derivatives flocculants and of the fillers, 35 and neutralization and patching were proposed as the 36 dominant mechanisms. 37Keywords Cationization Á Cellulose Á Fillers for 38 papermaking Á Flocculation Á Laser diffraction 39 spectrometry 40 Introduction 41 Non-renewable and scarcely biodegradable polymeric 42 aids, such as cationic polyacrylamides (CPAM) or 43 polyethyleneimine (PEI), are often applied in paper 44 mills to achieve good retention of mineral fillers. The 45 particle size of these fillers is generally much smaller 46 than the wire mesh at the forming and drainage section 47 of the paper machine, and thus mechanical retention A1 Electronic supplementary material The online version of A2 this article

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Cited by 13 publications

References 8 publications

The physicochemical investigation of hydrothermally reduced textile waste and application within carbon-based electrodes

The physicochemical investigation of hydrothermally reduced textile waste and application within carbon-based electrodes

The Effect of Non-Solvent Nature on the Rheological Properties of Cellulose Solution in Diluted Ionic Liquid and Performance of Nanofiltration Membranes

Cationic cellulosic derivatives as flocculants in papermaking

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