Radiation activation of cotton-cellulose prior to alkali treatment

2001 ◽  
Vol 27 (7-8) ◽  
pp. 837-845 ◽  
Author(s):  
E. Takács ◽  
L. Wojnárovits ◽  
Cs. Földváry ◽  
J. Borsa ◽  
I. Sajó
2000 ◽  
Vol 57 (3-6) ◽  
pp. 399-403 ◽  
Author(s):  
E Takács ◽  
L Wojnárovits ◽  
Cs Földváry ◽  
P Hargittai ◽  
J Borsa ◽  
...  

1992 ◽  
Vol 62 (5) ◽  
pp. 290-292 ◽  
Author(s):  
S. P. Bhatawdekar ◽  
S. Sreenivasan ◽  
R. H. Balasubramanya ◽  
K. M. Paralikar

The effect of an alkali pretreatment on never-dried fibers prior to enzymolysis has been studied using x-ray diffraction and electron microscope techniques. The reduced susceptibility of the never-dried fibers to enzymolysis after the alkali pretreatment has been traced to the specific morphological state of the fibrils.


2018 ◽  
Vol 69 (1) ◽  
pp. 191-195
Author(s):  
Elena Radu ◽  
Elena Emilia Oprescu ◽  
Cristina Emanuela Enascuta ◽  
Catalina Calin ◽  
Rusandica Stoica ◽  
...  

The dehydration of polysaccharides fraction in the presence of acid catalysts, is a chemical process in which results as secondary product humic matter. In our work, the humic acid mixture was for the first time based on our knowledge extracted from defatted microalgae biomass rich in polysaccharides by standard alkali treatment, followed by precipitation at acidic pH. The dried humic acid mixture has been characterized using infrared spectroscopic measurements (FT-IR). Exfoliated graphite nanoplatelets (xGnP) were used as new adsorbents for this type of humic acids mixture, their adsorption being investigated. The effect of several parameters such as: contact time, concentration of humic acid mixture, concentration of xGnP, temperature and pH of the solutions were studied. The process of adsorption took place with good results, in the following conditions: at a concentration of humic acid mixture of 18.6 mg L-1, an xGnP amount of 0.01 mg in 25 mL of solution, at a temperature of 25 �� and at acidic pH values, in aqueous solution.


2015 ◽  
Vol 55 (11) ◽  
pp. 2553-2558 ◽  
Author(s):  
Huihui Zhang ◽  
Ruihao Ming ◽  
Gesheng Yang ◽  
Yuzeng Li ◽  
Qiao Li ◽  
...  
Keyword(s):  

Cellulose ◽  
2021 ◽  
Author(s):  
Peixin Tang ◽  
Leilah-Marie E. Lockett ◽  
Mengxiao Zhang ◽  
Gang Sun

AbstractA chemical modification of cotton fabrics by 2-diethylaminoethyl chloride (DEAE-Cl) was achieved, and the resulted cotton fabrics demonstrated salt-free dyeing properties with anionic dyes. Nucleophilic property of hydroxyl groups in cotton cellulose was enhanced under alkaline conditions and could react with DEAE-Cl, a chemical possessing both nucleophilic and electrophilic sites. The monolayered DEAE-grafted cotton cellulose could further react with DEAE-Cl to form multiple cationic quaternary ammonium salts (denoted as DEAE@Cotton), which are highly interactive with anionic dye molecules. The strong electrostatic interactions between the DEAE@Cotton and the dyes eliminated the use of inorganic salts in cotton dyeing process. The chemical structure and property of DEAE@Cotton were characterized and compared with untreated cotton. The DEAE@Cotton can be dyed in a salt-free system, and the dye exhaustion was faster than the conventional dyeing method due to the robust electrostatic interactions of the fabrics with anionic dyes. The dyed fabrics demonstrated outstanding color fastness under repeated washing, light exposure, and crocking. The dye adsorption process on DEAE@Cotton follows Langmuir isotherm model (R2 = 0.9667). The mechanism of enhanced dyeability was experimentally proved by treating the fabric with other anionic dyes in a salt-free system, proving the process to be environmentally friendly and cost-effective. Graphic abstract


2021 ◽  
Vol 333 ◽  
pp. 125107
Author(s):  
Jing Li ◽  
Zhaomeng Liu ◽  
Chengqi Feng ◽  
Xiaoying Liu ◽  
Fangyu Qin ◽  
...  

2020 ◽  
pp. 1-10
Author(s):  
R. Sathish Kumar ◽  
Nivedhitha Muralidharan ◽  
Ravishankar Sathyamurthy

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