Sodium citrate as an eco-friendly complexing agent for the bioscouring treatment of the cellulosic/lignocellulosic fabrics

2018 ◽  
Vol 72 (8) ◽  
pp. 1881-1888
Author(s):  
Mihaela Dochia ◽  
Monica Pustianu ◽  
Cristian Moisă ◽  
Dorina Chambre ◽  
Simona Gavrilaş
2019 ◽  
Vol 97 (5) ◽  
pp. 230-236
Author(s):  
G. P. da Silva ◽  
R. N. de Lima ◽  
F. J. N. Santos ◽  
F. P. S. de Menezes ◽  
L. P. L. Morais ◽  
...  

2011 ◽  
Vol 233-235 ◽  
pp. 2739-2742
Author(s):  
C.G. Zhang ◽  
Zheng Fang Shi ◽  
J. Miao

There were carried on experiment in zinc sulfate and selenite sodium electrolyte solution. To further studying the influence of the ZnSe films ingredient and the appearance influence of electrochemical formation ZnSe thin films, the deposition parameters, which are the pH, Zn2+/SeO32- molar ratio, complexing agent sodium citrate, bath temperature and current density, are studied by the orthogonal experiment, the influence on Zn of the parameters from strong to weak are attained.


2020 ◽  
Vol 9 (6) ◽  
pp. 456-467
Author(s):  
Yassine Salhi ◽  
Sghir Cherrouf ◽  
Mohammed Cherkaoui

The electrodeposition of Cu-Zn-Sn (CZT) coating at ambient temperature was investigated. The bath consists of metal salts SnSO4, ZnSO4,7H2O and CuSO4,5H2O and sodium citrate (NaC6H5Na3O7,2H2O) as a complexing agent. For precipitation, the pH is maintained at 5. The reducing of copper, tin and zinc through Cu2HCit3−, Sncit2− and ZnHcit− complexes respectively are confirmed by the presence of three cathodic peaks on the voltammograms realized on steel and ITO glass substrate. X-ray diffraction patterns revealed peaks corresponding to the phases: Cu-Zn cubic, Cu-Sn hexagonal and β-Sn tetragonal. The deposition rate is 35 μm/h. SEM observation and EDAX analysis showed that the coating consists of a uniform CZT layer of which composition is 55% copper, 20% zinc and 25% tin at -1.5V.  A preliminary study showed a remarkable improvement in the corrosion resistance of CZT coated steel in comparison with bare steel.


2021 ◽  
Vol 42 ◽  
pp. 143-150
Author(s):  
Mihaela Dochia ◽  
Simona Gavrilaş

To be properly used in the textile industry, the natural materials are subject to different pretreatments. During the scouring, the non-cellulosic attendants (wax, pectin, pigments) are removed. The enzymes have proved their efficiency in this regard but also in terms of being friendly with the environment. The textile industry is a water large consumer, comprising many wet processes: bioscouring, bleaching, mercerizing, and dyeing. The water quantity needed for each step is very high. The resulted wastewater comprises different types of chemicals, most of them non-biodegradable: acids, sodium hydroxide, hypochlorites, peroxides, etc. The actual trends and legislation require the change of classical methods used with ecological ones. One particular reason for this tendency is also related to the economic issue, the use of eco-friendly treatments leading to significant economical savings. The present study was focused on enzymatic treatments with the use of two chelating agents (sodium citrate and EDTA) to remove the flax/cotton fabric impurities. The new proposed scouring treatment, with sodium citrate as a chelating agent, presents less aggressivity to the environment compared with the classical one. The temperature used was lower (55 °C), the pH close to the neutral point, and biodegradable chemicals were used. The chosen technology included a series of independent steps which they assumed: washing of flax/cotton fabric at 100 °C for dust and physically linked impurities removing, dried at room temperature, and conditioning at 105 °C in the oven for 2h. Afterward, the samples were immersed in the reaction bath which contained a mixture of pectinolytic products, the chelating agents (sodium citrate or EDTA), and the surfactant. The hydrolytic reaction was optimised following the influence of a pair of parameters: enzyme concentration/exposure time. Water samples from each reaction bath were collected and different physicochemical parameters were analysed: pH, salinity, TDS, conductivity, DO, CCOMn, turbidity and dry residue. The results obtained were following the legislation. In the case of the classical treatment, the data was up to 100 % higher compared with the new proposed treatment were complexing agent sodium citrate was used. Analysing from different points of view the results obtained, we can say that the considered treatment could be a promising alternative to the current one. It might contribute to less wastewater pollution and technological economical improvement.


2008 ◽  
Vol 373-374 ◽  
pp. 442-445 ◽  
Author(s):  
Sen Lin Wang ◽  
Wei Wei Yu

This paper reported the electrodeposition of the nickel manganese alloy coatings from a sulphate bath using sodium citrate as complexing agent. The cyclic voltammetric experiments showed that the alloy initiative codeposition potential was about –0.457 V (vs.SCE). The effect of the plating conditions on the composition and the structure of the Ni-Mn were studied by energy dispersive X-ray spectrum and X-ray diffractometer, respectively. As a result, with the increase of the cathodic current density from 10 to 40 mA·cm-2, the manganese content of the deposit increased from 4.4 at% to 10.3 at%, and then it slightly decreased. The phase structure of the coating was face centered lattice (Fm3m) Ni-Mn solid solution. The corrosive polarization experiments indicated that the deposit could work as sacrificial coating for carbon steel in 3.5 wt% sodium chloride solution.


2015 ◽  
Vol 819 ◽  
pp. 97-102 ◽  
Author(s):  
M.S. Nur Ariffah ◽  
M.S. Nurulakmal ◽  
A.S. Anasyida ◽  
E.K. Shiu

Complexing agent in the electroless nickel coating (Ni-P) solution plays an important role to maintain the coating deposition rate during the coating process. This paper studies the effect of two complexing agent; sodium citrate and sodium acetate in Ni-P coating. Ni-P coating was prepared in bath containing: NiSO4·6H2O, NaPO2H2·H2O, C2H5NO2, and Pb (NO3)2. Ni-P coating was coated on polished Cu substrate. Morphology, thickness and surface roughness of Ni-P coating were characterized using scanning electron microscope (SEM)/electron dispersive x-ray (EDX), optical microscope (OM), and atomic force microscopy (AFM). The result showed that sodium acetate have higher deposition rate up to 12 μm/h, whereas sodium citrate provided better surface morphology with lower surface roughness.


2017 ◽  
Vol 6 (4) ◽  
pp. 117-124
Author(s):  
Hassan El Grini ◽  
Khadija Rahou ◽  
Mohammed Cherkaoui ◽  
Jean-Noël Chazalviel ◽  
François Ozanam ◽  
...  

The present article concerns the metallization of silicon substrates by deposition of the nickelphosphorus alloy produced by an autocatalytic chemical process. The deposition electrolyte is composed of a metal salt, a reducing agent (sodium hypophosphite), a complexing agent (sodium citrate) and a buffer (ammonium acetate). The deposition could only be carried out after activation of the silicon by fixing catalytic species on its surface. The immersion of the silicon samples in palladium chloride made it possible to produce relatively thick and regular Ni-P coatings. The immersion time was optimized. The activation of Si was characterized by XPS and the Ni-P coating by XPS and SEM. The electrochemical study did not show any real mechanism changes compared to the Ni-P deposition on a conductive surface.


2012 ◽  
Vol 472-475 ◽  
pp. 1572-1576 ◽  
Author(s):  
Jie Liao ◽  
Hai Fang Zhou ◽  
Shu Ying Cheng

ZnS thin films were deposited on glass substrates using chemical bath deposition. The zinc sulfate and thiourea were used as precursors along with a stable complexing agent of sodium citrate in ammonia/ammonium chloride (pH=10.5) buffer solution. The ratio of Zn and complexing agent was changed from 6:1 to 1:1 by varying concentrations of the complexing agent. X-ray diffraction (XRD), scanning electron microscope (SEM) and UV-vis spectrophotometer were used to investigate the structure, micrograph and optical characteristics of the ZnS thin films respectively. The concentration of sodium citrate has an effect on the crystalline size and crystallization. For the as-deposited thin films, the values of transmittances and Eg are about 85% and 3.8 eV respectively. However, they are decreased to 75% and 3.4 eV respectively after annealing. In addition, the concentration of the complexing agent has no remarkable influence on both the transmittance and the energy gap. The results show that the ZnS thin films with resistivity of 4.34×104 Ωcm are suitable for optoelectronic applications.


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