scholarly journals Influence of different acids for adjusting the dyebath ph value on the dyeability of polyester knitwear dyed with disperse yellow 23

2011 ◽  
Vol 65 (3) ◽  
pp. 257-261
Author(s):  
Milena Miljkovic ◽  
Milovan Purenovic ◽  
Dragan Djordjevic ◽  
Milica Petrovic

In this paper the influence of the formic and oxalic acids, as substances for dyebath pH adjusting, on the dyeability of polyester fabric dyed with disperse dye Disperse Yellow 23 was examined. The polyester undyed knitwear samples were dyed in baths containing the acids under the same dyeing conditions. Color differences of the samples were assessed using the reflectiometry technique and expressed in terms of CIELcoordinates. The influence of the tested acids on the surface structure of dyed polyester fibers was examined using the scanning electron microscopy (SEM). It was found that the differences in obtained dyeabilities, in the presence of both formic and oxalic acid, are acceptable according to both M&S 83A and CMC (2:1) standards which was not the case with acetic acid. Therefore, acetic acid can be replaced with either formic or oxalic acid as substances for dyebath pH adjusting in the dyeing process described in this paper. SEM micrographs showed small differences in the surface structure of dyed fibers, as well as differences in the shape of undyed samples? reflectance curves in presence of the acids. Since all of the color differences were quite small, it can be concluded that the influence of formic and oxalic acids on the polyester knitwear dyeability is not significantly different than that of acetic acid.

2019 ◽  
Vol 90 (5-6) ◽  
pp. 655-665 ◽  
Author(s):  
Lihua Fan ◽  
Yongsong Tan ◽  
Jeremiah Amesimeku ◽  
Yunjie Yin ◽  
Chaoxia Wang

A novel functional disperse dye doped with graphene oxide for antistatic properties of polyester fabric was achieved, which means that the dyeing and antistatic finishing can be simultaneously obtained by a one-bath method. Functional dyes were used to dye polyester fabric by a high-temperature, high-pressure dyeing method. The surface microscopic morphology of the dyed polyester fabric, and the dispersion properties of the disperse dye, graphene oxide, and the functional disperse dye, were characterized by scanning electron microscopy. The effects of the dyeing temperature on the particle sizes of three dyeing liquors were explored; this revealed that the temperature of the dyeing process had no effect on particle size. The dosage and reduction time of graphene oxide were investigated. The surface electrical resistance of the dyed fabric, 9.8 × 106 Ω, obtained at a condition of 2% (o.m.f) graphene oxide with a reduction time of 30 min, achieved A-grade antistatic standard. Furthermore, the rubbing and washing fastness of the treated fabric were 4- and 4 ∼ 5 grades, respectively. This preparation of the functional disperse dye provides a possibility in one-bath dyeing and antistatic finishing of polyester fabric.


2020 ◽  
Vol 7 (5) ◽  
pp. 9-16
Author(s):  
Marija Kodric ◽  
Dragan Djordjevic

Modification of polyester fibers for more economical dyeing at lower temperatures without a carrier are considered in this study. Polyester dyeing is carried out industrially under rigorous conditions at high temperatures and under increased air pressure, and are treated with various solvents (primary alcohols) to make the fibers more permeable. As a result, the sorption properties, as well as the disperse dye dyeing ability, are improved. Dyeing of a modified polyester fabric at lower temperatures yielded better results than the standard dyeing of the unmodified polyester under the same conditions. The effects of fiber modification were analyzed through water absorption properties, wetting, swelling, differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) methods, and the degree of dyeing of the fabric was evaluated using CIELab parameters.


2012 ◽  
Vol 610-613 ◽  
pp. 534-537 ◽  
Author(s):  
Benjawan Siriphet ◽  
Jantip Suesat ◽  
Potjanart Suwanruji

The effect of dye dispersion preparation prior to dyeing on the dyeing ability of the disperse dye on polyester fabric was studied. The influence of sodium laurylsulphate (SLS) concentrations and the homogenization process was determined. The optimum SLS concentration for dyeing observed in this study was 0.01 M. The color yield of the dye passing through the homogenization process on polyester fabric was higher than that from the conventional dye preparation. Homogenization was also found to enhance disperse dyeability at a lower dyeing temperature. It infers that the dyeing process could be done at a lower temperature. The dyeing temperature could be as low as 110oC in the presence of homogenization. The effect of homogenization on the dyeability at different dyeing times was also examined.


2018 ◽  
Vol 2 ◽  
pp. 43-48 ◽  
Author(s):  
Aftab Jamal ◽  
Azam Khan ◽  
Muhammad Sharif ◽  
Hifsa Jamal

An incubation experiment was conducted on P solubilization from rock phosphate (RP) through different organic acids such as oxalic acid, citric acid, acetic acid, humic acid and sulphur in the laboratory of the Department of Soil and Environmental Sciences, KP Agricultural University Peshawar during fall 2011. The experiment was laid in a complete randomize design. There were three replications with six treatments. The organic acids were used at the rate of 2 % for 50 g RP in 250 ml conical flasks. These samples were kept in an incubator at 250c for four months and analysed for Mehlic-3 extractable P and pH values after 20 days interval. Statiscal analyses were made and maximum P concentration of 1.52% was observed in the treatment of oxalic acid mixed with RP followed by the treatments of RP mixed with humic acid with P concentration of 0.368% (Fig. 1). Rapid increases in P solubility from RP by mixing with oxalic acids were noted up to 60thdays of incubation period and then remained stable after this period. Solubilization of P from RP by mixing with other organic acids was inconsistent. The pH in treatment of citric acid mixed with RP was noted as 5.64, followed by the treatments of oxalic acid with pH values of 6.31. A dramatic increase in pH value of 9.33 was observed in the treatment of RP mixed with humic acid. It is because the humic acid contains sodium salt and sodium hummate causes increase in its pH values.


2017 ◽  
Vol 23 (1) ◽  
pp. 131-139 ◽  
Author(s):  
Marija Kodric ◽  
Sandra Stojanovic ◽  
Branka Markovic ◽  
Dragan Djordjevic

In this paper, modelling of dyeing, i.e. adsorptive behaviour of disperse dyes on polyester fibres (dyeing), under the influence of ultrasound has been considered with the aim of getting the data about mechanisms of binding the dyes and defining the conditions of dyeing process of this synthetic fibres along with additional energy source without the use of carriers, compounds that increase permeability of the fibres and help dyeing. Dyeing - adsorption is conducted under different conditions, and the concentration of dyes, mass of the substrate, recipes and time of dyeing were being varied. It has been established that ultrasound allows dyeing without carriers and the efficiency of dyeing depends on the time of contact, initial concentration of the dye and the amount of absorbent - material. There is the continuity of growth of the amount of bound dye to the mass of the absorbent. Characteristic graphs, obtained from Langmuir isotherm, have confirmed that this model ensures precise description of polyester dyeing by disperse dye. Kinetic of dyeing has been remarkably interpreted by pseudo second-order in regards to the high functionality.


2020 ◽  
Vol 9 (2) ◽  
pp. 41-47
Author(s):  
Marija Kodrić ◽  
Arianit Reka ◽  
Čedomir Dimić ◽  
Anita Tarbuk ◽  
Dragan Đorđević

The thermodynamics of sorption during the dyeing process of raw polyester fibers with disperse dye was studied in this article. Dyeing of fibers is carried out by a discontinuous batch process, according to standard procedures with varying of the initial dye concentration and the dyeing temperature. Several of the accepted models for calculation of thermodynamic parameters were used which define and clarify the sorption of disperse dyes on polyester fibers. High functionality of variables for the calculation of basic thermodynamic parameters was determined, which confirmed the validity of the results. Depending on the method of calculation , the change of free energy during the dyeing of the polyester was negative (-10-40 kJ·mol-1), which corresponds to the spontaneous and mainly the physical process of sorption. A positive value for the change in enthalpy during dyeing (1.1×10-2-2.9×10 1 kJ·mol-1) reflects the endothermic nature of the interactions, and a relatively lower value characterizes the physisorption phenomenon. A positive value for the change in entropy (1.1×10-4-1.5×10-1 kJ·mol-1 ·K-1) confirms that it is a physical sorption.


Author(s):  
N.C. Lyon ◽  
W. C. Mueller

Schumacher and Halbsguth first demonstrated ectodesmata as pores or channels in the epidermal cell walls in haustoria of Cuscuta odorata L. by light microscopy in tissues fixed in a sublimate fixative (30% ethyl alcohol, 30 ml:glacial acetic acid, 10 ml: 65% nitric acid, 1 ml: 40% formaldehyde, 5 ml: oxalic acid, 2 g: mecuric chloride to saturation 2-3 g). Other workers have published electron micrographs of structures transversing the outer epidermal cell in thin sections of plant leaves that have been interpreted as ectodesmata. Such structures are evident following treatment with Hg++ or Ag+ salts and are only rarely observed by electron microscopy. If ectodesmata exist without such treatment, and are not artefacts, they would afford natural pathways of entry for applied foliar solutions and plant viruses.


2021 ◽  
Vol 9 (8) ◽  
pp. 1597
Author(s):  
Dominic Stephenson ◽  
Audrey Perry ◽  
Andrew Nelson ◽  
Ali E. Robb ◽  
Matthew F. Thomas ◽  
...  

Nontuberculous mycobacteria are important respiratory pathogens in patients with cystic fibrosis (CF). For diagnosis, international guidelines recommend culture of sputum that has been decontaminated via chemical treatment. Fifty-six sputum samples from 32 patients known to be previously colonized or infected with NTM were subdivided, and the aliquots were subjected to six different decontamination strategies, followed by quantitative culture for NTM. Thirty sputum samples contained Mycobacterium abscessus complex (MABSC) and 11 contained Mycobacterium avium complex (MAC). Decontamination strategies included treatment with N-acetyl L-cysteine with 2% sodium hydroxide (NALC-NaOH), 4% NaOH, 1% chlorhexidine, 0.5 N sulfuric acid, 5% oxalic acid, double decontamination with NALC-NaOH, followed by 5% oxalic acid, and saline (0.85%) as a control. The samples were also cultured directly with no treatment. Treatment with NALC-NaOH resulted in an average reduction in colony count of 87% for MABSC when compared with direct culture. NaOH at 4% caused a 98.3% average reduction in colony count. All treatments that included NaOH resulted in colony counts that were statistically lower than those obtained from direct culture or the saline-treated control (p < 0.05). Standard treatments using sulfuric or oxalic acids were less deleterious, but still resulted in an average reduction in colony count of at least 30%. The viability of MAC was much less affected by most decontamination treatments. In conclusion, the viability of MABSC was severely compromised by standard decontamination regimens. This supports recent evidence showing that optimal recovery of MABSC is achieved by culture on an appropriate selective agar without decontamination of sputum samples.


2021 ◽  
Vol 22 (2) ◽  
pp. 396-404
Author(s):  
Lu Zhang ◽  
Qingquan Zhou ◽  
Qipeng Zhang ◽  
Minghua Wu

2016 ◽  
Vol 63 (3) ◽  
Author(s):  
Marcin Grąz ◽  
Kamila Rachwał ◽  
Radosław Zan ◽  
Anna Jarosz-Wilkołazka

Oxalate oxidase was identified in mycelial extracts of a basidiomycete Abortiporus biennis strain. Intracellular enzyme activity was detected only after prior lowering of the pH value of the fungal cultures by using oxalic or hydrochloric acids. This enzyme was purified using size exclusion chromatography (Sephadex G-25) and ion-exchange chromatography (DEAE-Sepharose). This enzyme exhibited optimum activity at pH 2 when incubated at 40°C, and the optimum temperature was established at 60°C. Among the tested organic acids, this enzyme exhibited specificity only towards oxalic acid. Molecular mass was calculated as 58 kDa. The values of Km for oxalate and Vmax for the enzyme reaction were 0.015 M and 30 mmol min-1, respectively.


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