Natural dyes are not harmful to the environment owing to their biodegradability. For dye application to textiles, salts are necessary as mordant or electrolytes and make an environmental impact. In ...this paper, the influence of cationization during mercerization to the dyeing of cotton fabric with natural dye from
was researched. For this purpose, bleached cotton fabric as well as fabric cationized with Rewin OS was pre-mordanted using iron(II) sulfate heptahydrate (FeSO
·7H
O) and dyed with natural cochineal dye with and without electrolyte addition. For the characterization of surface changes after cationization, an electrokinetic analysis on SurPASS was performed and compared to pre-mordanting. For determination of dye exhaustion, the analysis of dye solution was performed on a UV/VIS spectrophotometer Cary 50 Solascreen. Spectrophotometric analysis was performed using a Datacolor 850 spectrophotometer, measuring remission "until tolerance" and the whiteness degree, color parameters, color depth (K/S), and colorfastness of dyed fabric were calculated. Levelness was determined by visual assessment. Cationized cotton fabrics showed better absorption and colorfastness. Pre-mordanting and cationization showed synergism. The electrolytes improved the process of dye absorption. However, when natural dyeing was performed on cotton fabric cationized during mercerization, similar chromacity, uniform color, and colorfastness were achieved with and without electrolyte, resulting in pure purple hue of cochineal. For achieving a violet hue, pre-mordanting with Fe-salt was needed. Therefore, salt can be reduced or even unnecessary, which makes this process of natural dyeing more environmentally friendly.
High crystallinity leads to low hydrophilicity of fabric made of (poly(ethylene terephthalate)) fibers (PET) causing problems in finishing, washing, and dyeing processes. To improve these properties, ...the surface of PET fibers is usually modified by hydrolysis. Alkaline hydrolysis is a conventional process usually performed at a temperature higher than 100 °C for more than 1 h. However, the use of strong alkali and high processing temperatures (>100 °C) can lead to fabric damage and a negative impact on the environment. Therefore, in this paper, the possibility of hydrolysis of the PET fibers in the fabric in a sustainable, energy-efficient process was researched. The influence of low temperature (60-100 °C) and an accelerator (a cationic surfactant HDTMAC) to PET alkaline hydrolysis was studied through weight loss, the loss in breaking force, and fiber morphology. The kinetics of PET dissolution in 1.5 mol cm
NaOH at low temperature with and without the addition of HDTMAC was determined and the activation energy was calculated according to the theoretical model. It has been confirmed that PET hydrolysis can be carried out in 1.5 mol cm
NaOH with the addition of HDTMAC as an accelerator at 80 °C for 10 min. This process is more economically and energetically acceptable than the conventional process, and is therefore more sustainable.
Chitosan is an environmentally friendly agent that is used to achieve the antimicrobial properties of textiles. Nowadays, the binding of chitosan to the textiles has been thoroughly researched due to ...the increasing demands on the stability of achieved properties during the textile care processes. Most crosslinking agents for chitosan are not safe for humans or environment, such as glutaric aldehyde (GA) and formaldehyde derivatives. Eco-friendly polycarboxyilic acids (PCAs) are usually used in after-treatment. In this work, chitosan powder was dissolved in citric acid with sodium hydrophosphite (SHP) as a catalyst. Standard cotton (CO) and polyester/cotton (PES/CO) fabrics were pretreated in 20% NaOH, similar to mercerization, in order to open the structure of the cotton fibers and hydrolyze polyester fibers, continued by finishing in the gelatin chitosan bath. Afterwards, the hot rinsing process, followed by drying and curing, closed the achieved structure. The main objective was to achieve durable antimicrobial properties to multiple maintenance cycles CO and PES/CO fabric in order to apply it in a hospital environment. The characterization of fabrics was performed after treatment, first and fifth washing cycles according ISO 6330:2012 by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR-ATR), electrokinetic analysis (EKA), by the determination of tensile properties and mechanical damage (wear), and the antimicrobial activity. The application of 20% NaOH led to the swelling and mercerization of cotton cellulose, and hydrolysis of polyester, resulting in better mechanical properties. It has been confirmed that the chitosan particles were well implemented into the cotton fiber and onto to the polyester component of PES/CO blend. The presence of chitosan was confirmed after five washing cycles, but in lower quantity. However, achieved antimicrobial activity is persistent.
The paper examines the influence of cotton cationization on the print quality in terms of penetration, colour yield and colour depth, which have been analysed in comparison to cotton untreated and ...pretreated with conventional acrylate binder. The process of cationization during mercerization was performed with a cationizing agent Rewin DWR (CHT Bezema). Standard (non-cationized) and cationized fabric, with and without additional layering of binder have been printed by digital inkjet pigment printing method. Moisture management testing (MMT) and dynamic contact angle measurement (drop shape analyzer-DSA30S) were performed on standard and cationized fabric, with and without binder, both with and without pigment layer. After printing, the objective values of colour depth (K/S) and colour parameters L*, C* and h° were analysed. The samples were also analysed by the method of microscopic imaging using a DinoLite microscope. Printed samples were tested to washing fastness, and the results are presented in terms of total colour difference (dECMC), according to CMC(l:c) equation, after the 1st, 3rd, 5th, 7th and 10th washing cycles. Results showed that the cotton cationization will improve the uniformity and coverage of the printed area as well as increase the K/S value. For the samples with binder, the positive effect of cationization on the stability and bond strength between the polymer layer as a pigment carrier with the cotton fabric was confirmed.
This article deals with cationization of cotton during mercerization and its effects on trichromatic vat dyeing. If cationization is carried out during the after-treatment, regardless of cotton ...pretreatment, the reaction takes place on the surface and blocks cellulose groups, subsequently resulting in uneven coloration. However, when cationization is carried out with an epihalohydrin during the mercerization process, new cellulose is formed in which the cationic compound is uniformly distributed and trapped between cellulose chains, resulting in uniform coloration after the dyeing process. The reaction time for the process during mercerization is 24 h, thus a more favorable process was researched. Based on electrokinetic analysis, it was found that 5 h was sufficient for the reaction with 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (CHPTAC). The cationization of cotton contributed to the processes of vat dyeing. The change in charge upon cationization resulted in very high adsorption of vat-dye anions, indicating that ionic bonding occurred in addition to van der Waals forces. The color depth improved by more than 10 times. It should be emphasized that the colors with higher chroma and targeted color hue, especially in trichromatic dyeing, were obtained on cationized cotton, in contrast to standard cotton fabrics. The color differences obtained under the different light sources indicate the occurrence of metamerism. Considering the color fastness to laundering, vat-dyed cationized fabrics of all colors may be used in hospitals or other environments where high hygiene and oxidative bleaching are required.
Cellulose with a low level of oxidation is suitable for producing stable long-lasting materials with high added value, while extensively oxidized once is applicable for disposable products. In our ...previous comprehensive research, the fundamental behavior of the cotton under the action of different oxidants has been explored. Different levels of oxidation, as well as the type of functional groups, have been achieved by properly selected oxidants while controlling their concentration and treatment time. In this research, the electrokinetic ζ-potential of KIO
4
and TEMPO-oxidized cotton and the isoelectric point are measured by the streaming potential method, while the surface charge is calculated from the adsorbed cationic surfactant by the back-titration method. The results of electrokinetic phenomena are compared with the amount of created carboxyl groups determined by the calcium acetate method. The machine learning algorithms Waikato Environment for Knowledge Analysis for regression analysis is employed to develop models that make numeric predictions of the ζ-potential values based on the known number of carboxyl groups. The model with the correlation coefficient between the actual and the predicted value of ζ-potential is given for the first time.
Graphic abstract
In this work, the durability of chitosan functionalization of cellulosic textile substrates, cotton and cotton/polyester blended fabrics, was studied. Chitosan is a naturally occurring biopolymer ...that can be produced inexpensively. It should be dissolved in an acidic solution to activate its antimicrobial and other properties, i.e., good biocompatibility, bioabsorbability, wound healing, hemostatic, anti-infective, antibacterial, non-toxic, and adsorptive properties. The application of chitosan to textile products has been researched to achieve antimicrobial properties, but the durability, after several maintenance cycles, has not. Chitosan functionalization was carried out using maleic acid (MA) and 1,2,3,4-butanetetracarboxylic acid (BTCA) as crosslinking and chitosan-activating agents and sodium hypophosphite monohydrate as a catalyst. To determine durability, the fabrics were subjected to 10 maintenance cycles according to ISO 6330:2012 using Reference detergent 3 and drying according to Procedure F. The properties were monitored after the 3rd and 10th cycles. The crosslinking ability of chitosan with cellulosic fabrics was monitored by Fourier infrared spectrometry using the ATR technique (FTIR-ATR). Changes in mechanical properties, whiteness and yellowing, and antimicrobial properties were determined using standard methods. Compared to maleic acid, BTCA proved to be a better crosslinking agent for chitosan.
This study explores the impact of sodium periodate oxidation time (30 min, 60 min, or 120 min) and alginate coating on the capillarity of jute fabrics. Raw jute fabric exhibits a rapid increase in ...capillary rise height ( h) over time, reaching 72 mm at 1200 s. Fabrics oxidized for 30, 60, and 120 min show significantly lower h values of 19, 18, and 28 mm at 1200 s, respectively, which can be ascribed to the oxidation process itself. Precisely, oxidation-induced conversion of hydroxyl groups of cellulose (the main constituent of jute fiber) to aldehyde groups contributed to the fabric reduced affinity for water, hence negatively affecting its capillarity. Approximately 47% and 55% lower h values of fabrics oxidized for 30 and 60 min compared to that oxidized for 120 min can be explained by their lower weight loss after oxidation as well as less pronounced liberation of elementary fibers. Oxidized fabrics characterized by low capillarity can be used for the manufacturing of packaging materials, outdoor gear, and protective covers for crops. To expand jute fabric applications in biocarpet engineering, that is, to obtain polysaccharide-based supports, raw and oxidized jute fabrics were treated with a 1% sodium alginate solution. At 1200 s, oxidized fabrics coated with alginate exhibited 4.3–5.8 times higher h values compared to solely oxidized counterparts. The diffusion coefficients of oxidized fabrics coated with alginate increase up to 35% with prolonged oxidation, emphasizing the oxidation impact on alginate binding.
New materials that are as similar as possible in terms of structure and biology to the extracellular matrix (external environment) of cells are of great interest for regenerative medicine. ...Oligoproline and oligohydroxyproline derivatives (peptides 2–5) are potential mimetics of collagen fragments. Peptides 2–5 have been shown to be similar to the model collagen fragment (H-Gly-Hyp-Pro-Ala-Hyp-Pro-OH, 1) in terms of both their spatial structure and biological activity. In this study, peptides 2–5 were covalently bound to nonwovens based on chitosan and calcium alginate. Incorporation of the peptides was confirmed by Fourier transform -infrared (FT-IR) and zeta potential measurements. Biological studies (cell metabolic activity by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test and Live/Dead assay) proved that the obtained peptide-polysaccharide conjugates were not toxic to the endothelial cell line EA.hy 926. In many cases, the conjugates had a highly affirmative influence on cell proliferation. The results of this study show that conjugates of chitosan and calcium alginate with oligoproline and oligohydroxyproline derivatives have potential for use in regenerative medicine.
Limbal Stem Cell Deficiency (LSCD) is a very serious and painful disease that often results in impaired vision. Cultivation of limbal stem cells for clinical application is usually performed on ...carriers such as amniotic membrane or surgical fibrin gel. Transplantation of these grafts is associated with the risk of local postoperative infection that can destroy the graft and devoid therapeutic benefit. For this reason, electrospun scaffolds are good alternatives, as proven to mimic the natural cells surroundings, while their fabrication technique is versatile with regard to polymer functionalization and scaffolds architecture. This study considers the development of poly(ε-caprolactone) (PCL) immune-compatible and biodegradable electrospun scaffolds, comprising cefuroxime (CF) or titanium dioxide (TiO2) active components, that provide both bactericidal activity against eye infections and support of limbal stem cells growth in vitro. The PCL/CF scaffolds were prepared by blend electrospinning, while functionalization with the TiO2 particles was performed by ultrasonic post-processing treatment. The fabricated scaffolds were evaluated in regard to their physical structure, wetting ability, static and dynamic mechanical behaviour, antimicrobial efficiency and drug release, through scanning electron microscopy, water contact angle measurement, tensile testing and dynamic mechanical analysis, antimicrobial tests and UV-Vis spectroscopy, respectively. Human limbal stem cells, isolated from surgical remains of human cadaveric cornea, were cultured on the PCL/CF and PCL/TiO2 scaffolds and further identified through immunocytochemistry in terms of cell type thus were stained against p63 marker for limbal stem cells, a nuclear transcription factor and cytokeratin 3 (CK3), a corneal epithelial differentiation marker. The electrospun PCL/CF and PCL/TiO2 successfully supported the adhesion, proliferation and differentiation of the cultivated limbal cells and provided the antimicrobial effect against Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans.
PDF
