Extraction of polyphenolic dyes from henna,pomegranate rind,and Pterocarya fraxinifolia for nylon 6 dyeing

Acid and disperse dyes are two well‐known synthetic materials that are primarily used for dyeing of nylon 6 fibres. Despite their good performance, several negative impacts on the environment, including air and water pollution, are major concerns to researchers. An alternative ecofriendly approach to the dyeing of nylon 6 is the use of natural dyes, given their abundant natural sources, biocompatibility, biodegradability, non‐toxicity, non‐allergic responses, and non‐carcinogenic effects on human life. Based on these advantages, we extracted polyphenolic dyes from henna leaves, pomegranate rind, and Pterocarya fraxinifolia leaves and studied the dyeability on nylon 6 fabric using three compounds of aluminium sulfate, tannic acid, and tin chloride as toxic and non‐toxic mordants before dyeing. Fourier transform infrared spectra of the nylon 6 fabric confirmed the coordination complexes and π–π bonding between the mordants and the dyes. Colorimetric and fastness results showed that the mordants increased the colour strength and improved the fastness properties of the fibres. Our results suggest that tin chloride and aluminium sulfate as metal mordants can be successfully replaced with tannic acid as a biomordant in the natural dyeing of nylon 6. Also, cost assay showed that dyeing of nylon 6 with extracted natural dyes from waste leaves could be a sustainable and economical substitute for synthetic dyeing.     

Evaluation of antimicrobial and dyeing properties of walnut (Juglans regia L.) green husk extract for cosmetics

Walnut green husk is one of the main waste products from walnut and could be used as a source of natural dyeing compounds such as juglone. The present study was conducted to evaluate the effective use of walnut green husk extract as a natural hair dye. Dyeing properties, fastness and antimicrobial behaviours of dyed hair and also a skin irritation test for natural hair dye on rat skin were examined. When the extract was mixed with ascorbic acid as a developer, ferrous sulphate as a mordant, and Aloe vera extract used as a secondary mordant and also a cosmetic ingredient, the reaction resulted in a dark‐brown colour on hair samples. The dyed hair exhibited appropriate colour strength having excellent morphology for a hair surface coated with dye molecules. In addition, the dyed hair possessed good resistance to washing and daylight fastness, without any irritant properties as shown in a rat model, although high concentrations of iron‐based mordant may be problematic for long‐term usage. This paper also suggests the use of natural mordants such as lactic and oxalic acids to avoid any probable risks. Walnut green husk extract was an appropriate natural hair dyeing agent in practice and showed maximum antimicrobial activity compared with semi‐synthetic and commercial hair dyes. The results demonstrated that walnut green husk can be used as an economical, valuable, eco‐friendly and safe source of dyeing and antimicrobial agents for cosmetic products.     

An alternative natural dye,almond shell waste: effects of plasma and mordants on dyeing properties

In this study, the effect of the plasma process and the possibility of replacing metallic mordants with plasma treatment were investigated in natural dyeing with almond shell waste as a novel natural colorant. The use of a smaller amount of metallic mordants and plant than most of the current natural dye applications is a major advantage of dyeing with almond shell extract. Plasma‐treated and untreated wool fabrics were dyed without mordant and using a smaller amount (0.2 g/l) of alum, iron(ii ) sulfate and copper(ii ) sulfate. Three mordanting methods, namely premordanting, simultaneous mordanting and post‐mordanting, were applied. Colour measurements and light and wash fastness values were compared. Significant colour differences were observed among the mordanting methods. Simultaneous mordanting resulted in the lightest colours with all the mordants. Generally, post‐mordanting produced duller colours and lower a* and b* values than premordanting. The plasma process generated significant colour value differences and colour yield increases, giving more homogeneous dyeing visually, and also ensured a greater impact of mordanting. However, compared with metallic mordants, plasma itself did not create completely different colour shades and fastness improvement. It was necessary to use mordants in order to achieve increased fastness properties (especially light fastness) and a different colour gamut.     

Cetylpyridinium chloride cationic finishing improves the dyeing and antibacterial properties of madder dyed cotton

In this work, after cationic pretreatment of cotton fabric with cetylpyridinium chloride (CPC), the compound of citric acid (CA) and succinic acid (SUA) were used as crosslinking agents to dye cotton fabrics with natural madder dye to improve the dyeing and antibacterial properties and realise the multifunctional finishing of cotton fabric. The effects of mordant dyeing, CA + SUA crosslinked dyeing, and CPC/CA + SUA crosslinked dyeing on the microstructure and properties of cotton fabrics were compared. The dyeing by the three processes occurred primarily in the amorphous zone of the fibres, and all kept the original crystalline form of the cotton. CA + SUA crosslinked dyeing and CPC/CA + SUA crosslinked dyeing increased the thermal stability of the cotton fabric. CPC/CA + SUA crosslinked dyed cotton obtained excellent dyeing results with the colour depth value (K/S) of 12.3 and rubbing fastness and washing fastness of levels 4–5, and the levelness and dye permeability were acceptable. Furthermore, the antibacterial rate against Escherichia coli and Staphylococcus aureus reached 99.99%, and the ultraviolet protection factor (UPF) reached 50+. Moreover, the wrinkle recovery angle (WRA) increased by 55% compared with raw cotton. This showed that CPC/CA + SUA crosslinked dyed cotton had excellent antibacterial, anti-ultraviolet, and anti-wrinkle performances.     

Dyeing of silk fabric with phenazine from Pseudomonas species

Phenazines, namely oxychlororaphin and pyorubin, were extracted from Pseudomonas sp., purified and their dyeing potential as colorants for silk dyeing were examined. The effects of the process variables, such as phenazine concentration, pH, temperature, time, type of mordant, relative colour strength and fastness properties have been studied. The results showed that the optimum condition for dyeing was 90 °C at pH 3 and dyeing time 90 min for oxychlororaphin, and 70 °C at pH 3 and dyeing time 60 min for pyorubin. The K/S value of a pre‐mordanted silk fabric with oxychlororaphin was high when compared to that with the pyorubin. The antimicrobial activity of a dyed silk fabric was tested against Salomonella paratyphi, Escherichia coli and Shigella flexneri.     

Effect of reactive dyeing on the UV protection affected by knitted fabric made from different types of cotton fibre

In this study, 100% cotton knitted fabrics made from combed cotton and combed pima cotton were dyed with reactive dye, with different dye concentrations. Colour properties such as CIE L*a*b* values as well as dyeing uniformity of the dyed fabrics were measured. The relationships between colour properties and the ultraviolet protection afforded by cotton knitted fabrics were investigated. Experimental results revealed that dye concentration is the most important factor. In addition, only L* values have a direct mathematical relationship with the ultraviolet protection factor; a* and b* values and dyeing uniformity were not found to have a significant correlation with ultraviolet protection factor values. Meanwhile, knitted fabric made from combed cotton fibre has better ultraviolet protection performance than fabric made from combed pima cotton fibre.     

Preparation,characterization, antifungal activity,and mechanism of chitosan/TiO2 hybrid film against bipolaris maydis

A chitosan/TiO₂ hybrid film, as a powerful antifungal material for controlling southern corn leaf blight, which is caused by the fungus Bipolaris maydis (B. maydis), was prepared and characterized. Its antifungal activity toward B. maydis was studied, and the experimental results indicate that it had multiple attractive antifungal properties as follows: (1) it displayed strong antifungal activity against B. maydis, with an inhibition ratio of 100% under both visible‐light irradiation and in a dark environment; (2) it exhibited a superior antifungal efficacy of 100%, even after 4 h under the irradiation of visible light; and (3) its antifungal activity included the effect of hydroxyl radicals generated by the photocatalysis of TiO₂. The antifungal mechanism was attributed to the action of a large amount of positive charges on the structure of the hybrid film, which interacted with the negative charges from the cell and finally resulted in the inactivation of B. maydis. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Extraction of polyphenolic substances from bark as natural colorants for wool dyeing

In Europe, considerable amounts of bark are available from wood‐processing industries such as forestry and timber production. Polyphenolic components can be collected by hot water extraction. The extracted compounds can then be applied as colorants in textile dyeing operations. In this study, a comparative assessment of four different tree species with regard to their colouristic potential for wool dyeing was performed. Aqueous extracts from alder, ash tree, spruce and oak bark were prepared and analysed for their total phenolic content and ultraviolet (UV) absorption at 360–370 nm. The extracts were used for meta‐mordant dyeing by adding iron sulphate mordant (FeSO₄ × 7H₂O). For comparison, iron salt‐based dye lakes were prepared and used in dyeing experiments. For each tree species, a specific correlation between the total phenolic content of the dyebath and the colour depth in terms of K/S and CIELab coordinates was observed, both for the aqueous extracts and the dye lakes. Based on this relationship, standardisation and quality control of raw materials and dye lakes can be installed as important stages in the industrialisation of natural colorants from bark. The preparation of concentrated dye lakes permits formation of a concentrated colorant as dye product, which then can be standardised and delivered to textile dyehouses, similar to synthetic dyes. The preparation of dye lakes offers a relevant route towards achieving the commercialisation of bark extracts as natural colorants.     

A new approach to improve dyeability of nylon 6 fibre using a subtilisin enzyme

This study confirms the structural changes of nylon 6 fibres using protease by measuring the dyeability, hydrophilicity, chemical changes and fastness properties. For this purpose, nylon 6 fabrics were first treated with different concentrations of protease enzyme in aqueous solutions. The dyeing process was then carried out on the treated fabrics with disperse and acid dyes. Acid and disperse dyes showed higher exhaustion on the enzyme‐treated samples. The results of colour measurement in the CIELAB system showed that the darkness of the samples increased with an increase in the enzyme percentage in the solution. The results of moisture regain showed that treatment of nylon fabrics with a proteolytic enzyme caused an increase in moisture absorbency. The wash and light fastness properties of samples were measured according to ISO 105‐C05 and daylight ISO 105‐B01 and are discussed.     

Natural dyeing and antibacterial activity of atmospheric‐plasma‐treated nylon 6 fabric

Atmospheric plasma treatment as an environmentally friendly method was employed to modify the surface properties and improve the absorption of natural cationic dye on to nylon 6 fabric. Nylon fabric was treated in atmospheric air plasma, and the surface characteristics of the fabric were evaluated using attenuated total reflection Fourier Transform‐infrared analysis, scanning electron microscopy, and a wicking test. The effects of plasma treatment and mordanting with copper sulfate on the dye uptake of the samples were investigated. Plasma‐treated and mordanted samples showed the highest colour strength when dyed. The antibacterial activity of samples was evaluated according to AATCC test method 100‐2004. Premordanting with copper sulfate showed a synergistic effect on the antibacterial properties of the dyed fabric. The plasma‐treated and copper‐sulfate‐mordanted sample showed acceptable antibacterial activity against both gram‐negative and gram‐positive bacteria when dyed with an extract from Berberis vulgaris, berberine.     

Dyeing properties of Bombyx mori silks grafted with methyl methacrylate and methacrylamide

To improve their dyeing and colorfastness properties, degummed Bombyx mori silks were chemically modified by a grafting technique with either methyl methacrylate (MMA) monomer or methacrylamide (MAA) monomer. Both commercial synthetic dyes, that is, acid and basic dyes, and natural dyes extracted from turmeric, without and with potassium aluminum sulfate mordant, were used in this study. Percentage dye uptake increased with the presence of poly(methyl methacrylate) or polymethacrylamide in the silk fibroin structure regardless of the types of the dyestuffs. Furthermore, compared to the degummed silk, the colorfastness to washing of the MMA‐grafted and MAA‐grafted silks dyed with acid, basic, and curcumin dyestuffs were greatly improved. Colorfastness to both acid and basic perspirations with acid and basic dyestuffs was slightly improved, whereas perspiration fastness remained unchanged for curcumin dyeing without and with the presence of the mordant. Also, the low‐light resistances of the degummed and grafted silks dyed by curcumin dyestuff were notably improved by the MMA and MAA grafting technique. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100:1169–1175, 2006     

Textile applications of photochromic dyes. Part 4: application of commercial photochromic dyes as disperse dyes to polyester by exhaust dyeing

A series of commercial photochromic dyes was applied to polyester fabric as disperse dyes. The photocoloration properties of the dyed fabrics were investigated by applying techniques previously established in our laboratories using an independent source of ultraviolet irradiation and traditional colour measurement instrumentation. The dyed fabrics showed reversible photochromism, developing pronounced colours from weak background colours on irradiation with ultraviolet light and returning to their original state when the ultraviolet light source was removed. However, the extent of photocoloration and the depth of background colour varied significantly with the particular dye used. The dyeing procedure was optimised by maximising the degree of photocoloration, expressed as the colour difference (ΔE₁) between the colour developed after ultraviolet exposure and background colour, while minimising the background colour, expressed as the colour difference (ΔE₂) between unexposed dyed and undyed fabrics. Optimum dyeing concentrations were determined. The colour development and fading properties, fatigue resistance and storage stability of the dyed fabrics were investigated.     

Studies involving reactive dyes containing a benzophenone ultraviolet absorber

Nine new fibre reactive dyes containing a built‐in hydroxybenzophenone moiety were synthesised, characterised using electrospray mass spectroscopic analysis, applied to cotton fabrics and the ultraviolet protection factor values of the dyed cotton fabrics determined. The results showed that the anti‐ultraviolet properties of cotton were improved by dyeing with dyes containing a built‐in hydroxybenzophenone moiety, but that the benzophenone ultraviolet absorber need not be covalently linked to dye molecules to provide significant benefit.     

Antifungal effect of carbendazim supported on poly(ethylene‐co‐vinyl alcohol) and epoxy resin

Ethylene‐vinyl alcohol copolymers (EVOH) were prepared by the conventional saponification of poly(ethylene‐co‐vinyl acetate) using a solution of potassium hydroxide in ethanol. An organic fungicide, consisting of a 2‐benzimidazole carbamoyl (CBZ) group supported on EVOH (EVOH‐CBZ), was prepared by the transesterification reaction of methyl 2‐benzimidazole cabamate (carbendazim) with EVOH. The antifungal activity of the synthesized polymers was examined by the halo zone test against Aspergillus fumigatus and Penicillium pinophilum. The synthesized EVOH‐CBZ complex showed a strong antifungal activity. The bound CBZ units were susceptible to hydrolysis. CBZ bonded to an epoxy resin precursor, diglycidyl ether of bisphenol A (DGEBA‐CBZ), retained its antifungal activity, which was somewhat weaker in comparison with that of EVOH‐CBZ. When the DGEBA‐CBZ complex was crosslinked by isophoronediamine, the antifungal activity disappeared almost completely, indicating that it is necessary for the CBZ units to release from their polymer supports to have the antifungal effects. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 728–736, 2001     

Extraction of natural dyes from Alpinia blepharocalyx K. Schum. for dyeing of silk fabric

Natural dyes were extracted from the leaves and stems of Alpinia blepharocalyx K. Schum. Analysis of the designed experiment revealed that extraction at a plant/water ratio of 1:20 could reach an optimal production of natural dyes when extraction was performed at 80 °C, for 4 h, under 20 min ultrasound, in the presence of 10 g/l sodium hydroxide, and with two extractions. The extracted natural dyes were applied to the dyeing of silk fabrics using different methods, including or excluding a mordant. It was found that mordants had a significant effect on the colour of dyed silk fabrics. The silk fabric dyed with the pre‐mordant method using potassium aluminium sulphate as a mordant showed a bright yellow with a higher colour strength. The optimal dyeing conditions were reached when the extracted natural dyes were pre‐mordanted with 10 g/l potassium aluminium sulphate at pH 6, and for a 20 min dyeing time.     

Functionalization of electrospun nanofibers of natural cotton cellulose by cerium dioxide nanoparticles for ultraviolet protection

Nanofibers of natural cotton cellulose with a degree of polymerization above 10,000 were prepared by electrospinning; they were then functionalized with a rare‐earth nano‐oxide material of cerium dioxide (CeO₂) by means of the hydrothermal method to obtain the designated properties. The morphology, structure, and properties of the as‐obtained nanocomposite fibers were characterized by scanning electron microscopy, transmission electron microscopy, energy‐dispersive spectroscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, and ultraviolet (UV)–visible spectrophotometry. The results show that hydrothermally grown CeO₂ nanoparticles exhibited a polycrystalline cubic fluorite structure and could be dispersed uniformly on the surface of the cellulose nanofiber. The strong interface and electrostatic interactions between the nanoparticles and nanofibers effectively prevented nanoparticle fall‐off. The modified natural cotton cellulose nanofibers showed excellent protection against UV radiation because of the function of the CeO₂ particles. Such cellulose nanocomposite materials could have potential applications in UV protection for data‐storage or memory devices. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1524–1529, 2013     

Improving the antibacterial and UV‐resistant properties of cotton by the titanium hydrosol treatment

The titanium hydrosol was prepared and treated on the cotton fabrics to improve its antibacterial and UV‐resistant properties. The sol size and gel morphology on the fabric were characterized by Nanosizer, SEM, and AFM. The antibacterial reduction rate of the treated fabrics against Staphylococcus aureus and Escherichia coli reached above 95%, and the corresponding UV transmittance value of the treated fabrics decreased considerably, with a ultraviolet protection factor of 50 or excellent grade, and the protection was tested according to the Australian/New Zealand standards. In spite of 50 washing cycles, the antibacterial and UV‐resistant properties changed almost little because of the strong affinity between the gel particles and cellulose material. The strength tests of the treated fabrics also showed no negative effects from the treatment on the fabrics. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1478–1482, 2006     

Enzymatic hydrolysis of nylon 6 fiber using lipolytic enzyme

This study confirms the structural changes of nylon 6 fibers using lipase by measuring the dyeability, hydrophilicity, chemical changes, and fastness properties. For this purpose, nylon 6 fabrics were first treated separately with different concentrations of lipase enzyme. The dyeing process was then carried out on the treated fabrics with two disperse and acid dyes. A UV‐vis spectrophotometer was used for determination of dyebath exhaustion. Acid and disperse dyes showed higher dyebath exhaustion on the enzyme treated samples compared to raw material. The intensity of major peaks in FTIR spectra of the lipase treated samples are in favor of chemical changes of the polypeptide functional groups in fabric. Tensile strength of treated fabrics was decreased due to enzyme treatment. The results of color measurements in the CIELAB system showed that the darkness of the samples increased with an increase in the enzyme percentage in the solution. The results of moisture regain showed that treatment of nylon fabrics with lipolytic enzymes caused to increase the moisture absorbency. The wash and light fastness properties of samples were measured according to ISO 105‐CO5 and Daylight ISO 105‐BO1 and discussed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Pomegranate fallen leaves as a source of natural dye for mordant-free dyeing of wool

The application of metal mordants is usually necessary in dyeing of wool with natural dyes to improve the dye exhaustion and fastness properties. The majority of metal salts generally used as mordants are considered as toxic and it is important to find replacements for them. Plant sources with high content of tannins are good candidates as bio-mordant or colourant to overcome this drawback. In this study, the waste fallen leaves of pomegranate tree were used as a source of natural dye for the eco-friendly dyeing of wool fabric without the use of metal mordants. The dyeing process variables including dye concentration, dyebath pH, and temperature were optimised using response surface methodology to obtain the highest colour strength. The colour strength was increased by increasing the natural dye powder up to 100%owf while the optimum pH and dyebath temperature were 4 and 100°C, respectively. The sample dyed under the optimal condition exhibited good fastness properties against washing and light. This study approved the potential of Punica granatum fallen leaves for the dyeing of wool without any mordant, while high fastness properties were obtained.     

Development of biodegradable polymeric nanoparticles for encapsulation,delivery, and improved antifungal performance of natamycin

The aim of this study was to evaluate biodegradable poly(lactide‐co‐glycolide) nanoparticles as potential nano‐delivery systems for the food antifungal compound natamycin. Natamycin‐loaded nanoparticles were prepared at various ratios polymer/antifungal by the nanoprecipitation technique, resulting in nano‐size particles (80–120 nm) with a narrow distribution and a spherical morphology. Complexation of natamycin with PLGA and active participation to the nanoparticle formation were evidenced by a mean diameter reduction of 10–30 nm, although encapsulation levels remained low due to the zwitterionic and partially hydrophilic nature of natamycin. Physical state analyses highlighted the presence of natamycin in an amorphous or molecularly dispersed state within the polymeric matrix. This translates into high availability of free antifungal molecules reflected in burst release and fast in vitro release kinetics rates as well as enhanced antifungal performance against the model food yeast Saccharomyces cerevisiae, offering a potential benefit for antifungal protection compared with the commercially available natamycin products. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43736.