Adsorption of Procion Red MX‐5B and Crystal Violet Dyes from Aqueous Solution onto Corncob Activated Carbon

Textile and dyeing industries are considered as one of the main water utilizing industries and generate a huge amount of colored liquid effluents in their finishing and dyeing processes. In this paper, agricultural waste corncob has been chosen as a renewable source to produce activated carbon at 400 °C (corncob activated carbon, CCAC) for the removal of Procion Red MX‐5B (PR) and crystal violet (CV) from dye‐polluted effluent using a batch technique. The efficiency of CCAC in adsorbing CV and PR from the water has been carried out as a function of pH, adsorbent dose, contact time, agitation, and initial concentration. The Temkin, Langmuir, and Freundlich isotherm model equations were investigated to understand the adsorption mechanism of dye molecules. The Langmuir isotherm R² obtained was 0.9958 for CV and 0.9733 for PR. Maximum adsorption capacity obtained was 2.498 mg/g for CV and 2.86 mg/g for PR. Moreover, a pseudo‐second‐order kinetic equation with R² value of 0.9999 was found in this adsorption process. To identify the chemical and morphological characteristics and surface functional groups, nanocomposite of CCAC was characterized using field emission scanning electron microscopy and Fourier‐transform infrared spectrophotometry. The obtained results indicate that the prepared CCAC can be used as a promising low‐cost dye (CV and PR) removing adsorbent from aqueous solutions.     

Preparation of Long Glass Fiber Reinforced Poly(butylene terephthalate) Composites with Chemical Bonding Interphase

Long glass fiber reinforced poly(butylene terephthalate) composites (LGF/PBT) were prepared by a new process. PBT oligomers with low melt viscosity were impregnated into the reinforcing glass fiber and then grafted to the reinforcing glass fiber surface treated with a silane coupling agent during solid‐state polymerization. The reinforcing glass fiber, after removing ungrafted PBT from LGF/PBT, was investigated with the result showing the presence of a grafted PBT layer on the surface of treated glass fiber. The mechanical properties of the composites were significantly improved owing to the grafting of the PBT macromolecules. The fiber length distribution and fiber arrangement in the injection molded composites were also studied and the results showed that a small amount long glass fiber could be connected at junction points in the composites, which were of benefit to the mechanical properties of the composites.     

ξ-potential and surface dye-ability of poly(vinyl alcohol) fiber with different degree of formalization in a cationic dye solution

Summary The surface dyeability of the poly(vinyl alcohol) fiber with different degree of formalization was studied by measuring -potential of the fiber in alkaline aqueous solutions (pH 10) of a cationic dye Methylene Blue. With the increase in the dye concentration, the sign of the -potential of the fiber changed from negative to positive and thereafter the positive value approximated to saturated value, and the amount of dye adsorbed (expressed in mol/cm²-fiber) increased also. These results may possibly be attributed to the formation of the electrostatic bond between the fiber and the dye. The linear relations were found between and logC _d and its slope did not change with rise of temperature. The free energy of dyeing G (negative) calculated from the slope of the -logC _id curve, etc. increased with increasing the degree of formalization of the fiber. This fact corresponds to the increase in the surface dye adsorption with increasing the degree of formalization. With increasing the degree of formalization, the heat of dyeing H (negative) increased and the entropy of dyeing S (positive) decreased. The positive value of S for each fiber, suggests the formation of hydrophobic bond as a driving force to the dyeing of Methylene blue on the fiber surface in addition to the electrostatic bond.This paper is Part XXVII in a series on Studies on -potentials and Surface Dyeability of Natural and Synthetic Fibers in Dye Solution. Part XXVI: T. Suzawa andK. Kawakami, Nippon Kagaku Kaishi1975, No. 7,1134.     

Eco-friendly and protective natural dye from red prickly pear (Opuntia Lasiacantha Pfeiffer) plant

New natural dye extracted from red prickly pear was used for dyeing wool with different types of mordents. The effect of mordant concentration on the color strength was discussed; the results obtained indicated that the color strength decreases with the increase of mordant concentration. The effect of the dye bath pH, salt concentration, dyeing temperature and dyeing time was also studied. The color strength and the dye uptake have exhibited high values. Good fastness properties of the dyed fabric were achieved.Antimicrobial activity of wool fabric dyed with this dye was tested according to diffusion agent. Test organisms as Escherichia coli, Bacillus subitilus, Pseudomons aeruginosa and Staphylococcus aureus were used and the results indicated that the samples exhibited a high inhibition zone.According to the available literature, this is the first report concerning a natural dye for fabric from fruits of red prickly pear plants.     

Chemical recycling of PET waste into hydrophobic textile dyestuffs

The paper aims at effective chemical recycling of poly(ethylene terephthalate) (PET) fiber waste into useful products, such as hydrophobic disperse dyes for synthetic textiles. For this, PET fiber waste was glycolytically depolymerized using excess of ethylene glycol in the presence of sodium sulfate as catalyst. The product, pure bis(2-hydroxyethylene terephthalate) (BHET) was obtained with >60% yield by successive recrystallization. In order to synthesize hydrophobic disperse dyes, applicable to synthetic textile fibers, BHET was converted to bis(2-chloroethylene terephthalate), reacted with the p-nitro benzoic acid, reduced and then reacted with bromine and potassium thiocyanate to get benzothiazole derivative. Coupling with N,N-diethylaniline produced a bright yellow disperse dye (Dye A). Similarly, coupling of p-amino benzoic ester with N,N-diethylaniline led to an orange colored disperse dye (Dye B). These dyes were applied onto polyester fabric by conventional method. Results in terms of depth of dyeing, evenness and the performance characteristics were found to be promising.     

Synthesis of new reactive dyes containing commercial UV-absorbers with enhanced simultaneous dyeing and anti-UV properties for cotton fabric

Two new reactive anti-UV dyes were synthesized based on two commercial UV-absorbers, ethyl 4-aminobenzoate for dye 1 and 4-aminobenzophenone for dye 2, which were incorporated in a structure modified from commercial reactive dye CI Reactive Red 198 (dye 3). Optimum exhaustion and total fixation values were achieved at 80 ​g/l sodium sulphate for dye 1 and 60 ​g/l sodium sulphate for dye 2, 20 ​g/l sodium carbonate at 70 ​°C for dye 1 and 80 ​°C for dye 2 and 60 ​min fixation time for both dyes. The two new reactive dyes exhibited higher dyeing properties and UPF values than the commercial reactive dye over all the dye concentrations studied. The new reactive dye 1 achieved the highest exhaustion, total fixation and UPF values. The fastness properties obtained for all the dyeings ranges from good to excellent.     

Application of phenolic compounds as natural dye extracted from date-pits: dyeing studies of modified acrylic fibres

This research work involves the dyeing of acrylic fabric with natural dye extracted from date pits powders using Soxhlet extraction process. The effect of dye bath pH, salt concentration, dyeing time and temperature were studied. The optimal dyeing conditions where pH 4, 0 g/L salt, 60 min, and 80 °C. The COD and the BOD5 of the residual dye bath were measured and it was shown from the registered values that the residual dye bath presents an acceptable rate of organic discharge.     

Glebionis coronaria (L.) Cass. ex Spach (Asteraceae)- a new fabric dye with potential antibacterial properties

The paper elucidates first ever report on Glebionis coronaria (L.) Cass. ex Spach as a new dyeing agent with high antibacterial activity. Glebionis coronaria (L.) Cass. ex Spach which is also known as Garland/Crown Daisy belonging to the flowering plant family Asteraceae has been identified as a new precursor/candidate to produce highly efficient natural textile dye and a potential antibacterial agent. Natural dye from garland daisy was extracted from the dried petals using DCM and MeOH solvent system. Change in mordants yielded 12 different shades of colours. Spectroscopic analysis of these extracts revealed the presence of carotenoids and flavonoids pigments and hence giving varied shades of yellow, greenish yellow colours (Code No. is assigned to each colour). Alum and stannous chloride have been found to give bright colours while ferrous sulphate gave dark shades of colour. Antibacterial activity of the extracts was studied against non-pathogenic bacteria's, Staphylococcus aureus (Gram-positive bacteria) and for the first time for Aeromonas sp. (Gram-negative bacteria). Two different concentrations of 10 ​mg/ml DCM and methanol extracts using methanol as solvent were tested. Both DCM and methanol extracts have shown inhibition in Aeromonas sp. while only DCM extract was inhibiting S. aureus. The flower extracts has not been evaluated till date for its dyeing properties with different mordants along with their bactericidal activity. Therefore, our present work was to extract natural dye from the flowers of Glebionis Coronaria (L.) Cass. ex Spach. and to do a detailed study.     

Synthesis,Characterization and Properties of a Novel Environmentally Friendly Mono Azo Disperse Dye and Its Application on Polyethylene Terephthalate (PET)

The aim of this research is to achieve the synthesis of a novel mono azo disperse dye containing both a β‐naphthyl acetate group and carboxylic acid ester group and application on PET fabric. In this study the dyeing properties have also been investigated. The synthesized dye was characterized using UV‐Vis, FTIR, ¹H NMR and ¹³C NMR spectroscopic techniques. To investigate alkali‐clearability, both alkali‐hydrolysis behavior and the effect of its fastness properties with regard to PET fabric were examined. This dye showed a reasonable level of hydrolysis under relatively mild alkaline conditions. The application of the dye to PET fabric showed good leveling and building up properties. Estimating fastness properties of the dyed fabric showed excellent wash, rubbing fastness, good light and sublimation fastness. The results furthermore displayed that the synthesized dye offers the option of alkali‐clearing process over that of a conventional reduction‐clearing process. Therefore, the value of Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD) and water pollution as well as the expenditure of production were decreased.     

Characterization of extracts from Papaver rhoeas and potential valorization of these extracts in dyeing applications

The aim of our work is to study the dyeing properties of extracts from natural sources such as Papaver rhoeas by modifying the conditions of the dyeing process, choosing other substrates that could be pretreated by innovative and environmentally friendly processes. The results obtained show a fairly high fixation of the extracts on the natural and artificial fibers. The use of mordants allowed the dye to be better fixed on the dyed fibers and to give several shades to the fabric. The rate of essential oil contained in Papaver rhoeas was considered important by the Clevenger process. Screening of extractive revealed the presence of polyphenols, saponins, sterols, alkaloids and flavonoids. In this study, the extractive from Papaver rhoeas was investigated as textile dyestuff.     

Anthraquinone and Azo Dyes in Dyeing Processes of PET Films and PET Knitted Fabrics Using Supercritical CO2 Medium

Summary: Dyeing processes using supercritical fluid present advantages over the conventional dyeing process using aqueous medium. Previous works from our group on polymeric fibers such as N,N-dimethylacrylamide (DMAAm) modified poly(ethylene terephthalate), PET, showed higher sorption of disperse dyes in supercritical medium. Furthermore, recent studies showed that the association of UV radiation and DMAAm treatment leads to a better incorporation of dyes in modified PET soaked in aqueous medium. In this work, modified and non-modified PET knitted fabrics (KF) were dyed in supercritical CO₂ medium. Azo and anthraquinone dyes were used in order to compare the extent of incorporated dye in PET films and PET KF in supercritical CO₂. The dyeing process variables were studied by factorial design and by a response surface methodology (RSM) technique. The anthraquinone dye presented a better incorporation in PET than the azo dye. The UV light exposure and the dyeing times inputs showed positive main effects in the incorporation of dyes in PET films and PET KF. From the RSM data, DMAAm and UV light modified PET KF presented 7.43 mg of incorporated azo dye by g of PET if the optimized dyeing conditions, time: 135 min and pressure: 212 bar would be used. In the respective optimized dyeing conditions for the anthraquinone dye, time 150 min and pressure 229 bar, the incorporated dye would be 22.9 mg of dye by g of PET.     

“Surface-photografting”: new applications to synthetic fibers

“Surface-photografting” with UV-irradiation of polypropylene (PP) fiber and film and high-strength polyethylene (HSPE) yarn has been made with acrylic acid (AA) and acrylamide (AM) as monomers and benzophenone (BP), 4-chlorobenzophenone (4-BCP) and hydroxylcyclohexylacetophenone (HHA) as photoinitiators using a new continuous method. The grafting reaction occurs in a thin liquid layer on the fiber or film substrate, which is presoaked in a solution containing initiator and monomer. After irradiation with a highpressure mercury lamp, HPM 15 (2 kW) from Philips, for 5–20 sec at about 50°C the fiber and film surface is completely covered with a 2–8 nm thick layer of grafted polymer, analyzed by electron spectroscopy for chemical analysis. The grafting efficiency is 70–80%, i.e. only 20–30% of the polymer is homopolymer which can be removed by extraction. The grafted layers are so thin that they cannot be analyzed as weight increase (<0.1% of fiber weight). Absolute values for the amount of grafted AA polymer is analyzed by microtitration of the COOH groups at the fiber surface. The results agree well with the relative ESCA values. Grafting of commercial PP yarn with AA increases the adsorption of Crystal Violet dye with a factor of about 6. Grafting the same yarn with AM increases the adhesion to epoxy resin by a factor of 3–4 without affecting the mechanical properties of the fiber more than a few percent. For comparison, strips of blown PP film (5 mm wide) are modified by “surface-photografting” with AM. With increasing grafting, the contact angle for drops of distilled water decreases from 90° to 20°, indicating extensive wetting. The adhesion to epoxy resin increases from about 0.35 to 1.7 N/mm², i.e. with a factor of about 5 when the film surface is completely covered. Other comparisons are made with grafting of commercial HSPE yarn. Grafting with AA increases the adsorption of Crystal Violet dye by a factor of about 6. Grafting with AM increases the adhesion to epoxy resin from 0.25 to 1.3 N/nm², i.e. with a factor of 5. The bulk mechanical properties of the HSPE filaments are not affected by the grafting measured as tensile strength 2.7±0.1 GPa, elongation at break 4.8±0.3%, and Young's modulus 55±3 GPa, both before and after “surface-photografting”.     

Optimization of Functional Monomer Content in Protein‐Imprinted Polymers

Abstract

We have prepared synthetic materials having binding specificity toward lysozyme using molecular imprinting. The lysozyme‐imprinted polymers were prepared on silica beads using acrylic acid, acrylamide, and N,N′‐methylenebisacrylamide. The molar ratio of acrylic acid to the template affected the selectivity and the maximum binding specificity was yielded with the molar ratio of 5 to 1 (acrylic acid/template). No binding specificity toward lysozyme was observed when there was no acrylic acid, and the binding specificity decreased when the amount of acrylic acid was high. The functional monomer‐template ratio indicated in this study could be useful for improving the binding specificity in molecular imprinting of proteins.     

Anti‐static Agent Containing Zinc Oxide and its Modification for PA6 Fiber

A new anti‐static agent was synthesized from zinc oxide‐adipic acid‐polyethylene glycol and caprolactam by three‐step reactions. The antistatic agent (called poly(ether ester amide zinc oxide) or PEEAZ) was analyzed by IR and DSC. The results showed that zinc oxide existed in the main chain of PEEAZ. The glass temperature and melt temperature of poly(ether ester amide zinc oxide) (referred to as PEEAZ in the following) decreased with increasing poly(ether ester zinc oxide) increasing in PEEAZ. Antistatic PA6 fiber was obtained by adding PEEAZ 2–8% (wt/wt) to PA6 during blend spinning. The specific resistance and the static half‐value period of PA6 fiber was less than 10⁹Ω · cm and 60 sec, respectively. Excellent antistatic property remained after being washed 30 times.     

Environmentally benign preparation of bifunctional cation exchange fibers

A bifunctional cation exchange fiber was prepared by an efficient and environmentally benign method. In this method, sodium p‐styrene sulfonate (SSS) was cografted directly onto the polypropylene (PP) fiber along with acrylic acid (AA), which eliminated the sulfonation process of grafting fiber with concentrated sulfuric acid or chlorosulfonic acid in the conventional method. Effects of the grafting conditions such as reaction temperature, reaction time, pH value, and the influence of acrylic acid and metallic salt on the graft copolymer reaction were investigated. The physicochemical properties of the cation exchange fibers were characterized with diffuse reflectance infrared spectroscopy (FT‐IR), scanning electron microscopy (SEM), X‐ray diffractometer (XRD), thermal gravimetric analysis (TGA), TG‐IR analysis, and monofilament tensile properties test. The experimental results indicate that the optimal conditions of pre‐irradiation grafting are 80°C for 5 hr, and the mechanical properties and thermal stability of the product are better than those of commercial materials (Fiban.K‐1). The total static ion exchange capacity (IEC) of the cationic exchange fiber is up to 5.33 mmol/g. The maximal IEC contribution from the strong acid part is 2.47 mmol/g. This synthetic method provides a clean industrial way for the preparation of bifunctional cation exchange fibers. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis of an electron-rich aniline-containing dye and its dyeing behaviors on silk through a three-component Mannich-type reaction

Under the guidance of the finding that the tyrosine residues in proteins could undergo three-component Mannich-type reactions with formaldehyde and electron-rich aniline-containing compounds,which forms covalent bonding connections between the protein of interest and the aniline with high levels of selectivity under relatively mild conditions,an orange aromatic primary amine-containing acid dye AMODB was designed and readily synthesized.The molecular structure was characterized by FTIR,~1H NMR,mass spectrometry and elemental analysis.The synthesized dye and a similar control dye(C.I.Acid Yellow 11) without primary amine groups were applied to dye silk fabric by three dyeing processes:Mannich-type dyeing(with and without the addition of formaldehyde) and acidic dyeing.Their washing and rubbing fastness properties with different dyeing methods were examined and compared.It was found that the dyed silk fabric with AMODB by the Mannich-type dyeing showed higher color depth,better anti-stripping ability to DMF and better washing fastness than those of the dyed silk fabric with C.I.Acid Yellow 11 by acidic dyeing due to the covalent bond formation between the dye chromophore of AMODB and silk fiber.In addition,mild Mannich dyeing conditions suitable for silk(AMODB at 3%owf,75:1 liquor-to-goods ratio,dyebath pH 5.5,30℃,10 h) were provided.     

Effects of the chain length of crosslinking agent and dye-doped amount on the electro-optical properties of polymer-dispersed liquid crystal films prepared by nucleophile-initiated thiol-ene click reaction

ABSTRACT

A series of crosslinking agents with different chain lengths were used to explore their effect on electro-optical properties of dye-doped polymer dispersed liquid crystals (PDLCs) film prepared by nucleophile-initiated thiol-ene click reaction. The influences of dye contents and temperatures on electro-optical properties were also investigated. It was found that the increase in chain length of crosslinking agent leads to the increase in driving voltage and the decrease in memory effect. The decrease in reaction temperature causes a decrease in driving voltage and an increase in transmittance. Particularly, the dye content could be optimised to obtain promising materials with minimum driving voltage and high contrast ratio for display applications.     

Dyeing of PA 6.6 fibers

Dyeing fibers at low temperatures has many advantages such as savings in energy and avoiding alterations to the physical properties of the fibers being dyed or other fibers also present in blends. The problem of low temperature dyeing in synthetic fibers is that it difficults the dye diffusion into the fiber. In the case of polyamide 6.6 microfibers, by using benzyl alcohol as an auxiliary dyeing, it was shown that good diffusion was obtained for the dye exhaustion with metal complex dyes at temperatures more than 30°C below the normal dyeing temperature for the dye exhaustion with metal complex dyes. Using thermal analysis methods these results were shown to be caused by the lowering of the T _g of the fiber when in the presence of benzyl alcohol. This revised version was published online in July 2006 with corrections to the Cover Date.     

Stability of Dye Dispersions in the Presence of Various Surface Active Agents and Additives

Disperse dyes are hardly soluble in water. They are usually milled in the presence of large amounts of dispersing agents in the dye industry. The type and amount of these materials can affect the disperse ability of dyes in aqueous media. In this article, stability of prepared dye dispersions in the presence of various surface active agents and additives were investigated. In this respect, various dispersing agents such as Irgasol DAM, Asutol 644, Dispertane MF, and Irgasol P800 were used to prepare dye dispersions in milling stage. Furthermore, the formulations of dye dispersions were obtained by adding β-cyclodextrin, urea, and wetting agent. The dye dispersion quality was determined by its filtering property, turbidity, and centrifuging method. The obtained results proved the stability of dispersion containing of Irgasol DAM, wetting agent, and β-cyclodextrin as dispersing auxiliaries in dyeing process of disperse dye on polyester fabrics in high temperature method was the highest as compared to other dispersions. From the experimental results, it was found out that stability of prepared dispersions was improved by the presence of β-cyclodextrin. Also, utilization of β-cyclodextrin in formulations of dye dispersions caused to increasing of stability of dispersion in the dyeing of polyester fabrics.     

An evaluation of the dyeing behavior of sol–gel silica doped with direct dyes

A new dyeing process of sol–gel silica doped with direct dyes is investigated for improving color strength (K/S value) and dyeing fastness. Cotton fabrics are dyed in this direct dye silica solution. The results indicate that the K/S value of C.I. Direct Blue 86 and C.I. Direct Red 23 are enhanced by 12.8% and 16.8%, respectively. For C.I. Direct Blue 86, the washing staining fastness is improved by half a grade, and the rubbing fastness and the washing change fastness are enhanced by one grade, respectively. Compared to the fabric fixed with fixing reagent MMF-1, the K/S value is improved by about 23.7% and the wet rubbing fastness and washing change fastness are enhanced by half a grade. The formation of uniform continuous layers on the fiber surface dyed with direct dye silica solution is revealed by video microscope, and the calculated sol–gel weight gain on the fabric is 4.6%.