Eco-Friendly Sulfur Dyeing of Cellulosic Woven Fabrics

Abstract

This work demonstrated that conventional sulfur dyeing, which poses environmental problems, can be modified by using safer chemicals. The results indicate that: i) using reducing sugars as eco-friendly reductants results in an improvement in the extent of coloration; ii) the extent of improvement is determined by the reductant type; i.e., liquid glucose (LG) > thiourea dioxide (TUD) > glucose (G) > molass (M), dye/reductant ratio, as well as type of woven cellulosic fabric; i.e., viscose > cotton > linen; iii) raising the dyeing temperature to 80°C for 45 min, increasing NaCl concentration to 30 g/L, and/or minimizing the material-to-liquor ratio to 1/10 brings about an improvement in the extent of coloration; iv) efficiency of dye fixation is determined by the nature of the oxidant and follows the descending order (NH₄)₂ S₂O₈ > Na-perborate > H₂O₂ > none; and v) post-softening has positive impacts on the softness degree and washing fastness, as well as rubbing fastness properties, especially in the case of using the cationic softener, regardless of the sulfur dye used.     

Economical and Ecological Biotreatment/Half Bleaching of Cotton-Containing Knit Fabrics on Industrial Scale

ABSTRACT

Bio-scouring/half bleaching of cotton-containing knit fabrics was carried out on an industrial scale. A comparison between the traditional hot-alkaline scouring/half bleaching and the enzymatic scouring/half bleaching from product quality, economic as well as environment perspectives were made. The results detailed in this case study indicate that (1) the loss in fabric weight as well as the improvement in degree of whiteness are governed by the treatment method (i.e., hot-alkaline scouring/half bleaching > bio-scouring/half bleaching; (2) bio-scouring/half bleaching technique gives rise to better bleaching fabric softness, higher strength retention along with greater depth of shades; (3) the extent of improvement in fabric wettability follows the descending order: hot-alkaline scouring/half bleaching = bio-scouring/half bleaching > > untreated; and (4) the saving in materials and energy costs, the improvement in fabric properties as well as the reduction in pollutants concentrations (i.e., better wastewater quality are determined by the pretreatment technique and follow the descending order: bio-scouring/half bleaching > alkaline-scouring/half bleaching.     

Effective Acid Printing of Protein and Nylon-6 Fabrics Using New Thickening Agents

Printing of wool, silk, and nylon-6 substrates with acid dyes using new thickening agents based on free radical polymerization of acrylic acid (AA) with tamarind seed gum (TG) or karaya gum (KG) was investigated. The depth of the obtained prints follows the decreasing order: PAA/TG2 > PAA/TG1 > PAA/KG1 > PAA/KG2 > GG. Increasing the new thickener concentration up to 75 g and steam fixation at 105°C for 30 minutes gives higher K/S values. Printability substrates follows the descending order: wool > nylon-6 > silk.     

Selective Oxidation of Propane Over AMoVSbO Catalysts (A = Li, Na, K, Rb or Cs)

Alkali metal-containing Mo-V-Sb-O catalysts (AMoVSbO, with A = Li, Na, K, Rb or Cs), prepared hydrothermally and activated at 600 °C in N₂, have been characterized and tested for the selective oxidation of propane. Alkali-doped catalysts resulted to be more selective to acrylic acid and less selective to acetic acid than the corresponding alkali-free Mo-V-Sb-O catalyst. However, the nature of crystalline phases and the catalytic behaviour strongly depend on the alkali metal added. In this way, the catalytic activity decreases as follows: unpromoted > Li- ~ Na- ~ K- > Rb- > Cs-containing catalyst. However the selectivity to acrylic acid decreases in the order: K- > Rb- ~ Na- > unpromoted > Li- > Cs-containing catalyst. The role of the presence/absence of acid sites and cations on both the nature of crystalline phases and the catalytic performance will be discussed.     

Union Dyeing of Easy Care-Finished Wool/Viscose and Cotton/Wool Blends

Wool/viscose (60/40) and cotton/wool (70/30) blended fabrics have been easy-care finished in the presence of certain nitrogenous additives to produce readily dyeable cationic cellulose for competitive dyeing with wool dyes. The enhancement of easy care properties and improvement in post-dyeing of the finished fabrics were determined by the nature of substrate (wool/viscose > cotton/wool), type of catalyst (ammonium persulfate > ammonium sulfate > ammonium chloride > none), the kind of nitrogenous additive, as well as the type of polyethylene glycol (PEG-400 > PEG-200 > NONE). Using triethanolamine hydrochloride as a reactive/nitrogenous additive (30 g/L) in the finishing formulation as well as curing at 150°C/3 min make it possible to attain higher fabric resiliency along with better dye receptivity, regardless of the used anionic dye. However, the change in dyeing and fastness properties of obtained dyeing is governed by the nature of the anionic dye.     

New thickening agents for reactive printing of cellulosic fabrics

Four adducts were prepared by polymerizing acrylic acid (AA) in presence of either a pyrodextrin (D) or gum Arabic (GA), and termed as PAA/D₁, PAA/D_2, PAA/GA_1, and PAA/GA₂. These adducts were utilized as thickeners in reactive printing of cotton fabric in comparison with Na‐Alginate. Printing was carried out at different conditions including: NaHCO₃ concentration (0–40 g/K), urea concentration (0–200 g/k), steaming temperature (100–130°C) and time (5–35 min). At optimal NaHCO₃ concentration (30 g/K) the depth of shade of the prints, expressed as K/S values, depended on the nature of the thickener used, and followed the descending order PAA/D₂ > PAA/GA₁ > Na‐Alginate ?PAA/D₁ ≥ PAA/GA₂. Accordingly, PAA/D₁ and PAA/GA₂ were omitted in subsequent trials. Optimal printing conditions were found to be NaHCO₃ concentration (30 g/K), urea concentration (100 g/k), steaming temperature (110°C), and time (15 min). The apparent viscosity of a printing paste, as well as both of K/S value and fastness properties of a print were governed by the nature of the reactive dye and type of thickener. Storing of a printing paste up to 7 days resulted in a decrease in its apparent viscosity along with a slight reduction in K/S value and a little variation in some fastness properties of prints. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4430–4439, 2006     

Liquid – Liquid Extraction and Pertraction of Eu(III) from Nitric Acid Medium Using Several Substituted Diglycolamide Extractants

Solvent extraction and supported liquid membrane (SLM) transport properties of Eu(III) from nitric acid feed conditions were investigated using several substituted diglycolamide (DGA) extractants such as N,N,N′N′-tetra-n-octyl diglycolamide (TODGA), N,N,N′N′-tetra(2-ethylhexyl) diglycolamide (T2EHDGA), N,N,N′N′-tetra-n-hexyl diglycolamide (THDGA), N,N,N′N′-tetra-n-pentyl diglycolamide (TPDGA), and N,N,N′N′-tetra-n-decyl diglycolamide (TDDGA). Effects of feed acidity and phase modifier composition on Eu(III) extraction were investigated using the DGAs and the nature of extracted species were ascertained by slope analysis method. The Eu(III) distribution ratio (D_Eu) values were found to decrease in the presence of iso-decanol. In general, the D_Eu values decreased with increased alkyl chain length of the DGA. The extracted species contained only 2 extractant molecules when TPDGA and TDDGA were used while for TODGA about four extractant molecules were found to be present in the extracted species.

The supported liquid membrane transport of Eu(III) was studied under varying experimental conditions using the five DGA extractants. Transport studies using 0.1 M DGA as the extractant suggested the trend as TDDGA > TODGA > T2EHDGA ～ THDGA which significantly changed to TPDGA > THDGA > TODGA > TDDGA > T2EHDGA in the presence of 30% iso-decanol as the phase modifier. The permeability coefficient (P) values were also determined with membranes of varying pore sizes.     

New Approach for Improving UV-Protecting Properties of Woven Cotton Fabrics

Abstract

This study evaluates the impact of certain finishing formulations, posttreatment with copper acetate as well as type of cotton fabric on the easy-care properties and UV protection of treated fabrics. The results detailed in this article indicate that (1) increasing the finishing agent concentration results in a significant increase in both the nitrogen content and the fabric resiliency along with a marginal improvement in UV protection factor (UPF) values, regardless of the used cross-linking agent; (2) incorporation of choline chloride (20 g/L) or chitosan (5 g/L) in the finishing formulation brings about an increase in the nitrogen content, a decrease in fabric resiliency along with an improvement in UPF values; (3) inclusion of PEG-600 or β-cyclodextrin as a polyol additive (20 g/L) has a negative impact on the % N and fabric resiliency along with a positive impact on UPF values; (4) posttreatment of the aforementioned treated fabric samples with copper acetate solution (5 g/L) causes a dramatic improvement in the UPF, regardless of the used additive; (5) addition of citric acid or butantetracarboxylic acid (BTCA), 20 g/L, to the finishing formulation enhances both the % N and fabric resiliency along with an increase in UPF values; (6) post-treatment of cross-linked cotton fabric containing carboxyl groups with copper acetate solution (5 g/L) is accompanied by a sharp increase in UPF values, regardless of the added polycarboxylic acid; (7) the improvement in easy care properties is governed by the nature of the substrate (i.e., mill-scoured, bleached, and mercerized cotton > mill-scoured and bleached cotton > gray cotton), regardless of the used finishing formulation and type of additive; and (8) the opposite holds true for the UPF values especially before posttreatment with copper acetate.     

The quest for alternatives to microbial cellulase mix production: corn stover‐produced heterologous multi‐cellulases readily deconstruct lignocellulosic biomass into fermentable sugars

BACKGROUND: Production of cellulosic ethanol is still expensive compared with corn (maize) grain ethanol due to the high costs of bulk production of microbial cellulases. At least three cellulases including endo‐cellulase, exo‐cellulase and cellobiase are needed to convert cellulosic biomass into fermentable sugars. All these cellulases could be self‐produced within cells of transgenic bio‐energy crops. The production of heterologous Acidothermus cellulolyticus (E1) endo‐cellulase in endoplasmic reticulum and mitochondria of green tissues of transgenic corn plants was recently reported, and it was confirmed that the heterologous E1 converts cellulose into fermentable sugars. RESULTS: Biologically active A. cellulolyticus E1, Trichoderma reesei 1,4‐β‐cellobiohydrolases I (CBH I) exo‐cellulase and bovine rumen Butyrivibrio fibrisolvens cellobiase were expressed in corn plant endoplasmic reticulum (ER), apoplast (cell wall areas) and vacuole respectively. Results show that the ratio 1:4:1 (E1:CBH I:cellobiase) of crude heterologous cellulases is ideal for converting ammonia fiber explosion (AFEX) pretreated corn stover into fermentable sugars. CONCLUSIONS: Corn plants that express all three biologically active heterologous cellulases within their cellulosic biomass to facilitate conversion of pretreated corn stover into fermentable sugars is a step forward in the quest for alternatives to the present microbial cellulase mix production for cellulosic biofuels. Copyright © 2011 Society of Chemical Industry     

Properties of UV-cured pigment prints on textile fabric

This paper studies and evaluates the UV-curing of pigment prints on textile fabric using a prototype UV scanner. A printing paste comprising synthetic thickener, emulgator, binder, pigment dispersion and photoinitiator was applied using a flat screen printing technique onto the cotton fabric, then dried and exposed to heat or UV-radiation under a mercury vapour lamp (200 W cm⁻²). The characteristics of cured prints such as paste add-on, colour properties, colour fastness to washing and dry/wet rubbing were evaluated, together with fabric stiffness. The effects of UV-curing were evaluated by Attenuated Total Reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The properties of the UV-cured pigment prints were compared with those of the thermal cured prints. Analyses of the obtained results helped to define the optimum composition of the photo reactive pigment paste, and the UV-curing conditions under which satisfactory results were obtained, comparable with those from the thermal curing method.     

New Approach for Imparting Antimicrobial Properties for Polyamide and Wool Containing Fabrics

Direct fiber polymer/antibiotic interaction is a promising means of providing infection resistance textile fabrics. Ionic interaction between cationic reactive groups (antibiotic) and carboxylic groups in wool, wool/polyamide, wool/polyester, and polyamide was used as a tool to develop desirable, durable antimicrobial fabrics.

The finishing conditions such as pH, finishing temperature, and time were studied.

The results revealed that pH of the finishing bath and the antibiotic concentration as well as finishing temperature were very critical parameters in affecting exhaustion of the antibiotic by the fabric along with the extent of ionic interactions. Sorption of doxymycin antibiotic follows the descending order: wool > wool blends>polyamide. Zone of inhibition of all treated fabrics is governed by the pH and follows the descending order: pH 6.5 > pH9 > pH 2.3.

FTIR Spectroscopy confirmed the ionic interaction between wool 100%, wool/polyamide (50%/50%) and doxymycin, because of appearance of new bands at 1641 cm^?1 which attributed to NH₂ deformation amide I and band at 1514 cm^?1 corresponding to amide II (in case of wool 100%). For wool/polyamide blend it is noticed that appearance of new bands at 1415 cm^?1 corresponding to C-N stretching (amide III band for CONH₂, in addition to the appearance of new band at 927 cm^?1 which could be assignments for CO-NH in plane.

Reusing of the treatment bath was tried and proved to be very effective approach to produce infection-resistant biomaterials for medical applications.     

Adsorption of different dyes from aqueous solution using Si-MCM-41 having very high surface area

Adsorption characteristics of four different dyes Safranin O (cationic), Neutral Red (neutral), Congo Red (anionic) and Reactive Red 2 (anionic) on Si-MCM-41 material having very high surface area are reported. The surface morphology of Si-MCM-41 material before and after adsorbing dye molecules are characterised by FTIR, HRXRD, nitrogen adsorption–desorption isotherms, FESEM, and HRTEM. The adsorption capacities of Si-MCM-41 for the dyes followed a decreasing order of NR > SF > CR > RR2. The adsorption kinetics, isotherm and thermodynamic parameters are investigated in detail for these dyes using calcined Si-MCM-41. The kinetics and isotherm data showed that both SF and NR adsorb more rapidly than CR and RR2, in accordance with pseudo-second-order kinetics model as well as intraparticle diffusion kinetics model and Langmuir adsorption isotherm model respectively. The thermodynamic data suggest that the dye uptake process is spontaneous. The high adsorption capacities of dyes on Si-MCM-41 (q_m = 275.5 mg g^?1 for SF, q_m = 288.2 mg g^?1 for NR) is explained on the basis of electrostatic interactions as well as H-bonding interactions between adsorbent and adsorbate molecules. Good regeneration capacity is another important aspect of the material that makes it potent for the uptake of dyes from aqueous solution.     

Ozone Production with Dielectric Barrier Discharge from Air: The Influence of Pulse Polarity

ABSTRACT

This research aims to study the effects of different pulse modes of the power supply on ozone production from air. Single positive, negative as well as the bipolar voltage pulses (positive–negative and negative–positive) with a repetition rate of 300 Hz have been applied to coaxial dielectric barrier discharge arrangement. Results reveal that at fixed specific input energy (SIE), which is defined as the ratio of power to gas flow rate, the ozone generation efficiencies for different pulse modes are in the sequence of positive > positive–negative > negative–positive > negative, and the difference between positive and positive–negative pulse becomes considerable with SIE higher than 500 J/L. Results also reveal that the maximum NO₂ concentration is obtained at 400 J/L. Moreover, utilizing bipolar pulse can reduce N₂O production with SIEs higher than 250 J/L and hinder NO₂ production with SIEs higher than 350 J/L.     

UV-Protective Finishing of Cellulose/Wool Blended Fabrics

There is a growing need and special attention for using textile products to provide effective protection against such damage of UV-radiation, i.e., skin cancer, sun burn, and photo-aging, in the recent years. In this research work a new approach for upgrading the UV-protective properties of cotton/wool and viscose/wool blended fabrics for high quality/trans seasonal apparel, was investigated. Factors affecting the UVB-protection function of the aforementioned substrates such as type and concentration of finishing additives, as well as subsequent treatment with cu-acetate or dyeing with anionic or cationic dyes were studied. The experimental data show that: i) the enhancement in the UV-protection factor (UPF) of the finished fabrics is determined by the type of finishing additives, i.e., citric acid ≥ aspartic acid ≥ tartaric acid ≥ none, chitosan TEA.HCL ≥ choline chloride ≥ none, β-cyclodextrin CMC-30 PEG-600 > none, and Siligen® WW > W Siligen® PEP ≥ Leomin® NI-ET ≥ none, regardless of the used substrate, ii) UPF values are governed by the type of substrate, i.e., viscose/wool ≥ cotton/wool, irrespective of the used additives, iii) post-treatment with cu-acetate or post-dyeing with the used dyestuffs brings about a dramatic improvement in UPF values, and iv) UPF values are determined by the finishing regime and follow the descending order:

Resin finishing → post dyeing > resin finishing → posttreatment with Cu-acetate > resin finishing in presence of additives > resin finishing in absence of additives.     

Role of Temperature in the Structure of Zn(II)-1,4,-BDC Metal-Organic Frameworks and their Adsorption and Diffusion Properties for Carbon Dioxide

The role of reaction temperature in the structure of Zn(II)-1,4,-Benzendicarboxylic-MOFs (Zn-BDC-MOFs) and subsequently their CO₂ adsorption properties were investigated. Crystal morphology and phase structure of the Zn-BDC-MOFs were characterized by SEM and PXRD. Stability and textual properties of the Zn-BDC-MOFs were analyzed by using accelerated surface area and porosimetry apparatus (ASAP) and thermogravimetric analysis (TG). Adsorption equilibrium and diffusion of CO₂ on these materials were experimentally studied by the gravimetric method in the pressure range up to 1 atm at room temperature. Results showed that reaction temperature changed the coordination mode of 1,4,-Benzendicarboxylic acid ligand and caused the different structures and pore texture of Zn-BDC-MOFs. High reaction temperature was good for the generation of the three-dimensional MOFs with a higher adsorption capacity for CO₂ but lower gas diffusivity. In contrast, low reaction temperature could cause the monodentate ligand in metal centers and form the low-dimensional MOFs with a lower adsorption capacity for CO₂ but higher gas diffusivity. The order of CO₂ adsorption uptake and diffusion time constant were given as MOF-130T > MOF-50T > MOF-100T > MOF-75T and MOF-50T > MOF-75T > MOF-100T > MOF-130T, respectively.     

New Approach for Easy-Care Finishing of Woolen Fabric

Abstract

A new approach for improving the durable press properties of wool fabric was investigated. The new technique involves padding with finishing bath containing DMDHEU at pH 2 using different acids, batching for 2 h at room temperature, followed by passing through a neutralizing bath containing triethanolamine (3 g/L) as an acid scavenger, and drying at 120°C/5 min. The results indicate that: i) wool fabric samples finished with the aforementioned technique acquire better durable press properties, higher whiteness index, and higher extent of post-dyeing, regardless of the acid used; ii) of the various acids used, HCl along with its amine salt, constitute a highly efficient catalytic system; iii) increasing DMDHEU concentration up to a certain limit has a positive impact on the dry and wet fabric resiliency, whiteness index, protection properties against moth attack, as well as on the extent of post-dyeing; and iv) the extent of improvement in the aforementioned properties is governed by the type of finishing agent and follows the descending order: Arkofix®NG > Fixapret®Eco, irrespective of the catalytic system used.     

Adsorptive removal of nitrogen compounds from fuel oil by a poly ionic liquid PVIm-PXDC

ABSTRACT

A poly ionic liquid, poly(1-vinyl imidazole)-p-xylylene dichloride (PVIm-PXDC), was synthesized and used for fuel oil denitrogenation. The structure of PVIm-PXDC was characterized and the denitrogenation performance was investigated. Results indicate that the pseudo-second-order kinetic model and Langmuir model are appropriate to describe the adsorption kinetics and thermodynamics, respectively. The adsorption ability of PVIm-PXDC for different nitrogen compounds follows the order of indole > pyrrole > quinoline > pyridine. The equilibrium adsorption amount decreased about 10% for all the nitrogen compounds after six regeneration cycles and the denitrogenation and regeneration processes have no influence on the structure of PVIm-PXDC.     

Stable Tin Chloride Perovskite Sensitized Silver Doped Titania Nanosticks Photoanode Solar Cells with Different Hole Transport Materials

Perovskite sensitized solar cells (PSSCs) have recently been catapulted to the cutting edge of thin-film photovoltaic research and development because of their promise for higher power conversion efficiencies and ease of fabrication. In this work, an attempt has been made to fabricate CH₃NH₃SnCl₃ perovskite sensitized silver doped titania nanosticks photoanode solar cells with an efficient hole transport material (HTM), spiro-MeOTAD, poly(3-hexylthiophene-2,5-diyl) (PTTA) and CuI and attained light to electricity power conversion efficiency (PCE) of 10.46, 7.89 and 6.05 % respectively, under AM 1.5G illumination of 100 mW/cm² intensity. As well, PSSCs made with redox couple electrolytes namely quasi-solid state electrolyte (QSSE) and ionic liquid (IL) electrolyte exhibited the PCE of 4.92 and 3.20 % respectively. A metal oxide (HfO₂) layer is coated on the perovskite sensitized photoanode, which could increase the stability of PSSCs. The current density (Jsc)–open circuit voltage (Voc) study shows that PSSCs made with HTMs exhibited better fill factor and PCE. The electron impedance spectroscopy revealed that the electron lifetime (τ_n), electron mobility (µ) and charge collection efficiency (η_cc)in the PSSCs are in the order spiro-MeOTAD > PTTA > CuI > QSSE > IL. This work expresses that the nature of the HTM is essential for charge recombination and elucidates that finding an optimal HTM for the perovskite solar cell includes controlling the perovskite/HTM interaction.     

Kinetic Studies on the Exchange of Bivalent Metal Ions on Amberlite IRC‐718—An Iminodiacetate Resin

Abstract

The rate of uptake of alkaline earth metals, copper, and lead have been investigated by a chelating ion exchange resin containing iminodiacetic acid as ligand attached to the copolymer of styrene and divinyl benzene of macroporous matrix structure. It binds alkaline earth metals, Cu, and Pb by the formation of chelate complexes with the carboxylate group of this resin. The experiments discussed in this work have allowed to establish the paramount importance of the presence of this chelating group in obtaining practically useful rates of metal ion uptake. The kinetic parameters like diffusion coefficient (D _o), activation energies (ΔE _a) and entropy of activation have been evaluated under the conditions favoring a particle diffusion control mechanism and the study followed the three models i.e., Nernst Planck, B _t technique and Ash model. K _d values in demineralised water (DMW) were found in the order Cu²⁺ > Pb²⁺ > Mg²⁺ > Sr²⁺ > Ba²⁺ > Ca²⁺.     

Total Oxidation of Dichloromethane Over Metal Oxide Catalysts

Three different transition metals (V, Mn and Cu) supported on TiO₂, MgO and CeO₂, were investigated for their performances in dichloromethane oxidation (500 ppm, 704,867 h^?1) in moist conditions as a model reaction for the destruction of chlorinated volatile organic compounds. The catalysts were prepared by sol–gel method followed by wet impregnation of V, Mn or Cu precursors. The activities were evaluated in the temperature range from 100 to 500 °C with 5 °C min^?1 temperature rise. The orders of activity and selectivity to HCl of the catalysts is CuTi > VMg > CuCe > CuMg. A correlation between acidic properties of support and performances was observed as the activity of copper catalysts followed the acidity order of supports.