Adsorption of Aroma Chemicals on Cotton Fabric in Different Aqueous Environments

Surfactants enhance adsorption of an aroma chemical on cotton fiber. Strong hydrophobic and electrostatic interactions between surfactant and fiber substrate result in higher adsorption of surfactant/aroma chemical aggregates than for the aroma chemical alone, with higher adsorption for cationic systems than for anionic systems. Adsorption is attributed to solution physical entrapment, hydrophobic interaction, dispersion forces, and interaction with surfactant molecules adsorbed on fiber. Log P and water solubility are important factors in aroma chemical adsorption. Hydrophobicity increased selective partitioning of aroma chemicals on the fiber surface particularly in the presence of surfactants. Statistical analyses indicate some evidence of polar–polar interaction between aroma chemicals and cellulose. With no surfactant, more adsorption is often observed in systems with a higher concentration of NaCl. The screening effect of electrolytes increases with the electrolyte reducing the energy of the liquid–solid interface. Lower interfacial energy results in increased adsorption of an aroma chemical on the fiber surfaces. Electrolyte screening affects aroma chemical adsorption most for anionic surfactant systems. Increase in the concentration of the electrolyte increases the screening effect that reduces the repulsive forces between the anionic molecules and weakly electronegative cotton fiber surfaces. In a cationic system, the screening effect of the electrolyte reduces adsorption of aroma chemicals with increased electrolyte concentration, due to the screening-reducing attraction between cationic surfactant molecules and the fiber surface. Chemical functionality shows a significant effect (alkanol ≥ ketone ≥ aldehyde > ester) on adsorption. Adsorption increased with increasing molecule ovality. Statistical analyses indicate that molecular shape within a chemical class of compounds influences adsorption of the aroma chemical.

A quantitative study of factors that influence the substantivity of fragrance chemicals on laundered and dried fabrics

Model investigations of physicochemical aspects of the substantivity of fragrance raw materials on laundered fabrics were performed. The overall process was divided into two consecutive steps, laundry and dryout, which were characterized by affinity and tenacity, respectively. The affinities of fifteen fragrance raw materials to cotton and polyacrylonitrile were measured in standard fabric softener and detergent solutions. Affinities correlated with the corresponding partition coefficient, P(o/w). To study the impact of parameters independent of the chemical structure of the fragrance molecules, 1-[³H]-3-methyl-5-phenylpentanol (phenylhexanol) was selected, and aqueous solutions of defined anionic, nonionic and cationic surfactants were used as model detergent and fabric softener media. A sequence of experiments, based on the fractional factorial design, was planted for quantifying the relative contribution on substantivity of a number of variables: the concentration of the fragrance chemical, the type and concentration of the surfactants, the type and weight of the fabrics (cotton or polyacrylonitrile) and the washing temperature in the case of cotton. The affinity that characterizes the washing process depends mainly on the type of fabric and the type of surfactant and, to a lesser extent, on the surfactant concentration and the temperature. Anionic and nonionic surfactants, the main components of detergent powders, behave similarly, whereas the combination of cationic surfactant with cotton markedly enhances the affinity. For phenylhexanol, the tenacity after dryout is largely controlled by the type of fabric. The role of fiber swelling is discussed. The substantivity, which represents the global effect of laundering and dryout, shows the same trend as the affinity. The complexity of the physicochemical phenomena involved is highlighted by the importance of the interactions between the main contributing factors.     

Adsorption of dyes to cotton and inhibition by polymers

This paper addresses some key factors that control the transfer of dyes between garments during detergency. It is shown that adsorption of a series of substituted arylazo-2-naphthol dyes to cotton under simulated detergency conditions is influenced by the log P fragment value of the dye substituent; this suggests that hydrophobic interactions make an important contribution to the binding free energy. The comparative effectiveness of nonionic, zwitterionic and cationic polymers in inhibiting adsorption of dye to cotton was also investigated. Increase in polymer concentration reduces dye adsorption to cotton; increase in polymer molecular weight at constant polymer concentration also inhibits dye adsorption up to a molecular weight of ca. 20000, above which there is no further change. Anionic surfactants reduce the efficacy of polymers by displacing dyes from polymers. Surprisingly, certain dyes become relocated in polymer/surfactant complexes; binding is much more effective than in corresponding surfactant micelles.     

Mechanistic Studies of Particulate Soil Detergency: I. Hydrophobic Soil Removal

The mechanism of particulate soil detergency using aqueous surfactant systems is not well understood. In this research, carbon black (model hydrophobic soil) removal from a hydrophilic (cotton) and hydrophobic (polyester) fabric is studied using anionic, nonionic, and cationic surfactants. The zeta potential, solid/liquid spreading pressure, contact angle and surfactant adsorption of both soil and fabric are correlated to detergency over a range of surfactant concentrations and pH levels. Electrostatic repulsion between fabric and soil is generally found to be the dominant mechanism responsible for soil removal for all surfactants and fabrics. Steric effects due to surfactant adsorption are also important for nonionic surfactants for soil detachment and antiredeposition. Solid/liquid interfacial tension reduction due to surfactant adsorption also aids in detergency in cationic surfactant systems. Wettability is not seen as being an important factor and SEM photos show that entrapment of soil in the fabric weave is not significant; the particles are only attached to the fabric surface. Anionic surfactants perform best, then nonionic surfactants. Cationic surfactants exhibit poor detergency which is attributed to low surfactant rinseability.     

Effects of aroma chemical vapor pressure and fiber morphology on the retention of aroma chemicals on cotton and poly(ethylene terephthalate) fabrics

Aroma chemicals with vapor pressure in the range of 10–7460 mPa were applied onto cotton and poly(ethylene terephthalate) (PET) fabrics. Retentions on these two fabric substrates were measured using gas chromatography/mass spectrometry (GC/MS), while distribution on and within fiber was graphically demonstrated by backscattered electron microscopy (BSE). Aroma chemicals with low vapor pressures were retained on the fabrics to a larger extent than aroma chemicals with higher vapor pressures. Larger amounts of aroma chemicals were retained on cotton than on PET. Effect of fiber type on retention was largest for aroma chemicals with higher vapor pressures; for example, 20% of allyl cyclohexyl propionate (1360 mPa) was retained on cotton fabric after 480 min, while none was detected on PET as compared to ambrettolide (30 mPa) that had no difference between cotton and PET after 480 min. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1720–1723, 2006     

Effect of cotton substrate characteristics upon surfactant adsorption

It is shown that the reported differences in anionic surfactant adsorption on cotton can be largely attributed to the presence of variable amounts of natural wax on the fiber surface. High adsorption values with peaks near critical micelle concentration (cmc) result from surfactant adsorption on the wax surface. Wax-free surfaces fail either to show the same high maxima or the same relative magnitude of adsorption. At surfactant cmc the adsorption relationship for waxy cotton (millimoles/g. of cotton) cationic: nonionic: anionic was roughly 66 to 17 to 74. For dewaxed cotton, this became 40 to 10 to nil. Confirming the findings of others, no adsorption by cotton of sodium tripolyphosphate occurs either with waxy or wax-free cotton. Also addition of tripolyphosphate decreased the adsorption of several anionic surfactants. At concentrations greater than cmc and at sufficiently-high solution temperature, anionic surfactants can solubilize cotton wax, leaving a less waxy substrate upon which adsorption is then reduced.     

Adsorption of dyes to cotton and inhibition by surfactants, polymers and surfactant–polymer mixtures

A wide-ranging investigation has been made of the adsorption of direct dyes to cotton and of inhibition by surfactants, polymers and polymer–surfactant mixtures. Generally, the selected polymers are extremely effective at inhibiting adsorption of most of the direct dyes to cotton but are less effective at inhibiting adsorption of small, model azo dyes. Micellar solutions of zwitterionic and cationic surfactants can inhibit adsorption of both small dyes and commercial dyes. It is shown that anionic surfactants at sub-micellar concentrations can inhibit polymer-dye interactions due to displacement of dye and/or relocation into micelle-like polymer–surfactant complexes. New insights have been obtained into the interactions of dyes with cotton and with polymers, surfactants or their mixtures, particularly into observed dye selectivities.     

Applying the Taguchi method to examine the optimal parameters of cotton fabric dyeing by biodegradable surfactant

Wastewater from the cotton fabric dyeing process causes high levels of environmental pollution. In order to address this problem, this study used a series of biodegradable surfactants in cotton fabric dyeing and applied the Taguchi method to analyse the optimal parameters of cotton fabric dyeing by such surfactants. The test parameters included the hydrophobic group chain length of the surfactant, and surfactant concentration and the processing time. This study calculated the signal‐to‐noise ratio of the experimental results by the‐larger‐the‐better characteristic and applied analysis of variance to discuss its impact on the dyeing results. The results confirmed that the most important influential factor is processing time, followed by surfactant concentration. Moreover, the addition of surfactant could promote a dyeing effect during processing.     

Enhancement in electrical conductive property of polypyrrole‐coated cotton fabrics using cationic surfactant

Recently, great efforts have been made to gain highly conductive fabrics for smart textiles and flexible electromagnetic shielding materials. Different from the conventional chemical synthesis method, fibrillar polypyrrole was synthesized on the cotton fabrics via a simple chemical polymerization process with micelles of cationic surfactant (cetyltrimethylammonium bromide, CTAB) as soft template. The modified cotton fabric exhibited excellent electrical conductivity and electromagnetic interference shielding effectiveness due to the formation of fibrillar polypyrrole on the fiber surface. Electrical conductivity of fabric surface were studied by four‐probe resistivity system. The highly conductive fabric with surface conductivity of 5.8 S cm^?1 could be obtained by changing cationic surfactant concentration. The electromagnetic interference shielding effectiveness (EMI SE) of the modified fabrics was evaluated by the vector network analyzer instrument. Compared with the sample without using surfactant, the EMI SE value of PPy‐coated cotton fabrics increased by 28% after using 0.03 M CTAB as soft template. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43601.     

Development of Polyoxyethylene Zwitterionic Surfactants for High-Salinity High-Temperature Reservoirs

Substantial efforts are underway to improve the recovery factor from existing oil reserves to meet the ever-growing global oil demand. Surfactants are known to increase oil recovery through reducing interfacial tension (IFT) and/or altering the rock wettability. The selection of surfactants for high-salinity high-temperature oil fields is a challenging task owing to poor thermal stability, precipitation, and adsorption of surfactants on reservoir rocks. Sulfobetaine-based polyoxyethylene zwitterionic surfactants have shown excellent thermal and surface properties. However, their solubility in high-salinity brines becomes poor particularly with a long hydrophobic tail (>C17). Recently, we synthesized such types of surfactants by incorporating ethylene oxide (EO) units into the hydrophobic tail, which improved the solubility in formation water (213,734 ppm) and seawater (SW) (57,643 ppm). In this work, we investigated the IFT, thermal stability, rheological behavior, and foaming properties of two polyoxyethylene zwitterionic surfactants having different degrees of ethoxylation. Aging experiments exhibited excellent thermal stability and no change in the chemical structure was detected. The surfactant with lesser EO units (EASB-1a) showed a lower IFT compared to the surfactant with higher EO units (EASB-1b). Rheological studies revealed that the addition of both surfactants reduced the viscosity of the acrylamide copolymer. However, the effect of EASB-1a was more prominent compared to that of EASB-1b. The surfactant with a higher degree of ethoxylation showed lower adsorption compared to the surfactant with a lesser degree of ethoxylation. Both surfactants showed excellent foamability and foam stability compared to the commercial surfactants. Excellent thermal stability, water solubility under harsh reservoir conditions, foaming properties, and lower adsorption make them a suitable choice for high-temperature, high-salinity reservoirs.     

Effects of surfactants on rheological properties of a dispersed viscoelastic microsphere

The swelling ratio is an important performance for the application of viscoelastic microsphere. The reduction of swelling ratio can affect the particle size. The compatibility between particle size and formation pore can affect the plugging performance and EOR capability. Adsorption characteristics of cationic surfactant cetyltriethylammnonium bromide (CTAB), anionic surfactant petroleum sulfonate applied in GangXi oilfield (GXPS), and nonionic surfactant nonylphenol ether (TX‐10) onto viscoelastic microspheres and the effect of the three types of surfactant on swelling ratio of viscoelastic microspheres were investigated. Effects of surfactants on rheological properties of viscoelastic microspheres were researched in two different modes referring to steady shear and dynamic shear, respectively, using Physica MCR301 Rheometer. The results showed that the interactions between viscoelastic microsphere and surfactants CTAB were electrostatic attraction and hydrophobic association, that the interaction between viscoelastic microsphere and surfactants TX‐10 was just hydrophobic association, and that the interactions between viscoelastic microsphere and GXPS were electrostatic repulsion and hydrophobic association. At the same initial surfactant concentration, all these three types of surfactant could be adsorbed onto the surface of viscoelastic microspheres and reduce its swelling ratio and storage modulus. Because of different amount of adsorption, the extent of reduction order on swelling ratio and storage modulus was CTAB>TX‐10>GXPS. In addition, the yield stress of viscoelastic microspheres which was obtained from modeling the data to Herschel‐Bulkley model decreases with the increase of surfactant adsorption. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42278.     

The Impact of In‐situ Fabric Surface Energy on Dehydration of Fabrics

Reducing liquid surface tension is widely used to increase the efficiency of the centrifugal dehydration in textile wet processing. However, increasing the dehydration efficiency by decreasing fabric surface energy is seldom studied. In this work, the impact of in situ fabric surface energy on residual moisture content (RMC) of fabrics in the dehydration processes was investigated. Different types of fluorocarbon surfactants including cationic, anionic, nonionic and amphoteric were adopted as additives in this study. The liquid surface tension and RMC were efficiently decreased when fluorocarbon surfactants were used. Notably, a cationic fluorocarbon surfactant displays similar surface tension but distinct dehydration efficiency. The in situ fabric surface energy was evaluated by measuring the n‐octane contact angle on the cotton fabric surface under the surfactant solution using the captive bubble method. It was found that the cationic fluorocarbon surfactant system gave the lowest fabric surface energy, which was probably because cationic fluorocarbon surfactants are easier to adsorb onto the surface of cotton fabric to form a fluorocarbon layer. The chemical composition (¹⁹F, ¹²C and ¹⁶O) analysis of the cotton fabric surface by X‐ray photoelectron spectroscopy confirms the hypothesis.     

Nonionic surfactants and dispersants for biopolishing and stonewashing with Hypocrea jecorina cellulases

Cellulases are widely applied in textile finishing, such as for the removal of protruding surface fibrils to reduce pilling propensity and to achieve the worn‐out look in denim garments. The main drawback of enzymatic denim processing is the back‐staining of indigo, which reduces the desired blue–white contrast. Alongside an accurate selection of the type of cellulase or vigorous post‐washing of the garments, the simultaneous application of auxiliaries in the enzymatic treatment may help to reduce back‐staining and improve cellulase efficiency. In the present work, the influence of additives such as surfactants and dispersing agents on indigo adsorption and on the treatment of an undyed cotton fabric with Hypocrea jecorina cellulases was investigated. Indigo adsorption was successfully reduced by more than 75% with ethoxylated nonionic surfactants at concentrations below 0.2 g l^?1. The weight loss of cotton fabrics after 120 min treatment was significantly increased with nonionic surfactants and polyvinylpyrrolidone. It could be further shown that protein adsorption on the cotton fabric decreased with the increasing concentration of the additives, while the nonionic surfactants were more efficient than the polyvinylpyrrolidone. Adsorption of a complete cellulase mixture was affected differently by the surfactants than by an exoglucanase‐free endoglucanase‐rich preparation.     

Study of the Influence of Gemini Cationic Surfactants on the Dyeing and Fastness Properties of Polyester Fabrics Using Naphthalimide Dyes

In this paper, the dyeing and fastness properties of three monoazo naphthalimide dyes including different imide groups (dye 1: ethyl amine, dye 2: ethyl glycinate and dye 3: glycine) on a polyester fabric were investigated in the presence of two gemini cationic surfactants (symbolized as 12‐4‐12 or 14‐4‐14) and a conventional single chain surfactant, dodecyltrimethylammonium bromide (DTAB). The color strength (K/S) of naphthalimide dyes on polyester fabric was measured through the reflectance spectrophotometric method, and the values obtained in the presence of different cationic surfactants increased in the order of dye 3 < dye 2 < dye 1. Although the K/S values indicated that the gemini cationic surfactants had almost no effect on the dyeing behavior of dye 1, but they were effective in dyeing ability of dye 2 and dye 3. The data for dye 2 demonstrated that build up of polyester fabrics in the presence of gemini surfactants are more than the conventional cationic surfactant, and also K/S values of dye 3 on polyester fabrics were in the order: DTAB > 12‐4‐12 > 14‐4‐14. It was found that the washing and rubbing fastness properties improved with increasing the concentration of surfactants. In addition, the sublimation fastness of dye 3 was more than the other dyes owing to the presence of a polar group in its chemical structure, and the light fastness of naphthalimide dyes on polyester fabrics was generally moderate.     

Solubilisation of dyes by surfactant micelles. Part 3; A spectroscopic study of azo dyes in surfactant solutions†

A spectroscopic study (UV–vis and adsorption) has been made of the interactions of select model azo dyes with a range of surfactant types or their mixtures both above and below their respective critical micelle concentrations. All surfactants inhibit adsorption of the dyes to cotton above their critical micelle concentrations due to incorporation in micelles. However, formation of 1;1 complexes between dyes and cationic or zwitterionic surfactants in sub‐micellar regions results in enhanced deposition on cotton. It is shown that attractive or repulsive electrostatic interactions play a key role in dye binding to micelles. Unusually, spectra of complexes formed between the dye and cationic surfactant are typical of those of the azo tautomeric form as opposed to the hydrazone form that is prevalent in aqueous media. Addition of anionic surfactant to micellar solutions of nonionic or zwitterionic surfactants results in successive displacement of dye from the respective micelles, i.e. binding is competitive.     

ADSORPTION OF ETHOXYLATED NONIONIC SURFACTANTS FROM SILOXANE-BASED SOLVENT AND AQUEOUS SYSTEMS: USE OF QCM AND MODEL POLYMERIC SURFACES

Adsorption behavior was quantified with pure ethoxylated nonionic surfactants onto different polymeric surfaces (hydrophilic cotton and hydrophobic polyester) and model hydrophilic gold surface. The polymer materials used for the study were characterized using SEM. The role of ethylene oxide group variation in surfactant-polymer interaction was established using pure surfactant with the same alkyl chain length but varying ethoxylate chain lengths. It was observed that surfactant with more ethylene oxide groups per molecule, being more hydrophilic, interacts favorably with cotton in the hydrophobic siloxane solvent environment. The adsorption of the pure surfactants on model gold surface from hydrophobic solvent and water was also established using the quartz crystal microbalance with dissipation monitoring (QCM-D) system. Effect of ethylene oxide chain length and surfactant concentration on the extent of adsorption was quantified. At the gold-water interface, the plateau adsorption for C₁₂ E₃ (15.9 × 10^?6 mole/m²) is about four times higher than for C₁₂E₈. An opposite trend was observed for adsorption of the surfactants on gold in the hydrophobic D5 environment. Information about thickness, adsorption and desorption kinetics, and structure of adsorbed layer was obtained from the QCM-D frequency-dissipation data. The study is an important contribution towards fundamental understanding of applications involving the use of ethoxylated nonionic surfactants.     

Function of lipase in lipid soil removal as studied using fabrics with different chemical accessibility

Fatty stain removal is enhanced by the inclusion of lipase in washing compounds and leads to increased lipid removal from within the fibers. Cotton fabrics with varied morphology/chemistry were investigated to study the accessibility of soil in textiles to detergent and lipase. Three cotton fabrics (untreated, mercerized, and carboxymethylated cotton), differing in chemical accessibility, and Tencel^TM lyocell fabric, a microdenier manufactured cellulosic fiber, were subjected to three treatments—unwashed, washed with detergent, and washed with lipase—so as to understand further the effects of fiber morphology on lipase effectiveness. Both detergents and lipase removed more soil from the more chemically accessible and hydrophilic textiles. Lipase increased lipid removal for all fabrics and all morphological locations on the fiber, including fiber surfaces, interfiber capillaries, small capillaries, and the center of the yarn bundle. Lipase removed significant quantities of soil from the lumen in untreated and mercerized cotons; these fabrics showed the largest total increases in amount of lipid removed by lipase. When the fiber surfaces were smoother and the fiber structure was less open and not carboxymethylated, i.e., the mercerized cotton fabric, more lipase benefit was observed (72% of the residual soil left after washing with detergent was removed when lipase was added). The total soil removal from the mercerized cotton fabric by use of lipase was equal to that observed for the more open, hydrophilic carboxymethylated fabric and for the Tencel, which has no lumen or other morphological features of natural cotton such as crenulations. Lipase appeared to enhance lipid removal under conditions where removal by the detergent surfactant system was limited. Furthermore, we concluded that lipase acted to remove lipid soil from within the fibers by functioning at the interior surfaces of microfibrils and pores within the fiber structure at the lipid-water interface.     

Potentiometric Study of Carbon Nanotube/Surfactant Interactions by Ion-Selective Electrodes. Driving Forces in the Adsorption and Dispersion Processes

The interaction (adsorption process) of commercial ionic surfactants with non-functionalized and functionalized carbon nanotubes (CNTs) has been studied by potentiometric measurements based on the use of ion-selective electrodes. The goal of this work was to investigate the role of the CNTs’ charge and structure in the CNT/surfactant interactions. Non-functionalized single- (SWCNT) and multi-walled carbon nanotubes (MWCNT), and amine functionalized SWCNT were used. The influence of the surfactant architecture on the CNT/surfactant interactions was also studied. Surfactants with different charge and hydrophobic tail length (sodium dodecyl sulfate (SDS), octyltrimethyl ammonium bromide (OTAB), dodecyltrimethyl ammonium bromide (DoTAB) and hexadecyltrimethyl ammonium bromide (CTAB)) were studied. According to the results, the adsorption process shows a cooperative character, with the hydrophobic interaction contribution playing a key role. This is made evident by the correlation between the free surfactant concentration (at a fixed [CNT]) and the critical micellar concentration, cmc, found for all the CNTs and surfactants investigated. The electrostatic interactions mainly determine the CNT dispersion, although hydrophobic interactions also contribute to this process.     

Faserstruktur und Färbeeigenschaften von Cellulosefasern, 1. Zusammenhänge zwischen Veränderungen der Faserstruktur und der Farbstoffadsorption bei Baumwolle durch Mercerisation und Flüssigammoniak-Behandlungen

Changes of fiber structure and the adsorption of direct dyes in cotton subjected to different kinds of mercerisation and liquid ammonia treatment have been studied. Therefrom a new general relationship between dye adsorption and fiber structure of cellulosic fibres has been given as a result. The fiber structure in the water swollen state was characterized by measurements of specific pore volume, specific pore surface and pore size distribution. The dyeing behaviour of the different treated cotton was determined by adsorption isotherms. The results revealed that for equilibrium dye adsorption from aqueous solution a transitional pore region with pore diameters of 20–60 Å has a special importance. Changes of these pores by the different swelling treatments correlated directly with the dye uptake. This pore region is found in cotton between the elementary fibrils.     

Adsorption and fixation behaviour of CI Reactive Red 195 on cotton woven fabric in a nonionic surfactant Triton X‐100 reverse micelle

To achieve the goals of saving water and being salt‐free in the coloration of cotton fabric with reactive dye, nonionic reverse micelles were prepared and optimised with a surfactant, Triton X‐100, n‐octanol and isooctane by injecting a small amount of CI Reactive Red 195 aqueous solution. The adsorption, diffusion and fixation of this dye on cotton fabric in Triton X‐100 reverse micelle and bulk water were then investigated. The equilibrium and kinetic data of the dye adsorption process were evaluated. The colour strength and fixation rate of cotton fabrics dyed in the micelle and in bulk water were also examined and compared. The results indicated that the amount of dye adsorbed increased with the increasing temperature and the initial dye concentration. The dye adsorption process could be described using the Langmuir isotherm and pseudo‐second‐order kinetic equations. It was found that CI Reactive Red 195 showed a stronger adsorption property on cotton fabric in Triton X‐100 reverse micelle than in bulk water without the addition of sodium chloride. Using Triton X‐100 reverse micelle as the dyeing medium offered the reactive dye better diffusion performance within the cotton fibre as compared with bulk water. Moreover, higher fixation of the dyes absorbed on the cotton fibre was achieved when the optimum concentration of sodium carbonate was used as the alkali agent in Triton X‐100 reverse micelle.