Nonwoven Cotton Research Articles

Electrokinetic and hemostatic profiles of nonwoven cellulosic/synthetic fiber blends with unbleached cotton.

Greige cotton contains waxes and pectin on the outer surface of the fiber that are removed when bleached, but these components present potential wound dressing functionality. Cotton nonwovens blended with hydrophobic and hydrophilic fibers including viscose, polyester, and polypropylene were assessed for clotting activity with thromboelastography (TEG) and thrombin production. Clotting was evaluated based on TEG measurements: R (time to initiation of clot formation), K (time from end of R to a 20 mm clot), α (rate of clot formation according to the angle tangent to the curve as K is reached), and MA (clot strength). TEG values correlate to material surface polarity as measured with electrokinetic parameters (ζplateau, Δζ and swell ratio). The material surface polarity (ζplateau) varied from −22 to −61 mV. K values and thrombin concentrations were found to be inversely proportional to ζplateau with an increase in material hydrophobicity. An increase in the swell ratios of the materials correlated with decreased K values suggesting that clotting rates following fibrin formation increase with increasing material surface area due to swelling. Clot strength (MA) also increased with material hydrophobicity. Structure/function implications from the observed clotting physiology induced by the materials are discussed.

Atmospheric Plasma Effect on Cotton Nonwovens

The possibility of using atmospheric pressure plasma treatment (APT) without any additional functionalizing chemicals as an environmentally friendly technique for processing cotton nonwovens has been investigated. The quantitative determination of waxes suggested that APT results in the removal of waxes from cotton nonwovens and consequently increases its hydrophilicity. Fourier transform infrared studies showed that APT was capable of removing wax covering individual layers of cotton fibers. Intense plasma treatment causes a decrease in the strength of cotton nonwovens. Results show that APT can be a viable alternative for caustic soda treatment for dewaxing cotton.

Development of Cotton Nonwoven Composite Fabric for Toxic Chemical Decontamination and Characterization of its Adsorption Capabilities

Because of the current threat of toxic chemicals and chemical warfare agents, personal protection is important for soldiers and first responders, as well as the civilian population. This paper describes the development of a cotton non-particulate nonwoven composite fabric and the evaluation of its adsorption capability for protection against toxic chemical ingress which can be harmful or lethal. In addition, this paper focuses on the evaluation of toxic chemical adsorption capabilities of various chemical protective substrates that have the potential to be used in military applications. The development of a three-layered cotton based decontamination wipe and its adsorption of 0.1 % w/v pinacolyl methylphosphonate in butanol, is presented. Adsorption is quantified using a modified gravimetric procedure developed using a thermogravimetric analyzer. The results demonstrate the adsorption performance of a new cotton-based, non-particulate flexible composite that has a high potential to be used as a portable decontamination wipe. This research is unique in the area of individual protection and addresses the requirements of the U.S. Department of Defense (DoD) for seeking and evaluating highly efficient, non-particulate, and skin-friendly materials that provide necessary chemical protection while minimizing any discomfort or irritation.

Effect of Laundering Hydroentangled Cotton Nonwoven Fabrics

To study the effect of household machine laundering on hydroentangled cotton nonwoven developmental fabrics, several sets of such fabrics, uniformly made with cottons of different fiber quality characteristics, were sequentially laundered repeatedly for their performance evaluation after one washing and drying cycle (1 W), 5 W, 10 W, and 20 W, using a standard AATCC method for washing. The control greige fabrics (i.e., before any wash) and their respective versions after the 1 W, 5 W, 10 W and 20 W were examined for their physical and mechanical properties. The laundering results showed that the fabrics, even after 20 wash cycles, had held up unexpectedly well. Nonwovens generally are not considered wash-durable, and more than a third of nonwovens today are used in durable applications that necessarily do not require laundering since most nonwovens inherently are considered “disposable” after one end-use application. At any rate, all the researched fabrics, irrespective of their fiber quality origin, showed a significant drop in tensile strength, mainly after the first wash. The drop was more severe in the machine direction (MD) than in the cross direction (CD). To primarily investigate the cause of the declined fabric tensile strength due to washing, SEM images of the fabrics before and after the washing(s) were studied for any structural deformation. The SEM images clearly showed that the fabrics before the wash had symmetrical, almost uniformly spaced clusters of well-defined fiber entanglements (corresponding to the geometric locations of the orifices in the water jet-strip). After the first wash, those entanglements somewhat appeared to have been considerably “loosened,” disintegrated, and even lost. It seemed that the washing affected the fabric structure mostly in the (hydroentangling) MD. A possible reason for this phenomenon could be the fact that the cotton card used in preparing the native batt for hydroentanglement had aligned and stressed the fibers mostly in the machine direction. The subsequent crosslapping operation to some extent had been altered (randomized), and the fiber orientation in its web output was subjected to the hydroentangling, water jet forces that also stressed the fibers mostly in the MD. Upon washing the hydroentangled fabric in water, the stressed fibers, as expected, somewhat relaxed by releasing some of the stored mechanical energy that originally had held the fibrous structure together by creating strong inter-fiber cohesion or frictional or mechanical bonds. In other words, the washing basically loosened or broke up some of the “mechanical entanglements” and, consequently, their (MD) frictional bonds that had been created by the forceful water jets of the fabric formation process. Research has been planned to stabilize these mechanical bonds by means of special finishing, such as blending cotton with fusible/bonding fibers, resin finishing, and/or even layered fabric-film reinforced composites.

Fabrication and characterization of carbonized and activated cotton nonwovens

A needle-punched cotton nonwoven was produced as a precursor for making activated carbon material. Carbonization and activation of the cotton nonwoven was carried out in a high temperature clean room oven. Microporous properties of the nonwoven in terms of surface area, micropore volume, micropore size, and adsorption isotherms were characterized using a micropore physisorption analyzer. Influence of carbonization temperature and difference between the N2 and CO2 adsorptions was analyzed. Tensile strength of the cotton nonwoven before and after the carbonization and activation was evaluated. Microporous structure of the carbonized and activated cotton nonwoven was examined using an scanning electron microscopy technique. The study exhibited that the carbonized and activated cotton nonwoven was a special type of renewable and biodegradable material featuring lightweight, high microporosity, and high performance of chemical adsorption and separation.

Effect of cotton pectin content and bioscouring on alkyl-dimethyl-benzyl-ammonium chloride adsorption

Previous research has shown that both the rate and the total amount of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC) exhausted from a bulk solution of ADBAC are significantly greater for greige cotton nonwovens than cotton nonwovens that have been both scoured and bleached. The presence of pectin in greige cotton samples was offered as one of the possible explanations for this observed phenomenon. To elucidate the effect of pectin and cotton’s natural waxes on the adsorption of ADBAC on greige cotton nonwovens, low-weight greige nonwovens were bioscoured with a pectate lyase prior to being immersed in aqueous solutions of ADBAC. The eco-friendly scouring process was optimized for greige cotton nonwovens and the optimal process parameters were as follows: pH of 8.5, temperature of 55°C, and an incubation time of 90 minutes. Under these conditions, the amount of pectin removed from the fabrics was equivalent to that removed by traditional scouring and bleaching procedures. Pretreatment of greige cotton nonwovens with pectate lyase was found to significantly reduce the amount of ADBAC exhausted from the bulk solution. Through partial scouring via traditional and pectinase-based methods, the adsorption of ADBAC onto cotton nonwovens was found to be linearly dependent on the amount of pectin present in the fabric. Both waxes and pectin were found to play an important role in ADBAC adsorption; however, the observed effect of pectin was significantly greater than cotton’s natural waxes.

Synthesis of arsenic graft adsorbents in pilot scale

Synthesis of arsenic (As) adsorbents in pilot scale was carried out with a synthesizing apparatus by radiation-induced graft polymerization of 2-hydroxyethyl methacrylate phosphoric acid monomer (PA), which consists of phosphoric acid mono- (50%) and di- (50%) ethyl methacrylate esters onto a nonwoven cotton fabric (NCF), and following chemical modification by contact with a zirconium (Zr) solution. The apparatus which was equipped with reaction tanks, a washing tank and a pump can produce up to 0.3m×14m size of the As(V) adsorbent in one reaction. A degree of grafting of 150% was obtained at an irradiation dose of 20kGy with 5% of PA solution mixed with deionized water for 1h at 40°C. Finally, after Zr(IV) was loaded onto a NCF with 5mmol/L of Zr(IV) solution, the graft adsorbent for the removal of As(V) was achieved in pilot-scale. The adsorbent which was synthesized in pilot scale was evaluated in batch mode adsorption with 1ppm (mg/l) of As(V) solution for 2h at room temperature. As a result, the adsorption capacity for As(V) was 0.02mmol/g-adsorbent.

Adsorbent for Arsenic(V) Removal Synthesized by Radiation-Induced Graft Polymerization onto Nonwoven Cotton Fabric

A fibrous adsorbent for arsenic (As) removal was synthesized with nonwoven cotton fabric as a trunk polymer. 2-hydroxyethyl methacrylate phosphoric acid monomer which composed of phosphoric acid mono (50%) and di (50%) ethyl methacrylate ester was introduced with radiation-induced graft polymerization onto nonwoven cotton fabric. The degree of grafting of 130% was obtained at irradiation dose of 20 kGy with 5% of monomer solution for 2 hours reaction time at 40?C reaction temperature. After the grafted material was contacted with 10 mmol/L of zirconium (Zr) solution at pH 1, 0.38 mmol/g of Zr was loaded on phosphoric units as a functional group for As(V) removal. The resulting adsorbent was evaluated by column mode adsorption with 1 mg/L of As(V) solution at various pH with space velocity 200 h–1. The maximum capacity of As(V) adsorption was 0.1 mmol/g at pH 2.

Preparation and Analysis of Cotton Nonwoven Film Strengthened by Chitosan

The invention of plastic film has brought not only convenience but also environmental pollution to people. To use natural vegetable fiber is the mainly approach to solve the problem. In this paper, the waste cotton fiber was used as raw material and the cotton nonwoven sample was made through wet laying process, after strengthened by chitosan, degradable film was prepared. The performances of the film were characterized and analyzed by testing the strength, air permeability, moisture permeability and other indexes. The results showed that chitosan can be used as strengthening agent, the performances of the film strengthened were improved, and it was degradable.

Effect of water pressure on absorbency of hydroentangled greige cotton non-woven fabrics

A greige (non-bleached) cotton lint was used to fabricate non-woven fabrics on a Fleissner MiniJet, using different water pressures for the fiber entanglements. The greige cotton and its hydroentangled non-woven fabrics were primarily tested for their hexane extracts (waxes) and water-soluble (sugars) contents using the AATCC TM97 Standard Extraction Test. Tests have shown that a water pressure of 125 Bar or higher almost totally removed the greige cotton’s inherent hydrophobic waxes and water-soluble sugars. This discovery is a significant milestone in the development of greige cotton-based non-wovens because it could change the greige cotton’s native hydrophobic character into a desirable hydrophilic character for many end-uses. In fact, the AATCC Test Method 79-2007 has confirmed that the greige cotton non-wovens fabricated with high water pressure of 125 Bar are absorbent, as indicated by the 1-second time or less it took for the water drop to completely diffuse onto the fabric surface.

Covalent attachment of lysozyme to cotton/cellulose materials: protein verses solid support activation

Covalent attachment of enzymes to cellulosic materials like cotton is of interest where either release or loss of enzyme activity over time needs to be avoided. The covalent attachment of an enzyme to a cellulosic substrate requires either activation of a protein side chain or an organic functional group on the cellulosic substrate. Use of a water soluble carbodiimide to create an amide linkage as the covalent attachment between the enzyme and substrate represents an aqueous-based alternative which may be preferred for textile processes. Here we describe an amide bond-mediated lysozyme immobilization applied to cotton where either the carboxylate side chains of the protein or pendant carboxylates in a citrate, cross-linked cotton support are activated as the O-acyl-isourea intermediate, and the reactive amino nucleophiles are derived from amino-silanized cotton and the protein’s amino side chains, respectively. A comparison is made of the two activation approaches to covalently link lysozyme to two different cotton fabrics using the water soluble carbodiimide 1-cyclohexyl-3-(2-morpholinoethyl)-carbodiimide-metho-p-toluene sulfonate. A comparison of the resulting enzyme activities of lysozyme on two different cotton supports showed that linking lysozyme to citrate crosslinked cotton gave higher activity than on aminosilanized cotton. The lysozyme-cellulose conjugate formed on the citrate crosslinked nonwoven cotton fabric gave the highest yield and antimicrobial activity.

Adsorption of alkyl-dimethyl-benzyl-ammonium chloride on differently pretreated non-woven cotton substrates

The adsorption of alkyl-dimethyl-benzyl-ammonium chloride (ADBAC), a cationic surfactant commonly employed as an antimicrobial agent, on greige, alkaline scoured, and bleached non-woven cotton fabrics was investigated at varying surfactant concentrations using ultraviolet-visible spectroscopy. Results show greige cotton non-wovens adsorb roughly three times the ADBAC in aqueous solution than bleached cotton and 1.5 times more than scoured cotton non-wovens. At a constant ADBAC concentration of 0.625 g/l, the rate of surfactant adsorption approached equilibrium after 35 minutes in all fabrics studied. Increasing surfactant concentration increased the total mass of ADBAC exhausted onto the cotton fabrics at equilibrium. Adsorption of ADBAC on cotton fabrics can be attributed to bulk entrapment, dispersion forces, and hydrophobic and electrostatic interactions. Polyester fiber was blended with greige and bleached cotton fibers to further elucidate the adsorption of ADBAC. A linear decrease in the amount of surfactant exhausted was observed as the amount of polyester added to the blend was increased. This indicates that the adsorption of ADBAC on cotton fabrics is primarily an effect of surface interactions of the cotton fiber with the surfactant molecules rather than absorption via bulk entrapment. The results of this research can aid in the development of cotton-based antimicrobial wipes.

Advent of Greige Cotton Non-Wovens Made using a Hydro-Entanglement Process

Using greige (scour/bleach-less) cotton, non-woven fabrics have been successfully produced by adopting conventional fiber opening, cleaning and (modified) carding machines followed by cross-lapping, pre/light needling, and hydro-entanglement (HE) on modern commercial machinery and equipment. Using standard test methods and procedures, the fabrics were evaluated for their weight, thickness, burst strength, tensile and tear failures in both machine (MD) and cross (CD) directions, and absorbency. Dimensional characteristics of the fabrics were determined before and after an ordinary wash. Microscopic examinations of the fiber/fabric surfaces before and after various conditions/degrees of H-E were conducted. Results of these preliminary research investigations have shown that a run-of-the-mill greige cotton, processed on a conventional cotton cleaning and preparatory system, can indeed be efficiently processed on the downstream non-wovens production equipment. In addition, it has been shown that different processing conditions, especially the high-pressure (HP) hydraulic energy of the H-E system, have a considerable influence on properties of the fabrics produced. At the nominal fabric production rates deployed in the research trials, pressure greater than 100 bar (at the system’s two HP jet-heads) produces a fabric that is partially hydrophilic: a desirable attribute for many end-use applications of cotton non-wovens. Based on a previous in-house investigation, it seems that the HP (hydraulic energy) at certain levels partly removes some of the greige cotton fiber’s natural hydrophobic defensive membrane (outer-surface barrier) of heavy hydrocarbons, such as waxes, pectins, etc., thus making the fiber/fabric partially hydrophilic. Further, it has been observed that the high water pressures (HP), under otherwise similar processing conditions, tend to fracture some cotton fibers into tiny fibrils, as evidenced by scanning electron microscopy (SEM) images. These ruptured fibers, by way of exposing their inner (hydrophilic) walls, could also partly contribute to the fabric’s improved absorbency at elevated hydraulic energy levels. Furthermore, a rather unique fabric structure, comprising certain well-defined fibrous “strands and channels,” observed at elevated (HP) pressures is also deemed to partly contribute to the greige fabric’s improved wickability.

Biodegradable metal adsorbent synthesized by graft polymerization onto nonwoven cotton fabric

A fibrous adsorbent for Hg ions was synthesized by radiation-induced emulsion graft polymerization of glycidyl methacrylate (GMA) onto a nonwoven cotton fabric and subsequent chemical modification. The optimal pre-irradiation dose for initiation of the graft polymerization of GMA, which minimized the effects of radiation damage on the mechanical strength of the nonwoven cotton fabric, was found to be 10 kGy. The GMA-grafted nonwoven cotton fabric was subsequently modified with ethylenediamine (EDA) or diethylenetriamine (DETA) to obtain a Hg adsorbent. The resulting amine-type adsorbents were evaluated for batch and continuous adsorption of Hg. In batch adsorption, the distribution coefficients of Hg reached 1.9×10 5 and 1.0×10 5 for EDA- and DETA-type adsorbents, respectively. A column packed with EDA-type adsorbent removed Hg from 1.8 ppm Hg solution at a space velocity of 100 h −1, which corresponds to 16,000 times the volume of the packed adsorbent. The adsorbed Hg on the EDA-type adsorbent could be completely eluted by 1 M HCl solution. A microbial oxidative degradation test revealed that the EDA-type adsorbent is biodegradable.

Acoustical evaluation of carbonized and activated cotton nonwovens

An activated carbon fiber nonwoven (ACF) was manufactured from a cotton nonwoven fabric. For the ACF acoustic application, a nonwoven composite of ACF with cotton nonwoven as a base layer was developed. Also produced were the composites of the cotton nonwoven base layer with a layer of glassfiber nonwoven, and the cotton nonwoven base layer with a layer of cotton fiber nonwoven. Their noise absorption coefficients and sound transmission loss were measured using the Brüel and Kjær impedance tube instrument. Statistical significance of the differences between the composites was tested using the method of Duncan’s grouping. The study concluded that the ACF composite exhibited a greater ability to absorb normal incidence sound waves than the composites with either glassfiber or cotton fiber. The analysis of sound transmission loss revealed that the three composites still obeyed the mass law of transmission loss. The composite with the surface layer of cotton fiber nonwoven possessed a higher fabric density and therefore showed a better sound insulation than the composites with glassfiber and ACF.

실리콘 다중유제 (W/Si/W)를 이용한 화장용 티슈의 개발 및 평가

To develop cleansing tissue composed of silicone multiple emulsions which could easily remove make-up residues and confer skin protecting effect without damaging skin, we formulated various silicone multiple emulsions and evaluated the physicochemical properties including viscosity, cleansing effect, and safety effect. Also, cleansing tissue incorporated with silicone multiple (W/Si/W) emulsion was stored for 6 months, and judged its stability through microscopes under accelerated and long-term condition. Cleansing effect was evaluated by chromameter. Skin hydration effect was determined by corneometer and incorporation effect into non-woven fabric cotton was evaluated by volunteer survey. Low viscosity ranged from 400 centipoise (cP) to 1,000 cP was obtained from a stabilized W/Si/W emulsion containing more than 10% volatile silicone. Mean diameter of fresh W/Si/W emulsion was , but after storage for 3 months at , the particle size of the W/Si/W emulsion increased up to . Both W/Si/W emulsion-incorporated cleansing tissue and commercial product showed equally good cleansing effect. In addition, skin allergies such as erythema, edema, scaling itching, stinging, burning, tightness and prickling were not observed through macroscopic examination. From the transepidermal water loss results, the cleansing tissue consisting of W/Si/W emulsion showed superior hydration effect to commercial product. In conclusion, this study suggests cleansing tissue using W/Si/W emulsion could be used for an excellent efficacy compared with commercialized cleansing tissue.

Silver (I) antimicrobial cotton nonwovens and printcloth

AbstractIn this paper we discuss the preparation and comparative evaluation of silver (I) [Ag(I)] nonwoven and woven antimicrobial barrier fabrics generated from commercial calcium‐sodium alginates and laboratory prepared sodium carboxymethyl (CM) cotton nonwovens and CM‐cotton printcloth for potential use as wound dressings. Degrees of CM substitution (DS) in cotton nonwoven and printcloth samples by titrimetry were 0.38 and 0.10, respectively. Coordination of Ag(I) with carboxylates on fabrics was effected by ion exchange and nitrates were removed by washing to mitigate nitrate ion toxicity issues. Durability of silver coordinated fabrics was tested by soaking them in deionized water with slight agitation at 50°C. Ag(I) alginates and nonwoven Ag(I)‐CM‐cottons lost structural integrity in water. Ag‐CM‐cotton printcloth samples retained structural integrity even after four soak‐and‐dry cycles, were smooth to the touch when dry, and were smoother when moistened. They could be easily peeled from wound surfaces without inducing trauma. Solid‐state carbon‐13 (13C) nuclear magnetic resonance (NMR) spectrometry was used to observe changes in carbonyl resonances in Ag(I) alginates and Ag(I)‐CM‐printcloth, and the chemical shift positions of carbonyl resonances of uncoordinated and Ag(I) coordinated fabrics did not change. Inductively coupled plasma‐mass spectrometry (ICP‐MS) was used following fabric digestion to determine the total Ag(I) ion content in fabrics. Ag(I) alginates were found to hold about 10–50 mg Ag(I) per gram fabric; and Ag(I) cotton woven and nonwoven fabrics held about 5–10 mg Ag(I) ions per gram fabric. Kinetic release of Ag(I) after soaking once in physiological saline was studied with ICP‐MS to estimate the availability of Ag(I) upon a single exchange with Na(I) ions on wound surfaces. Alginates released between ∼13 and 28% of coordinated Ag(I), and CM‐cotton nonwovens and CM‐cotton printcloth released ∼14 and 3% of coordinated Ag(I) ions, respectively. Finally, Ag(I) alginates and Ag(I)‐CM‐cotton printcloth samples were evaluated against Gram‐positive Staphylococcus aureus and Gram‐negative Klebsiella pneumoniae. Ag(I) alginates suppressed 99.95% of bacterial growth in vitro. Even after four soak‐and‐dry cycles in deionized water Ag(I)‐CM‐cotton printcloth suppressed 99.99% of bacterial growth in vitro. Published in 2007 by John Wiley & Sons, Ltd.

Needlepunched Cotton Nonwovens and Other Natural Fibers as Oil Cleanup Sorbents

Abstract This study investigates a partial or complete replacement of synthetic sorbents by various biodegradable, natural sorbent materials. The sorbents examined are cotton, milkweed, kapok, wool, and kenaf fibers. It was found that (with the exception of kenaf) the oil sorption capacities of these natural sorbents (as loose fiber forms) were much greater than that of polypropylene. Nonwoven pads were prepared using cotton and polypropylene fibers and their oil sorption capacities were compared. The results indicate that for light crude oil, the oil sorption capacities of the needlepunched cotton‐containing sorbents were slightly greater than those of sorbents made of 100% polypropylene fibers. Individual bundles of both cotton and polypropylene fibers gave greater oil sorption than did the needlepunched nonwoven fabrics prepared from the respective fibers. In addition, sorption decreased as needling density increased. Analyses of sorption mechanisms using an environmental scanning electron microscope w...

Preparing Cotton Nonwoven Fabrics at Low Temperatures Using Hydrogen Peroxide Activated with Sodium Persulphate

A low temperature (25-45°C) bleaching process for a cotton patterned nonwoven fabric has been established using hydrogen peroxide activated with sodium persulphate. The combined scouring and alkaline peroxide bleaching treatment was done using a laboratory scale pad-batch kier model. Detailed laboratory experiments were performed to investigate the effects of hydrogen peroxide concentration, time required for bleach ing, and temperature of the bleaching bath on the measured property of whiteness. The whiteness values of the bleached fabrics were compared to values obtained for the same fabric prepared using conventional high temperature (250°C), high pressure shock bleach. A three-variable statistical regression technique with whiteness as the response factor was used to analyze the data. Surface diagrams were drawn and the optimum conditions determined for low temperature bleaching with respect to hy drogen peroxide concentration, time, and temperature.

Cotton Nonwovens as Oil Spill Cleanup Sorbents

We examined partial or complete replacement of synthetic sorbents by cotton- containing nonwovens for use in oil spill cleanup. The results indicate that with light crude oil, oil sorption capacities of the needlepunched cotton-containing sorbents were slightly greater than those of sorbents made from 100% polypropylene fibers. If necessary, a small portion of polypropylene fiber could be incorporated into nonwovens to increase mechanical strength properties and to maintain fabric integrity. The cotton- containing sorbents were reusable after a simple mechanical compression to remove oil. They also floated in an artificial seawater bath for a long period of time. We found that oil sorption of cotton fiber was controlled by adsorption on the fiber surface and capillary action through its lumen. Contrarily, the main mechanism for polypropylene was through capillary bridges between fibers. Detailed evaluation using an environ mental scanning electron microscope confirmed this mechanism. Individual bundles of both cotton and polypropylene fibers sorbed more oil than did the needlepunched nonwoven fabrics prepared from the respective fibers. In addition, sorption decreased as needling density increased. This study provides preliminary data for investigating other cotton nonwoven constructions with improved oil sorption properties.