Lipid distribution on textiles in relation to washing with lipases

Effectiveness of lipase in detergency was studied using three test soils (lard, artificial sebum, and olive oil) on a woven cotton fabric. Distribution of oily soil on fabrics was determined for three different treatments (unwashed, washed with detergent without lipase, and washed with detergent plus lipase). Osmium tetroxide was used to label lipid soil for analysis in the scanning electron microscope. Both longitudinal and cross-sectional backscattered electron images for unwashed samples showed that soil was present on surfaces of the cotton fibers and in interfiber spaces of the yarn bundle. Lard soiled samples had large deposits on the fabric surfaces, while artificial sebum and olive oil appeared more uniformly distributed throughout the textile. Oil was deposited in the interfiber capillaries of the yarn bundle and in the crenulation, secondary walls, and lumen of the fibers. Energy dispersive X-ray microanalysis was used to determine relative concentrations of oil at selected morphological locations within the fiber structure and at the fiber surface. Soil distributions within the fibrous structures differed with type of soil and laundry treatment. Backscattered electron images dramatically demonstrated the effect of lipase on cleaning. After washing with detergent plus lipase, yarn surfaces had much less residual soil; residual soil that remained was in the irregularities of the cotton fiber surfaces. Concentrations of oil in the secondary walls, crenulations, lumen, and the fiber surfaces were lower after lipase treatment for all three soils. While washing with detergent removed soil from the yarn and fiber surfaces and the crenulation of the cotton fiber, only the samples washed with detergent plus lipase had lower concentrations of soils within the secondary wall and lumen of the cotton fibers. Fabrics soiled with olive oil and washed with detergent plus lipase had the lowest concentrations of residual soil across the textile structure; the residual soil observed was mainly in the irregularities on the fiber surfaces.     

Lipid distribution on cotton textiles in relation to washing with cellulase

Enzymes are used widely as effective additives to laundry detergents for improved detergency on soiled fabric. They have potential for cleaning of “dingy” soils in addition to the stain removal benefits. Cellulases contribute to the overall whiteness of cotton-containing textiles when worn and washed several times, meaning that their cleaning is not associated solely with the regions characterized by high amounts of fatty material, e.g., collars/cuffs. The focus of this research was to study further the performance of cellulases for whiteness maintenance of cotton textiles. Cotton garments soiled by multiple wearings and washed using a cellulase treatment were evaluated using scanning electron microscopy and X-ray microanalysis. Washing with cellulase significantly reduced residual soil concentrations at all morphological locations on the cotton fibers for each set of matched garments. The relative concentrations of residual soil on the fabrics agreed well with the color differences measured at 440 nm. Cellulase affected removal of oily soil from within the cotton fiber secondary wall, resulting in residual oil concentrations similar to those at morphological locations that were more accessible for detergency such as the fiber surface and crenulations. Since cellulase hydrolyzes cellulose, it was expected that the effect would be within the structure of the fiber, i.e., secondary wall. The cellulase effect on redeposition garments was similar to garments worn and washed. As with lipase, the enhanced removal of soil from the interior bulk structure of the cotton fiber with use of cellulase is unique, since most other detergent components have higher functionality at fabric, yarn, and fiber surfaces. We think that cellulase is functioning by hydrolyzing cellulose from the internal surfaces of fibrils within the secondary wall, opening up the pore structure for enhanced detergency and forming a new surface with each washing.     

Lipid soil removal from cotton fabric after mercerization and carboxymethylation finishing

Soiling and soil removal from cotton fabrics that had been chemically modified by mercerization and carboxymethylation were studied using electron microscopy and radiotracer techniques. The distribution of lard soil in specimens before and after laudering was determined by means of chemical tagging with osmium tetroxide. Both the chemical and physical changes of the cotton resulted in differences in soiling and soil removal of lipid soil. Mercerization and carboxymethylation of cotton swell the cotton fiber, decrease the crenulation and the lumen, and smooth the fiber surface. These finishes also increase the pore volume and thus the chemical accessibility of the fibrillar structure. In addition, carboxymethylation causes changes in the chemistry of the fiber by increasing the carboxyl group content. These structural changes reduce the amount of soil deposited in the lumen of the fiber, particularly for the carboxymethylated cotton. They also increase soil removal from the crenulation and the interfiber spaces in the yarn bundle. Soil removal from fiber surfaces and from within the fiber—both lumen and secondary wall—was highest for the carboxymethylated cotton, and mercerization also enhanced lipid soil removal. The results of this experiment indicate that chemical accessibility and hydrophilicity of the fiber structure influence both soil deposition and soil removal of lipid soils. Soil removal of these modified cottons is enhanced by multiple mechanisms: (i) the decrease in small crevices and the crenulation or small capillary along the fiber, (ii) the increase in pore volume that enhances chemical accessibility and thus detergency within the fiber structure, (iii) the increase in hydrophilicity that enhances soil removal from the surface by the roll-up mechanism, (iv) the increase of mechanical action due to enhanced swelling of the carboxymethylated cotton, and (v) the reduction of soil redeposition on carboxymethylated surfaces.     

Improvement of cotton cloth soil removal by inclusion of alkaline cellulase from Bacillus sp. KSM-635 in detergents

Alkaline cellulase from Bacillus sp. KSM-635 (EC 3.2.1.4) had reproducible detergent effects on cotton cloth that was artificially or naturally soiled with oily and/or particulate matter, under European washing conditions. The detergent effects of the cellulase, in combination with surfactants, apparently were the result of enzymatic action on amorphous regions of cotton fibers in which soil was trapped. The contribution of cellulase to soil removal increased as (i) the amount of soil in the amorphous regions of fibers in test fabrics was increased and (ii) the inhibition, by soil that adhered to the fibers' surfaces, of the action of the cellulase on fibers was reduced. Alkaline cellulase had the potential to replace, in part, both surfactants and zeolite in detergents, and it reduced washing time and allowed washing at lower temperatures under European washing conditions. The marked detergent effect of cellulase on naturally soiled cotton fabric was visually apparent, and it inhibited the accumulation of ash, calcium, and other inorganic components on cotton fibers during wash-and-wear cycles. These contributions of cellulase to the cleanliness of cotton fabrics were clearly increased by repeated wash-and-wear cycles. Cotton fabrics were not degraded by washing with the cellulase because effective hydrolysis by the cellulase occurred only in the amorphous regions of cotton fibers.     

A kinetic study of fabric detergency

The kinetics of soil removal were investigated under domestic laundry conditions by incorporating small swatches of four artificially soiled test fabrics into a standard load of clean cotton goods. This prevented soil redeposition from affecting the soil removal rate. Two runs were analyzed, one with an anionic and the other with a nonionic detergent. Assessment of the amount of soil remaining on the fabric was made by reflectivity measurements interpreted according to the Kubelka-Munk equation. First-order kinetics were found to prevail for periods ranging from the first 6 min of the wash cycle to the entire 20 min, depending upon test fabric and detergent. For these lengths of time, the rate of soil removal was directly proportional to the amount of soil remaining on the fabric. The 8 first-order rate constants had rather similar values, varying at most by a factor of 2.3. The average value, 0.109 min⁻¹, corresponds to a 6.4-min wash period for removing one-half of the soil and to a 21-min period for removing 90% of the soil from the soiled fabric. The magnitude of the response of the four artificially soiled test fabrics to the two detergents is compared and discussed in terms of the soiling materials. The nonionic detergent was more effective in cleaning a fabric soiled mainly with kaolin and wool fat, while the anionic detergent was more effective with a fabric containing large amounts of liquid oily soil plus carbon black and oleophilic bentonite.     

Adsorption of aroma chemicals on cotton fabric from aqueous systems

The adsorption of aroma chemicals on cotton fabric was studied relative to the surfactant concentration, surfactant type, water solubility, and fiber morphology. The adsorption increased with increasing surfactant concentration to a maximum near the critical micelle concentration, then decreased with further increases in surfactant concentration. The adsorption also was found to be highly dependent on the fiber surface area and pore structure; dramatic differences were observed between untreated and mercerized cotton fabric and are believed to be due to morphological differences. Cationic and anionic surfactants increased the aroma chemical adsorption, which varied with surfactant type, with cetyltrimethylammonium chloride (CTAC)>sodium dodecyl sulfate (SDS)>H₂O. Water solubility also influenced adsorption; in most cases, adsorption increased with water solubility. In addition, adsorption was also influenced by chemical structure and hydrophobic interactions. The adsorption of aroma chemicals on cotton fabric can be attributed to the aqueous solution being physically held in capillaries and pore structures within the fibular structure of cotton fiber and also to molecular interactions among the aroma chemical molecules, surfactants, and cotton substrate.     

Application of Lipase from Marine Bacteria Bacillus sonorensis as an Additive in Detergent Formulation

The efficacy of lipase (triacylglycerol acylhydrolases EC 3.1.1.3) as a detergent additive from a newly isolated marine halophilic bacteria Bacillus sonorensis from marine clams Paphia malabarica collected in the Kalbadevi Estuary, Mumbai, has been assessed and reported. In terms of activity and stability, the lipase exhibited maximum activity in alkaline conditions and was observed to be stable over a temperature range from room temperature to 60 °C. The activity of the lipase increased in the presence of surfactants and detergents. Due to these properties of the lipase from marine bacteria, it was used as an additive in detergents to study its efficiency at corn oil removal from fabrics. The washing studies indicated that the efficiency of corn oil removal from the cotton fabrics increased by 20 % when lipase was incorporated in the detergent as compared to the treatment with detergent alone. The lipase was also capable of removing corn oil from natural as well as synthetic fabrics dyed with a respective, preferred class of dyes.     

The effect of sodium carboxymethyl cellulose on synthetic detergent systems

Summary Certain forms of sodium carboxymethyl cellulose have been shown to be highly effective as synthetic detergent promoters. Formulations containing a sodium alkyl aryl sulfonate type of synthetic detergent, alkaline salts and a type of sodium carboxymethyl cellulose developed for high detergency promoting properties surpass high quality fatty acid soaps in both carbon soil removal and whiteness retention on cottons. Methods having a relatively high order of precision for the evaluation of detergency have been presented in detail. By these methods two fundamental characteristics of detergency—as applied to the laundering of cotton fabrics may be independently measured.     

Mechanistic Studies of Particulate Soil Detergency: II: Hydrophilic Soil Removal

In this work, the removal mechanism of kaolinite and ferric oxide (model hydrophilic particulate soils) from hydrophilic (cotton) and hydrophobic (polyester) fabrics was studied using three surfactant types: sodium dodecyl sulfate (SDS), octylphenol ethoxylate (OP(EO)10), and cetyltrimethylammonium bromide (CTAB). This work investigated the relations between zeta potential, surfactant adsorption, contact angle, solid/liquid spreading pressure, and dispersion stability in washing solutions as compared to detergency performance and antiredeposition as a function of surfactant concentration and pH level. The SDS showed the best detergency for both particulate soils, followed by OP(EO)10, with CTAB being the least effective surfactant. For SDS, the electrostatic repulsion between fabric and soil was found to be the dominant force for hydrophilic particulate soil removal. For the nonionic surfactant OP(EO)10, electrostatics are also important and steric effects aid particulate soil detergency. Electrostatic forces and solid/liquid interfacial tension reduction aids CTAB detergency. These same detergency mechanisms have previously been found for the case of hydrophobic soil removal from fabrics. Dispersion stability did not prove to be a dominant mechanism governing particulate soil detergency. From the SEM photos of soiled fabric, ferric oxide attaches to the fabric surface with no entrapment between fabric yarns; moreover, ferric oxide tends to form larger aggregates on cotton compared to polyester fabric. The adhesion of larger particles is hypothesized to be weaker than the smaller ones. Therefore ferric oxide can be more easily removed from cotton fabric than polyester. The SEM photos for kaolinite show little visual difference in particle agglomeration on polyester compared to cotton. Removal of kaolinite from cotton was found to be higher than from polyester, but there is less difference than for ferric oxide.     

竹浆纤维/丝光羊毛混纺针织物的开发

利用竹浆纤维、丝光羊毛为原料,纺成竹浆纤维/丝光羊毛混纺纱,设计并开发出吸湿性良好的混纺针织面料。介绍了该面料的组织设计及工艺参数,测试比较了平针、罗纹组织结构的透气性、防紫外线性、透湿性、汽蒸收缩性,得出70%竹浆纤维和30%丝光羊毛罗纹针织物最适合服用。     

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.     

Changes in dyeability and morphology of cotton fiber subjected to cellulase treatment

Unprocessed and mercerized cotton fibers were treated with commercial crude cellulase. The changes in the dyeability and structural features of the fiber due to cellulase treatment were studied. The dyeability was examined in terms of uptake of three reactive dyes and the apparent affinity of Congo Red to cotton fiber. The dyeability of the unprocessed fiber was assumed to be influenced by some impurities present in it. This fiber probably resembled polynosic fiber in molecular aggregate at a certain stage of hydrolysis. Mercerized cotton showed a similar pattern in dyeability as weight loss increased, regardless of dye species. Enzyme more easily penetrated the mercerized fiber than the unprocessed fiber. Cellulase treatment influenced the X-ray crystalline reflection pattern for the mercerized fiber but nominally influenced that for unprocessed fiber. Scanning electron micrographs revealed that cellulase treatment caused swelling of the fibrils. They also revealed that the disordered regions between the fibrils in the secondary walls were removed at low weight loss for the unprocessed fiber. The mercerized fiber at high weight loss had large cracks oblique to the fiber axis and showed no individual fibrils in the secondary wall. The primary wall was removed in the initial stage of hydrolysis for both the unprocessed and mercerized fibers. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 155–164, 1997     

Detergency study of the synergism between oily and particulate soil on polyester/cotton fabric

The removal of multiphase, multicomponent soils from fibrous substrates depends upon the nature of the soil mixture, the order of application, wash temperature, and type of detergent formulation. By studying these factors, we investigated the synergism between residual oil (triolein) and particulate soil (clay) on a durable press polyester/cotton fabric after laundering with four different detergents at wash temperatures of 27 and 49 C. To probe the interaction between clay and oil, fabric specimens were soiled with clay only, triolein only, clay followed by an application of triolein, and triolein followed by an application of clay. Four detergent formulations were used to launder the soiled fabrics, including one unbuilt liquid and three powdered detergents with different builder systems. The amount of residual oil (triolein) was determined by radiotracer technique, and the quantities of clay were determined by measuring aluminum by neutron activation. Reflectance measurements were used to calculate fabric whiteness. The soil distributions on and within the textile structure were obtained by scanning electron microscopy using backscattered electron images, secondary electron images and X-ray mapping. Osmium tetroxide was used to tag the oil, while silicon was the elemental tag for clay in the microscopic analysis. Results of the four factors studied can be summarized as follows. (i) In agreement with observations by previous researchers, a mixture of clay and oil is more difficult to remove than either the oil or the clay applied singly. It appears that oil acts as a matrix to bind clay, forming a composite soil. (ii) The specimens that were soiled first with oil and then clay had more soil removed by laundering than the specimens soiled with clay and then oil. Detergency was limited by the encapsulation of clay by the oil and adsorbtion of oil by the clay. (iii) The built powdered detergents were temperature sensitive, while the unbuilt liquid detergent was not. (iv) The built powdered detergents removed more soil (oily and clay) than the unbuilt liquid detergent.     

Mechanism for the anti-redeposition action of sodium carboxy-methyl cellulose with cotton. IV. Practical-scale tests

A variety of cotton articles—such as tea towels, hand towels, and sheets—and test cloths, both cambric and sheeting, have been washed in a ‘Hotpoint’ Empress washing machine in a heavy-duty detergent product containing radioactive sodium carboxy-methyl cellulose (SCMC). There was good agreement between the results of laboratory tests using small discs of fabric and results of the practical test. Even when the cotton fabrics had been pre-washed up to 25 times in a product containing SCMC, some SCMC was still adsorbed (up to 40 μg/g of fabric) in each wash. It is suggested that in each wash some SCMC desorbs from the fabric and is replaced by SCMC adsorbed from solution.     

A double label radiotracer approach to detergency studies

The comparative detergency of a series of built detergents of commercial interest has been measured via the use of a doubly labeled multicomponent synthetic soil. Four test fabrics: cotton, nylon, Dacron, and Dacron/cotton were soiled with the seven-component soil, which was in turn almost completely and then individually labeled. The fabrics were washed in a conventional Tergotometer under cold-water and hot-water conditions. Analyses of the fabrics before and after washing were made by liquid scintillation counting. Two sets of experiments were run, the first based on cold-water detergent formulation (heavy-duty liquid), the second based on hot-water detergent formulation (heavy-duty powder). A number of nonionic surfactants were compared with linear alkyl aryl sulfonate in the first set, and two anionics were compared with two nonionics in the second set. Expressing results as total detergency, i.e., amount of soil removed from all four fabrics, it was found that, under cold-water conditions, LAS (average side chain C₁₃) is significantly less effective than the nonionics investigated. The linear primary alcohol (C₁₂-C₁₅ and C₁₄-C₁₅) ethoxylates removed slightly more soil than the ethoxylates of a Ziegler alcohol (C₁₄, C₁₆, C₁₈) and random secondary alcohols (C₁₁-C₁₅). The same tabulation for the heavy-duty powder formulations under hot-water conditions showed LAS to be least effective over-all, sulfated linear primary alcohol somewhat more effective, and ethoxylated linear, primary alcohol slightly more effective still. Redeposition of the various soil components onto unsoiled cotton was found to be slight, ranging from 0.2% to 1.7% of the amount in the wash water. Presented at the AOCS Meeting, Philadelphia, October 1966. US Testing Service, Hoboken, N. J.     

New detergent mechanism with use of novel alkaline cellulose

Microscopic studies of naturally soiled cotton undershirts showed that there was sebum in the microscopic spaces in the interior of the cotton fibers. Ordinary detergents did not remove this soil satisfactorily, although they readily removed sebum on the exterior of the fibers. Alkaline cellulase, which was compatible with the alkaline ingredients of detergents and which interacted selectively with celluloses in interfiber space in the interior of fiber, effectively removed sebum soil in the interfiber spaces in the presence of usual detergent ingredients. The removal of soil by the hydrolysis of the amorphous regions of fibers with cellulase is a new detergent mechanism. To whom correspondence should be addressed at: Plant Manager, Kawasaki Plant, Kao Corp., 1-2, Ukishimacho, Kawasaki, Kanagawa 210, Japan.     

Applying the sol–gel method to the deposition of nanocoats on textiles to improve their abrasion resistance

The thin-coat finishing of textiles carried out by the sol–gel methods gain greater and greater importance owing to their suitability for the versatile functionalization of textiles to impart to them properties being difficult and even impossible to obtain with the use of conventional finishing methods. This article presents the test results of the thin-coat protective finishing of cotton fabrics against abrasion. This treatment consists in depositing hybrid SiO₂*/Al₂O₃ sols synthesized from two precursors: (3-glycidoxypropyl)trimethoxy-silane and aluminum isopropoxide on fiber/fabric surface. The abrasion resistance of the fabric treated by the sol–gel method has been increased by about five times according to Martindale test and this effect is resistant to prolonged laundering. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Electron spectroscopy for chemical analyses (ESCA)—A tool for studying treated textiles

Electron spectroscopy for chemical analysis (ESCA) has been successfully used to determine the location of flame-retardant polymers or reagents and crosslinking and oil/water-repellent reagents in relation to fiber surfaces of chemically modified cotton fabrics and cotton/polyester blends. Changes in intensity of characteristic ESCA element signals were followed as the particle size of the treated fabric varied. Dimethyloldihydroxyethyleneurea (DMDHEU) and the flame-retardant polymer formed from tetrakis(hydroxymethyl)phosphonium chloride (Thpc) and urea penetrate and are homogeneously deposited throughout cotton fabrics. The oil/water-repellent finish, FC-218, and the flame retardants from the THPOH/NH₃ reaction and tris(dibromopropyl) phosphate are deposited on the surfaces of both cotton and polyester fibers.     

纳米氧化锌和纳米银对棉织物的多功能整理

以植物金银花提取物作为还原剂制备了纳米ZnO和纳米Ag,通过浸轧法将纳米ZnO单独整理以及将两者依次整理到棉织物上制备多功能棉织物(ZnO-棉织物、ZnO/Ag-棉织物).利用SEM、XRD、FTIR分析了整理前后棉织物的形貌和结构,并探讨了整理后棉织物的多功能性.结果表明,棉织物上的纳米粒子分布较均匀且发生了轻微团聚.与ZnO-棉织物相比,ZnO/Ag-棉织物对亚甲基蓝(MB)和红酒的降解率分别提高了7.09％和10.61％,说明纳米Ag提升了纳米ZnO的光催化活性.ZnO-棉织物经过10次洗涤后其纳米粒子含量虽有小幅下降,但对MB的降解率仍达到83.24％以上,说明负载纳米粒子后棉织物具有良好的自清洁能力和耐洗性能.此外,ZnO-棉织物和ZnO/Ag-棉织物的紫外防护系数(UPF)值分别达到33.23和41.06,对大肠杆菌和金黄色葡萄球菌的抑菌率均达到95％以上,表现出优良的抗紫外线性和抗菌性能.