The comparison of the effect of enzyme, peroxide, plasma and chitosan processes on wool fabrics and evaluation for antimicrobial activity

Pretreated (enzymatic and enzymatic+hydrogen peroxide) knitted wool fabrics were treated with atmospheric argon and air plasma to improve their adsorption capacity. After plasma treatments chitosan solution was applied to have antimicrobial effect on wool fabrics. The treated fabrics were evaluated in terms of washing stability as well as antimicrobial activity. The surface morphology was characterised by SEM images and FTIR analysis. From the results it was observed that atmospheric plasma treatment had an etching effect and increased the functionality of a wool surface. Atmospheric plasma treatment also enhanced the adhesion of chitosan to the surface and improved the antimicrobial activity of the wool sample. Argon was found to be more effective than air, since argon radicals played an important role in killing and removing bacteria. No significant difference in washing durability was observed in terms of plasma treatments. The samples of combined pretreatment processes had good washing durability even after 10 washing cycle. From the SEM images it was observed that combination of plasma and the other pre-treatment processes gave less damage than only one process.     

A new application method of chitosan for improved antimicrobial activity on wool fabrics pretreated by different ways

Antimicrobial treatments have become more important for the textile materials especially used in sportswear, activewear, and casual wear since they can easily be contaminated by perspiration leading to bacterial growth and body odor. In this work, antimicrobial activity of chitosan in a silica matrix on pretreated wool fabrics was studied. The pretreatment processes were applied by two different ways (enzymatic and enzymatic+hydrogen peroxide). Afterwards chitosan solutions were applied to the untreated samples and to the samples that were pretreated by two different ways to give antimicrobial effects. The antimicrobial activity of wool fabrics treated in various methods was assessed before and after repeated washings (up to 10 cycles) by the application of standard test method AATCC 147-1998. The morphology of the treated fabrics was investigated by SEM and their characterizations were made by the FT-IR spectral analysis. Results revealed that pretreatment ways and chitosan application methods were quite important for adsorption and diffusion of chitosan on wool fabrics and washing stability. From the SEM images, it was clearly observed that pretreatment processes caused some degradation on the surface of the fiber; but combined processes were found to be less degradative and more effective.     

The effect upon fermentation and nutritive value of silages produced after treatment by three different inoculants of lactic acid bacteria applied alone or in combination

Silages were made from the first cut of a predominantly perennial ryegrass sward. The silages were either untreated (W) or treated with formic acid (31 t⁻¹, F) or with 10⁶ lactic acid bacteria (LAB) g⁻¹ grass of each of three strains alone (A. Lactobacillus plantarum MTD1; B, Pediococcus species 6A2; C, L. plantarum 6A6) or in combination (AB. AC) to give seven treatments. The silage fermentation in 10-kg silos was followed chemically and microbiologically and the nutritive value of selected treatments evaluated using 2-t silos.
The control silage (W) fermented well. Addition of formic acid restricted fermentation and produced a silage with a high ethanol concentration. After day 4, all inoculated silages had lower pH values and higher lactic acid concentrations and a higher ratio of lactic acid to acetic acid than the control silage. Chemically there was little difference between the inoculated silages in terms of final composition. Microbiologically the LAB applied in treatments B and C dominated the LAB populations in those silages when applied alone; however, they were suppressed when applied in combination with inoculant A.
When fed to sheep, the intake of the formic acid-treated silage was significantly ( P < 0·01) lower than that of the other silages and the intake of silage treated with inoculant A significantly ( P < 0·001) higher than that of silages treated with inoculants B and C. The apparent organic matter ( P < 0·001) and nitrogen ( P < 0·01) digestibilities of the formic acid-treated silage were also significantly lower than those of the other silages.     

The effect of ultrasonication on the micro-splitting of wool fiber

In this study, normal and dichlorodicyanuric acid (DCCA)-treated wool slivers were ultrasonicated in formic acid aqueous solutions. The effect of the ultrasonication condition on the wool fiber splitting was examined and the mechanism of the splitting by ultrasonication in formic acid was elucidated. No wool fiber splitting occurred at formic acid content up to 70 %, but the fiber splitting accelerated as the formic acid content increased from 75 %. Although no fiber splitting occurred up to 450W ultrasonic power, the degree of splitting increased significantly with increasing ultrasonic power above 450W. The wool fiber splitting by ultrasonication was heterogeneous and FE-SEM observations revealed a three-step splitting process: 1) full removal of scale, 2) removal of cell membrane complex (CMC), and 3) fiber splitting. A comparison of the fiber splitting of normal and DCCA-treated wool revealed that the scale of the ultrasonication-treated wool was removed by peeling off rather than by dissolution.     

Study on the dyeing of wool fabrics with Phytolacca berry natural dyes

Dyeing of wool fabrics with natural dyes from Phytolacca berries has been studied. The effect of dye concentration, dye bath pH, dyeing time and temperature were discussed. The influence of chitosan application on the dyeing properties of wool fabrics was investigated. The SEM photographs of chitosan treated wool fabrics clearly depict the deposition of chitosan on the fibers. The effect of chitosan concentration, dye bath pH, dyeing time and temperature has been studied by orthogonal experiment. It has been proved that the dyed wool samples pretreated by chitosan have higher color fastness, faster dyeing rate, and better antibacterial properties compared with untreated ones.     

Eco-dyeing and antimicrobial properties of chlorophyllin copper complex extracted from Sasa veitchii

Cotton fabrics were dyed with the natural chlorophyll derivates (chlorophyllin, Chlin) after treatment with and without chitosan. The water-soluble Chlin extracted from Sasa veitchii based on Japanese bamboo leaves were investigated in order to improve the textile coloration and antimicrobial activity. The antimicrobial activity of the dyed fabrics that had been pretreated with chitosan as a biomordant over a concentration range of 0∼0.7 % was tested against two common gram pathogens: Staphylococcus aureus and Klebsiella pneumoniae. The color depth as measured by the K/S value, the color difference and the colorfastness to washing and light were also evaluated. The fabrics treated with chitosan resulted in an increase in dye uptake in all cases compared with the corresponding untreated fabrics, and did not affect fastness of washing and light. The cotton fabrics dyed with mordant and CuSO₄ extracts appeared to have over 99.9 % of antimicrobial activity, while MeOH extracts showed 71.8 %.     

Performance of cotton fabric treated with an amino-terminated hyperbranched polymer

An amino-terminated hyperbranched polymer (HBP-NH₂), synthesized from methyl acrylate and diethylene tri-amine by polycondensation, was applied to treat cotton samples by a pad-dry-cure method. Physical properties, salt-free dye-ability, antimicrobial activity, and antiultraviolet property of the treated cotton samples were tested. The crystallinity and mechanical properties, including breaking strength, breaking elongation, and Young’s modulus of the treated cotton fibers, increased slightly in comparison with those of the untreated cotton fibers. The thermal stability and the moisture regain were also improved slightly. Dyed with direct dyes and reactive dyes in the absence of the electrolytes, the treated cotton fabric showed similar or higher color strength compared with the untreated cotton fabric in conventional dyeing. The treated cotton fabric can also be dyed with acid dyes effectively. In addition, the treated cotton fabric showed good antimicrobial activities against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The study of the antiultraviolet properties of the treated cotton fabric indicated that the HBP-NH₂ contributed to the reduction of UV transmission and the increase of UPF.     

Process optimization of Aerva lanata extract treated textile material for microbial resistance in healthcare textiles

The focus of the present research work is on evaluation of the antimicrobial finished textile material from the extract of Aerva lanata plant and optimization of process parameters to get the maximum antimicrobial efficiency. The microencapsulated extracts of Aerva lanata plant (leaves and stalk) using citric acid as a cross linking agent were applied on plain-woven cotton fabric by pad-dry-cure method. The Aerva lanata extract treated fabric samples were tested for antibacterial activity against bacterial strains of Staphylococcus aureus and Escherichia coli under Agar diffusion test and AATCC 100–2004. It is observed that the treated cotton fabric shows a clear microbial resistance of about 19–25 mm zone of inhibition in the agar diffusion test against the above-mentioned bacterial strains. The treated samples showed 80 % of reduction against Staphylococcus aureus and 70 % reduction against Escherichia coli as per AATCC (100–2004). Process parameters like concentration of extract, citric acid and curing temperature were optimized using Box-Behnken design for better performance of antimicrobial treated material. The optimum values of 21.14 % extract concentration, 2.39 % crosslinking agent and 101.2 °C curing temperature were determined.     

Synthesis of some new thermally stable reactive dyes having 4(3<Emphasis Type="Italic">H</Emphasis>)-quinazolinone molecule for the dyeing of silk,wool, and cotton fibers

Diazotized 3-{4-[2-chloro-4-amino-5-carboxybenzyl]-5-chloro-2-carboxyphenyl}-6-iodo-2-phenylquinazolin-4(3H)-one (4) was coupled with various p-nitro anilino cyanurated coupling components (6a-j) to give the corresponding quinazolinone based reactive dyes (7a-j) in reasonable yields. All the reactive dyes (7a-j) were characterized by spectroscopic technique and elemental analysis. These dyes were applied to silk, wool, and cotton fibers as reactive dyes and their spectroscopic data, colorimetric data, antimicrobial activity, thermal stability, and fastness properties were evaluated.     

Effect of silage additives and wilting on silage fermentation, digestibility and intake, and on liveweight change of young cattle

Data from thirty-three experiments conducted at three ADAS Experimental Husbandry Farms were used to compare unwilted non-additive-treated silage with silage treated with formic acid, a formalin and formic-acid mixture, a calcium-formate and sodium-nitrite mixture, a formalin and sulphuric-acid mixture and wilted silage made without or with formic acid or a formalin and formic-acid mixture.
Formic acid significantly reduced pH and wilting significantly increased silage pH compared with other treatments. Formalin-acid mixtures significantly reduced pH compared with untreated silage. Formic acid in conjunction with formalin or wilting significantly increased water-soluble carbohydrate in silage compared with other treatments except wilting. Formic acid either alone or combined with either formalin or wilting significantly reduced silage butyric acid content compared with other treatments. Formic acid treatment either alone or combined with formalin significantly increased lactic acid as a proportion of total silage acids compared with other treatments except sulphuric acid-formalin.
All treatments significantly increased silage dry matter (DM) intake compared with untreated silage and intakes of wilted silage were significantly greater than of unwilted silage. Daily liveweight gains on all treatments were significantly higher than on untreated silage.
Herbage water-soluble carbohydrate necessary for successful preservation as silage without additive use was approximately 30 g (kg DM)⁻¹ and with additives containing formic acid it was approximately 25 g (kg DM)⁻¹.
It is suggested that formic acid application to unwilted silage either alone or in conjuction with formalin was the best treatment for improving subsequent preservation as silage, and that animal performance was enhanced by addition of acid-formalin additives to unwilted herbage or formic-acid application to unwilted or wilted herbage.     

Dimensional properties of low temperature plasma and silicone treated wool fabric

Three different silicone polymer systems, such as aminofunctional, epoxyfunctional, and hydrophilic epoxyfunctional silicone polymers, were applied onto plasma pretreated wool fabric to improve the dimensional properties. The results showed that the plasma pretreatment modified the cuticle surface of the wool fiber and increased the reactivity of wool fabric toward silicone polymers. Felting shrinkage of plasma and silicone treated wool fabric was decreased with different level depending on the applied polymer system. Fabric tear strength and hand were adversely affected by plasma treatment, but these properties were favorably restored on polymer application. Therefore, it has been concluded that the combination of plasma and silicone treatments can achieve the improved dimensional stability, and better performance properties of wool fabric. The surface smoothness appearances of treated fabrics were measured using a new evaluation system, which showed good correspondence with the results of KES-FB4 surface tester.     

A comparative study on wool bio-antifelting based on different chemical pretreatments

The enzymatic antifelting of wool with proteases, which is referred to as bio-antifelting, has become a promising eco-friendly alternative to conventional chlorination treatment. However, wool bio-antifelting in industrial scale has not been reached so far due to its unsatisfactory shrink-resistance and uncontrolled action in fiber damage. In this paper, the action and mechanism of two kinds of chemical pretreatments, i.e., hydrogen peroxide and dichlorodicyanuric acid pretreatments on the shrink-resistance of protease-treated wool fabrics were investigated and compared. The results show that although hydrogen peroxide treatment could decrease the shrinkage of wool in comparison with untreated one, its contribution to the enhancement of wool bio-antifelting with protease was not remarkable. An effective shrink-resistance can be obtained when the wool fabric was treated with dichlorodicyanuric acid and protease consecutively. Both of the two chemical pretreatments could improve the wettability and whiteness of protease-treated wool. The mechanism of different pretreatments for enhancing wool bio-antifelting with protease was further illustrated and compared via several microscopic analyses such as Allwörden’s reaction, FTIR-ATR and SEM. The comprehensive comparison for wool bio-antifelting based on different chemical pretreatments reveals the difference of hydrogen peroxide and dichlorodicyanuric acid pretreatments in antifelting mechanism, which is valuable for getting a clear understanding and further modification of wool bio-antifelting.     

Performance improvement of nonformaldehyde wrinkle resistant finished cotton fabrics treated with dialdehydes

Additives, such as sodium perborate and borax, were examined in dialdehyde wrinkle resistant finishing of cotton. Results indicated that the whiteness index (WI) of cotton treated with dialdehyde and additive showed about 90% of WI of the untreated cotton but with decrease in wrinkle recovery angle (WRA) due to inhibition effect of these additives. Effect of additive on the WRA reduction was more prominent with glutaraldehyde than with glyoxal. Reduction in WRA of cotton treated with both dialdehydes and boron compound was minimized by simultaneous addition of formic acid in the bath. Addition of formic acid was also generally beneficial in maintaining WI retentions after 8 months storage. Furthermore, boron compounds were also effective in improving retentions of mechanical properties. By FTIR analysis the residual aldehyde group was detected on the dialdehyde-finished cotton, whereas no peak was shown by addition of boron compounds. This suggested that the residual aldehyde group was a main cause of fabric yellowing on the dialdehyde-finished cotton. Dialdehyde with boron compound, therefore, can be used to replace a conventional formaldehyde-containing wrinkle resistant finishing of cotton.     

Improving certain properties of wool fibers by applying chitosan nanoparticles and atmospheric plasma treatment

The nanochitosan particles were prepared by ionic gelation method using sodium tripolyphosphate (TPP) as anionic chemical agent. Structural and morphological properties of the nanoparticles were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR) analyses. The results showed that nanoparticles were spherical with a diameter range of 17-105 nm. After nanochitosan synthesis, the effects of chitosan and nanochitosan concentrations on the dyeability, fastness properties, shrink-proofing, tensile strengths, and surface friction coefficients of untreated and plasma treated wool fabrics were investigated. The studies revealed that nanochitosan treated wool fabric possesses better dyeing and shrink-proofing properties in comparison with conventional chitosan treated fabrics.     

Eco-friendly dyeing using natural mordant extracted from <Emphasis Type="Italic">Emblica officinalis G</Emphasis>. Fruit on cotton and silk fabrics with antibacterial activity

Emblica officinalis G. dried fruit tannin was extracted and applied as a natural mordant alone and in combination with metal mordant namely copper sulphate for dyeing on cotton and silk fabrics using natural dyes. The color strength, color-coordinates, wash and light fastness were also evaluated for cotton and silk fabrics with and without mordanting. The pre-mordanted cotton and silk fabrics on dyeing gave better color strength, wash and light fastness than those dyeing obtained without mordanting. The total phenolic content of the extract was calculated. Cotton and silk fabrics resulted in good antibacterial activity using the Emblica officinalis G. mordant. When mordant was used along with 0.5 and 1 % copper sulphate mordant and the activity enhanced and was active up to 20 washes.     

Hemostatic,antibacterial and degradable performance of the water-soluble chitosan-coated oxidized regenerated cellulose gauze

In this research, the oxidized regenerated cellulose (ORC) gauze was prepared by oxidation of regenerated cellulose using NO₂/CCl₄, subsequently treated with the dissolved chitosan (CTS) in aqueous acetic acid (CTS/ORC) and finally neutralized with NaOH/C₂H₅OH (CTS/ORC-Na). The hemostatic, antibacterial and degradable properties of treated ORC-based gauze were evaluated. The results of the hemostatic test on rabbit liver and ear-artery injuries showed that the attachment of high molecular weight chitosan to the surface of ORC gauze significantly improved the hemostatic effect of ORC without compromising the antibacterial and degradability of ORC. It is found that the water-soluble CTS/ORC-Na gauze was more suitable as the hemostatic material applied in rabbit liver injury in comparison with in ear-artery injury and it further improved the hemostatic efficacy and enhanced the degradable rate. It is promised that the CTS/ORC gauze and the water-soluble CTS/ORC-Na gauze would be applicable in medical fields such as surgical absorbable hemostats for control bleeding.     

Process technology and properties evaluation of a chitosan-coated Tencel/cotton nonwoven fabric as a wound dressing

A double-layer nonwoven fabric containing Tencel, cotton, and chitosan was prepared by the immersion-precipitation phase-inversion method and evaluated as a wound covering. Macroporous structure of the chitosan membrane could control evaporative water loss, promote fluid drainage, and inhibit exogenous micro-organisms invasion due to inherent antimicrobial property of the chitosan. The chitosan membrane was hemostatic and could accelerate the healing of the wound. Histological examination showed that epithelialization rate was increased and the deposition of collagen in the dermis was well organized by covering the wound with the membrane. These results indicate that the chitosan-coated Tencel/cotton nonwoven fabric can be a potential material employed as a wound dressing.     

The effect of wilting and silage additives on the fermentation of autumn made grass silage ensiled in bunkers on commercial farms in South Wales 1983-85

Silage making practices in respect of 130 samples of autumn made grass silages ensiled in bunkers on commercial farms in South Wales during 1983-1985 were analysed to discern the effect of wilting and/or silage additives on fermentation. Silages were primarily made during late September and early October in fine weather from perennial ryegrass pasture which had not been grazed for 6 weeks. On average 13.9 ha of pasture was cut for silage. Analysis of 120 samples of grass showed it contained 176 g kg^?1 dry matter (DM) with (g kg^?1 DM) 215 protein, 240 modified acid detergent fibre (MADF), 78 water-soluble carbohydrate (WSC) and 95 ash. Most farmers attempted to pre-wilt grass for 1 day prior to ensilage and one quarter of them made unwilted silage. Silage making was usually completed within 6 days of starting to cut and was generally made with a precision-chop machine. Silage additives applied were (kg t^?1) formic acid (4·7), formic acid 4-formalin (5·5), sulphuric acid-+ formalin (5·0) sugars (14) and inoculants (0·65). Formic acid significantly reduced pH, and formic acid with or without formalin significantly reduced ammonia nitrogen (N) content of silages compared with other treatments. Protein contents of acid/formalin treated silages were significantly higher and MADF of acid with or without formalin treated silages were significantly lower than other treatments. Pre-wilting grass prior to ensilage did not significantly increase subsequent silage DM content and significantly increased the pH of non-additive treated silages. Unwilted silages treated with formic acid with or without formalin had a significantly lower ammonia-N content and higher residual WSC than other treatments. It is suggested that only formic acid application either alone or in conjunction with formalin to unwilted silage was successful in producing well preserved silages and that a grass WSC content of 17 g kg^?1 would be necessary to achieve this.     

Antibacterial finishing of cotton fabrics using biologically active natural compounds

The paper discusses a method to functionalize cotton fabrics using biologically active natural compounds to achieve the antibacterial characteristics required for medical application. The biologically active natural compounds include propolis, beeswax, and chitosan. Three 100 % cotton knitted fabrics with different degrees of compactness were impregnated in the emulsions containing the active ingredients and fabric variant G3 with the highest degree of impregnation was considered for the evaluation of the antibacterial properties and comfort characteristics. The results show that the treated cotton fabric had high antibacterial activity against both gram positive bacteria Staphylococcus aureus and Streptococcus β haemolytic, and gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The presence of the biologically active natural compounds on the cotton substrates modified the surface of the textile fibers as seen in the SEM images. The treatment also improved fabric comfort properties, the cotton substrates became less air permissive and more hygroscopic after the treatment. The experimental results indicated that propolis, beeswax and chitosan can be applied as an emulsion to functionalize cotton textile materials. The antibacterial performance of the functionalized fabrics suggested that the cotton fabrics treated with those biologically active natural compounds have the potentials to be used in medical fields.     

Changes in the distribution of nitrogen and plant enzymatic activity during ensilage of lucerne treated with different additives

Effects of formic acid, formaldehyde and two levels of tannic acid on changes in the distribution of nitrogen (N) and plant enzymatic activity during ensilage of lucerne (Medicago sativa) were studied. Lucerne [300 g dry matter (DM) kg^?1 forage] silages were prepared untreated (control) and with formic acid (4 g kg^?1 DM), formaldehyde (1 g kg^?1 DM) and two levels of tannic acid (20 and 50 g kg^?1 DM) as additives. Inhibition of proteolysis by formic acid was more effective than the other additives during the first 7 d of ensiling. Tannic acid was as effective at inhibiting production of non‐protein‐N, ammonia‐N and free amino acid‐N as formic acid and formaldehyde. However, increased concentrations of non‐protein‐N and free amino acid‐N in silage from day 1 to 35 of ensiling were less with the higher level of tannic acid than that in the control and other additive‐treated silages. Carboxypeptidase lost its activity slowly with increasing time of ensiling. At day 2, it still had 0·79 of the original activity in the control silage. After 21 d of ensiling, high levels of carboxypeptidase activity, proportionately 0·41, 0·49, 0·10, 0·35 and 0·30 of the original activity, remained in the control silage, and silages made with formic acid, formaldehyde, and low and high levels of tannic acid respectively. There were higher levels of activity of acid proteinase in formic acid‐treated silage than in the control silage until day 2 of ensilage indicating that the reduction of proteolysis by formic acid was probably due to acidifying the forage below the pH optima of plant protease. Aminopeptidase activity in all silages declined rapidly after ensiling.