Macro-micro structure,antibacterial activity,and physico-mechanical properties of the mulberry bast fibers

In this paper, the mulberry fibers were successfully obtained by a new pretreatment named alkali-assisted microwave plus biological enzymatic technique (AMBET). The morphology, microstructure, physico-mechanical and antibacterial properties of the mulberry bast fibers were investigated by means of scanning electron microscope (SEM), Fourier Transform-Infrared (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), instron tensile tester and antibacterial testing. The results showed that impurities of the bast fibers could be removed by AMBET treatment. AMBET treated mulberry fiber was even, smooth and fine, and typical cellulose I in the mulberry fibers was confirmed by FTIR and XRD analysis. The crystallinity of the AMBET treated fibers was higher than that of the raw mulberry and chemical treated mulberry fibers. Thermal analysis indicated that the mulberry fibers had a good thermal stability. Moreover, the AMBET treated mulberry fibers showed excellent antimicrobial activities against S.aureus. The physical properties of the mulberry fibers indicated the AMBET treated mulberry fibers were ideal candidates for new textile materials.     

Disperse inkjet inks with a new antibacterial agent as additive: Properties and application to polyester and polyamide fibres

Two water based disperse inkjet inks for polyester textile printing with antibacterial properties were prepared. The antibacterial activity was due to the presence of polyhexamethylene bisguanidine (PHMBG). The surface tension, pH, viscosity and conductivity of all inks formulations were monitored over a period of time for the evaluation of ink stability and suitability. The inks were used for application on polyester and polyamide samples by exhaustion (dyeing) and wash, light fastness and colour measurements were made on the dyed samples. The optimum application level required to give long lasting antimicrobial protection was determined by carrying out a series of antimicrobial testing.     

Errors related to image analysis technique applied for the investigation of textile local deformations

Due to the woven structure textile materials have excellent formability properties but their behaviour is difficult to investigate. Digital image analysis as non-disturbing and low cost method for the textile investigations has paid a lot of attention, still this method has some limits. The aim of the research is to analyse the accuracy and reliability of the method based on digital image analysis for the textile local deformations investigation and to determine the measurement errors. Depending on the results of experiments when input image acquisition parameters (capture distance d _i and lighting angle γ _j ) were changed the image analysis system was composed. To estimate the measurement errors of the method the scanned image was used as reference sample and parameters of each grid point A ₀, h ₀ ir b ₀ were compared calculating the measurement error depending on image resolution δ _Ai and illumination conditions δ _h60, δ _w60, δ _A60. Image quality evaluation while investigating different material types has shown that image analysis method can be applied for the fabrics the colour intensity of which differs, however it is necessary to ensure sufficient contrast of input image and to apply additional image processing operations.     

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.     

Micro-fading spectrometry: A tool for real-time assessment of the light-fastness of dye/textile systems

Micro-fading spectrometry is a technique that combines visible reflectance spectroscopy and accelerated light aging testing. Therefore, it is a useful tool for determining the light-stability of dyes applied on textile substrates in a relatively short amount of time. Traditional accelerated light aging methods usually require controlling many variables such as time and intensity of illumination, correct positioning of the sample during irradiation, and reproducible spot selection for each subsequent spectrocolorimetric measurement. The use of micro-fade testing as an alternative way of conducting light-fastness assessments of dye/textile systems has been explored. The results indicate that the technique is suitable for testing the color stability of cultural heritage materials and industrially manufactured textiles since it is a direct and non-contact method that takes into account the aforementioned experimental variables.     

Simultaneous application of silver nanoparticles with different crease resistant finishes

Textiles, especially those made of natural fibers, are suitable medium for the growth of microorganisms which causes disease transmission, stink, colorful spots, and reduction in fabric strength. This research focuses on the antimicrobial finishing of cotton fabrics using colloidal solution of silver nanoparticles. Due to the difficulties of adding a new step to the finishing process of cotton textiles, efforts have been made to combine the antimicrobial treatment with the conventional finishing processes. For this purpose two chemical finishes of Fixapret ECO as a crosslinking agent and Cellofix ME as a resin former have been used in anti crease finishing of cotton fabric and their effects were evaluated. The properties of the samples have been investigated by measuring the resistant of samples against bacteria, crease recovery angle, abrasion, and washing fastness. The results showed that treated samples by pad-dry method have the best antibacterial effect with a direct relation between the increase in drying temperature and antibacterial properties. However, the washing and abrasion fastness were not at the acceptable level. Co-application of the colloidal solution of silver nanoparticles with the crease resistant materials improved both fastness properties while at the same time limited the direct contact between the nanoparticles and the bacteria so the antibacterial efficiency was reduced. Subsequently, it was concluded that the antibacterial finishing method should be selected according to the end uses. In addition, antibacterial treatment could be one of the multi-purpose finishes for cotton fabric.     

Preparation and antibacterial property of the mulberry based textiles

The mulberry based textile products were prepared by means of degumming, dyeing, spinning and weaving using mulberry bark as raw materials. The structure of the mulberry based textiles was characterized by scanning electron microscope (SEM). The antibacterial property of the mulberry fibers was evaluated by means of antibacterial testing, and the antibacterial composition in the mulberry based textiles was investigated by FTIR and ¹³C-NMR. The results show that the mulberry based fibers, dyed fibers, yarns and fabrics with high quality can be prepared successfully by the above processes. The mulberry based textiles have excellent antibacterial property. The inhibitory rate of raw mulberry bark on Escherichia coli and Staphylococcus aureus is (67.2±3.1)% and (53.8±4.6)% respectively, and the inhibitory rate of mulberry fiber on Escherichia coli and Staphylococcus aureus is both above 80%. The inhibitory rate of the mulberry/cotton blended yarn on Escherichia coli and Staphylococcus aureus ranges from (51.7±5.1)% to (72.4±4.1)%, which has similar inhibitory rate with the mulberry/cotton blended fabric. The results of Fourier Transform-Infrared (FTIR) and ¹³C-nuclear magnetic resonance (¹³C-NMR) show that the typical functional group (hydroxyl, carbonyl, double bond and epoxy bond) exist in the composition of the mulberry fiber, which indicates that the flavones and phenolic compounds including in the mulberry fiber.     

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.     

Preparation of Copper Nanoparticles Coated Cotton Fabrics with Durable Antibacterial Properties

When copper nanoparticles (Cu NPs) were applied as an antimicrobial agent to finish cotton fabrics, there are two issues should be solved: the oxidization and the weak adsorbability onto cotton fiber surface. In the present work, we developed a new method that can achieve both immobilization and protection of the Cu NPs at the same time. As an effective binder, thioglycolic acid (TGA) was covalently linked to cotton fiber surface via an esterification with the hydroxyl groups of cellulose, then Cu NPs were introduced on the fabric surface in the presence of a protective reagent, citric acid. Due to the doubled stabilization acts of TGA and citric acid, the Cu NPs immobilized on the fabric surface showed an excellent antibacterial effect and outstanding laundering durability. Even after 50 consecutive laundering tests, the modified cotton fabrics still showed satisfactory antibacterial ability against both S. aureus and E. coli, which the bacterial reduction rates are all higher than 96 %. It is believed that this methodology has potential applications in a wide variety of textile productions such as sportswear, socks, and medical textiles.     

Antimicrobial activity of β-CD finished and apricot kernel oil applied fabrics

β-CD, which is composed of glucopyranose, is nontoxic and environmentally friendly. In addition, β-CD has a troidal shape and hydrophobic internal cavity that can form a host-guest complex with hydrophobic materials. Apricot kernel oil (AKO) is used as a food that it contains amygdalin and exhibits high antimicrobial activity compared to many other types of seed oil. In this study, the fabrics finished with β-CD and then applied with AKO were examined for their antibacterial effects against gram-positive C. xerosis and S. aureus as well as gram-negative K. pneumoniae. The β-CD finished fabric exhibited antimicrobial activity due to the unreacted carboxyl groups located in the supramolecular nano-assembled polymer. Moreover, the fabrics finished with β-CD followed by AKO showed bactericidal activity against most microbes. In regard to the durability of the antimicrobial property against washing, β-CD finished only and together with AKO included fabrics lost their antibacterial property as the number of washes was increased. The excellent antimicrobial activity of the β-CD finished fabrics was regained by spraying with an AKO-containing ethanol solution. β-CD finishing and application of AKO simultaneously can ensure antimicrobial activity against a variety of microbes.     

Polyphenol-Assisted Natural Coloration on Various Synthetic Textile Materials

With the increasing awareness of sustainability development and public health in the modern society, environmentally-friendly coloration process draws tremendous attention in the textile industry. Toxic heavy metal mordants are forbidden to be used in the application of natural colorants in the coloration process. In this study, an environmentallyfriendly coloration process with natural colorants on various synthetic textile materials was developed in the presence of dopamine, whose in-situ self-polymerization could produce rich polyphenolic coloration anchors. Using the proposed method, various synthetic textile materials could be easily coloured with natural colorants in a simple process, which is especially suitable to those materials which are difficult to be colored. Compared with the control process, synthetic textile materials were endowed with better exhaustions of natural colorants, as verified by their deeper colour appearance and higher K/S values. The colored materials were also characterized by colorimetric analysis as well as scanning electron microscopy and optical microscopic analysis, which also confirmed the successful application of the proposed coloration process. Moreover, the proposed strategy could also be applied on a wide variety of materials. It is an innovative green coloration process in the textile material fields.     

Impregnation of zinc oxide mediated chitosan nano-composites on polyester fabric for performance characteristics

Present study dealt with the fabrication of chitosan/zinc oxide nano-composites (CZNCs) using a facile preparation method. The structural features of nano-composites were investigated by using advanced analytical techniques. The developed nano-composites exhibited hexagonal structural pattern with an average particle size of about 51 nm. The developed CZNCs were dispersed in 2-propanol and applied on polyester by using the pad-dry-cure method. The treated fabric specimens were characterized for surface, functional and textile properties including antibacterial activity and (ultra violet) UV- blocking. The nano-composite treated polyester fabric exhibited durable antibacterial, UV- blocking and textile properties with fair whiteness index.     

Spinning performance and antibacterial activity of SeaCell® active/cotton blended rotor yarns

Microorganisms can lead to functional, hygienic and aesthetic (e.g. deterioration, staining) problems on textile products. Natural fibers especially cotton are more easily affected by microorganisms. Blending of cotton fibers with antimicrobial fibers can enhance the protective properties of products against microorganisms. Demand of antimicrobial performance from the products changes depending on the application area. Therefore determination of suitable antimicrobial fiber quantity for the desired application is important. In this study the spinning performance of SeaCell Active/cotton blended open end rotor yarns and antibacterial activities of fabrics produced by these blended yarns were investigated. Five different cotton/SeaCell Active blended slivers with SeaCell Active content from 3 % up to 53 % were prepared on drawframe machine and all slivers were spun into yarns on open end rotor spinning machine at a yarn count of 20 tex with α_Tt=3827 twist coefficient. The effects of rotor speed, opening roller speed, rotor, opening roller and navel type on the quality parameters of SeaCell Active/cotton blended yarns were investigated. Tensile properties, hairiness, unevenness and IPI values of the yarns were reported. All types of cotton/SeaCell Active blended yarns were knitted on a circular knitting machine. Antibacterial activity of the fabrics was analyzed quantitatively. Antibacterial tests showed that good antibacterial activity can be achieved after several washings even with 3 % of SeaCell Active fibers in fabrics.     

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.     

Comparison between oxygen and nitrogen plasma treatment on adhesion properties and antibacterial activity of metal coated polypropylene fabrics

In this paper, an attempt was made to apply low temperature plasma treatment to improve the adhesion property of polypropylene fabrics. Oxygen and nitrogen plasmas were used for pre-functionalization of polypropylene fabrics. Then treated and untreated samples were coated with copper using direct current magnetron sputtering for 10 minutes. And the effect of oxygen and nitrogen pre-functionalization on adhesion properties between copper particles and polypropylene surface were studied. The textile properties of treated and untreated samples were evaluated by different standard testing methods in terms of both physical and chemical performances. The morphology changes of fabrics after plasma treatment were characterized by scanning electron microscopy. Fourier transform infrared spectroscopy analyses revealed chemical surface modifications occurring after the plasma treatments. Experimental results of the adhesion properties and surface properties are presented for the metal coated-polypropylene samples before and after low pressure plasma treatment, and results are compared. The adhesion properties of the activated samples are determined by abrasion and rubbing tests. The antibacterial counting test was used for determination of antibacterial efficiency of both treated and untreated samples, and durability of antibacterial properties was compared. The adhesion improvement has been related to the formation of different functional groups and changes in the topology of the surface.     

A Lymphoid Organ Specific Anti-Lipopolysaccharide Factor from Litopenaeus vannamei Exhibits Strong Antimicrobial Activities

Different shrimp species are known to possess apparent distinct resistance to different pathogens in aquaculture. However, the molecular mechanism underlying this finding still remains unknown. One kind of important antimicrobial peptides, anti-lipopolysaccharide factors (ALF), exhibit broad-spectrum antimicrobial activities. Here, we reported a newly identified ALF from the shrimp Litopenaeus vannamei and compared the immune function with its counterpart in the shrimp Fenneropenaeus chinensis. The ALF, designated as LvALF8, was specifically expressed in the lymphoid organ of L. vannamei. The expression level of LvALF8 was apparently changed after white spot syndrome virus (WSSV) or Vibrio parahaemolyticus challenges. The synthetic LBD peptide of LvALF8 (LvALF8-LBD) showed strong antibacterial activities against most tested Gram-negative and Gram-positive bacteria. LvALF8-LBD could also inhibit the in vivo propagation of WSSV similar as FcALF8-LBD, the LBD of LvALF8 counterpart in F. chinensis. However, LvALF8-LBD and FcALF8-LBD exhibited apparently different antibacterial activity against V. parahaemolyticus, the main pathogen causing acute hepatopancreatic necrosis disease (AHPND) of affected shrimp. A structural analysis showed that the positive net charge and amphipathicity characteristics of LvALF8-LBD peptide were speculated as two important components for its enhanced antimicrobial activity compared to those of FcALF8-LBD. These new findings may not only provide some evidence to explain the distinct disease resistance among different shrimp species, but also lay out new research ground for the testing and development of LBD-originated antimicrobial peptides to control of shrimp diseases.     

Antimicrobial activity of textiles with selected dyes and finishing agents used in the textile industry

It is shown in this paper that cationic dyes and chemical finishing agents for textiles exhibit antimicrobial properties both in solution and when present on textile products. The dye Maxilon Navy 2RM has particularly high antimicrobial activity — its values of the minimum concentration inhibiting the growth of the studied microorganisms (MIC and MBC) are very low, in the range 0.0003–0.06 %. The tested dyes display mainly fungistatic action, while the fiber softener Sapamine OC and the dyeing fixative wet fastness improver Albafix WFF were more active against bacteria. The paper presents sensitivity series of microorganisms with respect to the tested dyes and finishing agents. Fabrics to which the substances had been applied showed reductions in microorganism numbers by 16 % to 99.9 %, depending on the type of substance and the microorganism. The studies showed that in some cases the use of a typical (justified technologically) quantity of dye or finishing agent imparts high antimicrobial activity to the textile materials, with bacteria or fungi reduced by more than 99 %.     

Effect of dispersing agents on synthesis of nano titanium oxide and its application for antimicrobial property

With the growing demand for comfortable, clean and hygienic textile goods, an urgent need for production of antimicrobial textiles has arisen. In this work, synthesis of nano titanium oxide has been done by sol gel method and the effect of dispersing agents with varying ionic character during synthesis on the particle size of the synthesised nano particles in terms of crystallinity and particle size was studied. It was observed that cationic as well as non-ionic dispersing agents led to reduction in size of the titania particles produced whereas anionic dispersing agent led to increase in the particle size. This method provides a simple method for reduction in size of titanium dioxide particles with a minor modification of a standard process. The synthesized nano titanium dioxide particles were successfully applied onto cotton to obtain Antimicrobial activity. The Durability of the antimicrobial activity was upto 10 washes with the help of Binder. The effect of the application of nano titanium oxide on the physical properties of the substrate, such as tensile strength, bending length, and crease recovery angle has been analysed.     

Green Approach for Multifunctionalization of Cellulose-Containing Fabrics

Development of multifunctional textile and clothing products with improved environmental profiles has been demanded both by textile industry and by consumer. Herein, dialdehyde sodium alginate (DASA) and dialdehyde carboxymethyl cellulose (DACMC) have been prepared, characterized and utilized, as an eco-friendly binding/ macromolecular crosslinking/hand building agents, in functional finishing of cellulose-containing fabrics. Fabric samples were treated with the nominated dialdehyde polysaccharide (DAPS, 10 g/l) along with the reactant resin (DMDHEU, 50 g/l), Ag- or TiO₂-NPs as active ingredients (20 g/l) and ammonium persulfate catalyst (5 g/l) using the padding method. After functional finishing, the finished fabrics demonstrated a remarkable improvement in their antibacterial efficacy, UV-blocking ability, self-cleaning capacity, and surface roughness functionality without adversely affecting fabrics resiliency. The variation in these functional properties is affected by kind of DAPS, type of added nanoparticles as well as the treated substrate. Additionally, FTIR, SEM, EDS, and durability to wash measurements for selected samples were performed. Moreover, pre-oxidation of DAPS, functionalization reactions/interactions among the nominated reactants and the textile materials were also suggested.     

Characterisation of Non-Autoinducing Tropodithietic Acid (TDA) Production from Marine Sponge Pseudovibrio Species

The search for new antimicrobial compounds has gained added momentum in recent years, paralleled by the exponential rise in resistance to most known classes of current antibiotics. While modifications of existing drugs have brought some limited clinical success, there remains a critical need for new classes of antimicrobial compound to which key clinical pathogens will be naive. This has provided the context and impetus to marine biodiscovery programmes that seek to isolate and characterize new activities from the aquatic ecosystem. One new antibiotic to emerge from these initiatives is the antibacterial compound tropodithietic acid (TDA). The aim of this study was to provide insight into the bioactivity of and the factors governing the production of TDA in marine Pseudovibrio isolates from a collection of marine sponges. The TDA produced by these Pseudovibrio isolates exhibited potent antimicrobial activity against a broad spectrum of clinical pathogens, while TDA tolerance was frequent in non-TDA producing marine isolates. Comparative genomics analysis suggested a high degree of conservation among the tda biosynthetic clusters while expression studies revealed coordinated regulation of TDA synthesis upon transition from log to stationary phase growth, which was not induced by TDA itself or by the presence of the C10-acyl homoserine lactone quorum sensing signal molecule.