Nanosilver leverage on reactive dyeing of cellulose fibers: Color shading, color fastness and biocidal potentials

Electrospinning Silk-Fibroin-Based Fibrous Membranes with AgNPs for Antimicrobial Application

Silk fibroin (SF) has excellent biocompatibility and is one of the most commonly used polymer materials. However, SF fibers have serious drawbacks as antibacterial materials due to their lack of stability and bacterial resistance. Therefore, it is of paramount significance to enhance the stability and bolster the bacterial resistance of SF fibers. In this study, SF fibers were fabricated and loaded with Ag nanoparticles (AgNPs) to improve the antimicrobial properties of the fibers. The impact of reduction conditions on the size of AgNPs was also investigated. In an antibacterial test, the fibers that were prepared exhibited over 98% bacterial resistance against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Therefore, as an efficient antibacterial material, these fibers are expected to become a candidate material in medical and textile fields. This study offers a novel approach for the utilization of SF fibers in the realm of antibacterial applications.

Involvement of silver and palladium with red peanuts skin extract for cotton functionalization

A systematic study is currently demonstrated approach for approving the superior role of silver and palladium metallic particles in acting the role of mordant with acquiring the dyed cotton fabrics excellence in color fastness with additional functions of antimicrobial potentiality and UV-protection action. Whereas, samples were dyed with extract of red peanuts skin as natural textile colorant (RPN dye). The represented data revealed that, in absence of mordant, the samples treated with metal precursors prior to dyeing were exhibited with the excellent color strength, color fastness, antimicrobial action and UV-protection action. Color fastness (washing, rubbing and light fastness) was estimated to be in the range of very good-excellent. Sample pretreated with silver salt and dyed in the absence of mordant was graded with excellent UV-protection action (UPF 31.5, UVB T% 2.6% and UVB blocking percent 97.4%). Antimicrobial potency against E. coli, S. aureus and Candida albicans through inhibition zone and the reduction percent was approved to be in the range of excellence (93.01-99.51%) for the samples dyed in absence of mordant and pretreated with either silver or palladium precursors.

Study on a cationic agent-based salt-free reactive dyeing process for cotton knit fabric and comparison with a traditional dyeing process

Since the majority of reactive dyes only have a moderate affinity for cotton, significant amounts of electrolytes are frequently needed to cause tiredness. As a result, wastewater contains significant amounts of salt and dye, and the increasing salinity of the rivers has an effect on the delicate biochemistry of aquatic life. The aim of the study was to find a sustainable dyeing process for cotton knit fabric using EPTMAC (2, 3-epoxypropyl trimethyl ammonium chloride) as a cationic agent and comparison of the cationic dyeing process (salt free dyeing) with the regular dyeing process (dyeing with salt). For this purpose, cotton knit fabric samples were dyed with reactive dyes following salt free process and with salt. Afterwards, color fastness (wash and rubbing), spectrophotometric evaluation, bursting strength test, analysis of dye bath discharge water and Scanning Electron Microscope (SEM) image of the dyed samples were carried out. Moreover, water consumption was also evaluated for the both cationic and regular dyeing process. In terms of color fastness, cationized dyed fabric showed no change to a slight loss in depth (rating of 4-5) for both wash and rubbing fastness. From the spectrophotometric evaluation, it was found that cationized dyed fabric appeared darker and less yellowish tone. Moreover, in case of bursting strength, cationized black, hot pink, and light pink colored fabrics possessed bursting strengths of 287 kPa, 337 kPa, and 440 kPa, correspondingly. After analysis of dye bath discharge water, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Dissolved Solids (TDS) value of regular colored water samples were 45%, 39%, 54% greater than that of cationized dyed water samples respectively. Cationized dyed water value for Dissolved Oxygen (DO) was 6.39 mg/l, which was within the acceptable limit. The SEM image asserted that the cationized colored samples had consistent dye dispersion, greater adhesion, and no dye anomalies. Considering water consumption, it was found that 37%, 27% and 23% less amount of water required for dyeing dark, medium and light shade of cationized samples due to fewer washes after dyeing and elimination of fixing steps. In addition of that, total cost of cationic dyeing process was less due to less chemical consumption, less utility use, shorter process time and less amount of dyes needed. Cationic dyeing process is a sustainable practice of dyeing cotton fabric with reactive dyes that offers numerous advantages when compared to the regular dyeing process with less cost consumption and low amount of environmental pollution.

Gamma Radiation Induced Synthesis of Novel Chitosan/Gold/Bioactive Glass Nanocomposite for Promising Antimicrobial, and Antibiofilm Activities

In the present study we reported, for the first time, the gamma irradiation induced synthesis of chitosan/Au/bioactive glass (CS/Au/BG) nanocomposite. The bioactive glass (BG), with the composition 45% SiO2, 32.5% CaO, 15% Na2O, and 7.5% P2O5 wt% was synthesized through the sol–gel technique. XRD, SEM, EDX, and elemental mapping images were utilized to evaluate the structure of pure BG and CS/Au/BG nanocomposite. The antimicrobial efficacy was evaluated by zone of inhibition (ZOI), minimum inhibitory concentration (MIC), growth curve assay, and Ultraviolet irradiation effect. Investigation was carried on the antibiofilm effectiveness. Membrane leakage as well as SEM imaging were used to evaluate the antibacterial reaction mechanism. The crystallite size of CS/Au/BG nanocomposite was determined via Scherer equation as 22.83 nm. CS/Au/BG possessed the most ZOI activity against the tested microbes. The highest inhibition % of BG, and CS/Au/BG nanocomposite was investigated for S. aureus (15.65%, and 77.24%), followed by C. albicans (13.32%, and 64.75%). The quantity of protein leakage was directly-proportional after increasing the concentration of BG, and CS/Au/BG and counted to be 70.58, and 198.25 µg/mL, respectively (after applied 10 mg/mL). The promising results suggested the use of novel CS/Au/BG nanocomposite as an encourage candidate for wastewater treatment application against pathogenic microbes.

Observable removal of pharmaceutical residues by highly porous photoactive cellulose acetate@MIL-MOF film

Pharmaceutical products are used tremendously worldwide and subsequently released into wastewater even at very low concentration caused serious environmental problem due to their high activity. Therefore, the present work focuses on remarkable removal of paracetamol as one from the most used pharmaceutical intermediates, by using porous film based on cellulose acetate@metal organic framework (CA@Ti-MIL-NH₂). The film was designed to achieve extreme removal of paracetamol by action of both of adsorption and degradation. Metal organic frame work was directly synthesized and inserted within the pre-prepared porous CA film to obtain porous CA@Ti-MIL-NH₂ film. The synthesized films were applied in adsorption and photo-degradation of paracetamol separately and together. Due to the photocatalytic activity of Ti-MIL-NH_2, the photo-degradation of paracetamol in visible-light was much effective and considerably high degradation of paracetamol was observed (k₁ = 760.0 m^-1) comparing to the adsorption (k₁ = 160.0 m^-1). The overall removal of paracetamol was significantly enlarged from 82.7 mg/g for CA film to 519.1 mg/g for porous CA@Ti-MIL-NH₂ film. The used film exhibited quite good reusability and the removal of paracetamol was lowered from 96% to 85% after 5 regeneration cycles. Results of total organic carbon confirmed that paracetamol was fully degraded to CO₂ and water.

Technical textiles modified with immobilized carbon dots synthesized with infrared assistance

Carbon quantum dots "CQDs" were investigated as photo-luminescent nanomaterials as it advantageous with nontoxicity to be alternative for metallic-nanomaterials in different purposes. Therefore, the presented report demonstrates an innovative strategy for industrialization of antimicrobial/fluorescent cotton textiles via exploitation of "CQDs". Unique/novel infrared-assisted technique was currently investigated for clustering "CQDs" form carboxymethyl cellulose. The successive nucleation of "CQDs" (8.0 nm) was affirmed via infra-red, Raman spectroscopy, NMR, TEM and Zeta-potential analysis. The clustered "CQDs" showed antimicrobial and fluorescent characters. The minimal inhibition concentration for "CQDs" (100 mg/mL) against E. coli and C. albicans showed pathogenic reduction of 96% and 82%, respectively. Fluorescent emission spectra for "CQDs" showed two intense peaks at 415-445 nm. "CQDs" were loaded upon pristine and cationized cotton to prepare CQDs@cotton and CQDs@cationized cotton. While, their physical/mechanical properties (air and water vapor permeabilities, tensile strength and elongation %) and thermal stability (TGA & DTG analysis) were studied. The CQDs@cationized cotton exhibited excellent antimicrobial activity with good durability as after ten repretitive washings, inhibition zone diameter against E. coli, was diminished from 21.0 mm to 14.0 mm. The fluorescent emmision intensity was diminished from 741 to 287 after 10 washing cycles. The produced cotton fabrics could be safely used in the medical and military textiles.

Improving the functionality of raw cotton: simultaneous strength increases and additional multi-functional properties

It has, nowadays, become indispensable to get multi-functional properties from a single piece of fabric or garment in the sector of textile and fashion. Cotton fabric is now extremely being utilized in garments all over the world. At the raw stage, cotton fabric has less reflectance, high ignition tendency, moreover the proclivity to be attracted by microorganisms. The strength of the fabric might be deteriorated because of frequent processing. In this study, a single jersey raw (grey) cotton fabric of 150 GSM was processed with a pertinent chemical treatment to convert the reflectance to about 100 % and impart flame resistance property together with the other functional properties. Due to the attainment of high reflectance and flame resistance traits, the heat-absorbing tendency of the fabric became low which improved the comfortability of the fabric. The strength of the processed fabric was increased by 4 %. Crease recovery angle was increased by 57 % in the course way and by 82 % in wales way direction that attributed crease-resistance and more stability to the modified fabric. Moreover, the processed fabric was also able to exhibit antimicrobial properties. Strength improvement, attainment of crease-resistance, and antimicrobial property could enhance the longevity of the fabric. The attainment of multifunctional properties together with the strength improvement simultaneously provided a unique feature to the modified cotton fabric. It was a permanent chemical treatment, and it modified the surface of the fabric, which ultimately enhanced the proclivity of cotton fabric to be more compact or crystalline and more stable. The addition of the new quality of the cotton fabric could endure even after washing. The modified cotton fabric with newly added characteristics could be a good choice to prepare garments with felicitous longevity to protect from heat, fire flame sensitivity. It really could create an opportunity in multi-functional fabric processing as well as modern textiles.

Biocidal activity of curcumin and cationic polymer possessing composites

There is a growing interest in new type of biocidal compounds with antibacterial properties against bacteria. In this study, new antibacterial synthetic materials bearing curcumin and cationic polymers were synthesized. In the synthesis stage, the methacrylate functional cationic monomer was synthesized via the Michael addition route by using 3-acryloxy-2-hydroxypropyl methacrylate and 3-amino pyridine to obtain Monomer 1. Monomer 1 was further quaternized with hexyl bromide to obtain a cationic methacrylate functional monomer. Free-radical polymerization of Monomer 1 and methyl acrylate was conducted in the presence of azobisisobutyronitrile under dimethylformamide solvent. The composite formulation was conducted by using turmeric extract Curcuma longa (curcumin), hydroxyapatite, montmorillonite, and silver nitrate. The materials were analyzed by using the methods of X-ray diffraction, nuclear magnetic resonance, Fourier transform infrared spectroscopy, and scanning electron microscopy. The biocidal activities against the bacteria Escherichia coli, Listeria monocytogenes, Salmonella, and Staphylococcus aureus were analyzed using agar well diffusion method. From the Fourier transform infrared, X-ray diffraction, and scanning electron microscopy analysis results of the synthesized nanocomposites, it is seen that they form strong connections with the components added to the composites and form an exfoliated structure. According to the antibacterial analysis results, the nanocomposites obtained have showed a strong antibacterial resistance against E.coli, L.monocytogenes, Salmonella, and S. aureus bacteria, and the high inhibition zone areas were obtained.

Facile coating of urinary catheter with bio-inspired antibacterial coating

Formation of bacterial biofilm on indwelling urinary catheters usually causes catheter-associated urinary tract infections (CAUTIs) that represent high percent of nosocomial infections worldwide. Therefore, coating urinary catheter with antibacterial and antifouling coating using facile technique is in great demand. In this study, commercial urinary catheter was coated with a layer of the self-polymerized polydopamine which acts as active platform for the in situ formation of silver nanoparticle (AgNPs) on catheter surface. The formed coating was intensively characterized using spectroscopic and microscopic techniques. The coated catheter has the potential to release silver ion in a sustained manner with a concentration of about 2-4 μg ml-1. Disk diffusion test and colony forming unites assay verified the significant bactericidal potential of the AgNPs coated catheter against both gram-positive and gram-negative bacteria as a consequence of silver ion release. In contrast to commercial catheter, the AgNPs coated catheter prevented the adherence of bacterial cells and biofilm formation on their surfaces. Interestingly, scanning electron microscope investigations showed that AgNPs coated catheter possess greater antifouling potential against gram-positive bacteria than against gram-negative bacteria. Overall, the remarkable antibacterial and antifouling potential of the coated catheter supported the use of such facile approach for coating of different medical devices for the prevention of nosocomial infections.

Antimicrobial cellulosic textiles based on organic compounds

Healthy body is one of the principle requirements of human beings, but the highly rated growth of harmful pathogens has challenged researchers for investigation of antimicrobial reagents. Infection of textile materials is a result of microbial adherence on the surface, and it is one of the vital clinical complications, which causes a high rate of mortality. New challenges as well as new opportunities in manufacturing of antimicrobial cellulosic textiles are the future concerns for textile and apparel industry. The major applications of antimicrobial textile could be ascribed according consumer demands, represented in more comfort, easy care, health, and durable to laundering. Such numerous properties could be achieved by the development of innovative methodologies with various finishing agents. Thus, the current review introduced an overview for the application of recent organic antimicrobial reagents in cellulosic textile finishing. The organic reagents are classified into two main categories; natural (chitosan, cyclodextrins and natural dyes) and synthetic (quaternary ammonium salts, triclosan, halogenated phenols and metal organic frameworks). The interaction between cellulose and such reagents, biological action mechanisms and factors affecting biocidal actions are all presented. For improvement of the durability and mechanical properties, pre-activation of cellulosic textile or using of cross-linkers is properly performed.

One-step green approach for functional printing and finishing of textiles using silver and gold NPs

In this study, we present a successful simple method for printing and finishing of polyester and cotton fabrics using gold and silver nanoparticles (Au-NPs and Ag-NPs, respectively) as stable, fast colorants and functional components. The surface plasmon resonance (SPR) bands of the colloidal gold and silver NPs were observed at λ_max 520 nm and 450 nm, respectively, indicating the presence of spherical Au-NPs and Ag-NPs, which was further confirmed by TEM analysis. The printed samples were subjected to SEM, XRD and EDX analyses. The SEM images and EDX spectra unequivocally confirmed the existence of embedded NPs on the fabric surfaces. Both the cotton and polyester samples possessed excellent color fastness, as indicated from the color fastness test. The functional properties of the printed fabrics indicated that the incorporation of Au-NPs and Ag-NPs into the fabrics simultaneously imparted multifunctional properties such as stable brilliant colors, highly durable antimicrobial activity and very good UV-protection properties.

In this study, we present a successful simple method for printing and finishing of polyester and cotton fabrics using gold and silver nanoparticles (Au-NPs and Ag-NPs, respectively) as stable, fast colorants and functional components.