Textile Coatings Research Articles

Graphitic Carbon Nitride/Zeolitic Imidazolate Framework-8 Nanoparticles with Antibacterial Properties for Textile Coating

Graphitic Carbon Nitride/Zeolitic Imidazolate Framework-8 Nanoparticles with Antibacterial Properties for Textile Coating

RETRACTED ARTICLE: Synthesis and characterization of CuO nanoparticles and evaluation of their bactericidal and fungicidal activities in cotton fabrics.

Textiles functionalized with copper oxide nanoparticles (CuO NPs) have become a favourable material to inhibit the spread of diseases due to their anti-microbial properties. In the present work, a successful procedure for in situ growth of CuO NPs in textiles was developed. Results showed that the combination of in situ synthesis and pad–dry–cure method promoting a uniform and dense adsorption of nanoparticles on the surface of the fabrics. The CuO NP-coated fabrics was characterized using XRD, SEM, EDX, TEM, and FTIR techniques. The CuO NP-coated cotton fabrics showed better anti-bacterial activity against various bacteria’s namely Staphylococcus aureus, Escherichia coli, Pseudomonas fluorescens and Bacillus subtilis. Besides, it also showed better antifungal activity against Candida albicans. The CuO NPs impregnated cotton fabrics exhibit a bacterial reduction of more than 90%, which is sustainable even after 20 washing cycles. Therefore, the CuO NP-coated fabrics has great potential to be used as coatings for medical, cosmetic or sports fabrics.

Textile Finishing Using Polymer Nanocomposites for Radiation Shielding, Flame Retardancy and Mechanical Strength

The uses of nanotechnologies in textiles are strategic and allow textiles to become multifunctional. There is an ever-increasing demand for new functionalities, like flame retardancy, radiation shielding, improved mechanical strength etc., for highly specific applications. There is no industrial supply for the above-mentioned functionalities. Keeping in view of this background, surface treatment becomes one of the most important methods to create new textile properties. Polymer nanocomposites based on coatings for textiles have a huge potential for innovative modifications of surface properties like flame retardancy, radiation shielding and improved mechanical properties, which can be applied with a comparatively low technical effort and at moderate temperatures. This review compiles recent research on polymer nanocomposites for functional finishing of textiles to understand the theoretical and experimental tools on polymer nanocomposites and their applications in textiles.

Improving the Antimicrobial and Mechanical Properties of Epoxy Resins via Nanomodification: An Overview.

The main purpose of this work is to provide a comprehensive overview on the preparation of multifunctional epoxies, with improved antimicrobial activity and enhanced mechanical properties through nanomodification. In the first section, we focus on the approaches to achieve antimicrobial activity, as well as on the methods used to evaluate their efficacy against bacteria and fungi. Relevant application examples are also discussed, with particular reference to antifouling and anticorrosion coatings for marine environments, dental applications, antimicrobial fibers and fabrics, and others. Subsequently, we discuss the mechanical behaviors of nanomodified epoxies with improved antimicrobial properties, analyzing the typical damage mechanisms leading to the significant toughening effect of nanomodification. Some examples of mechanical properties of nanomodified polymers are provided. Eventually, the possibility of achieving, at the same time, antimicrobial and mechanical improvement capabilities by nanomodification with nanoclay is discussed, with reference to both nanomodified epoxies and glass/epoxy composite laminates. According to the literature, a nanomodified epoxy can successfully exhibit antibacterial properties, while increasing its fracture toughness, even though its tensile strength may decrease. As for laminates—obtaining antibacterial properties is not followed by improved interlaminar properties.

Improved Biological Responses of Titanium Coating Using Laser-Aided Direct Metal Fabrication on SUS316L Stainless Steel.

Direct metal fabrication (DMF) coatings have the advantage of a more uniform porous structure and superior mechanical properties compared to coatings provided by other methods. We applied pure titanium metal powders to SUS316L stainless steel using laser-aided DMF coating technology with 3D printing. The purpose of this study was to determine the efficacy of this surface modification of stainless steel. The capacity of cells to adhere to DMF-coated SUS316L stainless steel was compared with machined SUS316L stainless steel in vitro and in vivo. Morphological in vitro response to human osteoblast cell lines was evaluated using scanning electron microscopy. Separate specimens were inserted into the medulla of distal femurs of rabbits for in vivo study. The distal femurs were harvested after 3 months, and were then subjected to push-out test and histomorphometrical analyses. The DMF group exhibited a distinct surface chemical composition, showing higher peaks of titanium compared to the machined stainless steel. The surface of the DMF group had a more distinct porous structure, which showed more extensive coverage with lamellipodia from osteoblasts than the machined surface. In the in vivo test, the DMF group showed better results than the machined group in the push-out test (3.39 vs. 1.35 MPa, respectively, p = 0.001). In the histomorphometric analyses, the mean bone-to-implant contact percentage of the DMF group was about 1.5 times greater than that of the machined group (65.4 ± 7.1% vs. 41.9 ± 5.6%, respectively; p < 0.001). The porous titanium coating on SUS316L stainless steel produced using DMF with 3D printing showed better surface characteristics and biomechanical properties than the machined SUS316L.

A Review on Synthesis of Plant-Mediated Metal Nanoparticles for Fabric Coating

Biosynthesis, or also known as green synthesis method, has received an enormous attention from the scientific community over the physical and chemical synthesis methods for the production of metal or metal oxide nanoparticles (NPs). Physical and chemical syntheses are typically expensive and generate a large number of hazardous by-products which can cause toxicity to either humans or the environment. Thus, biosynthesis is an alternative for production of NPs. Biosynthesis involves the use of plant extracts and natural bio-resources such as microorganisms and enzymes. It has been demonstrated that the biosynthesis method is suitable for large-scale production since it is simple, cheap, easy, fast, non-toxic, and environmentally friendly. This review mainly focuses on the synthesis of plant-mediated metal NPs for fabric coating. Importantly, the characteristics of the NPs and their applications after fabrication onto the fabrics are also highlighted. The morphology and size of the NPs are influenced by the concentration of plant extracts, control of metal salt concentration, temperature, and pH. This review also summarizes the advantages, limitations, and future challenges of biosynthesis towards the production of fabric coatings. There are several advantages in utilizing green substances, including moderate operation conditions with a minimal use of toxic chemicals and low energy consumption.

Bioactivity of Chitosan-Based Particles Loaded with Plant-Derived Extracts for Biomedical Applications: Emphasis on Antimicrobial Fiber-Based Systems.

Marine-derived chitosan (CS) is a cationic polysaccharide widely studied for its bioactivity, which is mostly attached to its primary amine groups. CS is able to neutralize reactive oxygen species (ROS) from the microenvironments in which it is integrated, consequently reducing cell-induced oxidative stress. It also acts as a bacterial peripheral layer hindering nutrient intake and interacting with negatively charged outer cellular components, which lead to an increase in the cell permeability or to its lysis. Its biocompatibility, biodegradability, ease of processability (particularly in mild conditions), and chemical versatility has fueled CS study as a valuable matrix component of bioactive small-scaled organic drug-delivery systems, with current research also showcasing CS’s potential within tridimensional sponges, hydrogels and sutures, blended films, nanofiber sheets and fabric coatings. On the other hand, renewable plant-derived extracts are here emphasized, given their potential as eco-friendly radical scavengers, microbicidal agents, or alternatives to antibiotics, considering that most of the latter have induced bacterial resistance because of excessive and/or inappropriate use. Loading them into small-scaled particles potentiates a strong and sustained bioactivity, and a controlled release, using lower doses of bioactive compounds. A pH-triggered release, dependent on CS’s protonation/deprotonation of its amine groups, has been the most explored stimulus for that control. However, the use of CS derivatives, crosslinking agents, and/or additional stabilization processes is enabling slower release rates, following extract diffusion from the particle matrix, which can find major applicability in fiber-based systems within ROS-enriched microenvironments and/or spiked with microbes. Research on this is still in its infancy. Yet, the few published studies have already revealed that the composition, along with an adequate drug release rate, has an important role in controlling an existing infection, forming new tissue, and successfully closing a wound. A bioactive finishing of textiles has also been promoting high particle infiltration, superior washing durability, and biological response.

Microemulsification of essential oils for the development of antimicrobial and mosquito repellent functional coatings for textiles.

To develop an essential oil (EO)-loaded textile coating using an environmentally friendly microemulsion technique to achieve both antimicrobial and mosquito repellent functionalities. Minimum inhibitory concentrations and fractional inhibitory concentrations of litsea, lemon and rosemary EOs were determined against Staphylococcus aureus, Escherichia coli, Staphylococcus epidermidis, Pseudomonas aeruginosa and Trichophyton rubrum. A 1 : 2 mixture of litsea and lemon EOs inhibited all the microorganisms tested and was incorporated into a chitosan-sodium alginate assembly by a microemulsification process. The EO-loaded microemulsions were applied to cotton and polyester fabrics using a soak-pad-dry method. The textile challenge tests demonstrated 7-8 log10 reductions of S. epidermidis, S. aureus and E.coli after 24 h and T. rubrum after 48 h. Aedes aegypti mosquito repellency was also assessed which demonstrated 71·43% repellency compared to 52·94% by neat EO-impregnated cotton. Textiles treated with the litsea and lemon EO microemulsion showed strong antimicrobial activity against the skin associated microorganisms E.coli, S. aureus, S. epidermidis and T. rubrum and potential mosquito repellent properties. EOs could be useful for the development of natural, environmentally friendly functional textiles to protect textiles and users from microbial contamination in addition to possessing other beneficial properties such as mosquito repellency.

Effects of outdoor weathering and laundering on the detection and classification of fluorinated oil-and-water-repellent fabric coatings.

Fluorinated polymer coatings are used to impart durable oil-and-water-repellent properties on fabrics, potentially offering a persistent fiber characteristic for forensic fiber comparisons. To evaluate the persistence of these coatings, we investigate effects of outdoor weathering and laundering on detection and classification of the fluorinated oil-and-water-repellent coatings on 9 garments and 2 spray-coated fabric samples. Single fibers from the samples are pyrolyzed and subjected to gas chromatography coupled to a fluorine-selective detector. The positive detection of coatings is indicated by a signal-to-noise ratio (S/N)>50 for the tallest peak in the pyrograms. Moreover, a multinomial logistic regression model trained using fibers prior to weathering and laundering is utilized to determine the class of the weathered and laundered fibers, providing a metric to evaluate the effect of these processes on fiber classification. Notably, fluorinated coatings are detected on all of the fibers exposed to outdoor elements in Arlington, VA, up to 12weeks from August to October 2020, while a detection rate of 95.5% is achieved for samples laundered up to 10 wash cycles. The detection rate prior to weathering and laundering was 98%, indicating negligible effect of these processes on detection of coatings. The classification accuracy is determined to be 99% and 100% for weathered and laundered samples, respectively, illustrating that these processes do not significantly affect the major pyrolysis products of the coatings responsible for classification. These results highlight the persistence of the fluorinated oil-and-water-repellent fabric coatings and their potential for forensic fiber discrimination at single-fiber level.

Highly efficient, transparent, and environment-friendly flame-retardant coating for cotton fabric

Environmentally friendly flame-retardant coatings for fabrics urgently need to have both high efficiency and transparency, but their development faces severe challenges. In this study, we reported a highly flame-retardant coating without halogen and formaldehyde via a facile one-pot sol–gel approach derived from ammonium polyphosphate (APP), sodium alginate (SA), and tetraethoxysilane (TEOS). In this system, SA serving as a negatively charged stabilizer can effectively inhibit APP agglomeration and further co-gelatinize with TEOS, thus leading to high transparency (transmittance in the visible region >90%) and colorlessness of the coating. Meanwhile, SA as a charring agent, APP as both acid and blowing sources, and TEOS as a silicon source together constructed a P/N/Si-containing hybrid intumescent system, so that the coating showed highly flame-retardant efficiency for cotton fabric at an ultralow loading of 10 wt%, much superior to other coatings previously reported. The resultant cotton fabric showed a high limiting oxygen index of 31%, self-extinguishing ability in the vertical burning test. Additionally, the total heat release value and total smoke production significantly decreased by 63.5% and 70.0%, respectively in the cone calorimeter test, while the mechanical property remained almost unchanged. The mechanism analysis confirmed that the dense P/N/Si-containing graphitized char layer formed in the condensed phase could effectively prevent the release of heat and the diffusion of combustible gases. This work provides new insights into the design and fabrication of the flame-retardant coating combined with the advantages of high efficiency, environment friendliness, transparency, and colorlessness.

Biobased Waterborne Polyurethane-Urea/SWCNT Nanocomposites for Hydrophobic and Electrically Conductive Textile Coatings.

Waterborne polyurethane-urea dispersions (WPUD), which are based on 100% bio-based semi-crystalline polyester polyol and isophorone diisocyanate, have been successfully synthesized and doped with single-walled carbon nanotubes (SWCNT) to obtain a finishing agent that provides textiles with multifunctional properties. The chemical structure of WPUD has been characterized by Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The thermal properties have been evaluated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical thermal analysis (DMTA). Mechanical properties have been studied by tensile stress–strain analysis. Moreover, the particle size, particle size distribution (PSD), and stability of developed waterborne dispersions have been assessed by dynamic light scattering (DLS), Z-potential, and accelerated aging tests (analytical centrifugation). Subsequently, selected fabrics have been face-coated by the WPUD using knife coating method and their properties have been assessed by measuring water contact angle (WCA), water column, fabric stiffness, and air permeability. The electrical conductivity of textiles coated with SWCNT-doped WPUD has been evaluated by EN 1149 standard. Finally, the surface morphologies of uncoated and coated fabrics have been studied by scanning electron microscopy (SEM). All of the synthesized polyurethane-ureas provide the coated substrates with remarkable water-repellency and water column, being therefore a more sustainable alternative to waterproof coatings based on fluoropolymers, such as PTFE. The additivation of the polymeric matrices with SWCNT has led to textile coatings with excellent electrical conductivity, maintaining water column properties, giving rise to multifunctional coatings that are highly demanded in protective workwear and technical textiles.

Plasma-based Nanotechnology for Textile Coating

This review presents the significance of nanotechnology as a new tool in textile printing to introduce multifunctional properties. Nanostructures, such as nano-fibers, nano-coatings, nano-finishing and nano-composites, have potentially revolutionized the textile manufacturing industry with high performance characteristics, such as electrically conductivity, self-cleaning, hydrophobicity or hydrophilicity, flame-retardant, antimicrobial properties and ultraviolet protection, as well as improving their printing performance, without changing the bulk properties of the coated fabrics. There are various techniques have been applied to explore the properties of the coated fabric surface, including scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning probe microscopy (SPM).

Perfluorooctane sulfonic acid (PFOS) degradation by optimized heterogeneous photocatalysis (TiO2/UV) using the response surface methodology (RSM)

Perfluorinated compounds (PFCs) are chemical substances widely used in industry, especially in textile coatings, often detected in waters all around the world. Those are persistent, bioaccumulative, and endocrine disruptors, causing damage to human health and the environment. Thus, this work aimed at evaluating the degradation of aqueous perfluorooctane sulfonic acid (PFOS), one of the most used PFCs, at near environmental concentrations (initially 100 μg L−1) by heterogeneous photocatalysis (TiO2/UV). At optimized conditions (CTiO2= 1.45 g L−1 and pH= 4.0), which were determined by the response surface methodology (RSM), 83 % PFOS removal was achieved in 8 h at 25 °C. A pseudo-first-order kinetic model was adjusted to the experimental data and the initial rate constant (k) was estimated as 0.64 h−1 with maximum oxidation capacity (MOC) of 86 %. No significant degradation was observed by direct UV-photolysis. Furthermore, the degradation products (DPs) were identified by high performance liquid chromatography coupled to high resolution mass spectrometry (HPLC-MS), acute and chronic ecotoxicities for three classes of organisms (fishes, daphnids, and green algae) and lipophilicity (log D, pH 7.4) of the DPs were estimated using the ECOSAR 1.11 and Chemicalize software, respectively. The main finding was that PFOS could be degraded by an advanced oxidation process under mild conditions and reasonable times, and that the lipophilicity of the formed DPs affects acute and chronic ecotoxicities of the organisms studied.

Usage of Barium Titanate in Fabric Coating and Investigation of Some Properties

In this study, nano-sized barium titanate powder was applied for the first time to polyester woven fabrics by knife coating at three different concentration rates. Some physical (thickness, mass per unit area, bending rigidity, air permeability and tear strength) properties, electromagnetic shielding efficiency and solar (transmittance, reflectance) properties of samples were presented. The samples were also characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Electromagnetic shielding effectiveness of the fabrics was determined according to the ASTM D4935-10 standard by using a coaxial transmission line measurement technique in the frequency range of 15–3000 MHz. The solar properties were measured according to EN14500 standard using a UV/VIS/NIR spectrophotometer and results were calculated according to EN 410 standard. Results revealed that the electromagnetic shielding effectiveness and solar reflectance property of samples improved with increasing barium titanate concentration.

Synthesis and characterization of UV-curable cellulose acetate butyrate-based oligomers and their cotton fabric coatings

In order to improve the thermal stability and flexibility, cellulose acetate butyrate (CAB) was modified with toluene diisocyanate–hydroxyethyl methacrylate (TDI–HEMA) adduct in various molar ratios. The obtained oligomer was characterized by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopies. Gloss, cross-hatch, contact angle, and Taber abrasion tests were all used to investigate the film forming performance of the modified CAB oligomers on glass plates. The UV-cured free films of the synthesized oligomers were examined in terms of the mechanical tests. By using the synthesized CAB oligomers, coating formulations were prepared and applied onto cotton fabrics in order to make the cotton fabrics more durable in outdoor environments. The existence of the coating layer on the fabric surfaces was investigated by scanning electron microscopy (SEM). The coated UV-cured fabrics were evaluated separately in terms of abrasion, thermal conductivity, and air and water vapor permeability properties. Results proved that the oligomer (50%-CAB) in which 50% of the hydroxyl groups of CAB were reacted with TDI–HEMA adduct showed the best mechanical properties with the highest tensile strength and modulus values. Considering the coated fabrics, the least deformation against abrasion, the highest air/water vapor permeability, and the best thermal conductivity were all recorded in 50%-CAB coated sample.

Pre-design plant of cellulose acetate from sugarcane bagasse using the Emil Heuser Method with a production capacity of 10,000 tons/year

Cellulose acetate is a cellulose derivative product that has high commercial value because it is widely applied to textile fibers, cigarette filters, plastics, photographic films, paper and membrane coatings. The need for cellulose acetate in Indonesia is quite large because Indonesia is one of the largest textile producing countries in the world. However, Indonesia does not yet have a factory that produces cellulose acetate. Therefore, the establishment of a cellulose acetate factory has a large market opportunity for domestic and foreign needs. The pre-designed plant of cellulose acetate from sugarcane using the Emil Heuser method is planned to operate with a production capacity of 10,000 tons/year. The factory location will be on Raya Krembung road, Krembung region, Sidoarjo Regency, East Java, Indonesia. The land area required is 25,000 m2. The planned of business entity is a Limited Liability Company (Ltd). The pre-designed plant has a Profit Margin of 41.69%, Break Even Point 30.99%, Return on Investment 27.53%, Pay Out Time 3 years 6 months 3 days, Return on Network 44.88%, and Internal Rate of Return 35.99%. Based on the analysis of this economic aspect, it can be concluded that this factory is feasible to be established.

Usage of Cellulose Acetate Butyrate Based Oligomeric Structures on Cotton Fabric Coatings

In this study, the hydroxyl groups of cellulose acetate butyrate (CAB) oligomer were reacted with toluene diisocyanate-hydroxyethyl methacrylate (TDI-HEMA) adduct, in order to improve properties of CAB such as flexibility, thermal stability etc. Then the obtained modified CAB oligomer was characterized by FTIR and 1H NMR analysis. UV-curable coating formulations were prepared by using the modified CAB oligomer, and then applied on cotton fabrics in order to reinforce cotton fabrics and make them durable to outdoor environments. Cotton fabrics were treated with a commercial washing detergent, alkali solution, and an enzyme prior to the UV-coating, in order to increase the adhesion between the cotton fabric and coating layer. Washed and coated fabrics were evaluated in terms of absorbency, tensile, and adhesion properties, respectively. Light microscopy was employed to observe the effects of washing processes on fibre, and to show the abrasion deformation on coated fabric. Results proved that the best washing process in fibrillation was found as enzymatic washing due to the having the highest adhesion strength and the least deformation against abrasion.

IN VITRO STUDY AND MECHANICAL CHARACTERISTICS OF DENTAL IMPLANTS MADE OF VARIOUS MATERIALS AND FABRICATION METHODS

Selecting materials and alloys, fabrication methods, surface characteristics and coatings, and topology design, all affect the mechanical properties, biocompatibility, and functionality of dental implants. The success in embedding implants in mouth and improving biocompatibility and consequently useful life of implants depends directly on proper adhesion of tissue to implant surface of a biocompatible alloy. In this research, experimental surface hardness and in vitro tests are carried out on samples with different alloys and different manufacturing methods. Various fabrication techniques, such as machining and 3D printing (Selective laser melting (SLM)), are considered for steel and titanium specimens. Results show that the hardness values of specimens made by the SLM method are higher than machined samples about 8% and also stainless steels samples have higher hardness than titanium specimens. A comparison of scanning electron microscopy (SEM) surface pictures indicates that applying modern fabrication methods for production which includes SLM improves the performance of implants in terms of mechanical and biocompatibility by increasing cell adhesion up to 21 times. In addition, results indicate that titanium alloys have almost 13% higher adhesion property than stainless steel and generally exhibit a higher balance of adhesion and cell growth.

Application of Polyaniline for Flexible Semiconductors

“In situ” polymerization method was used to develop PANI-PSSA /textile. Polyaniline doped with polystyrene sulfonic acid (PANI-PSSA) used as coatings for textiles were obtained by aqueous and emulsion route. The emulsion route uses chloroform as solvent. Polymerization has been achieved in one step on the wool or polyamide textiles. For coated and uncoated textiles, dried at room temperature, were characterized structurally by Infrared Spectroscopy with Attenuated Total Reflectance (ATR), morphologically by Scanning Electron Microscopy (SEM), and by Atomic Force Microscopy (AFM) and electrically. The synthesis methods lead to differences in structure, morphology and properties of the coated polyamide and wool textiles.

Antimicrobial finish on fabrics using phytoconstituents: A review

The use of plant-based natural colorants and some other bioactive natural extracts in textile coatings as antimicrobial textile finishes is gaining traction. Several plant-derived natural colors have potent antibacterial effects. As a result, coating cotton textiles with antimicrobial plant natural dyes and bioactive plant extracts is a new technique in the manufacture of medical cloths. According to current research, depending on the kind of components contained in the plant extract, many plant extracts may be effective against several gram positive and gram negative bacteria. As a result, research on environmentally friendly antimicrobial compounds based on natural ingredients for use in textiles is gaining traction throughout the globe. This article presents a thorough overview of natural product-based bioactive agents for antimicrobial finishing of textile substrates, including chitosan, natural dyes, neem extract, and other herbal items. The mechanism of antibacterial activity of several types of active components identified in extracts of natural products has been described. The goal of this article is to provide the most up-to-date scientific information on the extraction and use of natural colorants in textile processing. The advantages and disadvantages of using natural colorants on textiles, as well as various techniques of extracting natural colorants, have all been addressed.