Textile Coatings Research Articles

Bioactive textile coatings for improved viral protection: A study of polypropylene masks coated with copper salt and organic antimicrobial agents

The COVID-19 pandemic emphasized the importance of face masks in reducing virus transmission. However, mask contamination through interpersonal contact or handling demonstrates the need for the development of bioactive textile coatings to reduce mask changes and increase user protection. This study reports the development of polypropylene masks coated with organic antimicrobial agents such as polyethyleneimine (PEI) and lauric acid (Lau), in addition to Cu2+ salts, and their virucidal performance against coronaviruses (MHV-3 strain). Plasma treatment crucially improved the fabric impregnation by the coatings. PEI and Lau coatings significantly reduced viral titer from 99% to 99.99% after 2 h of contact. The PEI coating with copper salt exhibited rapid effect, with a virus inhibition of 99.9% to 99.99% in under a minute, indicating that CuSO4 can significantly enhance the virucidal effect of the coating. Although these coatings demonstrated comparable performance to other virucidal coatings, the presence of copper ions potentializes their effect, rapidly inactivating the virus. These findings highlight the potential of pure organic antimicrobial coatings to enhance mask efficacy and improve protective capabilities. The hybrid coating proves suitable for rapid inactivation of the virus, due to copper fast release and PEI prolonged inhibition effect, enhancing the protection against viral infections.

A Bioinspired Atomically Thin Nanodot Supported Single-Atom Nanozyme for Antibacterial Textile Coating.

Surface antibacterial coatings with outstanding antibacterial efficiency have attracted increasing attention in medical protective clothing and cotton surgical clothing. Although nanozymes, as a new generation of antibiotics, are used to combat bacteria, their catalytic performance remains far from satisfactory as alternatives to natural enzymes. Single-atom nanodots provide a solution to the low catalytic activity bottleneck of nanozymes. Here, atomically thin C3 N4 nanodots supported single Cu atom nanozymes (Cu-CNNDs) are developed by a self-tailoring approach, which exhibits catalytic efficiency of 8.09 × 105 M-1 s-1 , similar to that of natural enzyme. Experimental and theoretical calculations show that excellent peroxidase-like activity stems from the size effect of carrier optimizing the coordination structure, leading to full exposure of Cu-N3 active site, which improves the ability of H2 O2 to generate hydroxyl radicals (•OH). Notably, Cu-CNNDs exhibit over 99% superior antibacterial efficacy and are successfully grafted onto cotton fabrics. Thus, Cu-CNNDs blaze an avenue for exquisite biomimetic nanozyme design and have great potential applications in antibacterial textiles.

Yeşil Kimya İle Fotokürlenebilen Fosfor İçerikli Pamuk Kumaş Kaplamalari

In this work, a bio-based, lightweight, coated cotton fabric by using a cleaner manufacturing method, “photocuring” was proposed in order to be used as an alternative to the conventional heat-, solvent-, and water-based outdoor textile (tarpaulin, tent, etc.) manufacturing. For this purpose, photocurable bio-based phosphorylated oligomer was synthesized with the reaction between a monomethacrylate functional phosphorus containing monomer and epoxidized soybean oil (ESBO). The synthesized phosphorylated ESBO (P-ESBO) oligomer was used in cotton fabric coatings in different proportions and photocured with UV light exposure. The effects of the amount of P-ESBO oligomer in the formulation on the crystalline morphology, mechanical, thermal, surface wettability, flammability, and abrasion resistance properties of the cotton fabrics were all searched. It was revealed that the increasing amount of P-ESBO oligomer in the formulation increases the drapeability and tensile strength of the fabrics with enhanced flame resist property by giving higher char yields. Besides, phosphorylated oligomer also acted as an adhesion promoter between the fabric surface and coating layer resulting a better abrasion resistance property.

Preparation and characterization of intelligent thermochromic fabric coatings for the detection of fever diseases

Real-time monitoring of changes in skin temperature with smart thermochromic fabrics that act as sensors is extremely important in the early diagnosis of febrile diseases such as the COVID-19 epidemic that endanger public health. In this context, the study aims to detect fever, which is the immune response of the body, as a symptom in the diagnosis of various diseases and to prepare a thermochromic functional fabric by coating method to reduce the risk of contamination. For this purpose, a composition containing green pigment and zinc acetate dihydrate as the starting material was prepared using the sol-gel method. The prepared composition was applied to calico and alpaca fabric, and it was provided to show transformation at 37.5 °C with the effect of the pigment, which had a color change feature at 33 °C. The samples were analyzed using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) characterization methods. The results showed that it was possible to change the active conversion temperature of the pigment from 33 °C to 37.5 °C, depending on the composition. The use of the compositions developed in this study in alpaca fabric coating provides an area of use as an indicator if the human body temperature reaches 37.5 °C, which is considered the concept of fever.

Modification of hedgehog-like structured carbon nanohorns to promote flame retardant synergistic effect in assembled coatings for protective cotton fabrics

Considering the limitations of traditional halogen flame retardants to cotton fabrics, the modification of hedgehog-like structured carbon nanohorns was firstly proposed to improve flame retardant synergistic effect in assembled coatings for protective cotton fabrics. The assembled coatings containing 3-aminopropyl triethoxysilane (APTES), modified single-walled carbon nanohorns (SWCNHs-o) and ammonium polyphosphate (APP) endowed cotton fabrics with highly efficient flame retardancy at an ultralow spraying number of 4, which was much more favorable than other previously reported coatings. (APTES/SWCNHs-o/APP)4 effortlessly passed the vertical burning test and was capable of self-extinguishing. Furthermore, the LOI test showed that its LOI value could reach 29.0 ± 0.1%, suggesting a low fire exposure risk. Additionally, the results of cone calorimeter test displayed that pHRR, THR, MARHE and Av-EHC values of (APTES/SWCNHs-o/APP)4 significantly reduced by 93%, 57%, 89% and 98%, respectively. The morphology of its residual char remained complete, demonstrating that the P/N/Si heterocyclic char layer formed by SWCNHs-o and APTES in synergy with phosphorus provided a physical barrier to prevent the release of volatile combustibles and the transfer of oxygen and heat. This work provides an efficient and novel method for the design and fabrication of self-extinguishing intumescent coatings.

Bioinspired aldehyde-free and durable coatings for antibacterial, UV-resistant and flame-retardant cotton fabrics by the covalent bonding and in-situ coprecipitation

The development of functional and durable coatings is an effective solution for obtaining the satisfactory properties of cotton fabrics. Herein, the aldehyde-free and durable cotton fabrics (CZIF-8@CF) with well antibacteria, UV-resistance and flame retardancy had been obtained via an interfacial reaction strategy, where the well-organized zeolitic imidazolate framework-8 (ZIF-8) was in-situ grew on cotton fabrics pre-modified with chitosan (CS) and Zn ion. CZIF-8@CF displayed excellent antibacterial performances with 99.99 % antibacterial rates for both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Besides, the resulted cotton fabrics exhibited less than 5 % UV transmittance. Flame behaviors tests proved that the multifunctional coatings acted as “physical barrier” to reduce the heat produce coming from the synergistic effect of catalytic charring and high residual protection under high temperature of CZIF-8, and “vacuum cleaner” to decrease the smoke release resulting from the self-porous structure of ZIF-8. Even after 50 washing cycles, the CZIF-8@CF still showed less than 5 % UV transmittance, 99.99 % and 93.67 % antibacterial rates of S. aureus and E. coli, respectively. It was demonstrated that the covalent bonding between CS and part of Zn2+ in ZIF-8 could promote the durable antibacteria, UV-resistance and flame retardancy of cotton fabrics.

Application of Silver-Loaded Halloysite Nanotubes in Flame Retardant and Smoke-Suppressive Coating for Polyester-Cotton Fabric.

Despite the wide applications in clothing, furniture, and transportation, the well-known "scaffolding effect" in polyester-cotton fabric has caused significant fire hazards compared to sole polyester or cotton fabrics. Therefore, it is of practical significance to endow polyester-cotton fabric with excellent fire safety. In this work, an organic-inorganic composite coating comprising nitrogen-phosphorus-silicon-containing flame retardant and silver nanoparticle-loaded halloysite nanotubes (Ag@HNTs) was designed and prepared to improve the fire safety of polyester-cotton fabrics. Microscale combustion colorimeter results indicated that the peak heat release rate of the modified polyester-cotton fabric with such a composite coating was reduced by 47%. Meanwhile, it could self-extinguish in 9 s after being ignited, and the limiting oxygen index was up to 25%, indicating excellent fire safety. In addition, the total smoke release of the coated polyester-cotton fabric was reduced by 21%, illustrating that the coating of Ag@HNTs could eliminate the smoke generated. The treated fabric also exhibited superior water resistance. Flame retardant mechanisms were well investigated using thermogravimetric analysis-infrared spectrometry analysis and chemiluminescence by studying the gaseous degradation products and hydroxyl radical in the gas phase. This work provides an effective approach to fabricating high-performance flame retardant and smoke-suppressive coatings for textiles.

Fabrication of Robust and Effective Oil/Water Separating Superhydrophobic Textile Coatings.

A superhydrophobic (SH) surface is typically constructed by combining a low-surface-energy substance and a high-roughness microstructure. Although these surfaces have attracted considerable attention for their potential applications in oil/water separation, self-cleaning, and anti-icing devices, fabricating an environmentally friendly superhydrophobic surface that is durable, highly transparent, and mechanically robust is still challenging. Herein, we report a facile painting method to fabricate a new micro/nanostructure containing ethylenediaminetetraacetic acid/poly(dimethylsiloxane)/fluorinated SiO2 (EDTA/PDMS/F-SiO2) coatings on the surface of a textile with two different sizes of SiO2 particles, which have high transmittance (>90%) and mechanical robustness. The different-sized SiO2 particles were employed to construct the rough micro/nanostructure, fluorinated alkyl silanes were employed as low-surface-energy materials, PDMS was used for its heat-durability and wear resistance, and ETDA was used to strengthen the adhesion between the coating and textile. The obtained surfaces showed excellent water repellency, with a water contact angle (WCA) greater than 175° and a sliding angle (SA) of 4°. Furthermore, the coating retained excellent durability and remarkable superhydrophobicity for oil/water separation, abrasion resistance, ultraviolet (UV) light irradiation stability, chemical stability, self-cleaning, and antifouling under various harsh environments.

Design and fabrication of metal-organic-framework based coatings for high fire safety and UV protection, reinforcement and electrical conductivity properties of textile fabrics

Rational design and fabrication of multifunctional textile fabrics coatings were developed. The green coatings were facilely prepared from metal-organic-framework UiO-66 as porous crystalline framework which was easily decorated with green spherical polypyrrole nanoparticles of an average size of 165 nm and then wrapped with chitosan chains. The nanocomposites were synthesized in one-step method with the aid of cost-effective ultrasonication method to facilitate the individualization of polypyrrole nanoparticles and their decoration on UiO-66 surface. The as developed coating was then coated on cotton fabrics. The structure and crystalline structure of UiO-66 were elucidated, also the structure and morphological properties of polypyrrole nanoparticles were studied using FT-IR, XRD and SEM. The mass loadings of UiO-66 and polypyrrole nanoparticles were varied and their influence was studied. The flammability, thermal stability, mechanical properties, UV protection and electrical conductivity of coated textiles were studied. The newly developed multifunctional coating affords high flame retardancy to coated cotton fabrics achieving reduction in rate of burning by 54 % compared to uncoated sample. Significant thermal stability was attained recording 23 °C increase in temperature of maximum mass loss. Besides, the tensile strength of coated sample achieved 29 % improvement compared to uncoated one. Moreover, outstanding UV protection feature for coated cotton fabrics was obtained recording more than two-fold enhancement in ultraviolet protection factor compared to pristine sample. Interestingly, the smart coating layer fabricated on cotton fabrics impregnated the fabrics with electrical conductivity property recording electrical resistance of 2 MΩ compared to 45 MΩ for pristine fabrics. Additionally, the flame retardancy action was fully studied and elucidated.

Double-shell lignin microcapsules were prepared by one - step method for fabric coatings with UV resistance and durable antibacterial activity

The design and application of intelligent biomass microcapsules have gradually attracted widespread attention. In this study, double shell lignin microcapsules (DSLM) were prepared in one step by combining interfacial polymerization with free radical copolymerization. The biomass material lignin was grafted into the polyurethane shell at the interfacial polymerization stage to endow the microcapsule with a certain ultraviolet (UV) protection function. Lemon essential oil (LEO) with fragrance and antibacterial properties was further located at the core of the microcapsule and released by the thermal response. In the study, the morphological structure of the microcapsules and the release of the core material as well as the core-shell framework were characterized. Furthermore, these microcapsules were applied to the fabric coatings to give it UV protection and antibacterial properties. The whole preparation and functionalization process is facile and environmentally friendly. Due to the double-shell design, the encapsulated lemon essential oil is not easy to leak, which extends the antibacterial time and service life of the fabric coatings, and the release of the core material was controlled. At the same time, the outer shell of microcapsule plays a double protective role. These smart microcapsules are expected to be applied in outdoor fabric coatings and daily necessities in the future.

Conversion of waste polyolefins to polyethylene wax via pyrolysis

ABSTRACT Waste polyolefins can be converted into value-added products like oils and chemical waxes by a process called pyrolysis. In the present study, conversion of waste polyethylene to polyethylene (PE) wax was carried out via pyrolysis using a ZSM 5 (zeolite based) and Luperox as catalysts. The effect of pyrolysis residence time, catalyst type, loading on the yield, and properties of the PE wax were investigated. Further, a comparison of the properties of PE wax obtained via pyrolysis and the market sample of PE wax was made to optimize the reaction conditions of pyrolysis. It was observed that with an increase in the catalyst loading and residence time, not just the yield of PE wax reduced but it also led to the degradation in the properties of PE wax. The waxes produced via pyrolysis at residence time of 90 min for waste low-density polyethylene and 150 min for waste high-density polyethylene exhibited properties comparable to that of the market sample of PE wax. The PE wax thus obtained has application in textile coatings, plastic processing, and printing inks.

A Self-Healable and Recyclable Zwitterionic Polyurethane Based on Dynamic Ionic Interactions.

Polyurethanes with self-healing and reprocessing capabilities are promising in eco-friendly applications. Here, a self-healable and recyclable zwitterionic polyurethane (ZPU) was developed by introducing ionic bonds between protonated ammonium groups and sulfonic acid moieties. The structure of the synthesized ZPU was characterized by FTIR and XPS. The thermal, mechanical, self-healing and recyclable properties of ZPU were also investigated in detail. Compared with cationic polyurethane (CPU), ZPU shows similar thermal stability. The physical cross-linking network formed between zwitterion groups can dissipate strain energy as a weak dynamic bond, endowing ZPU with outstanding mechanical and elastic recovery properties, including the high tensile strength of 7.38 MPa, high elongation at a break of 980%, and fast elastic recovery ability. Additionally, ZPU exhibits a healing efficiency of over 93% at 50 °C for 1.5 h as a result of the dynamic reconstruction of reversible ionic bonds. Furthermore, ZPU can be well reprocessed by solution casting and hot-pressing with a recovery efficiency above 88%. The excellent mechanical properties, fast repairing capability, and good recyclability not only enable polyurethane with a promising application in protective coatings for textiles and paints but also make it a superior candidate as stretchable substrates for wearable electronic devices and strain sensors.

Enhancement and control of water vapor permeability and thermal conductivity of polymers: A review

AbstractThe water vapor permeability (WVP) and thermal conductivity of polymers are of great significance in personal cooling and even in responding to energy crises. This review attempts to discuss the factors that affecting these two properties at first, and then discusses the relationship between them from the aspects of hydrophilicity, porous structure, biomimetic layered structure, and so on. Generally, porous structure or hydrophilicity is beneficial to water vapor permeation, while dense structure is more conducive to the formation of heat conduction path and network, that is, to heat conduction. Of course, thermal conductive filler is the decisive factor for high thermal conductivity of polymer composites. Interestingly, the transmission process of water vapor also positively affects the heat conduction of polymer to a certain extent. Especially, the biomimetic fiber membrane with multi‐branch network following Murray's law, which integrates high WVP and high thermal conductivity, is one of the development directions of special concern. Finally, the related problems to be solved are put forward and prospected. It is hoped that this review will have positive guiding significance for developing polymer membranes and functional textile coatings with high moisture permeability and high thermal conductivity.

Sustainable Textile Fabric Coatings: From Materials to Applications

In order to meet the technical requirements, it is necessary to infuse new functions into textile fabrics due to the rapid advancement in the exploitation of textile-based materials in various industrial applications [...]

Reduced graphene oxide/polyurethane coatings for wash-durable wearable piezoresistive sensors

Graphene-based functional coatings for cotton textiles were realized through an easy dip-coating procedure. Cotton fabrics were coated with a reduced graphene oxide (rGO) layer and then protected with a very thin polyurethane (PU) layer that does not affect the flexibility and the hand of the pristine cotton. The application of the rGO coating induces electrical conductivity to the fabric and the application of the PU phase increases the durability of the coatings, that show very stable surface resistivity after 10 washing cycles performed at temperatures up to 40 °C. Furthermore, the rGO and rGO/PU coated fabrics show good comfort properties, increased thermal conductivity and breathability with respect to cotton. In particular, the realized coatings allow to confine the heat transfer in correspondence of a localized heating source, which is very interesting for thermal therapy applications. Finally, the rGO/PU coated fabrics present a piezoresistive behaviour characterized by very stable electrical response to applied stretching up to 50% deformation, high sensitivity especially at low deformations with gauge factor values up to 11.7 and fast response time down to 500 ms when stretched at 100 mm/min rate at 2.5% strain. Overall, the results demonstrate that rGO/PU coated fabrics are very promising wash-durable electrically conductive e-textiles with improved comfort, enhanced thermal conductivity for possible thermal therapy applications, and piezoresistive properties for sensing applications as human motion monitoring.

Effect of Fabric Electrode Surface Coating Medium on ECG Signal Quality under Dynamic and Static Conditions

This study intends to explore the influence of a fabric electrode skin interface filling medium on ECG signals under dynamic and static conditions, so as to be able to better monitor both stable and dynamic ECG signals. In this paper, cotton fabric electrodes were prepared using electroless silver-plated conductive cotton fabric, and then the electrodes were integrated into a physiotherapy-grade elastic bandage to assemble the fabric ECG tape. The electrode impedance tester and the BIOPAC physiological recorder were used to measure the fabric electrode-skin impedance and electrocardiogram under dynamic and static conditions, respectively. Later, the influence of the fabric electrode coated medium on the acquisition effect of an electrocardiogram signal under dynamic and static conditions is discussed. The results show that in the absence of a dielectric reagent coating, the cotton fabric electrode is easily disturbed by external noise which leads to large electrode-skin contact impedance. However, the electrode-skin contact impedance is greatly reduced after coating the fabric electrode with the dielectric reagent. At the same time, after applying the conducive paste coating, the corresponding change curve of the fabric electrode became more stable, and the impedance value was less than 0.005 MΩ·cm2, which meets the standard requirement for textile dry electrode skin impedance. In a state of rest, a clear and stable ECG can be collected regardless of whether the medium reagent is coated or not. However, only after applying the conductive paste can a stable ECG signal be collected under the three motion modes, or can a P wave, QRS wave group, or T wave be clearly distinguished. In addition, there is a high correlation with the disposable gel electrode, which can satisfy the requirements of the long-term monitoring of ECG signals under dynamic conditions.

Anchoring silver nanoparticles using catechol-derived resins: An efficient and versatile approach for producing durable antimicrobial fabrics

Silver nanoparticles (Ag NPs) are one of the most popular antibacterial agents, but Ag NP-modified antibacterial fabrics often show poor laundering durability owing to the weak binding force of Ag NPs to the fabric. In this work, a hydrothermal synthesis of catechol formaldehyde resins (CFR) and Ag NPs from catechol, hexamethylenetetramine, and AgNO3 was developed, and a kind of coating called Ag/CFR was constructed in situ on the surface of cotton, polyester, polyamide, and their blended fabrics. Micromorphologies and chemical structures of the fabric and Ag/CFR coatings were studied, while the antimicrobial performance and other important properties of the fabrics were also investigated. The studies showed that CFR were generated in the solution and anchored Ag NPs onto the surface of the fabric. All the modified fabrics presented high antimicrobial activity with superior laundering durability, achieving a bacteriostasis and fungistasis rate of 99.99 % against S. aureus, E. coli, and C. albicans, even after 50 laundering cycles. Ag/CFR coatings had little influence on the mechanical properties, air permeability, and feel of the fabric. All the antimicrobial fabrics showed low cytotoxicity to NIH3T3 mouse fibroblasts and contained no residual formaldehyde. This work provides an efficient and versatile approach for producing durable coatings for antimicrobial fabrics, which can be widely applied to clothing, bedding, and decorations.

Colloidal latex / liquid crystal coatings for thermochromic textiles

Latex is a colloidal dispersion of polymeric particles dispersed in water. They can be used to make complex dispersions of a complex mixture of pigments, surfactants etc. that are stable for long periods of time. In this paper we report cholesteric liquid crystals (CLCs) dispersed in a commercial water-based latex varnishes coated on fibers and fabrics. The CLC-latex coatings displayed bright, stable colors that change with temperature. The optical and stability properties of CLC-latex coated polyester fibers and fabrics are compared with previously reported LC materials. We find that the enhanced brightness of the latex coated materials is a result of the flattening of the phase separated CLC droplets during water evaporation from the latex varnishes. Owing to the stability of the commercial latex varnishes to UV irradiation and water exposure, these CLC-latex coatings are durable, environmentally friendly, inexpensive, and easy to coat on fibers and fabrics. The resulting smart textiles could be used for numerous biosensing, medical and decorative applications.

Valorisation of leather waste from automobile industry to develop innovative textile coatings

The development of a new generation of coated textile solutions based on the incorporation of industrial natural leather waste from automobile cutting operations, conferring new functionalities with eco-design and fashion effects was studied. This work provides new insights to major consumer trends, including ethical, environmental, and sustainable attitudes, focusing on sustainability from a circular economy and industrial symbiosis perspective. Herein, leather wastes from the automobile industry were transformed using both mechanical and chemical processes. Subsequently, the recycled residues were used to develop new coating formulations and applied as textile coatings, to obtain a new generation of more sustainable-coated textile solutions. The coated substrates were fully characterised and a series of normalized tests were conducted to determine and assess their mechanical and functional properties. The newly developed solutions met and even exceeded the performance standards and specifications of the fashion, shoes and accessories, furniture and home textile sectors. With the elaboration and application of novel coating formulations, a series of prototypes were developed with enhanced and innovative material. The Life Cycle Assessment of these new textile products demonstrated that they hold a lower environmental impact in comparison to natural leather used for clothing and shoe applications. Hence, the valorisation of hydrolysed natural leather wastes by textile coating applications was successfully achieved.

Textile bio-based and bioactive coatings using vegetal waste and by-products

This work aimed to fulfil one of the great consumer trends related to ethically and environmentally sustainable attitudes. The main concept was to develop an alternative material to natural and synthetic leather by creating new bio-coated textile structures with improved environmental credentials, and to use vegetable wastes and by-products from agroforestry industries, as well as biopolymers. Different residues, such as sawdust and pine bark were successfully incorporated in polymeric aqueous formulations and applied as textile coatings. The Life Cycle Assessment of these new textile products showed that they present a lower environmental impact in comparison to natural leather used for clothing and shoe applications. Overall, the alternative material developed here is a favourable sustainable material. The use of by-products to create bio-based materials comprises a great potential for a broad spectrum of applications in other fields in the Textile and Clothing Industry such as fashion, eco-design, sports and protection apparel, furniture decoration, home textiles, footwear, fashion accessories, in addition to others.