Novel and durable flame-retardant modification based on the Schiff base and Pudovik reaction for wool fabric

Durable and formaldehyde-free flame-retardant (FR) modification of wool fabric using phosphorous compounds is of great interest. In this study, Schiff base imine groups were firstly introduced onto wool fiber through aldehyde-amine condensation between p-hydroxybenzaldehyde and wool fiber. Then, an efficient and durable FR wool fabric was fabricated by incorporating diethyl phosphite (DEP) into a Schiff base intermediate via the Pudovik reaction. The potential reaction mechanism among p-hydroxybenzaldehyde, DEP and wool fiber was explored. The thermal stability, smoke generation ability, FR ability and washing durability of the modified wool fabric were studied. The FR modification significantly increased the thermal resistance of wool fabric and suppressed smoke generation by half. The wool fabric modified by 20 g/L DEP was able to self-extinguish during the burning test, suggesting the higher FR efficiency of the DEP-incorporated Schiff base system. The modified wool fabric still self-extinguished after 20 commercial launderings, which is attributed to the covalent grafting of DEP onto wool fiber. Char residue analyses revealed the condensed charring FR mechanism of the DEP-incorporated Schiff base system on wool. This work provides a novel approach to prepare efficient and durable FR functional wool fabric via the Schiff base reaction and Pudovik reaction among p-hydroxybenzaldehyde, DEP and wool fiber.

Interior vs. Exterior Incorporation of Silver Nanoparticles in Cotton Fiber and Washing Durability

The popular use of silver nanoparticles (Ag NPs) in commercial textile products that inhibit odor- and/or infection-causing bacteria has continuously raised concerns about their washing durability. The poor durability not only deteriorates the antibacterial performance, but also results in unwanted leaching of NPs into washing solutions. In this study, we showed how the incorporation location of Ag NPs—interior vs. exterior of cotton fiber—governs their durability against consecutive simulated home launderings. The superior washing durability of interior NPs was confirmed. The Ag losses after 50 laundering cycles for interior and exterior systems were 16% and 63% in water and 24% and 78% in detergent solution, respectively. The cotton fabric containing interior NPs predominantly released ionic Ag, whereas the fabric containing exterior NPs released particulate Ag.

A self-healing fluorine-free superhydrophobic cotton fabric under heat stimulation

Superhydrophobic cotton fabrics have been widely explored for their excellent properties, although there are still a few limitations in the practical applications for the reasons of poor environmental performance and short service life. In this study, the hexadecyltrimethoxysilane emulsion was prepared using O2-plasma and ultrasound for the superhydrophobic functional finishing of raw cotton fabric by immersion method. The prepared cotton fabrics showed a superior hydrophobicity with water contact angles larger than 156.0°, as well as an excellent self-healing ability. This self-healing ability was gained by simple heating treatment, which could restore the superhydrophobicity of the hydrophilic cotton fabric damaged by abrasion or O2-plasma treatment. The superhydrophobic cotton fabrics demonstrated excellent washing durability, which can withstand 50 times accelerated laundering cycles. Besides this, the superhydrophobic coatings also displayed fair chemical stability in strong acidic and alkaline solutions. The prepared nonfluorinated superhydrophobic cotton fabric with self-healing ability shows a potential for practical functional textile application.

Chitosan Nanoparticles Functionalized Viscose Fabrics as Potentially Durable Antibacterial Medical Textiles

This research proposed two pretreatments of viscose fabrics: oxidation with 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO) and coating with TEMPO-oxidized cellulose nanofibrils (TOCN), to introduce functional groups (COOH and CHO) suitable for irreversible binding of chitosan nanoparticles without and with embedded zinc (NCS and NCS + Zn, respectively) and consequently achieving washing durable antibacterial properties of the chitosan nanoparticles functionalized fabrics. The characterizations of pretreated and chitosan nanoparticles functionalized fabrics were performed by FTIR and XPS spectroscopy, elemental analysis, inductively coupled plasma optical emission spectrometry, zeta potential measurements, scanning electron microscopy, determination of COOH and CHO groups content, and antimicrobial activity under dynamic contact conditions. Influence of pretreatments on NCS and NCS + Zn adsorption, chemical, electrokinetic, and antibacterial properties as well as morphology, and washing durability of NCS and NCS + Zn functionalized fabrics were studied and compared. Washing durability was evaluated through changes in the chitosan and zinc content, zeta potential, and antibacterial activity after 1, 3, and 5 washing cycles. Pretreatments improved washing durability of antibacterial properties of chitosan nanoparticles functionalized fabrics. The NCS and NCS + Zn functionalized pretreated fabrics preserved antibacterial activity against S. aureus after five washing cycles, while antibacterial activity against E. coli was preserved only after one washing cycle in the case NCS + Zn functionalized pretreated viscose fabrics.

Citric acid as environment friendly crease-resistance finishing agent for silk fabric combined by ß-cyclodextrin

Purpose The purpose of this paper is to assess the possibility of cross-linking silk fabric using citric acid (CA) as the cross-linking agent and nano-TiO2 (NTO) particles as a catalyst at low temperature and under UV irradiation. This paper also assesses the possibility of treated samples with suitable combinations of CA and NTO to impart multiple functional properties such as self-cleaning and antimicrobial properties. Design/methodology/approach In this research, ß-cyclodextrin (ß-CD) grafted onto silk fabric using CA as a crosslinking agent and NTO particles as a catalyst through a pad-dry-cure technique and with UVA irradiation. The effects of different concentrations of CA, ß-CD and NTO particles on some properties of the treated samples are evaluated, and the optimum finishing conditions are obtained. The author also investigated the washing durability of the modified product after ten times of washing. Findings The results showed that CA plays the role of a linking agent through an esterification reaction with the hydroxyl groups of both ß-CD and silk fabrics and improves the durability of materials on the textile surface. Also, the silk fabrics treated with CA only were found to have excellent photocatalytic properties and better antibacterial activity than the control sample and the fabrics treated with a mixture of ß-CD/CA. Originality/value This study was conducted to achieve multiple functions such as antibacterial and photocatalytic activities, good dry crease recovery angle and wet crease recovery angle behavior without a significant adverse effect on the Yellowness index and tensile properties for treated silk fabrics.

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.

Synthesis of Copper Nanoparticles on Cellulosic Fabrics and Evaluation of their Multifunctional Performances

Two different kinds of copper nanoparticles (CuNPs) (brown colour and greenish colour) were synthesised by using simple solution route and applied on cotton by exhaust method to achieve multidimensional functionalization on one of the most popular cellulose materials e.g., cotton fabric. The synthesised CuNPs imparted different colours to cotton textile due to different conditions of synthesis and localized surface plasmon resonance. Physico-chemical characterizations of the synthesized nanoparticles were performed by using scanning electron microscope (SEM) and EDX analysis whereas the optical properties of the nanoparticles were studied using UV-visible spectroscopy. The prepared CuNPs of both the types demonstrated very good antimicrobial activity up to 97%. In addition, cotton fabric treated with CuNPs showed very high catalytic activity for reduction of 4-nitroaniline in presence of sodium borohydride to phenylene diamine. Washing durability and rubbing fastness of the treated fabric have also been measured by following standard testing methods and found to be very good with a rating 4.

Hot–Dog Structured Protective Nanocoating for Multifunctional Cotton Fabric Through Spray Assisted Layer–by–Layer Assembly

Multifunctional cotton fabric was preparation by low–cost and environmental–friendly spray–assisted layer–by–layer assembly to achieve simultaneously excellent self–extinguishing ability, antistatic property and antimicrobial activity. Especially, a novel hot–dog structured protective coating was designed through introducing polyaniline nanofibers into graphene nanosheets, which can exhibit unique structural advantages and give full play to the compound synergetic effect. More clearly, 3–aminopropyl triethoxysilane, ammonium polyphosphate and polyaniline were selected for phosphorus–silicon–nitrogen synergism in the assembled layer, while PANI nanofibers doped with various organic acids were penetrated into the graphene nanosheets for constructing more stable and efficient protective space. The optimized coated fabric exhibited the excellent self–extinguishing ability for 5 composite layers including phytic acid doped nanofiber, and a significantly enhanced LOI to 35.1 % from 18.1 % for neat cotton fabrics. Moreover, the peak heat release rate and the total heat release values were significantly declined by 78.3 % and 49.0 %, respectively. Furthermore, a low sheet resistance of 264.7 kΩ/sq for antistatic property, as well as remarkable growth inhibition of E. coli and S. aureus can be achieved. In addition, the fabrics also displayed the good washing durability. Therefore, such eco–friendly and facile large–scale fabrication approach has great potentials in application for multifunctional advanced textiles and could be employed to various other cellulose fibers.

Study on the Grafting of Chitosan-Essential Oil Microcapsules onto Cellulosic Fibers to Obtain Bio Functional Material

The purpose of this work was to prepare chitosan–essential oil microcapsules using the simple coacervation method and to graft them onto cellulosic fibers to obtain bio functional textile. The microcapsules morphology was characterized by optical microscopy. The 2D dimethyloldihydroxyethylene urea resin (DMDHEU) was used as a binding agent to graft microcapsules on the surface of cellulosic fibers. Scanning Electron Microscopy (SEM) photographs and Attenuated Total Reflectance-Fourier Transformed Infrared (ATR-FTIR) analyses were performed to prove the interaction between cellulosic fibers and microcapsules. Furthermore, the properties of the different fabrics such as mechanical strength and air permeability were investigated. Furthermore, washing durability was evaluated. Finally, the antibacterial activity of the finished fibers against the strains Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was evaluated. The results evidence the ability of treated fabrics to induce bacteria growth inhibition. The coacervation method is a simple process to incorporate cinnamon essential oil on the cellulosic fiber’s surface. The use of essential oils as active agents seems to be a promising tool for many protective textile substrates such as antimicrobial masks, bacteriostatic fabrics and healthcare textiles.

A critical study of the effects of flame retardancy on different knit fabrics

A novel flame retardant especially Pekoflam HFC was synthesized to improve the flame retardancy of fabric. Pekoflam HFC is especially suitable for flame retardant back coatings of synthetic fibre based home textiles and high-performance technical textiles. The flame retardancy of the samples was characterized by the spray method and the vertical burning test. The results indicated that the flame retardant had excellent flame retardancy and durability for cellulosic fabrics. The cotton knit fabric treated with Pekoflam HFC obtained the optimum flame retardancy with the decreased char length. Combustion behaviors of treated cotton fabric were tested by manual observation. After treatment, it found that the ignition time increased, and the values of total heat release, heat release rate and mass loss decreased. The strength and durability of treated fabric were studied by tear force test and washing durability test, respectively.