The use of immobilized enzymes in enhancing the biodegradability of cotton textiles is of great interest for sustainable textile waste management. Understanding how enzyme activity influences biodegradation rates is crucial for optimizing textile disposal strategies. This study aims to assess the impact of enzyme immobilization on the biodegradability of cotton fabrics, compared to microcrystalline cellulose and cotton treated with both active and inactivated enzymes. Biodegradability was evaluated by measuring CO₂ production over 75 days when the fabrics were buried in soil, as a proxy for microbial degradation. The study compared untreated cotton, cotton treated with immobilized enzymes, cotton with inactivated enzymes (via thermal treatment), and microcrystalline cellulose as reference. CO₂ emissions were monitored to quantify the biodegradation levels in each sample. The results indicated that microcrystalline cellulose exhibited the lowest biodegradability, with significantly lower CO₂ production. Among the cotton samples, the highest biodegradability was observed in the fabric treated with immobilized enzymes that had been inactivated by heat. This was followed by the cotton treated with active immobilized enzymes, while untreated cotton exhibited the lowest biodegradability of all the cotton samples. Although enzyme immobilization can enhance the stability and sustainability of degradation processes, thermal inactivation of enzymes unexpectedly increased biodegradation rates in cotton fabrics. This suggests that not only enzymes but others, such as structural changes in the cotton fibers, may play a role in facilitating biodegradation. Further research is needed increasing time and to clarify the mechanisms involved and optimize immobilization techniques for textile waste management.

In an era where hygiene and safety are paramount, antibacterial textiles have revolutionized the way we approach cleanliness in various settings. The need for antibacterial textiles that are sustainable and environmentally friendly and provide comfort for the user has made research in this area popular. In this context, this work reports a novel approach to the preparation of chitosan ink for digital printing on cotton fabric for antibacterial and comfort properties. The aim of the study is to prepare antibacterial textiles without compromising their comfort properties. For that, valve-jet printing method was used as resource efficient and digital preparation method for functional antibacterial textiles. Chitosan was used as a natural, non-toxic, and biodegradable antibacterial agent for the antibacterial textiles. Chitosan ink was prepared and printed on cotton fabric through digital valve-jet printer and cured at 150°C for 1 minute to stabilize the chitosan on cotton. Three types of printed fabrics were produced with different number of printing passes and the fabrics were characterized by various quantitative and qualitative methods to investigate the performance of printed chitosan ink on the antibacterial and comfort properties of the cotton fabric. Results indicate a successful printing of chitosan ink on cotton fabric through valve-jet printing method. Results further showed that multiple printing passes of chitosan ink on cotton fabric can result in higher antibacterial activity. Further analysis of the results showed that, the increase of chitosan amount on the fabric is proportional to the antibacterial activity of functionalized cotton fabric, however, with excessive increase of chitosan, the fabric compromises the hand feel and softness. Results from Air permeability analysis showed an increase in air permeability with the increment in the amount of chitosan on the cotton fabric, whereas capillary rise decreased with the increase of chitosan. Contact angle measurement and hydrostatic pressure test showed that the hydrophilic nature of cotton fabric was not changed after printing. The result of the work is of great importance as they introduce new printing process for the fabrication of antibacterial textile with comfort properties for various technical and smart applications.

Current immobilization techniques often face significant challenges, including uneven distribution of enzymes, reduced enzymatic activity, and material waste, all of which can limit the effectiveness of immobilized enzymes in industrial applications. To address these issues, this study introduces a hydraulic spray automation system specifically designed for the immobilization of redox enzymes on textile substrates, providing a novel, resource-efficient, and continuous method for enzyme immobilization. For this, glucose oxidase (GOx) was chosen as the model enzyme and was immobilized onto polyester textiles (PET) using the hydraulic spray system. To optimize the immobilization process,  several critical parameters, including enzyme concentration, pickup percenatge, and the technique of layer-by-layer assembly of GOx was studied. Results revealed significant improvements in both the stability and activity of the immobilized GOx, which are crucial for its effectiveness in industrial applications. Results showed that, the loading of GOx on PET  had no influence on type of PET (activated or pristine) used. However, surface activation  offered  better  stability of   GOx against rinse cycles. Results also showed that, with the increase of pickup percentage the activity of immobilized GOx increases until it reaches to the plateau. The results were promising and demonstrated significance in uniformity and reduction in waste and  time during enzyme immobilization. This immobilization method not only minimizes resource consumption by reducing waste but also facilitates large-scale production, making it particularly well-suited to meet the evolving demands of the industry. Ultimately, this research demonstrates the potential of hydraulic spray automation technology to revolutionize enzyme immobilization, paving the way for more sustainable and efficient industrial applications.

Mechanical finishing techniques play an increasingly important role in industrial wet textile processing. The technique involves physical processes that modify the textile structure and surface properties, enhancing the fabric's functionality and aesthetic appeal without the need for chemicals. The field of mechanical finishing in textiles has seen significant advancements, especially in the development of functional textiles. These advancements are driven by the increasing demand for specialized applications, and enhanced functionality offered by mechanical finishing techniques. Additionally, the push for sustainability has led to the advance of mechanical finishing into an eco-friendly alternative to chemical finishing techniques. These processes reduce the reliance on chemical treatments, thereby minimizing environmental impact and promoting greener manufacturing practices. As the industry continues to innovate, mechanical finishing remains a critical component in producing textiles that meet the evolving needs of both consumers and industries. This chapter will present a general overview of various mechanical finishing techniques in textile and their progress and prospects in developing functional textiles. Historical development of mechanical finishing techniques in textiles, mechanical forces for different mechanical finishing techniques, as well as emerging applications and potential challenges in mechanical finishing have also been discussed. 

The aim of this study is to investigate the feasibility of an alternative Fenton-based advanced oxidation process for the discoloration of reactive-dyed waste cotton as a pre-treatment for textile recycling. For that, pre-wetted dark-colored (black and blue) knitted samples of 300 cm2 are treated in 1200mL Fenton-solution containing 14 mM Fe2+ and 280mM H2O2 at 40 °C. Characterization of the textiles before and after the treatments are performed by UV VIS-spectrophotometry measuring color strength, microscopy, FTIR spectroscopy, thermal analysis and tensile testing measuring tenacity and elongation. Afterwards, the cotton is mechanically shredded for qualitative analysis of the recyclability. The color-strength measurements of the black and blue cotton led to discoloration-efficiencies of respectively 61.5 and 72.9%. Microscopic analysis of discolored textile fabric also showed significant fading of the colored textiles. Mechanical analysis resulted in reduced tensile strength after treatment, indicating oxidation of the cellulosic structure besides the degradation of the dye-molecules, also confirmed by reductions in thermal stability found after thermal analysis. Shredding of the fabric resulted in enhanced opening, but shorter remaining fibers after treatment. The findings of this study provide a proof-of-concept for an alternative color-stripping treatment concerning a Fenton-based advanced oxidation process as a pre-treatment for textile recycling.

The increase in the human life expectancy coupled with the rise in population has boosted the use of pharmaceuticals. These biologically active compounds do not fully metabolize by the human body and excreted out into the wastewater which often resistant to conventional wastewater treatment processes.  Herein, this study presents the progress and prospects of catalytically active textiles-based heterogeneous bio-electro-Fenton reactor for effective removal of pharmaceutical residue from wastewater. The reactor consists of a bio-anode prepared by immobilized redox enzyme on synthetic nonwoven textiles and a cathode by zerovalent iron nanoparticles immobilized functional textiles has been extensively explored for removal of pharmaceuticals from simulated wastewater. The results of this current study will be of great importance as its expected to deliver the much-needed upgrade in the conventional wastewater treatment system with bio-based, sustainable, and textiles-based system. 

This study introduces hydraulic spray (HS) atomizing system as new resource-efficient continuous dyeing-finishing method for wool fabric. Here, wool fabric was dyed and finished by using commercial dyes and finishes through either one-step or two-steps HS method. Results obtained from color strength (K/S), color difference (ΔECMC) and color fastness analysis presented the apprehension of HS method in dyeing of wool fabric with different GSM and dyes. Finishing performance of wool fabric was measured through water contact angle analysis. Analysis shows that, the finishing performance of HS method were substantial to reach water contact angle as high as 145° while maintaining high fastness to wash and abrasion. Between one-step and two-steps HS method, one-step method showed better performance with high resource efficiency compared to two-steps method. Results from statistical analysis shows no statistical significance of fabric weight, type of dyes, and finishes to the performance of new HS method which is crucial for true-scale industrial implementation and scaling up of this process. The findings of this report are of great importance as it presents a greener alternative to the conventional resource-intensive dyeing-finishing methods of wool fabric.

The immobilization of biocatalysts or other bioactive components often means their transformation from a soluble to an insoluble state by attaching them to a solid support material. Various types of fibrous textiles from both natural and synthetic sources have been studied as suitable support material for biocatalysts immobilization. Strength, inexpensiveness, high surface area, high porosity, pore size, availability in various forms, and simple preparation/functionalization techniques have made textiles a primary choice for various applications. This led to the concept of a new domain called-biocatalyst immobilization on textiles. By addressing the growing advancement in biocatalysts immobilization on textile, this study provides the first detailed overview on this topic based on the terms of preparation, progress, and application in wastewater treatment. The fundamental reason behind the necessity of biocatalysts immobilized textile as well as the potential preparation methods has been identified and discussed. The overall progress and performances of biocatalysts immobilized textile have been scrutinized and summarized based on the form of textile, catalytic activity, and various influencing factors. This review also highlighted the potential challenges and future considerations that can enhance the pervasive use of such immobilized biocatalysts in various sustainable and green chemistry applications.

Katalytiska system är en av de effektivaste teknikerna för moderna kemiska processer. I processen används en molekyl, en ”katalysator” som är kapabel att pådriva en kemisk reaktion utan att själv bli producerad eller förbrukad under processens gång. Katalytiska system kräver separation av katalysatorerna från andra produkter efter varje cykel, vilket är både kostsamt och resurskrävande. Därför är det relevant att immobilisera katalysatorerna genom att binda dem till ett solitt stödmaterial som möjliggör att katalysatorerna enkelt kan separeras. Immobiliserade katalysatorer kan återanvändas och visar ofta på bättre stabilitet än fria katalysatorer. Men det är en långdragen process att immobilisera katalysatorer då det kräver exklusiva stödmaterial och ett komplext förberedelseförlopp. I många fall är stödmaterialen mer kostsamma än katalysatorerna själva. 

I denna doktorsavhandling arbetar jag därför med ett innovativt koncept, där jag använder textil som ett billigt och enkelt stödmaterial för immobilisering av katalysatorer. Genom systematiskt utförda experiment har underlag samlats in för att visa på immobilisering av en oorganisk katalysator (nollvalent järnpartikel-Fe0) och ett biokatalysator (glukosoxidasenzym-GOx) på en textil stödstruktur. Syftet med denna avhandling är att fastställa möjligheten att använda textil som stödmaterial för immobilisering av katalysatorer i jakten på framställningen av ett heterogent katalytiskt system (oxiderande och reducerande) för rening av avloppsvatten. Ett nonwoventyg av polyester (PF) valdes som textilt stödmaterial för immobilisering av katalysatorer för dess kvalitativa (hög styrka, porositet, biokompabilitet och resistans mot de flesta syror, oxiderande medel samt mikroorganismer) och kommersiella (tillgänglighet, låg kostnad och enkelhet att modifiera) fördelar. En kombination av miljövänliga och resurseffektiva processer (så som plasmabehandling, användning av hypergrenade dendrimerer, biobaserade polymerer) har använts för att modifiera PF ytan till fördelaktiga ytkemiska egenskaper gällande hög och stabil utdelning av immobiliserade katalysatorer.  

Avhandlingen består av tre separata delar som handlar om immobilisering av katalysatorer på textiler: (a) immobilisering och stabilisering av oorganiskt Fe0 på PF och optimering av dess möjligheter i oxiderande och/eller reducerande katalytiska system, (b) immobilisering av GOx på PF och optimering av dess användning i biokatalytiska system, (c) utformning av heterogena bio-Fentonsystem med hjälp av immobiliserade katalysatorer (Fe0 och GOx). I alla delar aktiverades PF:s hydrofobiska fiberyta genom en plasmabehandling (antingen atmosfärisk plasma -AP eller kall fjärrplasma -CRP) efterföljt av kemisk ympning med hypergrenade dendrimerer (polyetylenglykol-OH/polyamidoamin-etylendiaminkärna) eller polymerer som innehåller den funktionella gruppen amin/tiol (3-aminopropyl-trietoxysilan/polyetylenimin, kitosan/1-tioglycerol) innan immobilisering av endera katalysatorerna. Immobiliseringen av Fe0 genomfördes med in-situ eller ex-situ reduktions-immobiliseringsmetod, medan GOx immobiliserades genom en fysisk adsorptionsmetod. Ett antal tillvägagångssätt utforskades i sökandet efter optimala förhållanden för immobilisering av katalysatorer samt förbättringsmöjligheter av immobiliserade katalysatorers katalytiska förmåga.  

Olika analytiska och instrument-tekniker användes för att kontrollera ytmodifieringen av textilier, effektiviteten av immobiliserade katalysatorer, fysiokemiska egenskaper av immobiliserade katalysatorer och deras katalytiska aktivitet för avlägsnandet av färgämnen, fenoler eller patogena föroreningar från vatten. Resultaten från plasmabehandlingen visade att båda AP och CRP framgånsrikt aktiverat PF ytan genom integrering av polära funktionella grupper (–COOH och –OH) genom AP och karboxyl/hydroxyl-grupper (–COOH/–OH) och aminogrupper (–NH2) genom CRP. Dessutom kunde ympade hypergrenade dendrimerer och funktionella polymerer på plasma-aktiverad PF ge en skräddarsydd yta med specifika funktionella ändgrupper. När det gäller immobiliseringen av Fe0 på en PF-yta visade resultaten att reduktionsmetoderna (in-situ eller ex-situ) för framställning av Fe0-partiklar hade synergieffekter på hur väl immobiliseringen lyckades när det gäller morfologi, stabilitet, partikelstorlek och spridning av immobiliserad Fe0. Ytkemiska egenskaper av PF påverkade också stabiliteten av immobiliserad Fe0 och tillhörande egenskaper, något som observerats genom flertalet studier. Detaljerade resultat visade att en PF-yta som innehåller de funktionella grupperna –COOH, –OH, och –SH främjar belastning och stabiliseringen av Fe0 mer än en yta rik på de funktionella grupperna – NH2. Slutligen, alla Fe0-immobiliserade PF prov visade hög katalytisk aktivitet i avlägsnandet av föroreningar i vatten i både oxiderande och reducerande system. När det gäller GOx-immobiliserade PF prov fanns det att lyckad immobilisering av enzym på textil var relaterad till typen och omfattningen av funktionella ytgrupper integrerade i PF-ytan. Resultaten visade vidare att en PF-yta med –COOH eller – NH2-grupper garanterade högre belastning och stabilitet hos GOx jämfört med -COOH och -OH rika ytor. Dessa resultat är viktiga eftersom de styrker interaction mellan den textila ytan och enzymer, vilket utgör en grund för möjligheterna för starka immobiliseringar av GOx på textila stödmaterial. Som validering av konceptet så visar denna avhandling också den första lyckade framtagningen av ett komplett heterogent bio-Fenton system för rening av avloppsvatten med hjälp av immobiliserade katalysatorer (Fe0 och GOx). 

Denna avhandling om immobilisering av katalysatorer på textil och applicering av immobiliserade katalysatorer i rening av avloppsvatten (både oxiderande och reducerande system) bidrar inte bara till allmän kunskap om heterogena katalytiska system, Fenton/Fenton-system och bio-Fenton system, utan öppnar också upp för lovande möjligheter att använda textilier som stödmaterial för immobilisering av olika katalysatorer för ett brett spektrum av användningsområden. 

This study reports the first approach of immobilizing a redox (glucose oxidase-GOx) enzyme on the amino functional group-integrated tailor-made textile (polyester nonwoven fabric-PF) support matrix. To achieve that, polyethylenimine if not chitosan was chemically grafted on plasma (with O2/N2 gas)-activated PF before immobilizing the GOx enzyme through physical adsorption. Diverse qualitative and quantitative characterization methods were used to validate the successful activation and GOx immobilization on amino functional group-integrated tailor-made PF. Results showed that integration of amino functional groups on PF offers a great deal of favorable conditions during enzyme immobilization through covalent or ionic interaction between counter functional groups as reflected in high loading (55.46%) and good operational (78.37%) and thermal stability (∼60 °C) with excellent recyclability (60% activity/15-cycles) and poor leaching (22%) of immobilized GOx. Enzymatic reaction kinetics of free and immobilized GOx revealed the existence of relative mass transfer and diffusion limitation of immobilized GOx as apprehended in the apparent Michaelis constant (Km) and maximum velocity of the reaction (Vmax). The resultant immobilized GOx’s were studied for the first time in the removal of pollutants (10 mg L–1 crystal violet) from water in a heterogeneous bio-Fenton system. Results showed as high as 88.69% pollutant removal at 1.19 × 10–2 min–1 following pseudo-first-order kinetic model as supported by R2 values beyond 97. These results are of great importance as they provide fundamental evidence and proof of concepts regarding immobilizing biocatalysts on textiles and their potential application in a robust heterogeneous catalytic system for environmental and green chemistry applications.

The resource-intensive preparation procedures and difficulty in free structure formation have restricted the widespread application of existing enzyme immobilization strategies. In this study,valve-jet printing as a resource-efficient process for robust immobilization of redox enzyme (Glucoseoxidase-GOx) on polyester fabric support has been reported for the first time. For that, GOxenzyme has been directly printed on plasma-activated polyester fabric in a predefined pattern. Along with superficial analysis of the textile before and after the modifications, the loading, stability, and activity of the immobilized enzyme have also been studied in detail. The results indicated successful activation of polyester textile air atmospheric plasma treatment (O2/N2) through integrating carboxyl, amine functional groups. The enzymatic colorimetric analysis shows that most of the loaded enzymes retained to their activity where few were inactivated due to blocking of their active site during printing. This study herein provides further proof of the fundamental enzyme printing concept as a resource-efficient enzyme immobilization strategy for sustainable and green chemistry applications.

A graphene/Fe loaded polyester fabric-PET with high electrical and catalytic properties has been successfully developed for the first time, via simple coating-incorporation method using hyperbranched poly(amidoamine)-PAMAM dendrimer as binder. Both graphene oxide (GO/rGO) and zerovalent iron (Fe⁰) nanoparticles were loaded on polyester fabric surface before and after chemical grafting of PAMAM.  Full characterization of fabrics before and after modifications has been studied through sessile droplet goniometry, ζ–potential, K/S coating evenness, SEM, XPS, FTIR, TGA and DSC analysis. Results showed successful and uniform coating of GO/rGO and loading of Fe⁰ on PET; also allowed correlating the type of chemical moiety responsible for uniform GO coating, high Fe⁰ loading and their electrical and catalytic activities. Sheet resistance (R_sh) analysis was carried out to measure the conductivity of the samples. The lowest R_sh (corresponds to high conductivity) has been found in PET-PAM-rGO-Fe⁰ (0.74±0.13 kΩ/sq) followed by PET-rGO-Fe⁰ (1.32±0.18 kΩ/sq), PET-PAM-rGO (2.96±0.08 kΩ/sq) and PET-rGO (3.41±0.34 kΩ/sq). Furthermore, Fe⁰ –loaded samples were found to be effective in catalytic removal of toxic water pollutants (crystal violet dye) with ~99% removal of pollutants in around one hour, as observed by UV-vis spectroscopy. Relatively high electrical and catalytic activity in PET-PAM-rGO-Fe⁰ is related to the role played by PAMAM in uniform rGO coating and high Fe⁰ loading. These findings are of great importance as they allow envisaging the development of multifunctional textiles for combined smart and green chemistry application.

This study reports a facile fabrication of multifunctional cotton-modal-recycled aramid blended protective textiles through the deposition of a three-dimensional tetrakis(hydroxymethyl)phosphonium chloride (THPC)-urea polymer coating. For this, blended fabrics with different compositions, weaving structures, thicknesses, GSMs and thread densities have been fabricated, followed by chemical deposition of the THPC-urea polymer coating on the fibrils of the yarn and then in the amorphous region through ammonia treatment. Full characterization of the resulting fabrics through SEM and FTIR allowed confirmation of the deposition of THPC-urea on each blended fabric. Treated and untreated samples were evaluated for their water repellency, flame retardance and antibacterial properties through diverse experimental tools. The results show that the lowest average char length (warp - 3.18 cm, weft - 2.84 cm) and radiant heat flux density (11.021 kW m<SUP>-2</SUP>), and highest LOI% (36.8%), were found in the 40%-cotton-30%-modal-30% aramid fabric, whereas the best thermal protective performance (t<INF>12</INF>- 4.0 s,t<INF>24</INF>- 5.9 s) was observed in the fabric with a high thickness and GSM. Regarding the water repellent properties, all treated samples showed superior water repellence properties expressed as water contact angle (theta<INF>H<INF>2</INF>O</INF>) as high as 141.70 degrees to 151.50 degrees. Besides, the 3D polymer coating deposited on blended fabrics exhibited high antibacterial properties (99.90%) againstStaphylococcus aureusATCC 6538 andKlebsiella pneumoniaeATCC 4352 as calculated according to the KS K 0693:2016 method. These results herein provide fundamental grounds to design blended textiles with necessary functionalities for smart and protective applications.

In this study, a flexible multifunctional fibrous membrane for heterogeneous Fenton-like removal of organicand pathogenic contaminants from wastewater was developed by immobilizing zerovalent ironnanoparticles (Fe-NPs) on an amine/thiol grafted polyester membrane. Full characterization of theresulting polyester membranes allowed validation of successful grafting of amine/thiol (NH2 or SH)functional groups and immobilization of Fe-NPs (50–150 nm). The Fenton-like functionality of ironimmobilized fibrous membranes (PET–Fe, PET–Si–NH2–Fe, PET–NH2–Fe, and PET–SH–Fe) in thepresence of hydrogen peroxide (H2O2) was comparatively studied in the removal of crystal violet dye(50 mg L1). The effect of pH, amount of iron and H2O2 concentration on dye removal wassystematically investigated. The highest dye removal yield reached 98.87% in 22 min at a rate constant0.1919 min1 (R2 ¼ 95.36) for PET–SH–Fe providing 78% toxicity reduction assessed by COD analysis.These membranes could be reused for up to seven repeated cycles. Kinetics and postulated mechanismof colour removal were proposed by examining the above results. In addition, the resultant membranesshowed substantial antibacterial activity against pathogenic bacteria (Staphylococcus epidermidis,Escherichia coli) strains studied through disc diffusion-zone inhibitory and optical density analysis. Thesefindings are of great importance because they provide a prospect of textile-based flexible catalysts inheterogeneous Fenton-like systems for environmental and green chemistry applications.

This work focuses on the optimization of heterogeneous Fenton-like removal of organic pollutant (dye) from water using newly developed fibrous catalysts based on a full factorial experimental design. This study aims to approximate the feasibility of heterogeneous Fenton-like removal process and optionally make predictions from this approximation in a form of statistical modeling. The fibrous catalysts were prepared by dispersing zerovalent iron nanoparticles on polyester fabrics (PET) before and after incorporation of either polyamidoamine (PAMAM, –NH2) dendrimer, 3-(aminopropyl) triethoxysilane (APTES, –Si–NH2) or thioglycerol (SH). The individual effect of two main factors [pH (X1) and concentration of hydrogen peroxide-[H2O2]μl (X2)] and their interactional effects on the removal process was determined at 95% confidence level by an L27 design. The results indicated that increasing the pH over 5 decreases the dye removal efficiency whereas the rise in [H2O2]μl until equilibrium point increases it. The principal effect of the type of catalysts (PET–NH2–Fe, PET–Si–NH2–Fe, and PET–SH–Fe) did not show any statistical significance. The factorial experiments demonstrated the existence of a significant synergistic interaction effect between the pH and [H2O2]μl as expressed by the values of the coefficient of interactions and analysis of variance (ANOVA). Finally, the functionalization of the resultant fibrous catalysts was validated by electrokinetic and X-ray photoelectron spectroscopy analysis. The optimization made from this study are of great importance for rational design and scaling up of fibrous catalyst for green chemistry and environmental applications.

Highly oxidation tendency of zerovalent iron nanoparticles limits itsvarious practical applications. In this work, stabilization of zerovalent ironnanoparticles (nZVI) in 3-Mercapto-1,2-propanediol (α-thioglycerol, α -TG)modified polyester nonwoven (PN) for improved catalytic and antibacterialapplication has been studied for the first time. Changes in wettability as wellas structural, morphological, thermal and catalytic properties of the resultingPN/α -TG/nZVI material were investigated by scanning electron microscopy,energy dispersive X-Ray, zeta potential measurements, thermogravimetricanalysis, differential scanning calorimetry, fourier transform infrared and UV–visible spectroscopies. Prior to functionalization, hydrophilic functional groupshave been introduced in PN surface by air atmospheric plasma treatment.Iron nanoparticles were immobilized by α-thioglycerol on the polyester fiberswith a multi-meter particle size. α -TG stabilized nZVI by reducing thetendency of easy oxidation. nZVI insertion resulted in high thermal stability ofPN. As an application, PN/α-TG/nZVI exhibited an excellent catalytic activityin the reduction of 4-nitrophenol with appreciable recyclability. The resultsfurther demonstrate that PN/α-TG/nZVI can be employed not only for toxiccompounds removal but also to inhibit the growth of bacteria at normalconditions which herein open new prospects for concrete industrialapplications of nZVI based multifunctional systems.

Dispersion of iron nanoparticles (Fe-NPs) was achieved on polyester fabrics (PET) beforeand after incorporation of dendrimers (PAMAN), 3-(aminopropyl) triethoxysilane (APTES) orthioglycerol (SH). The catalytic activity of the resulting materials (PET-Fe, PET-PAMAM-Fe,PET-APTES-Fe and PET-SH-FE) was comparatively investigated in the degradation of 4-nitrophenol(4-NP) and methylene-blue (MB. Full characterization through diverse instrumentalmethods allowed correlating the type of the organic moiety incorporated to the Fe content,catalytic properties and stability. The highest 4-NP degradation yield reached 99.6 % in 12 minsfor PET-SH-Fe. The catalytic activity was explained in terms of reactant interaction with Fe-NPs. The 1st order reaction kinetics and pseudo-1st order adsorption kinetics provide evidenceof the key-role of reactant adsorption. These findings allow envisaging the preparation of fiberbasedcatalysts for potential uses in environmental and green chemistry.

This study reports the synthesis, immobilization and stabilization of multiscale zero valent iron (Fe⁰=ZVI)particles on fibrous polyester (PET) nonwoven membrane for heterogeneous Fenton-like removal of hazardouspollutants in water. Activation of PET fiber surface by air atmospheric plasma with or without a consecutivegrafting of hyperbranched poly-(ethylene glycol)-pseudo generation 5 dendrimer having hydroxyl (-OH) endgroup functionality created polar reactive functional groups allowing immobilization and stabilization of ZVIparticles. Synthesis of ZVI was carried out through chemical reduction of ferric ions, either through a single stepin-situ, or a two-step ex-situ reduction-immobilization method. The nonwovens were characterized usingwettability, Fourier transform infrared spectroscopy (FTIR), optical microscopy, scanning electron microscopy(SEM), X-ray energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD) and thermo-gravimetric analysis(TGA). Results confirmed the formation and immobilization of nano to sub-micronic multi-scale ZVI particles.The particle size, distribution and stability of ZVI were found to be influenced by the methods of ZVI synthesisand PET surface activation used. The ZVI particles initially formed, quasi-instantaneously turned to yellowishbrown indicating the formation of oxide layer, except in the case of dendrimer grafted PET, where higher content(22.30%) and stability of ZVI was detected. All ZVI immobilized nonwovens exhibited high effectiveness towardsFenton-like degradation of malachite green dye (20 ppm), with fastest color removal (98% in 20 min) achievedby dendrimer/ex-situ nonwoven. This nonwoven could be used up to eight repeated cycles providing low TDS (52 ppm) and high COD reduction (66.23%). Combined use of eco-friendly plasma and dendrimer grafting,provides efficient fibrous textile base heterogeneous catalysis.

Robust immobilization of glucose oxidase (GOx) enzyme was achieved on poly(ethylene terephthalate) nonwoven fabric (PN) after integration of favourable surface functional groups through plasma treatments [atmospheric pressure-AP or cold remote plasma-CRP (N2 + O2)] and/or chemical grafting of hyperbranched dendrimers [poly-(ethylene glycol)-OH or poly-(amidoamine)]. Absorption, stability, catalytic behavior of immobilized enzymes and reusability of resultant fibrous bio-catalysts were comparatively studied. Full characterization of PN before and after respective modifications was carried out by various analytical, instrumental and arithmetic techniques. Results showed that modified polyester having amine terminal functional groups pledged better surface property providing up to 31% enzyme loading, and 81% active immobilized enzymes. The activity of the enzyme was measured in terms of interaction aptitude of GOx in a given time to produce hydrogen peroxide using colorimetric assay. The immobilized GOx retained 50% of its original activity after being reused six (06) times and exhibited improved stability compared with the free enzyme in relation to temperature. The reaction kinetics, loading efficiency, leaching, and reusability analysis of enzyme allowed drawing a parallel to the type of organic moiety integrated during GOx immobilization. In addition, resultant fibrous bio-catalysts showed substantial antibacterial activity against pathogenic bacteria strains (Staphylococcus epidermidis and Escherichia coli) in the presence of oxygen and glucose. These results are of great importance because they provide proof-of-concept for robust immobilization of enzymes on surface-modified fibrous polyester fabric for potential bio-industrial applications.

A facile approach for immobilization of zero-valent iron (ZVI, Fe0) on plasma treated polyester nonwovens (PET-NWs) using hyper-branched G5-PEG10k-OH dendrimer (G5-D) was studied. The objective was to investigate the potential use of dendrimer for immobilization of ZVI on fibrous PET textiles. For that, air atmospheric plasma treatment of PET-NWs was carried out followed by grafting of G5-D onto the hydrophilic PET-NWs surface. ZVI was immobilized on the designed PET-NWs@G5-D by means of reductive formation and immobilization. Microscopic image analysis and thermo-gravimetric analysis studies indicate successfully synthesis and formation of PET-NWs@G5-D-ZVI complex. The produced hybrid metrics is able to exhibit catalytic reaction in an aqueous system and degrade organic contaminants which suggest a significant prospect of potential use of dendrimers to immobilize iron onto porous textiles for a broad range of environmental remediation.

Toxic colorants are threatening the aquatic environment due to their slow degradation. Immobilization zero-valent iron (ZVI) supported on polyester nonwoven (PET-NW) to catalyze fenton reaction in presence of hydrogen peroxide, has been studied. Plasma activated nonwoven was placed in reactor to create complex with ferric irons followed by subsequent formation and immobilization of ZVI. The morphology and structure of the resulting material was systematically characterized using optical microscopy and thermogravimetric analysis. Results indicate successful immobilization of ZVI on nonwoven. It shows superior ability to invoke fenton reaction for degradation of methylene blue in aqueous solution, without precipitation of iron sludge. UV-visible spectrophotometer was used for quantitative measurement of dye degradation. Results suggest significant prospects of the immobilized iron for a broad range of environmental application.