Next Article in Journal
Antimicrobial Efficacy of Sodium Dichloroisocyanurate Washing and Coating for Reduction of Foodborne Pathogens on Fresh Blackberries
Previous Article in Journal
Sintering Kinetics, Mechanical Properties, and Electrical Conductivity of Ti-67 at% Al Targets Fabricated via Spark Plasma Sintering
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Coatings
Volume 15
Issue 9
10.3390/coatings15091030
coatings-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

The Influence of Low-Pressure Plasma and Ozone Pretreatment on the Stability of Polyester/Chitosan Structure in the Washing Process—Part 1

by
Tea Bušac
1,
Mirjana Čurlin
2,
Tanja Pušić
1 and
Sanja Ercegović Ražić
1,*
1
Faculty of Textile Technology, University of Zagreb, Prilaz baruna Filipovića 28a, 10000 Zagreb, Croatia
2
Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottieva 6, 10000 Zagreb, Croatia
*
Author to whom correspondence should be addressed.
Coatings 2025, 15(9), 1030; https://doi.org/10.3390/coatings15091030
Submission received: 25 June 2025 / Revised: 5 August 2025 / Accepted: 27 August 2025 / Published: 3 September 2025
(This article belongs to the Section Functional Polymer Coatings and Films)
Browse Figures
Review Reports Versions Notes

Abstract

The global problem of environmental pollution by textile particles from various sources has led to the need to research preventive methods to reduce the occurrence of particles in environmental systems. In this research, plasma and ozone pretreatment are used as environmentally friendly technologies to achieve specific surface modifications of polyester fabrics and create a stable polyester/chitosan structure that reduces the release of fibre particles during the washing process and does not affect mechanical and functional properties. The effects of advanced treatments of the surface of polyester fabrics were realised with argon (Ar) and oxygen (O2) plasma and ozone (O3) after subsequent modification with a chitosan agent. The efficiency of such pretreatments of the fabric surface as well as the stability of the polyester/chitosan structure was analysed on the basis of the changes in the physical-mechanical and chemical properties of the treated polyester standard fabric. Despite the changes in the mechanical properties of the pretreated materials, the favourable protective effect of chitosan in the resulting polyester/chitosan structures after advanced pretreatments was confirmed in all washing cycles, especially in the first cycles, which are considered crucial for significant particle release.

1. Introduction

With a worldwide production of about 1000 tonnes of textile fibres, fabrics and garments per day [1,2], the textile industry is the fourth largest industry in the world. The textile industry is in search of innovative production techniques to improve product quality, focussing on the development of new techniques that are in line with sustainable development and the protection of the environment. Textiles have been identified as one of the main sources of microplastics in the dry and wet system, as the tendency to release particles depends on the characteristics of the textiles and the phases of the technological (spinning, weaving, wet processing) and utilisation (wearing, washing, drying) cycles as well as disposal. It is therefore important to reduce the number of particles released and to remove them before they enter the wastewater treatment system or the natural recipient. Synthetic textiles release fibres of different lengths and fineness during wear and especially during the washing process. The release of fibres is influenced by numerous factors, the most important of which are the type and composition of the fabric, the type of yarn and the processing of the fabric [3,4]. Of particular importance are the final functional treatments, which have the task of improving the performance properties of the fabric and protecting aquatic ecosystems from pollution by potentially released particles [5,6,7,8].
Chitosan (CH), a natural linear polysaccharide having exceptional biological and physicochemical properties, is used in various fields such as medicine, biomedicine [9], pharmacy [10], cosmetics [11], the textile industry [12,13], the paper industry and agriculture [14,15]. Due to its non-toxicity, biodegradability and biocompatibility, it is used as an environmentally friendly biopolymer to modify the properties of textile materials. It has an effect on mechanical properties, improves sorption properties, has an antimicrobial effect, reduces the tendency to become charged with static electricity and reduces the number of particles that enter wastewater during washing [16,17,18]. The compatibility of chitosan with polyester can be improved by functionalising the polymer using chemical or physical methods [1,19].
Due to increasingly stringent environmental regulations in modern textile technology processes, there is a need to replace traditional pretreatments and there is a growing emphasis on environmentally friendly treatments. Alternative technologies such as plasma and ozone are increasingly being researched and utilised as environmentally friendly technologies that reduce the use of chemicals, time, energy, water and waste. Surface treatments with plasma, ozone, biopolymers, etc., which are currently being researched and implemented with the aim of changing the properties of textile materials, are not only environmentally friendly but also more energy efficient than the well-known conventional pretreatments [20]. In this sense, the focus of modern treatments is on achieving positive effects (impacts) by modifying the surface of textile materials, which ultimately contribute to the overall quality.
Plasma treatment as an environmentally friendly technology is used to achieve special properties that cannot be easily achieved using conventional treatments. It can be applied to individual threads and fabrics and leads to surface modifications at the micro and nano level [21,22,23]. In recent years, plasma technology has played an important role in modifying the surface of textiles to obtain multifunctional textile products [24]. The impact on the environment is lower as no harmful pollutants are produced, no wastewater is generated and fewer chemicals are needed [25,26]. Plasma-treated textiles have shown significant changes in surface structure and hydrophilicity [27]. The plasma-induced changes in polymer surfaces are highly dependent on the type of gas and the conditions of plasma generation [28]. Therefore, plasma treatment has an important advantage over other methods as the process can be easily controlled by many independent parameters such as gas pressure, exposure time and discharge [29]. This activation process leads to an increase in surface energy and an increase in affinity for other substances. The increase in surface energy is a thermodynamically unstable state and the groups formed tend to return to their original state. Therefore, the process of plasma activation is not permanent and should be carried out immediately before further treatment [20,30]. The oxygen (O2) plasma interacts with the surface of the material, breaking C-C and C-H bonds and effectively decomposing organic contaminants into CO2, H2O and light hydrocarbons. After removing the impurities, the species in the O2 plasma react with the free radicals formed on the surface. The result of this reaction is the grafting of oxygen-containing functionalities such as carbonyl (C=O), carboxyl (–COOH) and hydroxyl (–OH) groups onto the surface of the material. As a result, the surface becomes polar and hydrophilic. Argon (Ar) plasma is typically used for cleaning and physical etching of polymer surfaces as there are no reactive neutral species and the relatively large atomic mass of argon results in more efficient energy transfer through the ionic species generated in this type of plasma. Due to its nature, argon gas produces a “physical plasma”, i.e., a plasma that interacts with the target only through physical interactions and no chemical reactions [24,29,31].
Ozone has been known as an environmentally friendly agent in various industries since the beginning of the 20th century, and in the last two decades it has been used mainly for wastewater treatment [32,33,34,35,36,37,38], washing, dyeing [39,40,41], bleaching [39,42,43] and fibre modification [44]. The well-developed application of ozone has made a significant difference in these areas, especially in terms of environmental protection, as ozone has a high oxidation potential without causing secondary pollution and can be rapidly decomposed into oxygen after processing [45]. The oxidation potential of ozone (2.07 V) in an acidic medium is higher than the oxidation potential of hydrogen peroxide (1.77 V), which makes ozone an excellent oxidising agent [37,39,46,47] that can react with the surface of polymers [39]. In addition to the surface, ozone also influences changes in the crystalline and amorphous regions of polyesters [46,48,49]. Several authors [37,50,51] have also found that ozone treatment has the potential to reduce energy consumption in the processing of polyester fibres.
This study investigates the development and application of treatment processes for polyester fabrics using low-pressure argon and oxygen plasma at ambient temperature and ozone technology, which are presented as alternative pretreatment processes for modifying the surface of polyester fabrics. After pretreatment, the standard polyester fabric was treated with the biopolymer chitosan to form a stable polyester/chitosan structure (PES/CH), which was subjected to a repeated washing process to prove its stability. The characterisation of the plasma- and ozone-pretreated and chitosan-modified fabric before and after washing and in comparison to untreated polyester fabric was performed by analysing the structural, physical-mechanical and chemical properties.

2. Materials, Procedures and Methods

2.1. Materials

For this study, a standard white polyester fabric (PES) from the Dutch supplier Centre for Testmaterials BV Employees, CFT, was used, the properties of which are listed in Table 1.
For the preparation of tested samples to prevent the potential effects of “loose” fibres at the edges of the polyester fabric during the modification and washing, an ultrasonic cutter (TTS-400, Sonowave, Legnano, Italy) was used.

2.2. Procedures

A low-pressure plasma system of the type Nano LF-40 kHz (Diener Electronic GmbH & Co. KG, Ebhausen, Germany), consisting of a vacuum pump of the type D&B (Leybold, Cologne, Germany), with a suction capacity of 25 m3/h and the gases oxygen and argon (>99.998% purity), was used for plasma pretreatment (Figure 1). In the chamber of the low-pressure plasma system (volume 20 L and round shape), four ground-level electrode systems were used (4 cm distance between each tray) to ensure uniform plasma generation. The pretreatment was carried out with argon (Ar) plasma for 10 min (sample designation: PES_P-Ar) and oxygen (O2) plasma for 5 min (sample designation: PES_P-O2) with a power of 300 W, as optimum parameters. The initial pressure in the vacuum chamber was increased to 0.20 mbar before pretreatment, while a working pressure of 0.28 mbar and a gas flow rate of 200 cm3/min were set for all the pretreatments. The prepared samples had the dimensions 200 × 200 mm.
The pretreatment of the fabrics with ozone was carried out using the Pro Series Ozonator, Digital UV Ozone System (Novascan Technologies, Inc., Boone, IA, USA). Samples of polyester fabric measuring 200 mm × 200 mm were placed in an ozone generator in which ozone (O3) was generated using a mercury mesh lamp and UV radiation with a wavelength of 185 nm for generating reducing radicals. The ozone pretreatment was carried out for 30 min (sample designation: PES_O3-30) and 60 min (sample designation: PES_O3-60).
The second phase of the research involved the functional coating of biopolymeric chitosan on untreated and on plasma- and ozone-pretreated samples of polyester fabrics using the process. A chitosan (CH) solution having a concentration of 0.5% was prepared by dissolving chitosan [18] in distilled water with constant stirring on a magnetic stirrer (200 rpm) and adding 0.1 mol/L hydrochloric acid (HCl(aq)) to adjust the pH to 3.6. The untreated and plasma-pretreated polyester fabric samples were immersed in the prepared chitosan solution using the pad-dry-cure method with an Ernst Benz, LFV/2 350R + TKF 15/M35 at a pressure of 12.5 kg/cm. Drying took place at 90 °C for 40 s and curing at 130 °C for 20 s. The samples pretreated with ozone were impregnated under the same conditions on a Werner Mathis AG Ch-8155 Nieder-hasli/Zurich at a pressure of 1 bar, while drying and thermocondensation were carried out on a Werner Mathis AG machine under the same conditions. The samples were dyed with 1% dye, based on the weight of the material, at a temperature of 60 °C for 30 min at a rotation speed of 100 rpm with an OK of 1:50 in a Polymat P 4502 (M) laboratory apparatus (Werner Mathis AG, Oberhasli, Switzerland). Due to the low concentration of the dye, its stock solution was prepared. Rinsing was carried out in four cycles in cold water, followed by soaping with Kempon 30 (Kemo, Zagreb, Croatia), 2 g/L, at 90 °C for 10 min.
The standard polyester fabric and the samples after modification were subjected to a washing process using the standard detergent ECE A without phosphate and optical bleach according to HRN EN ISO 6330:2021 [53]. The washing process was carried out using a standard detergent concentration of 1.25 g/L in hard water at a temperature of 60 °C. All the samples were weighed and washed in separate cuvettes in a Rotawash washing machine (SDL Atlas), with OK 1:7 for 5 and 10 cycles. After washing, the samples were rinsed with OK 1:8, removed using forceps and rinsed with water for 4 cycles. After washing, the samples were air-dried at room temperature. The summarised names of the samples used in the experiment are listed in Table 2.

2.3. Methods

The characterisation of the properties of the polyester fabrics to assess the degree of alteration and the uniformity of the treatments applied was carried out using standardised and physical, chemical and mechanical analysis methods.
The thickness (T, mm) of the polyester fabric was determined using a thickness gauge, DM 2000-Wolf (Wolf Messtechnik GmbH, Freiberg, Germany), with a high precision of up to 0.001 mm at a pressure of 0.5 kPa. The measurement was carried out in accordance with the HRN EN ISO 5084:2003 standard [54]. The results are expressed as the average thickness value (T) of five randomly selected individual positions on the sample where no damage or wrinkles were present.
The measurement of tensile strength (Fp, N) and elongation at break (ε, %) of the polyester fabric according to the HRN EN ISO 13934-1:2013 standard [55] (strip method) was performed using a MesdanLab Strength Tester in the warp direction (in triplicate) to test the influence of treatments and washing processes on the tensile properties of the fabric. The pre-tension was 5 N (corresponding to the mass of the sample per unit area). The prepared samples were 200 ± 0.5 mm long and 50 ± 0.5 mm wide. The experiments were carried out with a measuring length of the tensile testing machine of 100 ± 1 mm. The rate of extension of the tensile testing machine was set to 100 mm/min. The tensile properties of the samples after the ozone pretreatment having the set dimensions of 100 × 50 mm were measured on a Statigraph M, Textechna tester according to DIN 53857 in triplicate. All the measurements of the tensile properties were carried out on the conditioned samples under standard atmospheric conditions according to HRN EN ISO 139:2008 [56] (T = 20 ± 2 °C, RH = 65 ± 4%).
The mass changes (∆m, %) of the samples were determined using the gravimetric method in accordance with the requirements of the HRN ISO 3801:2003 [57] standard, whereby the samples were conditioned under standard atmospheric conditions in accordance with HRN EN ISO 139:2008 (T = 20 ± 2 °C, RH = 65 ± 4%). The samples were weighed in triplicate on a KERN ALJ 220-5DNM laboratory analytical balance, with a high degree of accuracy and precision (0.0001 g).
The procedure for determining the pH value of the aqueous extract of the polyester fabric samples was carried out in accordance with HRN EN ISO 3071:2020 [58]. The multimeter model SevenCompact™ Duo S213 (Mettler Toledo, Melbourne, Australia) with an InLab Expert Pro-ISM® electrode was used to measure the pH.
Detection of the presence of chitosan on the polyester fabric was performed using an anthraquinone dye, Remazol® Red RB 133% (C.I. Reactive Red 2) [59,60,61]. The red colour of the sample was observed using the Dino lite digital microscope and the spectrophotometric parameter colour strength (K/S). A Datacolor 850 spectrophotometer (Switzerland), with computer support from the Datacolor Tools Plus programme was used for this purpose. The difference between the colour strength, K/S value, unmodified and modified samples was determined according to the standard for colour fastness testing HRN EN ISO 105-J01:2003 [62].
The zeta potential parameter was chosen to monitor the effects of pretreatment, modification with chitosan and washing stability. The streaming potential method, in which the properties of the samples were monitored by the zeta potential (ζ) as a function of the pH of the electrolyte solution (1 mmol/L KCl) using a titration procedure, was used. The measurements were performed using the electrokinetic analyser SurPASS (Anton Paar GmbH) and SurPASS 3 (Anton Paar, Graz, Austria) with computer support by the software VisioLab for SurPASS 2.30/SurPASS 3 software, which systematically collects all measurement parameters on the basis of which the zeta potential is calculated.
The morphological properties of the polyester fabrics before and after pretreatment and modification with the biopolymer chitosan were analysed using a field emission scanning electron microscope (FE-SEM), Mira II LMU (Tescan, Brno, Czech Republic).
The test of pilling tendency by the surface abrasion method of the material according to the standard HRN EN ISO 12945-2:2020 [63] was performed with a certain number of cycles (125, 500, 1000, 2000, 5000, 7000) using a Martindale 2561E Abrader (MesdanLab, Brescia, Italy), under standard atmosphere for the test. The procedure was carried out by abrading the fabric using a low force (from 100 to 1200 cN), cutting the test fabric to a size of 90 mm and 140 mm with a circular cutter. The surface appearance, valued from 1–5, was harmonised with a standard HRN EN ISO 12945-2:2020. Assessment was performed according to standard photographs from EMPA. The lowest tendency to pilling was indicated by a grade of 5 (no pilling) and the highest by a grade of 1.

3. Results and Discussion

Characterisation refers to the physical-mechanical properties, which are an important structural feature and must be monitored in order to assess the efficiency of the pretreatment and the degree of modification. For this purpose, the thickness (T, mm), breaking force (Fp, N) and elongation at break (ε, %) of the polyester fabrics (untreated, plasma- and ozone-pretreated, and all modified with chitosan) were determined. The mass gain/loss (∆m, %) of the pretreated and modified samples was calculated in relation to the untreated polyester fabric (N). The change in mechanical strength (MSC, %) was calculated for the expression of the reduction in tensile strength compared to the untreated sample. The characterisation of the physical-mechanical properties of all the polyester samples is shown in Table 3.
The thickness of the polyester fabric pretreated using advanced methods and modified with chitosan was slightly increased (from 0.36 to 0.38 mm) compared to the untreated polyester fabric (0.35 mm). In the chitosan-treated samples, a positive change in mass was observed in all the samples, demonstrating the presence of chitosan on the PES surface. The reduction in mass of the samples pretreated with argon plasma and ozone (PES_P-Ar, PES_O3-30, PES_O3-60) was caused by the etching reaction (a slight increase in mass of 0.06% was observed for the PES_P-O2 sample). Almost the same effects were obtained by authors who used DBD plasma for the treatment of polyester fabrics to improve a flame-retardant treatment [41].
The tensile strength of the polyester fabric pretreated with argon and oxygen plasma was slightly reduced compared to the untreated PES sample (approx. 7%), without this having a significant impact on the quality of the fabric, which is important in view of the use of environmentally friendly low-pressure plasma at ambient temperature for this purpose. It is important to point out that the mechanical properties of the tested samples were not affected differently by the different types of Ar and O2 gases used in the generation of the plasma, while after ozone pretreatment a significant reduction in tensile strength (approx. 34%) and consequently an increase in elongation at break could be observed. However, the reduction in tensile strength achieved by ozone was less than the reduction in tensile properties achieved by the conventional pretreatment, an alkaline hydrolysis with cationic promoter [18], so that this pretreatment can also be considered favourable in terms of environmental and energy impact. The results of the reduction in mechanical properties indicate that the reactive particles generated in the plasma/ozone ablate the surface layer of the PES fibres and correlate with the reduction in the mass of the treated samples. The effects of modification with chitosan (PES_P-Ar/CH, PES_P-O2/CH) on the polyester fabrics were followed in the same way as the previous results of tensile strength of the samples pretreated with plasma (PES_P-O2, PES_P-Ar) for 5 and 10 min, which resulted in a slight decrease in tensile strength (6.5%–12.1%) compared to the chitosan-modified fabric (PES/CH). The effect of modification with chitosan on the PES fabrics pretreated with ozone (PES_O3-30, PES_O3-60) for 30 and 60 min resulted in an overall equal decrease in tensile strength (33.7%–35.0%) compared to the previously tested pretreated samples and chitosan-treated samples. According to [64], only a minimal impairment of the basic strength of the PES fabric is to be expected if the ozone treatment is carefully controlled. Otherwise, too long an exposure time can lead to degradation and deterioration of the mechanical properties of the tested fabric, in contrast to optimal treatment.
The effect of chitosan can also be seen in the higher values for the mass of the pretreated polyester fabric modified with chitosan compared to the untreated fabric. These results confirm the adsorption/absorption of chitosan on the surface of polyester fabric after pretreatment with plasma and ozone, whereby the etching process results in micro-roughness and the introduction of polar groups (e.g., –COOH, –OH) into the polyester surface. The oxygen plasma treatment makes the surface polar, hydrophilic and acceptable for the adsorption of chitosan (as a natural polymer with positively charged amines) to negatively charged or polar surface groups created by the plasma treatment (hydrogen bonds, electrostatic interactions), as shown graphically in Figure 2 [65,66].
A very similar effect is observed when polyester fabric is pretreated with ozone and then treated with chitosan, whereby chitosan in an acidic medium has positively charged amino groups that are strongly attracted to the newly formed negative carboxyl groups on the ozone-treated polyester surface. This significantly increases the binding strength of the chitosan film. The introduction of -OH and -COOH groups increases the possibility of the formation of hydrogen bonds between chitosan and the surface of the PET fibres. The surface having more hydrophilic and acidic groups allows the chitosan to deposit more evenly in a thin layer without forming lumps or localised defects. In addition, the rough, microporous surface enables better coverage and binding of the chitosan [18,64].
By determining the pH value of the aqueous extract, the migration potential of certain substances from the polyester fabrics can be determined. The untreated polyester fabric (N) shows a neutral pH value of the aqueous extract (pH 7.0). Polyester/chitosan structures show a pH value of the aqueous extract of 6.0, which is lower compared to the values before modification with chitosan. The pH values obtained for the aqueous extract of the polyester/chitosan structure are extremely favourable from an ecological and dermatological point of view. For the samples pretreated with plasma and ozone, the pH value does not change significantly and is in a very narrow range of 5.5–5.6 for all the samples treated with chitosan. The ozone and plasma treatment reduces the zeta potential, making the surface more negative due to a higher proportion of deprotonated carboxyl groups. At the same time, the pH value of the surface layer decreases, which indicates a higher proportion of acid groups [64]. Accordingly, the physical-mechanical properties were analysed after 5 and 10 washing cycles and are listed in Table 4.
The results presented in Table 4 show the influence of the washing cycles on the tensile properties (breaking force and elongation), thickness, mass changes, changes in mechanical strength and pH values of the polyester/chitosan structure compared to the untreated standard PES and PES/CH fabrics. The obtained results of thickness and mass changes indicating the compactness of the fabric structure and the partial removal of the chitosan layer deposited on the fibre surface after repeated washing cycles can be seen in the SEM images (Figure 9). A fibrillation effect on the fibre surface probably contributes to a higher physical stability of the fabric structure (with better cohesion between the fibres) and an overall lower decrease in tensile strength. To better understand the physical-mechanical and chemical changes on the surface of the polyester fabrics, which are influenced by the plasma/ozone pretreatments and chitosan as well as by the washing process, the surface of the polyester fabrics was analysed by determining the zeta potential. Figure 3, Figure 4 and Figure 5 show the zeta potential of the polyester fabrics before and after pretreatments, modification and washing at different pH values of 1 mmol/L KCl.
The titration curves of the polyester fabric modified with chitosan (PES/CH) compared to the untreated polyester fabric (PES, zeta potential ζ = −20 mV, at pH 8) are different in shape, magnitude and position of the isoelectric point (IEP). As Figure 3 shows, the IEP of the untreated polyester fabric was ~pH 3. The positive modification effect proved the presence of chitosan on the surface of the polyester fabric (PES/CH). The efficiency was indicated by the position of the IEP shifting to a higher pH value and the positive values of the zeta potential in the pH range being less than 8.0. The surface of the polyester fabric is cationised due to the presence of chitosan. Five and ten washing cycles of the PES/CH fabric led to further surface changes (PES/CH_WC_5 and PES/CH_WC_10) compared to the unwashed PES/CH fabric. The change is reflected in the magnitude of the zeta potential as well as an opposite IEP shift towards a pH less than 6.0. Slight differences were observed in the zeta potential curves of the PES/CH sample after 5 and 10 washing cycles (Figure 3). The zeta potential of the washed samples proved the deposition of chitosan and its semi-permanent stability in an alkaline washing condition. These titration curves indicate the removal of chitosan by 5 cycles, while further washing cycles (up to 10 cycles) have no effect on the surface changes. The surface properties of the polyester fabric pretreated with plasma characterised by zeta potential titration curves are given in Figure 4.
The zeta potential of (i) the polyester fabric modified with chitosan (PES/CH) and (ii) the polyester fabrics pretreated with argon/oxygen plasma and modified with chitosan (PES_P-Ar/CH; PES_P-O2/CH) is positive in the range of pH values < 8.0.
The shift in the IEP proves the surface modification of the polyester with chitosan. The titration curves for the washed polyester samples show that the chitosan was not stable during 5 and 10 washing cycles. The titration curves of the polyester fabric pretreated with argon plasma and modified with chitosan clearly confirmed the differences between 5 (PES_P_Ar/CH_WC-5) and 10 washing cycles (PES_P_Ar/CH_WC-10). In contrast to these samples, no differences were found in the samples pretreated with oxygen plasma, so that the stability of the chitosan on the polyester fabric treated with O2 plasma and coated with chitosan was not dependent on the washing cycles.
According to the zeta potential parameter, plasma pretreatment with oxygen is a more favourable surface treatment for coating with chitosan than argon plasma pretreatment, which is due to the different nature of the gases and the interaction of the plasma with the textile surface.
The titration curves obtained for the polyester fabric pretreated with ozone and modified with chitosan are identical to the titration curve of the polyester fabric modified with chitosan at all pH values indicated (Figure 5). This proves that the ozone treatment has improved the compatibility between the chitosan and the polyester. The influence of chitosan on the surface of the samples pretreated with ozone can be seen from the positive zeta potential values of these modified fabrics at pH values < 8. Ozone treatment for 30 min resulted in better washing stability of the chitosan than treatment with ozone for 60 min. The IEPs of all the samples washed for 5 and 10 cycles are the same (approximately pH 5.0), confirming the instability of the chitosan coating on the surface of the ozone-treated samples. The zeta potential values also indicate a certain instability of the surface layer of the chitosan under alkaline washing conditions.
The red colouring of the fabrics treated with chitosan confirms that this biopolymer is deposited on the polyester fabrics. The higher intensity and the uniformity of the colouring also show differences between the samples, and a better effect was obtained with polyester fabrics pretreated with plasma and ozone and modified with chitosan compared to the untreated polyester samples (Figure 6).
The polyester fabric (PES) is colourless. The red colour of the chitosan-treated samples and the colour strength (K/S) indicate the presence of chitosan on the surface of the pretreated polyester fabric. The intensity and uniformity of the colouring varies between the individual samples. The intensity and uniformity of the colour on the chitosan-treated polyester fabric (/CH) is the weakest compared to the other pretreated polyester fabrics.
To determine the presence of chitosan on polyester/chitosan structures and its persistence after 5 and 10 wash cycles, a qualitative test for chitosan was performed using an azo-reactive bifunctional dye. The intensity of the colouring indicates the degree of modification of the polyester fabric with this biopolymer [59,67,68,69,70,71]. The reduced colour intensity, expressed as K/S values (Figure 7), shows that chitosan is not completely stable under the alkaline conditions of the washing process.
The displayed values show the highest loss after five washing cycles. Further washing cycles, up to the analysed 10, did not lead to significant changes.
The identification of the chitosan-coated PES fabric with the Remazol® Red RB 133% dye proved to be a useful and rapid indication of the efficiency of the modification, so that it can be preferred to other qualitative-quantitative methods. The chitosan stability results were consistent with the zeta potential results. In addition, the structural properties and confirmation of chitosan modification were determined by FE-SEM. As a result, SEM images using a magnification of 1000× and 1060× are presented.
The SEM images of the polyester fabrics pretreated with plasma and ozone and modified with the biopolymer chitosan confirm the presence of chitosan on the surface of the polyester fibres (in Figure 8), which is consistent with the results of the identification of the chitosan with the Remazol® Red RB dye. The surface of the fibres is smooth, with a visible layer of chitosan overlaying the fibre. More pronounced areas having a uniform layer of chitosan on the fibre surface are indicated by blue arrows.
Figure 9 shows that the alkaline washing conditions, the mechanics during several washing cycles and the temperature caused changes to the surface of the polyester/chitosan structure, which are visible in the form of a fibrillation effect that can impact the physical-mechanical properties of such polyester fabrics.
Table 5 shows the results of testing the pilling tendency of the surface of the polyester fabrics after modification with chitosan with and without pretreatment, in order to analyse the tendency to release fibre particles into the environment during wear and care and to investigate the effects on the quality of use of such a modified material.
From the results obtained, it can be seen that the surface appearance ratings of all samples show the highest values (grade 5) after up to 1000 abrasion cycles, decreasing slightly as the number of abrasion cycles increases. Differences between the samples are observed after 2000 abrasion cycles, with the sample after plasma pretreatment showing a more favourable effect of the chitosan. The final score after the maximum abrasion cycle according to the standard photo is 3/4, at a sample pretreated with ozone and modified with chitosan. A similar effect is observed after 10 washing cycle processes, with a decrease in the final grade.
A similar effect is observed in the evaluation of the pilling tendency after 10 washing cycles, with the pilling tendency in the untreated polyester sample decreasing to lower grades after 1000 cycles (grade 3/4), as shown in Table 6. The plasma-pretreated sample with the PES/CH structure shows a decreasing effect after 7000 cycles, compared to the ozone-treated samples where grade 3/4 is reached after 2000 cycles.

4. Conclusions

In order to achieve an ecological and more efficient modification of polyester fabrics, current research focuses on green technologies, argon and oxygen plasma at low pressure and an ozone oxidation process to improve the stability of chitosan and polyester fabrics before and after the washing process. The optimisation of parameters must be the focus if we want to achieve optimum mechanical properties of polyester fabrics and a high quality of use. The pretreated and activated surface of the polyester fabric showed an increased affinity for coating with the biopolymer chitosan. The streaming potential method is suitable and makes a valuable contribution to the characterisation and identification of chitosan and the efficiency of plasma and ozone pretreatments.
The spectroscopic evaluation of the red colour of the polyester samples modified with chitosan showed that the K/S values of the modified samples before washing were higher than those of the washed samples. This indicates a certain instability of the chitosan and proves that although the applied chitosan layer is only partially durable, it is still sufficient to protect the surface and reduce the release of particles in the washing process. The characterisation of the wash effluent, with a focus on the analysis of the volume distribution of the detached particles, is being prepared for part 2.
Some of the future research mentioned by the authors [72] will focus on the actual problem of releasing fibre particles into the water environment and preventing the detachment of microplastic fragments of textile origin during the washing process, forming chitosan-based hydrogels as sustainable materials for environmental cleaning application.

Author Contributions

Conceptualisation, S.E.R., M.Č. and T.B.; methodology, T.B.; validation, M.Č., S.E.R. and T.P.; data curation, M.Č.; writing—original draft preparation, T.B.; writing—review and editing, S.E.R., M.Č. and T.P.; project administration, T.P. All authors have read and agreed to the published version of the manuscript.

Funding

This research has been partly supported by the Croatian Science Foundation under the project IP-2020-02-7575.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Acknowledgments

Authors’ special thanks are due to Matej Zadravec from the University of Maribor, for ozone pretreatments of polyester samples.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Palacios-Mateo, C.; Van der Meer, Y.; Seide, G. Analysis of the polyester clothing value chain to identify key intervention points for sustainability. Environ. Sci. Eur. 2021, 33, 2. [Google Scholar] [CrossRef] [PubMed]
  2. The Fiber Year. The Fiber Year: World Survey on Textiles and Nonwovens; The Fiber Year: Roggwil, Switzerland, 2019. [Google Scholar]
  3. Haap, J.; Classen, E.; Beringer, J.; Mecheels, S.; Gutmann, J.S. Microplastic fibers released by textile laundry: A new analytical approach for the determination of fibers in effluents. Water 2019, 11, 2088. [Google Scholar] [CrossRef]
  4. Gaylarde, C.; Baptista-Neto, J.A.; da Fonseca, E.M. Plastic microfibre pollution: How important is clothes’ laundering? Heliyon 2021, 7, e07105. [Google Scholar] [CrossRef]
  5. Miraftab, M.; Horrocks, A.R. (Eds.) Ecotextiles: The Way Forward for Sustainable Development in Textiles; Elsevier: Amsterdam, The Netherlands, 2007. [Google Scholar]
  6. Soljačić, I.; Pušić, T. Njega Tekstila, Knjiga 1; Sveučilište u Zagrebu: Zagreb, Croatia, 2005; Volume 23, p. 139. [Google Scholar]
  7. Carney Almroth, B.M.; Åström, L.; Roslund, S.; Petersson, H.; Johansson, M.; Persson, N.K. Quantifying shedding of synthetic fibers from textiles; a source of microplastics released into the environment. Environ. Sci. Pollut. Res. 2018, 25, 1191–1199. [Google Scholar] [CrossRef]
  8. Hernandez, E.; Nowack, B.; Mitrano, D.M. Polyester textiles as a source of microplastics from households: A mechanistic study to understand microfiber release during washing. Environ. Sci. Technol. 2017, 51, 7036–7046. [Google Scholar] [CrossRef] [PubMed]
  9. Anitha, A.; Sowmya, S.; Kumar, P.S.; Deepthi, S.; Chennazhi, K.P.; Ehrlich, H.; Tsurkan, M.; Jayakumar, R. Chitin and chitosan in selected biomedical applications. Prog. Polym. Sci. 2014, 39, 1644–1667. [Google Scholar] [CrossRef]
  10. Dodane, V.; Vilivalam, V.D. Pharmaceutical applications of chitosan. Pharm. Sci. Technol. Today 1998, 1, 246–253. [Google Scholar] [CrossRef]
  11. Hirano, S.; Hirochi, K.; Hayashi, K.I.; Mikami, T.; Tachibana, H. Cosmetic and pharmaceutical uses of chitin and chitosan. In Cosmetic and Pharmaceutical Applications of Polymers; Springer: Boston, MA, USA, 1991; pp. 95–104. [Google Scholar]
  12. Shahid, M.; Mohammad, F. Green Chemistry Approaches to Develop Antimicrobial Textiles Based on Sustainable Biopolymers—A Review. Ind. Eng. Chem. Res. 2013, 52, 5245–5260. [Google Scholar] [CrossRef]
  13. Lalov, I.G.; Guerginov, I.I.; Krysteva, M.A.; Fartsov, K. Treatment of waste water from distilleries with chitosan. Water Res. 2000, 34, 1503–1506. [Google Scholar] [CrossRef]
  14. Morin-Crini, N.; Lichtfouse, E.; Torri, G.; Crini, G. Applications of chitosan in food, pharmaceuticals, medicine, cosmetics, agriculture, textiles, pulp and paper, biotechnology, and environmental chemistry. Environ. Chem. Lett. 2019, 17, 1667–1692. [Google Scholar] [CrossRef]
  15. Del Valle, L.J.; Díaz, A.; Puiggalí, J. Hydrogels for biomedical applications: Cellulose, chitosan, and protein/peptide derivatives. Gels 2017, 3, 27. [Google Scholar] [CrossRef]
  16. Santos-Moriano, P.; Fernandez-Arrojo, L.; Mengibar, M.; Belmonte-Reche, E.; Peñalver, P.; Acosta, F.N.; Ballesteros, A.O.; Morales, J.C.; Kidibule, P.; Fernandez-Lobato, M.; et al. Enzymatic production of fully deacetylated chitooligosaccharides and their neuroprotective and anti-inflammatory properties. Biocatal. Biotransform. 2018, 36, 57–67. [Google Scholar] [CrossRef]
  17. Kang, H.; Park, S.; Lee, B.; Ahn, J.; Kim, S. Impact of chitosan pretreatment to reduce microfibers released from synthetic garments during laundering. Water 2021, 13, 2480. [Google Scholar] [CrossRef]
  18. Kaurin, T.; Pušić, T.; Čurlin, M. Biopolymer textile structure of chitosan with polyester. Polymers 2022, 14, 3088. [Google Scholar] [CrossRef] [PubMed]
  19. Samiey, B.; Cheng, C.H.; Wu, J. Effects of surfactants on the rate of chemical reactions. J. Chem. 2014, 2014, 908476. [Google Scholar] [CrossRef]
  20. Peran, J.; Ercegović Ražić, S. Application of atmospheric pressure plasma technology for textile surface modification. Text. Res. J. 2020, 90, 1174–1197. [Google Scholar] [CrossRef]
  21. Guimond, S.; Hanselmann, B.; Amberg, M.; Hegemann, D. Plasma functionalization of textiles: Specifics and possibilities. Pure Appl. Chem. 2010, 82, 1239–1245. [Google Scholar] [CrossRef]
  22. Seki, Y.; Sarikanat, M.; Sever, K.; Erden, S.; Ali Gulec, H. Effect of the low and radio frequency oxygen plasma treatment of jute fiber on mechanical properties of jute fiber/polyester composite. Fibers Polym. 2010, 11, 1159–1164. [Google Scholar] [CrossRef]
  23. Chinta, S.K.; Landage, S.M.; Kumar, S. Plasma Technology & Its Application In Textile Wet Processing. Int. J. Eng. Res. Tehnol. 2012, 1, 18. [Google Scholar]
  24. Ražić, S.E.; Čunko, R. Modification of textile properties using plasma. Tekst. J. Text. Cloth. Technol. 2009, 58, 55–74. [Google Scholar]
  25. Mercado-Cabrera, A.; Jaramillo-Sierra, B.; López-Callejas, R.; Valencia-Alvarado, R.; De La Piedad-Beneitez, A.; Peña-Eguiluz, R.; Barocio-Delgado, S.; Muñoz-Castro, A.; Rodríguez-Méndez, B. Surface modification of polypropylene fiber for hydrophilicity enhancement aided by DBD plasma. Prog. Org. Coat. 2013, 76, 1858–1862. [Google Scholar] [CrossRef]
  26. Nikitin, D.; Lipatova, I.; Naumova, I.; Sirotkin, N.; Pleskunov, P.; Krakovský, I.; Khalakhan, I.; Choukourov, A.; Titov, V.; Agafonov, A. Immobilization of chitosan onto polypropylene foil via air/solution atmospheric pressure plasma afterglow treatment. Plasma Chem. Plasma Process. 2020, 40, 207–220. [Google Scholar] [CrossRef]
  27. Peran, J.; Ercegović Ražić, S.; Sutlović, A.; Ivanković, T.; Glogar, M.I. Oxygen plasma pretreatment improves dyeing and antimicrobial properties of wool fabric dyed with natural extract from pomegranate peel. Color. Technol. 2020, 136, 177–187. [Google Scholar] [CrossRef]
  28. Wrobel, A.M.; Kryszewski, M.; Rakowski, W.; Okoniewski, M.; Kubacki, Z. Effect of plasma treatment on surface structure and properties of polyester fabric. Polymer 1978, 19, 908–912. [Google Scholar] [CrossRef]
  29. Saleem, M.; Naz, M.Y.; Shoukat, B.; Shukrullah, S.; Hussain, Z. Functionality and applications of non-thermal plasma activated textiles: A review. Mater. Today Proc. 2021, 47, S74–S82. [Google Scholar] [CrossRef]
  30. Rombaldoni, F.; Mahmood, K.; Varesano, A.; Songia, M.B.; Aluigi, A.; Vineis, C.; Mazzuchetti, G. Adhesion enhancement of electrospun nanofiber mats to polypropylene nonwoven fabric by low-temperature oxygen plasma treatment. Surf. Coat. Technol. 2013, 216, 178–184. [Google Scholar] [CrossRef]
  31. Raffaele-Addamo, A.; Selli, E.; Barni, R.; Riccardi, C.; Orsini, F.; Poletti, G.; Meda, L.; Massafra, M.R.; Marcandalli, B. Cold plasma-induced modification of the dyeing properties of poly (ethylene terephthalate) fibers. Appl. Surf. Sci. 2006, 252, 2265–2275. [Google Scholar] [CrossRef]
  32. Tehrani-Bagha, A.R.; Mahmoodi, N.M.; Menger, F.M. Degradation of a persistent organic dye from colored textile wastewater by ozonation. Desalination 2010, 260, 34–38. [Google Scholar] [CrossRef]
  33. Turhan, K.; Ozturkcan, S.A. Decolorization and degradation of reactive dye in aqueous solution by ozonation in a semi-batch bubble column reactor. Water Air Soil Pollut. 2013, 224, 1353. [Google Scholar] [CrossRef]
  34. Venkatesh, S.; Quaff, A.R.; Pandey, N.D.; Venkatesh, K. Decolorization and mineralization of CI direct red 28 azo dye by ozonation. Desalination Water Treat. 2016, 57, 4135–4145. [Google Scholar] [CrossRef]
  35. Contreras Iglesias, S. Degradation and Biodegradability Enhancement of Nitrobenzene and 2, 4-Dichlorophenol by Means of Advanced Oxidation Processes Based on Ozone; Universitat de Barcelona: Barcelona, Spain, 2003. [Google Scholar]
  36. Tzortzakis, N. Ozone: A powerful tool for the fresh produce preservation. In Postharvest Management Approaches for Maintaining Quality of Fresh Produce; Springer International Publishing: Cham, Switzerland, 2016; pp. 175–207. [Google Scholar]
  37. Santos, V.L.V.F.D.; Barcellos, I.O.; Piccoli, H.H. Pre-alvejamento de materiais têxteis com ozônio e avaliação de suas propriedades de superfície, físicas e tintoriais. Matéria 2017, 22, e11790. [Google Scholar] [CrossRef]
  38. Tzitzi, M.; Vayenas, D.V.; Lyberatos, G. Pretreatment of textile industry wastewaters with ozone. Water Sci. Technol. 1994, 29, 151–160. [Google Scholar] [CrossRef]
  39. Eren, H.A. Afterclearing by ozonation: A novel approach for disperse dyeing of polyester. Color. Technol. 2006, 122, 329–333. [Google Scholar] [CrossRef]
  40. Prabaharan, M.; Rao, J.V. Study on ozone bleaching of cotton fabric–process optimisation, dyeing and finishing properties. Color. Technol. 2001, 117, 98–103. [Google Scholar] [CrossRef]
  41. Gabardo, R.S.; de Carvalho Cotre, D.S.; Lis Arias, M.J.; Moisés, M.P.; Martins Ferreira, B.T.; Samulewski, R.B.; Hinestroza, J.P.; Bezerra, F.M. Surface modification of polyester fabrics by ozone and its effect on coloration using disperse dyes. Materials 2021, 14, 3492. [Google Scholar] [CrossRef]
  42. Avinc, O.; Eren, H.A.; Uysal, P. Ozone applications for after-clearing of disperse-dyed poly (lactic acid) fibres. Color. Technol. 2012, 128, 479–487. [Google Scholar] [CrossRef]
  43. Wakida, T.; Tokuyama, T.; Doi, C.; Lee, M.; Jeong, D.S.; Ishida, S. Mechanical properties of polyester/cotton and polyester/rayon fabrics treated with ammonia-gas. Sen’i Gakkaishi 2004, 60, 34–37. [Google Scholar] [CrossRef]
  44. Bradley, R.H.; Clackson, I.L.; Sykes, D.E. UV ozone modification of wool fibre surfaces. Appl. Surf. Sci. 1993, 72, 143–147. [Google Scholar] [CrossRef]
  45. Eren, H.A.; Avinc, O.; Erişmiş, B.; Eren, S. Ultrasound-assisted ozone bleaching of cotton. Cellulose 2014, 21, 4643–4658. [Google Scholar] [CrossRef]
  46. Lee, M.; Lee, M.S.; Wakida, T.; Tokuyama, T.; Inoue, G.; Ishida, S.; Itazu, T.; Miyaji, Y. Chemical modification of nylon 6 and polyester fabrics by ozone-gas treatment. J. Appl. Polym. Sci. 2006, 100, 1344–1348. [Google Scholar] [CrossRef]
  47. Sargunamani, D.; Selvakumar, N. A study on the effects of ozone treatment on the properties of raw and degummed mulberry silk fabrics. Polym. Degrad. Stab. 2006, 91, 2644–2653. [Google Scholar] [CrossRef]
  48. Wakida, T.; Lee, M.; Jeon, J.H.; Tokuyama, T.; Kuriyama, H.; Ishida, S. Ozone-gas treatment of wool and silk fabrics. Sen’i Gakkaishi 2004, 60, 213–219. [Google Scholar] [CrossRef]
  49. He, Z.; Li, M.; Zuo, D.; Xu, J.; Yi, C. Effects of color fading ozonation on the color yield of reactive-dyed cotton. Dye. Pigment. 2019, 164, 417–427. [Google Scholar] [CrossRef]
  50. Eren, H.A.; Anis, P. Surface trimer removal of polyester fibers by ozone treatment. Text. Res. J. 2009, 79, 652–656. [Google Scholar] [CrossRef]
  51. Jang, J.; Jeong, Y. Nano roughening of PET and PTT fabrics via continuous UV/O3 irradiation. Dye. Pigment. 2006, 69, 137–143. [Google Scholar] [CrossRef]
  52. Diener Electronic GmbH & Co. KG, Nagolder Straße 61, 72224 Ebhausen, Germany. Available online: https://www.plasma.com (accessed on 30 July 2025).
  53. HRN EN ISO 6330:2021; Textiles—Domestic Washing and Drying Procedures for Textile Testing. International Organization for Standardization: Geneva, Switzerland, 2021. Available online: https://www.iso.org/standard/75934.html (accessed on 26 August 2025).
  54. HRN EN ISO 5084:1996; Textiles—Determination of Thickness of Textiles and Textile Products. International Organization for Standardization: Geneva, Switzerland, 1996. Available online: https://www.iso.org/standard/23348.html (accessed on 26 August 2025).
  55. HRN EN ISO 13934-1:2013; Textiles—Tensile Properties of Fabrics—Part 1: Determination of Maximum Force and Elongation at Maximum Force Using the Strip Method. International Organization for Standardization: Geneva, Switzerland, 2013. Available online: https://www.iso.org/standard/60676.html (accessed on 26 August 2025).
  56. HRN EN ISO 139:2005; Textiles—Standard Atmospheres for Conditioning and Testing. International Organization for Standardization: Geneva, Switzerland, 2005. Available online: https://www.iso.org/standard/35179.html (accessed on 26 August 2025).
  57. HRN ISO 3801:1977; Textil—Woven Fabrics—Determination of Mass per Unit Length and Mass per Unit Area. International Organization for Standardization: Geneva, Switzerland, 1977. Available online: https://www.iso.org/standard/9335.html (accessed on 26 August 2025).
  58. HRN EN ISO 3071:2020; Textiles—Determination of pH of Aqueous Extract. International Organization for Standardization: Geneva, Switzerland, 2020. Available online: https://www.iso.org/standard/74203.html (accessed on 26 August 2025).
  59. Pušić, T.; Kaurin, T.; Liplin, M.; Budimir, A.; Čurlin, M.; Grgić, K.; Valh, J.V. The Stability of the Chitosan Coating on Polyester Fabric in the Washing Process. Tekstilec 2023, 66, 85–104. [Google Scholar] [CrossRef]
  60. Pušić, T.; Bušac, T.; Šimić, K.; Čurlin, M.; Šaravanja, A.; Grgić, K.; Volmajer Valh, J. Sustainability-Oriented Surface Modification of Polyester Knitted Fabrics with Chitosan. Sustainability 2024, 16, 1121. [Google Scholar] [CrossRef]
  61. Bhavsar, P.S.; Dalla Fontana, G.; Zoccola, M. Sustainable superheated water hydrolysis of black soldier fly exuviae for chitin extraction and use of the obtained chitosan in the textile field. ACS Omega 2021, 6, 8884–8893. [Google Scholar] [CrossRef] [PubMed]
  62. HRN EN ISO 105-J01:1997; Textiles—Tests for Colour Fastness—Part J01: General Principles for Measurement of Surface Colour. International Organization for Standardization: Geneva, Switzerland, 1997. Available online: https://www.iso.org/standard/3862.html (accessed on 26 August 2025).
  63. HRN EN ISO 12945-2:2020; Textiles—Determination of Fabric Propensity to Surface Pilling, Fuzzing or Matting—Part 2: Modified Martindale Method. International Organization for Standardization: Geneva, Switzerland, 2020. Available online: https://www.iso.org/standard/75375.html (accessed on 26 August 2025).
  64. Ngo, H.T.; Vu Thi Hong, K.; Nguyen, T.B. Surface Modification by the DBD Plasma to Improve the Flame-Retardant Treatment for Dyed Polyester Fabric. Polymers 2021, 13, 3011. [Google Scholar] [CrossRef] [PubMed] [PubMed Central]
  65. Vesel, A.; Recek, N.; Zaplotnik, R.; Kurinčič, A.; Kuzmič, K.; Zemljič, L.F. A method for the immobilization of chitosan onto urinary catheters. Int. J. Mol. Sci. 2022, 23, 15075. [Google Scholar] [CrossRef]
  66. Vesel, A. Deposition of Chitosan on Plasma-Treated Polymers—A Review. Polymers 2023, 15, 1109. [Google Scholar] [CrossRef] [PubMed]
  67. Hilal, N.M.; Gomaa, S.H.; ELsisi, A.A. Improving dyeing parameters of polyester/cotton blended fabrics by caustic soda, chitosan, and their hybrid. Egypt. J. Chem. 2020, 63, 2379–2393. [Google Scholar] [CrossRef]
  68. Walawska, A.; Filipowska, B.; Rybicki, E. Dyeing polyester and cotton-polyester fabrics by means of direct dyestuffs after chitosan treatment. Fibres Text. East. Eur. 2003, 11, 71–74. [Google Scholar]
  69. Volmajer Valh, J.; Stopar, D.; Selaya Berodia, I.; Erjavec, A.; Šauperl, O.; Fras Zemljič, L. Economical Chemical Recycling of Complex PET Waste in the Form of Active Packaging Material. Polymers 2022, 14, 3244. [Google Scholar] [CrossRef]
  70. Ristić, N.; Jovančić, P.; Ristić, I.; Jocić, D. One-bath dyeing of polyester/cotton blend with reactive dye after alkali and chitosan treatment. Ind. Textila 2012, 63, 190–197. [Google Scholar]
  71. Kabir, M.P.; Islam, M.M.; Masum, S.M.; Hossain, M.M. Adsorption of remazol red RR onto chitosan from aqueous solution. Bangladesh J. Sci. Ind. Res. 2014, 49, 111–118. [Google Scholar] [CrossRef]
  72. Wang, H.; Yang, L. A sustainable solution for environmental purification: A review of high-performance hydrogels based on chitosan. Int. J. Biol. Macromol. 2025, 309, 142834. [Google Scholar] [CrossRef]
Coatings 15 01030 g001
Figure 1. Schematic of kHz and MHz plasma systems (reprinted with the permission of Diener Electronic GmbH & Co. KG, Ebhausen, Germany; https://www.plasma.com) [52].
Figure 1. Schematic of kHz and MHz plasma systems (reprinted with the permission of Diener Electronic GmbH & Co. KG, Ebhausen, Germany; https://www.plasma.com) [52].
Coatings 15 01030 g001
Coatings 15 01030 g002
Figure 2. Various types of noncovalent interaction of chitosan with the plasma-treated surface (reprinted from [65,66]).
Figure 2. Various types of noncovalent interaction of chitosan with the plasma-treated surface (reprinted from [65,66]).
Coatings 15 01030 g002
Coatings 15 01030 g003
Figure 3. Zeta potential of untreated polyester fabric modified with chitosan before and after 5 and 10 washing cycles; curve as a function of the pH value 1 mmol/L KCl.
Figure 3. Zeta potential of untreated polyester fabric modified with chitosan before and after 5 and 10 washing cycles; curve as a function of the pH value 1 mmol/L KCl.
Coatings 15 01030 g003
Coatings 15 01030 g004
Figure 4. Zeta potential curves as a function of the pH value 1 mmol/L KCl of plasma-pretreated polyester fabric, and modified with chitosan before and after 5 and 10 washing cycles.
Figure 4. Zeta potential curves as a function of the pH value 1 mmol/L KCl of plasma-pretreated polyester fabric, and modified with chitosan before and after 5 and 10 washing cycles.
Coatings 15 01030 g004
Coatings 15 01030 g005
Figure 5. Zeta potential curve as a function of the pH value 1 mmol/L KCl of ozone pretreated polyester fabric, and modified with chitosan before and after 5 and 10 washing cycles.
Figure 5. Zeta potential curve as a function of the pH value 1 mmol/L KCl of ozone pretreated polyester fabric, and modified with chitosan before and after 5 and 10 washing cycles.
Coatings 15 01030 g005
Coatings 15 01030 g006
Figure 6. Identification of chitosan by dyeing with azo-reactive bifunctional dye. Photographs taken with a camera (above) and Dino lite microscope (below) with 50× magnification, with K/S value of polyester fabric and advanced pretreated polyester fabric modified with chitosan after identification of chitosan by dyeing.
Figure 6. Identification of chitosan by dyeing with azo-reactive bifunctional dye. Photographs taken with a camera (above) and Dino lite microscope (below) with 50× magnification, with K/S value of polyester fabric and advanced pretreated polyester fabric modified with chitosan after identification of chitosan by dyeing.
Coatings 15 01030 g006
Coatings 15 01030 g007
Figure 7. Photographs taken with a camera (above) and Dino lite microscope (below) with 50× magnification, with K/S value of polyester fabric and advanced pretreated polyester fabric modified with chitosan after 5 and 10 washing cycles, for identification of chitosan by dyeing.
Figure 7. Photographs taken with a camera (above) and Dino lite microscope (below) with 50× magnification, with K/S value of polyester fabric and advanced pretreated polyester fabric modified with chitosan after 5 and 10 washing cycles, for identification of chitosan by dyeing.
Coatings 15 01030 g007
Coatings 15 01030 g008
Figure 8. SEM images of untreated and pretreated polyester fabrics with advanced treatments and modified with the biopolymer chitosan.
Figure 8. SEM images of untreated and pretreated polyester fabrics with advanced treatments and modified with the biopolymer chitosan.
Coatings 15 01030 g008
Coatings 15 01030 g009
Figure 9. SEM images of untreated and pretreated polyester fabrics with advanced treatments and modified with the biopolymer chitosan, after 10 washing cycles.
Figure 9. SEM images of untreated and pretreated polyester fabrics with advanced treatments and modified with the biopolymer chitosan, after 10 washing cycles.
Coatings 15 01030 g009
Table 1. Properties of standard polyester fabric.
Table 1. Properties of standard polyester fabric.
Supplier (CFT)Mark (PN-01)
Mass per unit area (g/m2)156.0
Number of threads (wwa,wwe/cm)warp27.7
weft20.0
Thickness (mm)0.35
Yarn fineness (tex)warp30.4
weft31.9
Weaveplain
Table 2. Polyester fabric/treatment sample designation.
Table 2. Polyester fabric/treatment sample designation.
AbbreviationPolyester Fabric DesignationWash Cycles (WC)
PESuntreatedWC-5/WC-10
PES/CHmodified with chitosanWC-5/WC-10
PES_P-Ar/CHpretreated with Ar plasma and modified with chitosanWC-5/WC-10
PES_P-O2/CHpretreated with O2 plasma and modified with chitosanWC-5/WC-10
PES_O3-30/CHpretreated with ozone 30 min and modified with chitosanWC-5/WC-10
PES_O3-60/CHpretreated with ozone 60 min and modified with chitosanWC-5/WC-10
Table 3. Tested properties of untreated and plasma- and ozone-pretreated polyester fabrics before and after modification with chitosan.
Table 3. Tested properties of untreated and plasma- and ozone-pretreated polyester fabrics before and after modification with chitosan.
SampleT (mm)∆m (%)Fp (N)MSC (%)ε (%)pH
PES0.35/1015.00 /18.66 7.0
PES/CH0.370.851031.00/19.326.0
PES_P-Arn/a−0.08 945.00−6.820.18 /
PES_P-Ar/CH0.370.87964.33−6.519.83 5.5
PES_P-O2n/a0.06 945.65−6.817.90 /
PES_P-O2/CH0.380.98 906.00−12.118.68 5.6
PES_O3-30n/a−0.66 668.46 −34.233.88 /
PES_O3-30/CH0.360.55 684.67 −33.731.60 5.5
PES_O3-60n/a−0.33 672.85 −33.833.48 /
PES_O3-60/CH0.372.69 670.34 −35.031.08 5.5
n/a—not detected; /—not measured; MSC (%)—the change in mechanical strength.
Table 4. Influence of washing cycles on the tested properties of polyester fabrics pretreated and modified with chitosan.
Table 4. Influence of washing cycles on the tested properties of polyester fabrics pretreated and modified with chitosan.
SampleWCsT (mm)∆m (%)Fp (N)MSC (%)ε (%)pH
PESWC-50.38 0.79 975.00 −3.920.80 6.8
WC-100.40 1.13 956.67 −5.721.68 6.6
PES/CHWC-50.39 1.55 959.00 −6.921.38 6.9
WC-100.40 1.62 946.33 −8.221.47 6.7
PES_P-Ar/CHWC-50.42 1.50959.00−6.921.607.0
WC-100.43 1.75 968.67 −6.021.84 6.7
PES_P-O2/CHWC-50.42 1.77928.00−9.920.256.8
WC-100.43 1.78 972.67 −5.621.64 6.6
PES_O3-30/CHWC-50.411.03701.00−32.029.316.9
WC-100.52 1.51 936.33 −9.224.28 6.6
PES_O3-60/CHWC-50.44 3.14673.00−34.728.717.0
WC-100.45 1.01 936.67 −9.223.60 6.7
WCs—wash cycles; breaking force of the untreated PES fabric: Fp = 1015.00 N; breaking force of the PES/CH: Fp = 1031.00 N.
Table 5. Evaluation of the surface appearance after abrasion of the chitosan-modified polyester fabrics.
Table 5. Evaluation of the surface appearance after abrasion of the chitosan-modified polyester fabrics.
SampleCycles
1255001000200050007000
Grade
PES55554/53/4
PES/CH55554/53/4
PES_P-Ar/CH5554/544
PES_P-O2/CH5554/544
PES_O3-30/CH5554/543/4
PES_O3-60/CH5554/543/4
Table 6. Evaluation of the surface appearance after defined abrasion cycles of the chitosan-modified polyester fabrics, after 10 washing cycles.
Table 6. Evaluation of the surface appearance after defined abrasion cycles of the chitosan-modified polyester fabrics, after 10 washing cycles.
SampleCycles
1255001000200050007000
Grade
PES_WC-10543/4333
PES/CH_WC-10554/54/543/4
PES_P-Ar/CH_WC-10554/54/544
PES_P-O2/CH_WC-10554/54/543/4
PES_O3-30/CH_WC-104/5443/43/43/4
PES_O3-60/CH_WC-104/54/543/43/43/4
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Bušac, T.; Čurlin, M.; Pušić, T.; Ercegović Ražić, S. The Influence of Low-Pressure Plasma and Ozone Pretreatment on the Stability of Polyester/Chitosan Structure in the Washing Process—Part 1. Coatings 2025, 15, 1030. https://doi.org/10.3390/coatings15091030

AMA Style

Bušac T, Čurlin M, Pušić T, Ercegović Ražić S. The Influence of Low-Pressure Plasma and Ozone Pretreatment on the Stability of Polyester/Chitosan Structure in the Washing Process—Part 1. Coatings. 2025; 15(9):1030. https://doi.org/10.3390/coatings15091030

Chicago/Turabian Style

Bušac, Tea, Mirjana Čurlin, Tanja Pušić, and Sanja Ercegović Ražić. 2025. "The Influence of Low-Pressure Plasma and Ozone Pretreatment on the Stability of Polyester/Chitosan Structure in the Washing Process—Part 1" Coatings 15, no. 9: 1030. https://doi.org/10.3390/coatings15091030

APA Style

Bušac, T., Čurlin, M., Pušić, T., & Ercegović Ražić, S. (2025). The Influence of Low-Pressure Plasma and Ozone Pretreatment on the Stability of Polyester/Chitosan Structure in the Washing Process—Part 1. Coatings, 15(9), 1030. https://doi.org/10.3390/coatings15091030

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop