Aslıhan Koruyucu, A.Özgür Ağırgan Namık Kemal University; Çorlu Engineering Faculty, Textile Engineering Department, Çorlu, Tekirdağ, Turkey
Gaining antibacterial protection in fabrics is one of the increasingly important functional properties. In this study, the development of fabrics for specific application areas was foreseen using copper oxide, which is the center of attention of the whole world because of its economic status. The purpose of this article is to produce cotton fabrics with enhanced antibacterial functions using copper oxide particles and It is planned to investigate the possibilities of using these fabrics in the technical textiles field. Thus, it is aimed to reduce the microbial infections originating from the surfaces that people have contacted many times during the day. In this article, when different particulate copper oxide chemical substances applied to the textile industry for antibacterial purposes are used changes in the performance characteristics of cotton fabrics have been investigated. For this purpose, cotton fabrics are coated with antibacterial Cu (I) O, Cu (II) O particles and isocyanate and glycidimethacrylate structures with cross-linkers. The selection of copper oxide particles as antibacterial was made by examining previous studies. Another benefit of the use of copper oxide particles in the presence of an antibacterial property it is an attempt to form an alternative to the antibacterial property provided by silver, zinc oxide and titanium oxide in previous studies. Besides, the silver used is expensive compared to other used antibacterial materials is an important problem. Zhang et al.(2008) refered to strong evidence that silver ions show cytoxidic and genotoxic effects for high organisms (including humans). After coating with Cu(I)O and Cu(II)O antibacterial agent, the tensile strength properties of cotton fabric samples increased and mechanical effects after coating with isocyanate crosslinker because it damages the fabric structure reduction in tear strength was achieved. In the FTIR spectra of the fabric after coating, the new bands would be a sign of a modification due to coating processes are occurred.
Substances or environments that inhibit bacterial growth and inhibit are defined as antibacterial. Due to the harmful and bad smell of the bacteria; the use of antibacterial materials, especially in garments and fabrics , are becoming even more important. Antimicrobial agents are defined as those that kill microorganisms such as bacteria, mold, yeast and fungi. On the other hand, it is also defined as a natural, synthetic or semisynthetic chemical that inhibits growth, proliferation or activity. The importance of the antibacterial based functional textiles is given below: In the study of transferring silver nanoparticles from antibacterial fabric to artificial sweat are connected to on amount of silver transferred artificial sweat to the initial coating, fabric quality, pH and artificial sweat formulation. In this study, the effects of silver molecules on human health were examined(1). Silver nanoparticles, silver ions exhibit bacteriocidal action when are used alone or in various combinations. By increasing the permeability of the bacterial cell membrane, the energy requirement of the cell is triggered. At this point, there is a flow of phosphate, cellular contents leak, and DNA proliferation is interrupted (2). Kathirvelu et al. (2008) investigated the self-cleaning, antibacterial and UV protection functions of the fabrics coated with TiO2 NPs at different temperatures and concentrations produced with a hydrolytic reaction starting with HNO3 and titanium tetrachloride. They found that there was no change in the self-cleaning activities of the prepared sample fabrics. However, they found that the UV protection effect was higher in PES / Cotton fabrics, woven fabrics and fabrics coated with small NPs. It was determined that woven fabrics, 100% cotton fabrics and fabrics coated with small NPs exhibited antibacterial properties at a higher level. When examined for all three functions, it was observed that the use of TiO2 in coatings made with ZnO and TiO2 is more advantageous than the use of ZnO (3). In previous studies; There is strong evidence that silver ions show cytoxidic and genotoxic effects for high organisms (including humans) (4). Performance changes and antimicrobial activity amounts of chemicals known to antimicrobial activity such as silver, triclosan, dichlorophenol, quarternary ammonium and chitosan, which are frequently used in the industry, on 100% cotton fabrics have been compared comparatively. In working with this, however, the antimicrobial fabrics produced with the specified chemicals, antimicrobial performance values after 1, 5, 10, and 20 washings were compared (5). In previous studies; antibacterial agents bonded with aluminum or titanium compounds, antibacterial surfaces treated with cotton fabrics. One of the metal compounds, oxytetracycline, tetracycline, pyrithione, or the antibacterial agent to which the process is applied by passing the same through different baths, is effective against Staphylococcus aureus bacteria. Some of the tetracycline treated fabrics continue to exhibit antibacterial activity even after 20 washes. Because of some problems encountered during the application of titanium compounds, the antibacterial activities of the aluminum compounds have been found to be more satisfactory (6).
2. Materials and Methods
In the experiments; The cotton fabric used as the material was supplied by Bossa. In the experiments; The characteristics of cotton fiber as material are given in the Table. In the study, copper(I) oxide and copper (II) oxide were used as nano and micro particle size materials in order to provide antibacterial property.
In this study, as coating chemicals; two different polyurethane binders, the cross-linker in two different structures, a antifoaming for cutting the foam formed in the coating path, an emulsion to provide homogeneous distribution of copper oxide particles in the path, dispersion material; a thickener was used to adjust the flow of the path. One of the binders is of an aliphatic polyester polyurethane structure, the another one is; the coating should contain a polysiloxane compound to increase the resistance to hard water salts and washing of the path. In this study; for the purpose of improving the activity of antibacterial treated cotton fabrics, crosslinkers were used in the coating recipe for isocyanate and glidimethacrylate structures. Antibacterial finish treatment was applied to the fabric samples according to the knife-over-roller coating method. Physical tests such as breaking strength, tear strength and abrasion resistance were applied to the fabric samples after the coating process. Besides, SEM image for the purpose of examining the morphological changes occurring on the fabric sample surfaces after coating, FTIR analysis was carried out to examine the changes in bond structure of the post-coating fabrics. Physical tests applied to sample fabrics are given in the table.
3. Conclusions and Discussion 3.1. Breaking, tearing and abrasion resistance properties of treated fabrics
It is thought that antibacterial finishing will cause a change in the strength of the positive or negative fabric breaking. The results of the tensile strength test for cotton fabrics are given in Figure 3.1. Based on the weight of the specimen, the pre-tension applied during the test was set at 5N. As shown in the figure, Cu (II) O in nano particle size was found to cause the greatest strength increase in the warp and weft direction of the coating with glidimethacrylate crosslinker.
By applying glycidemethacrylate as a cross-linker to the cotton fabric, there is more cross-linking between the fiber and the coating. Since this gives extra strength to the coated cotton fabric, no overall loss of tear strength was observed. As a result; the chemical substances containing the isocyanate group in the coating path, oxide release the CO2 gas during reactions with water, the resulting pressure of this carbon dioxide gas causes the foam to form in the polymer, which leads to reduced cross-linking in the coating and reduces the breaking strength of the coating.
Tear strength measurements were made in the weft and warp directions on each fabric sample, the percent change values of the tear strength according to the control groups are calculated and shown in Figure 3.2. Tearing in the weft direction, breaking of the warp fibers, while tearing in the warp direction corresponds to the break of the weft fibers. The highest strength loss was observed for the 1st fabric and 2nd micro particle size after coating with Cu(I)O, Cu(II)O antibacterial agent and isocyanate crosslinker 29,26% and 20,15% respectively. Particle size is constant; the highest strength loss was observed after coating with the isocyanate cross-linker. Mechanical effects after coating with antibacterial agent particle size and isocyanate cross-linker, resulting in loss of tear strength as it damages the fabric structure. The highest strength loss was observed in the first and second cumulative microparticle sizes after coating with Cu (I) O and Cu (II) O antibacterial agent and isocyanate crosslinker were calculated as 31.53% and 19.66% respectively. Particle size is constant; maximum loss of strength was observed after coating with isocyanate cross-linker. Mechanical effects after coating with antibacterial agent particle size and isocyanate cross-linker resulting in loss of tear strength as it damages the fabric structure.
3.2. SEM properties of treated fabrics
In the figure, SEM images of micro and pure Cu (I) O applied fabrics are given. Polyurethane binders used in coating process, blocked isocyanate and cross-linkers in glycidmethacrylate structure has been observed that polymerization is carried out with the surface.
3.3. FTIR properties of treated fabrics
FT-IR analysis was used to investigate the presence of the chemical bonds in the coating path structure in the applied cotton. The FT-IR spectra of the cotton fabrics pretreated in the formulations were given in blue color. The characteristic peaks of the cotton fabrics pretreated in the spectra are summarized in Table 4.1. Pre-treatment followed by micro Cu (I) O and two different crosslinkers FTIR spectra of the antibacterial coated cotton fabric are shown in Figure 4.14.a and 4.14.b. Cu (I) O and two different cross-linkers FTIR spectra of antibacterial coated cotton fabric the characteristic absorption band indicating the presence of the C = O groups in the ester groups has changed in the range of 1732-1750 cm-1. In addition, the shear characteristic band of -CH- groups is in the range of 1374-1383 cm-1 ,the strain range for C-O groups is 1083-1088 cm-1, the strain range for C-O groups is 1083- 1088 cm-1, the tensile vibrations of the -OH groups of the cotton fiber structure give wide and severe bands at 3325 cm-1. Glicidmethacrylate cross-linker with antibacterial coating path when the FTIR spectrum of the coated cotton fabric is examined; aliphatic esters in the structure of glycidmethacrylate carbonyl groups in the isocyanate structure at 1740 cm-1 appears to give a sharper peak. This gives us the antibacterial Cu (I) O chemical shows better binding of cotton fiber together with the coating path.
Pre-treatment followed by micro Cu (II) O and two different crosslinkers FTIR spectra of the antibacterial coated cotton fabric are shown in Figures 4.15.a and 4.15.b. O-H and C-H stretching in the spectrum (3333, 2910 and 2161 cm-1) O-H and C-H bending (1645, 1428 and 1315 cm- 1), C-C and C-O stretching (1160, 1107 and 1030 cm-1) The change in the transmittance band at 1645 cm -1 is due to the deformation vibration of the hydroxyl groups. After the antibacterial coating process, new bands emerged which would be a sign of modification. Particularly after coating with glidimethacrylate crosslinker the shear characteristic band for the -CH- groups is 1374-1383 cm-1, the strain range for CO groups is in the range of 1083-1088 cm-1 , while the tensile vibration bands of –CH– groups show more in the range of 2940-2949 cm-1, the stress vibration bands of CH- groups show more in the range of 2940-2949 cm-1. This holds the antibacterial Cu (II) O chemical of the glycidylmethacrylate cross-linker, indicating that the coating material is better maintained to the fiber.
Antibacterial treated textile materials are mainly medical, aesthetic and hygienic applications are spreading rapidly in various industrial fields. In this study, coating method was used to impart antibacterial activity to cotton fabrics as material and the effects of the processes are examined step by step. In the FTIR spectra after coating, new bands emerged that would indicate a modification due to coating processes. Carbonyl groups are formed on the surface of the cotton fabric after coating and copper oxide particles in the microparticle size are cross-linked to these groups. It has been observed that the breaking strength of the fabric samples increases after the coating. The binders used in the coating form a lm layer on the surface of the yarn, therefore it sticks all layers of yarn together. In case of polysiloxane based polyurethane; forming a lm layer on the outer side of the yarn, penetrates into the bers, as it allows the bers to stick together, causing an increase in the breaking strength. As a result, the copper oxide particles used in coating path depending on the glycidyl methacrylate cross-linker structure are further increases in the breaking strengths in the weft and warp direction of the fabric. In other words; chemical substances containing the isocyanate group of the coating lm, in the reactions with water, emit CO2 gas, the pressure created by the resulting CO2 gas causes the foam to form in the polymer. This causes a decrease in cross-linking in the coating and reduces the breaking strength of the coating. The H atom after coating, substituted with other atoms or groups, it forms as a C=0 functional groups. At the same time, due to the groups formed on the surface and containing oxygen, oxihijyen dation occurs in fabrics. This has been quite effective on fabric strengths. According to ISO 13937-1 test method, in the tear test on the Elmendorf device it was observed that the rupture of coated fabrics more easily than the untreated fabrics.
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