This research aimed to optimise the structure of the multifunctional water- and oil-repellent, antibacterial, and flame-retardant hybrid polysilsesquioxane coating to increase its washing fastness to cotton fibres. In the pre-treatment process, pre-prepared Stöber silica particles were applied to the fibres by a pad-dry-cure process followed by the in situ generation of a tetraethyl orthosilicate (TEOS)-based particle-containing polysiloxane layer. A three-component equimolar sol mixture (MC), which included 1H,1H,2H,2H-perfluorooctyltriethoxysilane (SiF), 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (SiQ) and P,P-diphenyl-N-(3-(trimethoxysilyl)propyl) phosphinic amide (SiP) in combination with two different concentrations of TEOS (T and 3T) or organocyclotetrasiloxane 2,4,6,8-tetrakis(2-(diethoxy(methyl)silyl)ethyl)-2,4,6,8-tetramethyl–cyclotetrasiloxane (T4) as crosslinkers, was applied to the pre-treated cotton fibres by a pad-dry-cure process. The functional properties of the coated samples before and after repeated washing were investigated by the water (W) and n-hexadecane (C16) static contact angle as well as water sliding (roll-off) (α) angle measurements, antibacterial tests, thermogravimetric analyses and burning behaviour studies. The results showed that the inclusion of T4 into the MC sol increased the washing fastness of the coating to a significantly greater extent than the inclusion of T, and the washing fastness even further it increased if silica particles were deposited on the fibres in the pre-treatment process. The structural optimisation of the coating also led to the improvement of the functional properties of the coating, which exhibited the “Lotus effect” ((W) = 161° and α = 4°) and simultaneously demonstrated high antibacterial activity (the R values for E. coli and S. aureus were 81.6 and 100 %, respectively), enhanced thermo-oxidative stability and “glow” retardancy. The only weakness of the optimised coating is the impairment of its oleophobicity.
COBISS.SI-ID: 3354736
The cellulose fabrics made from 100 % cotton with antibacterial and UV protective properties were successfully created by loading of Ag/TiO2 nanocomposite during and after dyeing with yellow, red and blue reactive dye. Blank dyeing (dyeing with all chemicals except dye) was performed to show that reactive dyes have an ability to increase the adsorption and adhesion of Ag/TiO2 nanocomposite on cotton fabrics. The colour of the samples before and after washing and exposure to artificial light was measured by reflectance spectroscopy. The presence of nanocomposite on samples was confirmed by scanning electron microscope. The increased adsorption capacity of cotton towards Ag/TiO2 nanocomposite due to the presence of reactive dyes was confirmed by measuring the quantity of silver using inductively coupled plasma mass spectroscopy. The same samples showed excellent UV protective properties with UV protection factor (UPF 50+), and excellent antibacterial properties against E. coli and S. aureus. Due to a good adhesion of nanocomposite on samples where loading of nanocomposite and dyeing with reactive dye was performed simultaneously, the samples retained their excellent protective properties after repetitive washing cycles.
COBISS.SI-ID: 3231856
To achieve colourful and antibacterial textiles using ecologically friendly processes, cotton and bamboo rayon knitted fabrics were treated using radio-frequency low-pressure water vapour plasma and dyed with the extract of Fallopia japonica (Japanese knotweed) rhizome. Optical emission spectroscopy (OES) was used to observe plasma during the sample treatment and scanning electron microscopy (SEM) to study morphological changes of samples. The adsorption of F. japonica on cellulose substrates was studied by measuring the colour (CIE L*a*b*) and colour yield (K/S) of dyed samples. The antibacterial properties against Escherichia coli and Staphylococcus aureus were tested as well. The results show that water vapour plasma induces weak etching effect on the surface of the cellulose samples, since water molecules in plasma dissociate to produce hydroxyl radicals and oxygen atoms. Plasma-treated samples had higher dye uptake, and better antibacterial properties against S. aureus. The samples did not have antibacterial properties against E. coli.
COBISS.SI-ID: 29466151
In this study, a long-lasting highly oleophobic “lotus effect” was developed on the cotton fabric surface by fabricating the hierarchically roughened bumpy-surface topography with a low surface energy. The process was performed in two stages, where the three following approaches were used for the first stage: (i) surface incorporation of Stöber silica particles, which were prepared in advance with average diameters of 50 ± 15, 230 ± 20 and 780 ± 30 nm, (ii) in situ generation of a particle-containing polysiloxane layer, (iii) in situ generation of the particle-containing polysiloxane layer on the cotton fibres with the previously incorporated Stöber silica particles. In the second stage, the nanometre-scale structures with a simultaneous reduction of surface free energies were obtained using the sol–gel processing of fluoroalkylfunctional water-born oligosiloxane (FAS). The static contact angle measurements with water θ(W) and n-hexadecane θ(C16) and sliding (roll-off) (α) angle measurements with water on the FAS-coated surfaces show that the in situ created particle-containing polysiloxane layer on the cotton fibres with surface-incorporated Stöber particles remarkably minimized the solid/water interface and maximized the water/air interface, which enabled the fabrication of the artificial “Lotus effect”. This effect was characterized with the extremely low roll-off angle, i.e., α = 2°, and was accompanied by an exceptionally high oleophobicity, where θ(C16) approaches the value of 150°. The noteworthy high durability of these coatings successfully preserves their outstanding performances even after two laboratory washings that correspond to ten domestic washings.
COBISS.SI-ID: 3255152
Low-temperature application process for the functionalization of cotton fibres with organic–inorganic hybrid materials is proposed using titanium tetraisopropoxide (TiP) and aminopropyltriethoxysilane (APTES) to achieve bacteriostatic photocatalytic properties. Proposed application process enabled preservation of amorphous TiO2 within TiP/APTES hybrid film, which influenced the achievement of synergistic bactericidic activity between amino functional groups of APTES polymeric system and TiO2, reflecting 60% increase of bacteriostatic activity of theTiP/APTES modified cotton fabric in comparison to one component APTES coating. The presence of Si–O–Ti bonding within the sol–gel hybrids between silica and titania and Si–O–C– bonding between the hybrid materials and the cotton fibres was proven. Strengths of the introduced low-temperature process are: (i) creation of a hybrid film throughout the entire volume of the fibres, and not solely on their surface, (ii) excellent wash durable photocatalytic bacteriostatic activity of new hybrid film, which was not achieved in the case of one-component APTES film, (iii) simple feasibility and technological acceptance of the proposed application process.
COBISS.SI-ID: 3153520