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
The preparation of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide-functionalised polysilsesquioxane (Si-DOPO)-coating was described and its flame retardant efficiency for cotton fabric was thoroughly investigated. The 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide–vinyltrimethoxysilane (DOPO–VTS) was synthesized and applied to cotton fabrics at different concentrations using a sol–gel process. The structure of the synthesized DOPO–VTS was characterized using FTIR spectroscopy and nuclear magnetic resonance spectroscopy. The characteristics of the Si-DOPO coatings formed on the cotton fibres were investigated using X-ray photoelectron spectroscopy, time-offlight-secondary ion mass spectrometry and scanning electron microscopy. The flame retardant properties of the Si-DOPO-coated cotton samples were evaluated by thermogravimetric analyses, vertical flame spread tests and cone calorimetry analyses. The Si-DOPO coating increased the thermo-oxidative stability of the cotton fibres by increasing the stability of the protective char and inhibited cellulose fibres degradation. The Si-DOPO coating did not decrease the time of flaming combustion but did completely stop the vigorous combustion of the fibres. The results also suggest that the flame retardation by the Si-DOPO coating is due to the quenching of active radicals from the decomposing cellulose and the cellulose phosphorylation by the DOPO component as well as the silicon oxide formation by the silsesquioxane component on the fibre surface. These findings indicate that the flame retardant efficiency of the Si-DOPO coating can be ascribed to the combined activity of phosphorus acting in both gas and condensed phases and silicon acting in the condensed phase.
COBISS.SI-ID: 3109744
Textured cotton substrates are drawing interest as a new class of non-wetting and non-fouling materials. We investigated the effect of temperature, solvent and substrate presence on the in situ particle growth process for the production of self-cleaning, wash-resilient and air-permeable superhydrophobic and oleophobic cotton textiles. By comparing the size of particles grown in solution with those grown on cotton fibres, we show that the uniform solution growth follows a faster reaction rate. In general, the cotton surface favours the production of hierarchical structures that provide a liquid-repellent behaviour, when combined with low surface free energy nanocoatings, such as an organically modified silane precursor or perfluoro ethers. In addition, the influence of an oil-based lubricant on the pinning effect was evaluated. On the basis of these findings, we present a low-cost method to manufacture nanostructured coatings to achieve optimal roughness and liquid repellence.
COBISS.SI-ID: 5767706
Silica aerogel is a nano-porous material with a very low density and the lowest thermal conductivity of any known solid material. The use of pure silica aerogel is limited because it’s rigid and fragile nature. Silica-aerogel composite, a silica-aerogel reinforced with fibrous matting, are being considered as an isolative material for footwear. The suitability for such applications has been investigated in the study presented in this article. Experiments were conducted on a silica aerogel composite with a thickness of 2.7 mm and mass per unit area near 500 g/m2. Spreading of crushed silica aerogel dust into surrounding was successfully resolved with a lamination of silica aerogel composite with a solid membrane which is usually used in footwear as a waterproof and permeable barrier. Thermal conductivity of laminated silica aerogel composite was comparable to that of the non-laminated one and amounted to 16 mW/(mK). Water vapour permeability of laminated silica aerogel composite was controlled by two layers of membrane and was 81.8% lower than the WVP of the non-laminated composite. Silica aerogel composite were subjected to 30,000 cycles of flexing to study the impact of the irreversible crushed structure of silica aerogel on the permeability and thermal resistance of laminated and non-laminated samples. It was found that flexing did not have a statistically significant effect on the thermal resistance and did not damage the membrane on the laminated composite. In the study was confirmed that the newly developed laminate has potential applications in apparel and footwear for extreme temperature environments.
COBISS.SI-ID: 3166064
A knit fabric from regenerated bamboo fibres was bleached with four different PAA bleaching processes: with only PAA, with PAA or H2O2 in combination with TAED, and with H2O2 in combination with arylesterase enzymes. The knit fabric was also bleached conventionally with H2O2 for comparison purposes. Whereas the conventional H2O2 process was carried out at 90℃ and in highly alkaline pH media, the bleaching processes with PAA were carried out at 65℃ and in neutral to slightly alkaline pH media. The bleaching processes with PAA have a strong whitening ability that is comparable to that of the conventional bleaching process with H2O2. The highest whiteness index of the bamboo knit fabrics bleached by different processes was measured after the bleaching process with PAA in combination with TAED (WI 71.2). Overall, with PAA bleaching processes, bamboo knit fabrics with a high degree of whiteness, high water absorbency, and high tenacity can be obtained with low water and energy consumption.
COBISS.SI-ID: 3093872