The study discussed the synthesis of silica sol using the sol-gel method, doped with two different amounts of Cu nanoparticles. Cotton fabric samples were impregnated by the prepared sols and then dried and cured. To block hydroxyl groups, some samples were also treated with hexadecyltrimethoxysilane. The average particle size of colloidal silica nanoparticles were measured by the particle size analyzer. The morphology, roughness, and hydrophobic properties of the surface fabricated on cotton samples were analyzed and compared via the scanning electron microscopy, the transmission electron microscopy, the scanning probe microscopy, with static water contact angle (SWC), and water shedding angle measurements. Furthermore, the antibacterial efficiency of samples was quantitatively evaluated using AATCC 100 method. The addition of 0.5% (wt/wt) Cu into silica sol caused the silica nanoparticles to agglomerate in more grape-like clusters on cotton fabrics. Such fabricated surface revealed the highest value of SWC (155° for a 10-μl droplet) due to air trapping capability of its inclined structure. However, the presence of higher amounts of Cu nanoparticles (2% wt/wt) in silica sol resulted in the most slippery smooth surface on cotton fabrics. All fabricated surfaces containing Cu nanoparticles showed the perfect antibacterial activity against both of gram-negative and gram-positive bacteria.

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In this study, the effect of dicarboxylic acid chain length on the amount of TiO2 nanoparticles (TiO2NPs) adsorption-produced self-cleaning property and washing durability on cotton fabrics were investigated. First, cotton fabric samples were treated with three kinds of dicarboxylic acids--oxalic, succinic, and adipic acids--and then dipped in TiO2NP solution with a certain concentration. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was used to investigate bonds formation between dicarboxylic acid groups and hydroxyl groups of cellulose, and a scanning electron microscope (SEM) was applied for the analysis of surface morphology in specimens. Drop absorbency time was determined for samples using the AATCC TM 79:2000. Washing stability and the amount absorption of TiO2NPs were determined by weighing and absorption spectrophotometry procedures, and the stain removal evaluation was conducted to assess the self-cleaning property. Results showed that all of the dicarboxylic acids used in this experiment improved the amount of TiO2NPs absorbed onto cotton samples and their durability to washing. In addition, color variation of samples treated with oxalic acid after 180 min of UV irradiation and drop absorbency time for samples treated with succinic acid were significantly increased by about 126 and 600%, respectively. The best durability was obtained from adipic acid, while a better self-cleaning property was obtained from oxalic acid.