Fabrication of superhydrophobic and antibacterial surface on cotton fabric by doped silica-based sols with nanoparticles of copper

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

Thermal properties of conductive nanocomposite core-shell filament yarns

380-386<span style="font-size:9.0pt;mso-fareast-font-family:SimSun;mso-bidi-font-family: " times="" new="" roman";mso-fareast-language:zh-cn;mso-bidi-language:th"="" lang="EN-GB">Thermal properties of conductive nanocomposite core-shell filament yarns have been investigated as a structure of a textile for the purpose of generating heat from an electrical power source. A fine copper monofilament is coated with a composite of polypropylene and various filler content of copper nanoparticles by an injection molding process to study the thermal properties of yarn as a function of filler shell content. Electrical analogy of Fourier’s law in thermal circuit has been used for development of a theory for thermal parameters. Then theoretical approaches are compared with modeling results obtained by ANSYS software and experimental results. Results reveal that although increase in filler content causes an increase in electrical and thermal conductivity of composite shell of yarn, heat generation in shell is negligible compared to that in core. Furthermore, results reveal that optimum value of filler fraction for desirable heat transfer is achieved at = 0.065. </span