Nanofibers are among the most widely used nanomaterials due to their unique physical and chemical properties. When fiber diameter reaches the nanoscale, exceptional properties such as a very high surface-to-volume ratio, high efficiency compared to known materials, and good flexibility can be expected. Unique features of these materials include flexibility, tissue engineering applications, thermal insulation, filtration, energy conversion and storage, smart textiles, and protection against diseases including coronaviruses. High-throughput nanofiber production (production rate), controlling production costs, equipment used, manufacturing quality, and maintaining quality standards remain challenging. Current challenges in research and industry include the cost-effective production of nanofiber fabrics for respiratory filters, filters in water desalination systems, and wound dressings. In addition to the numerous limitations regarding the type of solvents, their high cost, and harmful evaporation for the environment, the biodegradability of polymers and drug loading, rapid fiber fabrication and formulation, and its ability to produce nano/microfibers are key factors in their practical application in various fields such as medicine and filtration. This research, after designing and adding several new parts to improve system performance, focused on the fabrication and eva‎luation of a nano/microfiber production system using a solution blowing method with rotating air pressure without a needle. Then, by performing functional tests of the system, the feasibility of producing fibers reinforced with nano/micro materials such as titanium dioxide, zinc oxide, and curcumin was investigated. Furthermore, the optimal parameters of the system for the production of polyvinyl alcohol and polyvinyl pyrrolidone nano/microfibers with various solvents such as water, ethanol, and isopropyl alcohol, and the preparation of fiber fabrics were determined. In the second phase, using the best sample, mechanical, structural, and thermal characterization tests, as well as water and oil contact angle tests, were performed. Several fiber collection methods were investigated in this research. By employing several parallel strands of nylon yarn to feed the polymer solution, the efficiency and production capacity increased significantly, which is a considerable advantage compared to other methods, including electrospinning. The results showed that increasing the solution concentration and feed rate also increases the fiber diameter. The diameter of the fibers produced with this system in the polyvinyl alcohol fiber fabric sample was 650 nm. With an excessive increase in the solution feed rate, the Taylor cone becomes unstable, the necessary stretching is not performed, and as a result, no fibers are produced, and the polymer solution is ejected drop by drop. The maximum stress applied in the tensile test in the polyvinyl alcohol fiber fabric sample was 3.6 MPa, and the maximum elongation was 125%. Also, the elastic modulus of this sample, from the linear region of the stress-strain curve, was calculated to be 400 MPa. In this system, by increasing the gas temperature using a hot air chamber, the evaporation rate of the solvent increases, and completely dry and high-quality fibers are obtained.

مهدي كاروان

عليرضا فدائي تهراني , سعيد نوري خراساني