Development of multifunctional nanofibrous materials via electrospinning
Electrospun nanofibers are very attractive for many applications including functional textile, biomedical, energy, sensor, biotechnology, food packaging and filtration due to their large surface area to volume ratio, pores in nano range, high encapsulation efficiency, low basis weight and design flexibility for physical/chemical modification. Cyclodextrins (CD) are applicable in several industries such as pharmaceutical, cosmetic, textile, functional food and filtration owing to their intriguing ability to form non-covalent host-guest inclusion complexes (IC) with a variety of molecules. Furhermore, atomic layer deposition (ALD) technique can be effectively used to deposit metal oxides onto temperature-sensitive polymeric substrates. In this dissertation, initially, CD-IC of bioactive compounds (vanillin, eugenol, geraniol, triclosan) having antibacterial and/or antioxidant properties were incorporated into electrospun nanofibers via electrospinning. Higher thermal stability, controlled/sustained release, enhanced solubility and functionality of these compounds have been provided by CD-IC. These specific properties of CD-IC have been combined with high surface area and nanoporous structure of electrospun nanofibers. Thereby, the resulting functional nanofibrous materials can be quite applicable in active food packaging in order to prevent foodborne diseases by providing safety/quality of nutrition and extending shelf life of food. On the other hand, CD incorporated electrospun nanofibers have also been developed for efficient removal of unpleasant odors, hazardous organic waste molecules from air by taking advantages of not only high surface area and nanoporous structure of nanofibers but also IC capability of CD. Since CD are water soluble, CD polymer (CDP) coated onto nanofibers have been also obtained for molecular filtration of polyaromatic hydrocarbons from aqueous environment. Moreover, metal oxides (ZnO, TiO2) have been deposited onto electrospun nanofibers via ALD in order to develop efficient and energy saving innovative nanofibrous membrane materials for water purification and waste treatment. Thus, organic pollutants in water have been effectively disintegrated by photocatalytic activity of these nanofibrous filtering materials having high surface area. Overall, the multifunctional electrospun nanofibrous materials have been improved by incorporating CD-IC or CD into the fiber matrix; by coating either CDP or metal oxides (ZnO, TiO2) onto fiber surface to enhance possible applications of nanofibers for filtration, food packaging, functional textiles, etc.