AUTEX2019 – 19 th World Textile Conference on Textiles at the Crossroads, 11-15 June 2019, Ghent, Belgium ELECTROSPINNING OF SILICA NANOFIBERS WITHOUT CARRIER POLYMER FOR ADVANCED ENGINEERING APPLICATIONS E. Loccufier 1 , J. Geltmeyer 1 , D. Esquivel², D.R. D’hooge 1 , K. De Buysser³, K. De Clerck 1 1 Department of Materials, Textiles and Chemical Engineering, Faculty of Engineering and Architecture, Ghent University, Technologiepark 70A, 9052 Zwijnaarde, Belgium ²Department of Organic Chemistry, University of Cordoba, Edificio Marie Curie, E14014 Cordoba, Spain ³ Sol-gel Centre for Research on Inorganic Powders and Thin Films Synthesis (SCRiPTS), Department of Chemistry, Faculty of Sciences, Ghent University, Krijgslaan 281 S3, 9000 Ghent, Belgium Eva.Loccufier@UGent.be ABSTRACT Nanofibrous materials produced via electrospinning are characterized by a high porosity, large specific surface area, and high pore interconnectivity and, therefore, show potential for, e.g., separation and filtration. The development of more inert nanofibers with higher thermal and chemical resistance extends the application field. Silica nanofibrous membranes produced by direct electrospinning of a sol –gel solution without a sacrificing carrier meet these challenging demands. A combination of hydrolysis and condensation reactions of the tetraethoxysilane (TEOS) precursor, results in dense silica nanofibers with superior mechanical properties, without a rough and uneven surface, allowing the use in advanced engineering applications. Key Words: ELECTROSPINNING, SILICA, SOL-GEL SYNTHESIS, HYDROPHOBICITY, VISCOSITY 1. INTRODUCTION Electrospinning of polymer nanofibers has been studied extensively and has shown to be possible via stable, reproducible and controllable processes [1]. Studies on ceramic nanofibers are less comprehensive. Ceramic materials are hard and inert and are therefore known for their excellent properties such as high temperature resistance and chemical inertness. These promising characteristics allow ceramic nanofibers to be investigated for various applications such as biological applications, filtration, composites, catalysis, etc [2–4]. Electrospinning is a simple and versatile technique for the production of polymer and ceramic nanofibers. Using electrostatic forces, continuous nanofibers can be obtained having controllable compositions and controllable diameters below 500 nm [5,6]. The combination of electrospinning and the sol –gel technique is relatively recent but has already been used to obtain ceramic nanofibers with various compositions such as SiO2, TiO2, Al2O3 and ZrO2. So far, the most common technique to obtain ceramic nanofibers is the electrospinning of solutions containing a sol–gel precursor and an organic polymer, added to control the rheological properties of the solution [7–9]. Afterward, this polymer is removed via a thermal treatment to obtain pure ceramic nanofibers. Recently, our group successfully produced ceramic silica nanofibers without the need of this sacrificing polymer [10–12]. In contrast to other work, in which a well-spinnable organic polymer is mixed with a metal oxide precursors to facilitate the electrospinning process, direct electrospinning of a sol –gel solution of a tetraethyl orthosilicate (TEOS) precursor eliminates the need for a post-production removal of the added organic polymer. This results in dense silica nanofibers with superior mechanical properties, without a rough and uneven surface of the fibers [13,14]. In addition and even more important, it offers the benefits of a simple, more tunable material design. 2. MATERIALS AND METHODS