Electrospinning of ternary composite of PMMA-PEG-SiO2 nanoparticles: Comprehensive process optimization and electrospun properties

Abstract

Electrospinning has been realized to be a promising method for creating nano-composite fibers due to its significant growth for producing innovative composites with advanced applications. In this method a polymeric solution subjected to an electrohydrodynamic process and slim charged liquid jet is formed inside a high potential electric field. The high voltage enables the production of continuously long fibers on a collector surface. Addition of different polymers and NPs to the one-component solution to modify the physicochemical characteristic and decorating the surface of electrospun fibers has proven to be challenging and imperative for many fields especially novel bioengineering and filtration applications. In this study, the effects of major parameters on the fabrication of electrospun fibers were extensively investigated. At the first step, formation of nanofibers on the surface of collector and optimization of process parameters were determined based on the mean diameter of resulting fibers, through SEM (Scanning Electron Microscopy) images. The optimum values for concentration, applied voltage, the distance between the tip of needle and collector, and flow rate determined to be 10 wt%, 12 kV, 20 cm, and 0.6 mL h−1, respectively. Afterwards, the hydrophilicity of fibers was modified by adding different poly (ethylene glycol) (PEG) concentrations (20, 30, and 40 wt%) to the polymeric solution. The contact angle analysis revealed that the poly (methyl methacrylate) (PMMA) and 30 wt% PEG fabricated fibrous mat exhibited a better wettability and 71.61% lower hydrophobicity compared to pure PMMA electrospun mats. In the next step, silica NPs (nanoparticles) were introduced to the polymeric solution of electrospinning in the form of an IPA (isopropanol)-based collide solution. The dispersed solution-based addition of silica NPs prevented the aggregation state of NPs in the nanofibers. The addition of silica nanoparticles also changed the thermal and mechanical properties of the ternary composite, which were analyzed in TGA (thermogravimetric analysis) and tensile tests. Noteworthy, the addition of 30% PEG and silica NPs increase 3 times the tensile strength and around 2 times elongation in comparison with pure PMMA electrospun mats. These results highlight that the hybrid composite leads to a promising new electrospun mat for filtration and bioengineering applications.