Microscopy Study of Morphology of Electrospun Fiber-MOF Composites with Secondary Growth
- PDF / 1,105,289 Bytes
- 7 Pages / 612 x 792 pts (letter) Page_size
- 21 Downloads / 148 Views
Microscopy Study of Morphology of Electrospun Fiber-MOF Composites with Secondary Growth Mitchell R. Armstrong, Bohan Shan, Bin Mu* *Chemical Engineering, School for Engineering of Matter, Transport, and Energy, Arizona State University. 501 East Tyler Mall, Tempe, Arizona, US 85287. Email: [email protected] ABSTRACT Microscopy studies were performed over a series of metal-organic-framework (MOF) imbedded electrospun fibers. Analysis of as-spun fibers revealed five different MOF particlefiber imbedded morphologies including complete particle encasement, over-filled, surface-bound, welded, and agglomerated. To mitigate issues with fiber breakup during electrospinning (ES) due to MOF particle incorporation, secondary growth method was used. Secondary growth was performed on both Matrimid and polysulfone fibers impregnated with a MOF, ZIF-8, in either water or methanol solvents. Results show that when water was used, crystal formation was limited to formation on the top layer of the fiber mat due to hydrophobicity. When methanol was used in place of water, MOF crystal growth occurred in a patchwise manner, where crystals grow across fibers and span the entire fiber mat. From this work, it was determined that successful secondary growth of MOF imbedded electrospun fibers can be accomplished when particles are either highly exposed along the fiber surface for adequate exposure to solvent, or the solvent used promotes reactant penetration into the polymer to allow access to the seeded MOF crystals.
1. INTRODUCTION Functionalized fibers, and particularly electrospun nanofibers, have emerged as a strong materials platform for designing composite materials for a variety of applications including tissue engineering, biosensors, protective clothing, and immobilization of enzymes [1]. This is largely due to the high tunability, surface areas, and strength of these fibers [2]. Electrospinning (ES) is one of the most effective methods to produce cell scaffold, which has similar morphology as fibrillar structure of the extracellular matrix [3, 4]. Fu et al. reported the synthesis of magnetic iron oxide nanoparticles imbedded tri-block copolymer electrospun fiber composite as a potential dermal dressing, which can prevent tumor recurrence and facilitate healing [4]. Glucose sensor consists of polyvinyl alcohol styrylpyridinium polymer, carboxylated multiwall carbon nanotubes and glucose oxidase was fabricated via ES reported by Lagarde et al [5]. Electrospun fibers enhanced sensor sensitivity through its outstanding contact surface area and incorporated carbon nanotubes. The electrospun polyacrylonitrile/Ag-AgBr@Bi20TiO32 composite fibers exhibit excellent photocatalytic and antibacterial activities [6]. Another emerging class of porous materials explored to fabricate the electrospun composites is metal-organic frameworks (MOFs) [7–11]. Researchers have produced MOF functionalized electrospun nanofibers (MOFNF) with various applications such as separation [12], sensing [13], and catalysis [14]. Sultana et al. reported the fabrication of
Data Loading...
