Stable Mesoscale Nonwovens of Electrospun Polyacrylonitrile and Interpenetrating Supramolecular 1,3,5-Benzenetrisamide Fibers as Efficient Carriers for Gold Nanoparticles

Abstract

The immobilization of metal nanoparticles without agglomeration and leaching within composite nonwovens is often challenging and of great importance, for example, for catalytic applications. In this study, we prepared composite nonwovens based on electrospun polyacrylonitrile (PAN) short fibers and supramolecular terpyridine-functionalized benzene-1,3,5-tricarboxamide (BTA1) nanofibers by a sheet-forming wet-laid process. The formation of an interpenetrating and entangled network of supramolecular BTA1 nanofibers and PAN short fibers results in mechanically stable mesoscale nonwovens. Because of the peripheral terpyridine substituents of the BTA1, nonaggregated gold nanoparticles (AuNPs) could be immobilized efficiently in the composite nonwovens. The functionality of the resulting AuNPs-loaded composite nonwovens was verified by catalytic reduction of 4-nitrophenol to 4-aminophenol as a standard model reaction. The AuNPs-loaded PAN/BTA1 composite nonwovens showed high catalytic activity, reusability, and excellent stability.

Functional Mesostructured Electrospun Polymer Nonwovens with Supramolecular Nanofibers

“…Fibrous supramolecular composites featuring a high surface area with distinct functional groups on the surface are highly suitable for metal nanoparticle capture from solution, [4,43] rendering our mesostructured nonwovens with a barbed wire-like morphology and functional N,N-diisopropylaminoethyl groups promising candidates.…”

“…This includes for example personal protective equipment such as face masks with improved moisture permeability, antiviral and antibacterial properties as well as fibrous membranes with self‐sustained long‐range electrostatic adhesion for energy generation and compact composite sheets for catalysis. [ 1–4 ]…”

“…For this, we employed the wet‐laid technique using a mixture of short electrospun PAN and supramolecular nanofibers based on BTAs with functional terpyridine side groups in the periphery resulting in compact functional nonwoven sheets. [ 4 ]…”

“…This includes for example personal protective equipment such as face masks with improved moisture permeability, antiviral and antibacterial properties as well as fibrous membranes with self-sustained long-range electrostatic adhesion for energy generation and compact composite sheets for catalysis. [1][2][3][4] Conventional polymer micro-and nanofibers are achieved by top-down methods such as melt blowing, [5] centrifugal spinning, [6][7][8] and electrospinning. [9][10][11] These spinning processes are wellestablished and typically allows to create free-standing nonwovens or nonwovens deposited on top of a support.…”

“…For this, we employed the wet-laid technique using a mixture of short electrospun PAN and supramolecular nanofibers based on BTAs with functional terpyridine side groups in the periphery resulting in compact functional nonwoven sheets. [4] Besides these kinds of nonwovens, whose morphologies are a result of the combination of different fiber types, nature uses an intriguing approach based on hierarchically mesostructured fibers as present in plants like thistles and animal feathers. Such hierarchically mesostructured fibers comprise a middle strand with off-standing thinner branches and feature a superior property profile.…”