Porous Fibers Templated by Melt Blowing Cocontinuous Immiscible Polymer Blends

Abstract

We report a scalable melt blowing method for producing porous nonwoven fibers from model cocontinuous polystyrene/high-density polyethylene polymer blends. While conventional melt compounding of cocontinuous blends typically produces domain sizes ∼1–10 μm, melt blowing these blends into fibers reduces those dimensions up to 35-fold and generates an interpenetrating domain structure. Inclusion of ≤1 wt % of a block copolymer compatibilizer in these blends crucially enables access to smaller domain sizes in the fibers by minimizing thermodynamically-driven blend coarsening inherent to cocontinuous blends. Selective solvent extraction of the sacrificial polymer phase yielded a network of porous channels within the fibers. Fiber surfaces also exhibited pores that percolate into the fiber interior, signifying the continuous and interconnected nature of the final structure. Pore sizes as small as ∼100 nm were obtained, suggesting potential applications of these porous nonwovens that rely on their high surface areas, including various filtration modules.

Extensibility-Enriched Spinnability and Enhanced Sorption and Strength of Centrifugally Spun Polystyrene Fiber Mats

“…Inventing and optimizing spinning techniques for high throughput, cost-efficient production of fibers from both commercial and novel polymers has driven extensive academic and industrial research for over a century. − Many applications in tissue engineering and healthcare, environmental safety and remediation, energy storage and production, and separations require nonwoven fiber meshes or membranes that simultaneously satisfy multiple design needs and functionalities, including ultrahigh surface-to-volume ratio, suitable permeability, mechanical and chemical stability, and appropriate wettability. − Despite significant progress in making nonwovens with electrospinning (ES), challenges with scalability, the need for a high voltage source, limited solvent choices, and low production rates are driving the search for viable alternatives. − ,− Here, we focus on addressing the spinnability challenge using an alternative method called centrifugal force spinning (CFS). Although similar methods were first patented over a century back and then used to make cotton candy and glass wool, intense activity to make polymeric fibers using this technique began a decade back under many names: centrifugal spinning, force spinning, rotary spinning, or rotary jet spinning. − ,− In contrast with melt-CFS used for making cotton candy or glass wool from viscous fluids and/or reactive CFS that uses monomer-based spinning dope, , we focus on solution-CFS that requires the processing of rheologically complex polymer solutions.…”

Potential Loading of Virgin Coconut Oil into Centrifugally‐Spun Nanofibers for Biomedical Applications

“…Various techniques have previously been reported to fabricate nanofibers, such as centrifugal jet spinning (CJS) [82][83][84][85][86], electrospinning [40,87,88], self-assembly [89][90][91], melt blowing [92][93][94], template synthesis [95,96], islandin-the-sea spinning [97][98][99], phaseseparation [100][101][102], and drawing [103]. A summary of the advantages and disadvantages of various nanofibers production techniques is given in Tab.…”

Fiber Engineering Trifecta of Spinnability, Morphology, and Properties: Centrifugally Spun versus Electrospun Fibers

“…The choice of PEO as the model system presents an opportunity to benefit from the extensive fundamental studies of its crystallization behavior, 23,24 rheological response 25−28 (including by the coauthors 29−33 ), and fiber formation using electrospinning (ES) and centrifugal force spinning (CFS), as discussed herein. Despite the relative success of ES for producing submicron and nanoscopic fibers using various polymers, the need for high voltage sources, low production rates, and limited range of spinnable formulations has driven the search for alternatives [4][5][6][7]10,34,35 including CFS, 6,35−37 melt-blown, 38,39 template synthesis, 40 phase separation, 41 and CO 2 laser supersonic drawing, 42 among others. However, designing applicationready fibers involves multifaceted challenges 1−6,21,28,34−56 related to correlating the processing parameters and formulation properties, including rheological response to the trinity of spinnability, morphology, and properties that we refer to as the fiber engineering trifecta.…”

“…Despite the relative success of ES for producing submicron and nanoscopic fibers using various polymers, the need for high voltage sources, low production rates, and limited range of spinnable formulations has driven the search for alternatives − ,,, including CFS, ,− melt-blown, , template synthesis, phase separation, and CO 2 laser supersonic drawing, among others. However, designing application-ready fibers involves multifaceted challenges − ,,,− related to correlating the processing parameters and formulation properties, including rheological response to the trinity of spinnability, morphology, and properties that we refer to as the fiber engineering trifecta. CFS features a spiraling jet ejected from a fast-rotating spinneret or nozzles under the influence of centrifugal forces.…”