Empirical model to simulate morphology of electrospun polycaprolactone mats

Abstract

This work is the first to report a study aimed at generating 3D virtual geometries that represent the microstructure of an electrospun fibrous mat comprised curly fibers. Polycaprolactone (PCL) mats are considered in our study as an example of such fibrous structures. We started with simulating the formation of PCL filaments and observed good agreement between the predicted and measured fiber diameters. In the absence of quantitative information about the shape of a curly PCL fiber, we treated these fibers as arrays of beads arranged on epitrochoid profiles. We then used the fiber deposition diameter and velocity in a mass-spring-damper (MSD) model to generate 3D fibrous geometries comprised hundreds of such curly fibers. The damping and spring constants in the MSD model were obtained through calibration with experimental data reported for single electrospun PCL nanofibers. The size of the epitrochoid-like fibers was obtained empirically through matching the average thickness of the resulting mats with those measured experimentally. With the calibrated code, we studied the effects of electrospinning conditions on the porosity of PCL nanofiber mats. It was found that increasing the voltage or decreasing the needle-to-collector distance results in PCL mats with thicker fibers, and consequently, lower porosities.

Effect of starch ratio and compatibilization on the viscoelastic behavior of POE/starch blends

“…Using viscoelastic models are the ways of studying the viscoelastic behavior of the materials . The creep behavior of the blends was studied by the standard linear solid model (SLS) in the Maxwell form.…”

Synthesis and characterization of carbon black modified by polylactic acid (PLA‐g‐CB) as pigment for dope dyeing of black PLA fibers

“…Besides spinning, drafting process was another important process to produce PLA fiber, which would greatly improve the properties of the fiber . Drafting temperature should be higher than glass temperature of PLA polymer.…”

“…Besides spinning, drafting process was another important process to produce PLA fiber, which would greatly improve the properties of the fiber. [35][36][37] Drafting temperature should be higher than glass temperature of PLA polymer. As shown in Figure 7(a), breaking strength of dope dyed black PLA fiber was first increase and then decrease when the drafting temperature was increased from 65 to 95 C. At low temperature, the PLA polymer chain was restricted and would not be preferably aligned along the fiber axis during drafting process.…”

PVDF/TiO2/graphene oxide composite nanofiber membranes serving as separators in lithium‐ion batteries

“…A lithium‐ion cell consists of a positive electrode, a negative electrode, an electrolyte, and a separator . With the development of the production and research on polymeric nanofibers many research works concerning the usage of composite nanofiber mats as electrodes and/or separators in LIBs have been published . The only inactive compound in the electrochemical reaction is the separator for LIBs, that is, a permeable membrane between the electrodes, which plays a vital role in preventing the electrodes to physically come into contact with one another .…”

“…2,6 With the development of the production and research on polymeric nanofibers many research works concerning the usage of composite nanofiber mats as electrodes and/or separators in LIBs have been published. [7][8][9][10][11][12][13][14][15][16] The only inactive compound in the electrochemical reaction is the separator for LIBs, that is, a permeable membrane between the electrodes, which plays a vital role in preventing the electrodes to physically come into contact with one another. [17][18][19] The separator provides channels for the lithium ions to move between two electrodes, yet it disallows the electrons to pass through.…”