Mathematical Modeling of the Relation between Electrospun Nanofibers Characteristics and the Process Parameters

Abstract

Electrospinning, the most favorable process of obtaining nanofibers, is capable of processing solution or melt polymers, ceramic materials or metals in many morphological variants, thus providing diverse functionalities. The chapter reviews the main ways in which nanofibers' characteristics can be influenced by solution parameters, process parameters and ambient conditions, afterwards focusing on the role of some of the most significant electrospinning parameters (applied voltage, flow rate, nozzle to collector distance) on the diameter of the nanofibers. Experimental studies to model the influence of process parameters in the case of electrospinning polyetherimide solutions are presented. Response surface methodology and MATLAB simulation software have been used to obtain the mathematical models that indicate the most favorable parameters.Electrospun nanofibers have many applications in filtration processes, bio-medicine (tissue engineering, drug delivery, scaffolds and wound healing), in energy devices and sensors, depending on their morphological characteristics. The morphology of the fibers obtained through electrospinning is governed by many factors. These factors are related to the polymer solution characteristics, process and ambient parameters. Main electrospinning parameters affecting nanofibers morphologyThe morphology of the nanofibers obtained through electrospinning is influenced by many factors. These factors can be grouped into three categories: polymer solution characteristics, process parameters and ambient parameters. Knowing the way these factors influence the electrospinning process, it becomes easier to obtain nanofibers with controlled structure and required functions [1, 2]. Polymer solution ViscositySome of the key parameters of the electrospinning process are the surface tension and the viscoelastic properties of the polymer solution [3][4][5]. The correct choice of the concentration of the polymer solution has a decisive effect on these processes, respectively, on the characteristics of the obtained nanofibers (diameter and morphology) [6,7].It is generally accepted that the viscosity of the polymer solution is the decisive parameter of the process, including the possibility of electrospinning and the characteristics of the nanofibers. In order to make electrospinning possible, the viscosity must be in a relatively narrow range. At very low viscosity values, the polymer filaments break and polymer droplets are produced, while at very high viscosity values, the polymer solution cannot pass through the nozzles and electrospinning does not take place. The area of optimum viscosity depends essentially on three parameters: the nature of the polymer, the nature of the solvent and the concentration of the polymer solution.There is a direct proportionality relationship between the concentration of the electrospun polymer solution and the diameter of the obtained nanofibers, but the value of the ratio of proportionality varies within relatively large limits.Electrospinning Method Used to Create F...

Associated Polymers, Solvents and Doping Agents to Make Polyaniline Electrospinnable

“…When the composition is further modified by the addition of AgNO 3 , three-component electrospun composite fibers are obtained [51]. Enzymes, such as urease, were also used as dopants for PANI [52][53][54][55][56][57][58]. The urease is fixed in the PANI-PVP matrix, which results in an increase in the sensitivity of the nanofibers to ammonia.…”

“…Alternatives to obtain the electrospinning solution/dispersion (associated polymers and solvents) Despite the great potential of PANI, its processing remains a difficult problem to handle, due to its insolubility in ordinary organic solvents. Because of this, PAN is hardly processed alone by electrospinning, and various other polymers are mixed with PANI in the spinning solution [14][15][16][17][18]. Approximately 1% solubility was observed in N-methyl, 2-pyrrolidone (NMP), which also acts as a plasticizer [19][20][21][22][23].…”

Fibrous Polymers in Textile Prospect for Tissue Engineering Development

“…biodegradability degree, absorption and immune responses. At the same time [13], nanofibres or nanoparticles toxicity depends on particles morphology [16][17][18][19][20][21][22][23][24][25][26]. There are many factors that can affect the final properties of the basic material.…”

“…In this case, one needs access to some of the following procedures [55,[59][60][61][62]: electrospinning, wet or melt spinning, heat-induced phase separation, self-assembling, multilayer techniques and others, to produce nanofibrous or microfibrous structures using natural or synthetic biodegradable polymers. One has tried to produce nanometer assembles through electrospinning, gauging, tensioning, self-assembly, extraction, vapor polymerization.…”

Flexible Acrylate Dentures versus Chromium Cobalt Removable Partial Dentures - a Viable Therapeutical Solution

“…This material is claimed to have greater resistance to wear, flexibility, fatigue strength, dimensional stability, wear characteristics and solvent resistance. It also matches the color of the tooth and the color of the gingival tissue, has low weight and heat resistance [19][20][21][22][23]. There is a small number of papers in the literature on the efficacy * email: raluca_baciu2002@yahoo.com; zanaamaseluta@yahoo.com; ioanamartu@yahoo.com of this material as a substitute for the chromium-cobalt alloy and it needs testing in different clinical situations to allow for universal acceptance [24].…”