Electrospun Polymer Nanofibers

Arkadii Arinstein

• Publisher: Jenny Stanford Publishing
• Year: 2017
• Print ISBN: 9789814745277
• eBook ISBN: 9781315340951
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Biology

Discussing the electrospinning process, the book covers in great depth the current research interest in nanoscience and nanotechnology, especially electrospinning of polymer nanofibers. The main distinction of the proposed book from others devoted to the electrospinning process is in the consideration of the problem in question from the physical point of view. Focusing on physical aspects, the book contains physical basics regarding the unique features of electrospun polymer nanofibers and the electrospinning resulting in fabrication of these nanofibers.

Contents

Preface

1. Introduction

Part I The Necessary Basics

2. Nano-objects

2.1 What “Nano-objects” Mean?

2.2 Physical Properties of Nano-objects Compared to the Bulk

2.2.1 Mechanical Properties

2.2.2 Thermodynamic Properties

2.2.3 Size-Dependent Behavior of Nano-objects

3. Experimental Examination of Electrospun Polymer Nanofibers

3.1 Experimental Examination of Nanofiber Mats

3.2 Experimental Examination of Single Nanofiber

3.2.1 Atomic Force Microscopy

3.2.2 Tensile Test

3.2.3 Resonance method

Part II Nanofiber Fabrication

4. Electrospinning of Polymer Nanofibers

4.1 Spinability of Polymer Solution

4.2 Hydrodynamics of Electrospinning

4.3 Hydrodynamic Instabilities of Spinning Jet

4.4 Solvent Evaporation and Polymer Solidification

4.5 Post-fabrication Relaxation

4.5.1 Experimental Observations

4.5.2 Preliminary Estimates

4.5.3 Kinetic Equations Describing the System Evolution

4.5.4 Pressure and Velocity Distribution

4.5.4 Meniscus Moving (Kinetics of Solvent Evaporation)

4.5.6 Experimental Proof of Post-fabrication Relaxation

4.6 Post-processes in Electrospun Tubular Nanofibers

4.6.1 Formation of Gas Bubbles

4.6.2 Buckling of Tubular Nanofiber

5. Polymer Dynamics in Semi-dilute Solution During Electrospinning

5.1 Theoretical Model Describing Stretching of a Polymer Topological Network

5.1.1 Initial State of Entangled Semi-dilute Polymer Solution

5.1.2 Axial Stretching of an Entangled Polymer Network during Electrospinning

5.1.3 Radial Contraction of an Entangled Polymer Network during Electrospinning

5.2 Experimental Observations of Polymer System Evolution under High Stretching

5.2.1 Radial Contraction of an Entangled Polymer Network during Electrospinning

5.2.2 Stretch-Induced Phase Separation in Polymer Solutions

5.3 Disentanglement of Polymer Topological Network in Further Stages of Electrospinning

5.3.1 Multiple Necking

5.3.2 Short Fiber Fabrication

5.3.3 Simulation of Disentanglement Processes with the Help of a Pulley System

5.3.4 Spontaneous Symmetry Breaking in a Thermodynamic System of Pulleys

5.3.4.1 Mathematical description

5.3.4.2 Motion analysis

5.3.4.3 The energy balance

5.3.4.4 The thermodynamic system

5.3.4.5 Numerical simulations

Part III Unique Properties of Electrospun Polymer Nanofibers

6. Size-Dependent Behavior

6.1 Size-Dependent Behavior of Electrospun Nanofibers

6.1.1 Size-Dependent Behavior in Mechanical Properties

6.1.2 Size-Dependent Behavior in Thermodynamic Properties

6.2 Do Surface Effects Explain the Unique Elasticity of Polymer Nanofibers?

6.3 Concept of Near-Surface Layer

6.4 Confinement Concept

6.4.1 Physical Model of the Phenomenon

6.4.2 Theoretical Estimations

7. Explanations of the Size-Dependent Behavior by a Physicist: Some Possible Reasons and Mechanisms

7.1 Confinement Mechanism of Electrospun Polymer Nanofibers Reinforcement

7.1.1 Structure of an Amorphous Nanofiber Polymer Matrix

7.1.2 Mathematical Model for Polymer Nanofiber Elongation

7.1.3 Scaling Properties of the Size-Dependent Elastic Modulus of Electrospun Polymer Nanofibers

7.2 Shifting of Melting Point for Semi-Crystalline Polymer Nanofibers

7.2.1 Theoretical Background

7.2.2 Experimental Results and Discussions

7.3 Nonequilibrium State of Polymer Matrix Inside Electrospun Nanofibers

7.3.1 Orientation of Polymer Macromolecules as a Result of Electrospinning

7.3.2 Stretching of Polymer Matrix of Electrospun Nanofibers

7.3.3 Orientation versus Stretching under Confinement

Final Remarks

Bibliography

Index

Preface

“By making something absolutely clear, someone...

Table of contents

• Cover
• Halftitle
• Title
• Copyright
• Table of Contents