Mechanical Modeling Analysis Of Nanofiber Membranes For Tissue Engineering Scaffolds

Silk fibroin(SF) / poly(ε-caprolactone)(PCL) blend nanofiber membranes were manufactured by electrospinning with using formic acid solvent in this thesis. The tensile mechanical behavior of single fibers in these membranes were tested by the Agilent T150 Universal Testing Machine. The results showed that the property of the fibrous tensile mechanics are diverse from each other. Their stretch curve manifest similar shape. When the fiber is stretched, it will proceed elastic stretching first, with a young modulus on a scale of 0.5 to 3 GPa. After that, the stress is not increases linearly, it gains slowly. This behavior is similar with polymer materials with large scale. After analysis and curve fitting, the functional equations of the single nanofiber tensile behavior were get. This is advantageous to the study of tensile properties of nanofibers.Using scanning electron microscopy(SEM), the structure of blend nanofiber membranes were tested, and through the Image-Pro Plus® software to carry on the analysis of nanofiber membrane structure parameters. According to the properties of the electrospinning membranes, ignoring secondary factors, retain the main factors of influence on its mechanical properties do the analysis. Combine the electrostatic spinning membrane structure parameters and the equation of single fiber mechanical properties functions, the theoretical model was constructed to analyze the mechanical properties of the membrane. Models can be divided into uniaxial tensile model and biaxial tensile model, and has carried on experiments to test the model’s simulation results.The SF/PCL blend nanofiber membranes’ uniaxial tension process was studied. By the conditions of idealized, ignoring secondary factors, the equation used to describe the membranes’ tensile deformation process was built. Equation can be used to provide the theoretical explanation of electrostatic spinning nanofiber membranes mechanical properties change with blended ratio change. In order to validate the rationality of the model, using the KES-G1 Multi-Purpose Tensile Tester tested the uniaxial tensile properties of nanofiber membranes.Electrospinning nanofiber membranes’ biaxial stretching property have more reference value for its practical application. Change with biaxial stretching ratio, the deformation of the membrane is different. Therefore a electrospinning nanofiber membrane biaxial tensile theory model was built to describe this process. this model have certain help to the electrospinning membranes’ deformation analysis and the application. Using the KSM-BX5450 Compact Biaxial Tensile Tester test the fiber membranes’ biaxial tensile behavior proved that the model has certain rationality.In particular, the electrospinning membranes’ biaxial tensile experiment of stretching rate ratio 1 ? 1, after calculation modeling, showed that this way has the ability of testing single nanofibrous performance. This approach in the case of very fine to test fiber, could get more accurate data than the other direct mechanical test method. With different fiber by adjusting the conditions to obtain, this method also can be used to study the scale effect of nanofibers. Supplement the current experimental conditions of nanofibers with under 100 nanometers diameter mechanical properties test.