Naturally Inspired Multi-layer Composite Films on Planar and Modulated Surfaces

Abstract

Biomimetics is a field of engineering which aims to mimic what has been present in nature. High ceramic-content biomineralized structures like abalone nacre and antler bone have a layered-architecture at the nano- and microscale, consisting of a majority phase of elastic reinforcement platelets or fibrils embedded in a minority viscoelastic phase of proteins and polysaccharides. The synthesis of such systems artificially has attracted widespread interest, with a goal to designing tough composites with adaptable mechanical properties The results of synthesis pathways towards fabricating such materials are reported herein, including a chemical infiltration route, where growth occurs inside precursor organic multilayers. The structural and mechanical similarities with natural biomineralized systems will also be explored. TGA was used to calculate the rate of mineralization within multilayer films, micromechanical-testing techniques were implemented to compare synthetic composite’s mechanical performance with natural biomineralized tissues like nacre. Finally, the mineralization process in three-dimensional multi-layer assembly is discussed using nano-patterning techniques. To gain a better reading on the presented work and contents discussed, an introduction followed up by comprehensive literature review over polymer assemblies and composite natural and man-made film are presented. Following this, the experimental section containing materials, methods and instruments are described in Chapter 4. In Chapter 5, infiltration process in layer-by-layer films on planar films producing flat substrates is reported. Chapter 6 describes peculiarities of multilayer films made of biopolymers and the chemical infiltration process in such structures, while Chapters 7 and 8 present the research data and analysis of multilayer films with chemical infiltration made modulated nano-imprinted surfaces using both synthetic and biological polymers assessing the bio-mimicking mineralisation in these systems. Finally, Chapters 9 and 10 present conclusions and future outlook.