Development of biopolymeric patterned thin films
Banta, Russell A.
University College Cork
Patterned surfaces are a crucial technology in material science. According to the OECD (Organisation for Economic Co-operation and Development), over 20% of emerging technologies (in renewable energy, biomedical devices, smart devices and anti-reflective surfaces) utilize patterned surfaces. The widespread use of these materials is because nanoand microscale patterns on a surface impart specific physicochemical properties to that surface. Thus, being able to control the nano and micro- surface patterns allows for modification of a material’s surface properties, which in turn allows for tailorable materials for technological needs.However, currently the fabrication methods of almost all the necessary technologies of everyday life are unsustainable, including the current generation of patterned surfaces, which rely on inefficient manufacturing methods (in certain instances), and unsustainable feedstocks (petrochemically derived polymers) that require expensive extraction. We are living through an unprecedented sustainability crisis. Almost every functional system humans rely on – energy, transport, food, technology, communications – is dependent on fundamentally unsustainable materials and practices. To alleviate this, we must produce as much of the critica components of our technologies as sustainably as possible. Patterned surfaces are just such a critical component. To ensure that things like future renewable energy technologies are truly renewable, we must ensure that their fundamental components are sustainable. Patterned surfaces are produced by phase separating synthetic polymer blends or block copolymers (BCPs), Figure 1.1. Little work has been done in producing patterned surfaces using sustainably sourced materials. This thesis describes the production of patterned surfaces using waste biopolymers. Biopolymers, unlike synthetic polymers, are renewable, biocompatible, biodegradable and are some of the most abundant materials on the planet. Utilizing waste biopolymers, agricultural waste can be minimized using a circular economy system, while simultaneously reducing our reliance on petrochemicals. Not only are biopolymers more sustainable but their innate physico-chemical characteristics will permit larger scale pattern features and superior, application-specific functionalities. The aim of this project was to produce patterned thin-films (PTFs), using biopolymer blends. To produce these biopolymer blend thin films, a technique called segregative phase separation was used to promote pattern development using a protein and polysaccharide biopolymer, in an acidic solvent. These patterned films have similar size profiles and chemistries to synthetic polymer blends, and demonstrate that we need not rely on petrochemically derived polymers when producing patterned surfaces.
Biopolymer , Blend , Phase separation , Protein , Polysaccharide , Surface patterning , Humidity , Metal , Lithography , Chelation , Pattern transfer
Banta, R. A. 2020. Development of biopolymeric patterned thin films. PhD Thesis, University College Cork.