Dr. Fernando Ruipérez
Research Lines

My research plan involves theoretical studies relevant in polymer science. Basic research activities addressing synthetic methods to control the chemical composition and distribution of the polymers, their assembly and other processing methods are main challenges toward the comprehension of these materials, which nowadays play a major role in the development of new technologies. Thus, issues such as structural properties, reactivity and design of catalysts for improved catalysis provide with a better understanding of polymerization reaction mechanisms. Besides, our society needs to develop new forms of clean and sustainable energy in order to ensure the development and life quality of future societies. Therefore, new polymeric materials with applications in energy, such as organic batteries or organic light emitting diodes, among others, have emerged in a high number of innovative structures whose singular properties indicate a bright future. In this context, theoretical calculations would enhance the progress of the experimental work and also be of great help in the prediction of polymer properties. The main research lines are the following:

1. Self-healing materials

Self-healing materials are a class of materials that are able to autorepair and recover the original properties after damage. These materials are based on reversible chemistry involving dynamic covalent bonds, non-covalent weak interactions or a combination of both. When damage occurs, the generated interfaces at the fractured surface contains a multitude of unbound covalent and non-covalent bonds the may recombine, closing the gap and healing the damaged site. Disulfide compounds play a crucial role in several fields including materials science due to the dynamics and reversibility of the S-S bond cleavage. Thus, in this research line, new disulfide-based compounds are designed to improve the self-healing properties of these materials, by investigating the prevalent reaction mechanism as well as the main interactions among molecular chains in the material. Besides, polyurea-based self-healing materials are also investigated, including mechanochromic properties and reaction mechanisms, in collaboration with the Department of Materials of IK4-CIDETEC. Finally, the study of changing the disulfide bond by a diselenide is also currently ongoing. 

2. Redox and optical properties of organic diradicals

The growing interest in organic singlet open-shell diradicals relies in the potential applications they show in organic electronics such as ligh-emitting diodes or photovoltaics. They exhibit relevant properties like high-yield singlet-fission processes or low-lying excited states. However, there is a lack of fundamental research focused to unveil the redox behavior of these open-shell systems, a key feature for the design of new organic electrode materials, which show several advantages compared to metal-containing meterials in terms of flexibility, weight and environmental issues. Therefore, this line of work involves the study of optical and redox properties, at the molecular level, of organic polymeric materials which are relevant in the development of new organic and metal-free optical devices and batteries. 

3. Design of ionic liquids as organocatalysts for polymer recycling

Conventional chemical methods for recycling polymers include methanolysis, hydrolysis and glycolysis. These processes are usually catalyzed by metal acetates, metal oxides or solid superacids, among others. Besides, high pressures and temperatures are needed and the product is difficult to separate from the catalyst. Recently, ionic liquids have emerged as environmentally friendly alternative catalysts. However, due to the high cost and the low reaction rates, their industrialization has been hampered. Thus, the aim of this line of work is the improvement of the reaction conditions, enhancing the reaction rates and exploring new ionic liquids as efficient catalysts for the depolymerization reactions of polyesters, polycarbonates and polyamides. The rational design of organocatalysts will improve the performance of known reactions and also open the door for new organocatalysis techniques in polymerization reactions, which is still an incipient field that will acquire high importance in the next years. 

4. Polymer/graphene composites for selective CO₂ capture

Several technologies already exist to capture CO₂ and liquid absorption is the most extensively used, but it presents serious drawbacks, such as the corrosive nature of the amines and the high energy required. Physical adsorption avoids these issues and, currently, the design of new high-performance solid sorbents is an active area of research, however polymer-inorganic composites have not been explored for this aim yet. In this line of work is proposed, a detailed study of the interactions between polymers and reduced graphene oxide, as well as between the composite structures and CO₂ will be carried out. The quantum chemical simulations may shed light on structure, dynamics and interactions at the molecular level that will allow an a priori selection of suitable polymers for the synthesis.