Arnau Carné-Sánchez

　Porous materials are important because they are essential in fundamental industrial processes such as gas storage, catalysis, and separation. For example, CO2 capture by porous materials is considered to be one of the most viable strategies to managing the current issue of excessive CO2 emissions into the atmosphere. The success of porous materials is dictated by the degree of control that is achieved by their pore size. The general approach to the synthesis of porous materials with controlled pore apertures is based on linking small molecules into crystalline extended networks in which the pores come from the architecture of the network. This strategy has the limitation of producing materials that are difficult to tailor morphologically, which is an important consideration for materials processing and hinders their practical application.

　We thought that we could start by building from the pore. By introducing the porous unit at the beginning of the reaction as a building block, its presence would be ensured by the components of the network and not only by the overall structure. This way, we would have more freedom to think about the final morphology of our materials and how to shape them, without worrying about crystallinity and long-range order. To do this, we used pre-formed, porous molecules as building blocks, or as we began to call them “porous monomers,” in the coordination polymerization reactions.

　Without any doubt, the moment I will never forget is the first time I saw that our molecules were successfully polymerized in the form of a purple, transparent gel. To see that the reaction we had imagined the night before occurred as we expected, and that the result of this reaction was a macroscopic material, was one of the most satisfying moments of my research career.

　Once we saw that the reaction worked we wanted to know its mechanism. This was challenging because we were a team used to working with crystalline materials and so this was the first time that we had to determine how an amorphous material was formed. We had to use and combine different characterization techniques to demonstrate that the key to our polymerization technique was the formation of a kinetically trapped molecule. The characterization of these molecules is challenging as they are not very stable in time and are difficult to crystallize. We solved the puzzle by combining UV-VIS spectroscopy to determine the coordination of the linker with the porous monomer, using light scattering to see its size evolution, and NMR to determine its composition.

　Definitely this work is a turning point in my career. This project gave me the opportunity to know these “porous monomers.” I realize that these molecules offer us the freedom to design porous materials free from the restriction imposed by conventional porous crystalline materials. I intend to use this freedom to fabricate new soft materials which marry the exceptional processability of organic polymers with the controlled porosity of porous monomers to achieve soft matter that is both permanently porous and amenable to materials processing. These materials would not only be scientifically relevant but would also represent a step forward in the implementation of supramolecular microporous materials for real world applications.

　I am currently a postdoc researcher at the Catalan Institute of Nanoscience and Nanotechnology (ICN2) in Barcelona. The experience which I acquired at iCeMS was key to achieving my current position and also helped me to gain scientific independence.

　iCeMS is a great place to do research. It is a multidisciplinary research center where one has the opportunity to exchange ideas with fellow researchers in different fields. I advise everybody working in iCeMS to take advantage of this to learn about other scientific fields. iCeMS retreats are a good opportunity for that!

*All the information on this page, including the researcher’s affiliation, is current at the time of the interview.