The use of graphene in building construction Potentiality and questions

Graphene is a material that ignites the imagination of researchers and fascinates the entire scientific community because, right from the start, it represented the emblem of the possibilities of research. With its extraordinary properties it won the ad honorem title of “material of wonders” in a very short time, opening a new historical era in the scientific progress of two-dimensional materials. The uproar aroused by graphene has been recorded precisely since 2010, following the awarding of the Nobel Prize in Physics to the two scientists of the University of Manchester, who isolated it, for the first time, from its constituent, carbon. The two scientists, Andrei Gejm and Konstantin Novosëlov, thus attested to a material that seemed a chimera until then. Since then, the study on the potential of graphene and its possible uses has never stopped. The empirical confirmation of the existence of graphene has revolutionized the world of physics, influencing many other sciences and scientific disciplines like wildfire, including architecture. At the same time as the Nobel Prize was awarded, the nanomaterial jumped to the headlines, enthusing scholars, entrepreneurs, universities and institutions. The European Union, for example, invested a billion euros in research on graphene in 2013, establishing the Graphene Flagship, a new form of a joint and coordinated research initiative on an unprecedented scale. Numerous institutions, universities and research bodies immediately began to identify possible scenarios and fields of application for the neo-material according to its best performance, given its exceptional physical properties. From a quick analysis of its physical peculiarities and strengths, one immediately realizes that graphene can be used in many applications in different sectors, from engineering to medicine, from electronics to the energy sector. Graphene opens the way to a new era of high-performance materials, which heralds a future in which material performance will play an increasingly crucial role in multiple industrial sectors concerning the urgent environmental issue we are experiencing.

Architecture has acknowledged the entry of graphene into its disciplinary sphere, in parallel through the scientific and academic production of application projects and the industrial production of graphene-based application prototypes. At the industrial level, there are already various types of graphene-based products on the market, such as cement that conducts electricity or improves thermal insulation. For the most part, these are construction products that take advantage of the excellent physical characteristics of graphene, used as an additive, to enhance the performance of existing building materials.

On the academic perspective, the most relevant projects derive from the IaaC - Institute for Advanced Architecture of Catalonia - which, being a Fab Lab, produced, between 2016 and 2019, a series of architectural projects as experiments guided by design. Combining theoretical knowledge, design and empirical experience, the projects examined by the IaaC are excellent design references on the topic under consideration, helping to reduce the distance between the architectural project and contemporary design needs, between thought and the product. In this sense, projects such as "Synapse"(fig.1), "Pro_Skin", "Flux In", "Graphene Composite" (fig.2), "Clayphene" (fig.3), use the material experimentation of graphene to develop alternative architectural solutions projected towards the future of the architectural practice. Some of these projects are based on the design of smart materials and intelligent interfaces that are digital and physical at the same time, incorporated into the materiality of the architectural prototype.

In the wake of IaaC's references, the research aims to fully understand how material experimentation, in this case with graphene, can influence design. We can define new uses and potential of building materials by prototyping an architectural project, improving and innovating traditional construction materials, or designing new ones. The topic of materiality is the thematic focus of the research, on which the entire research activity has evolved up to now.

The research method was divided into two key moments: the theoretical part, the qualitative method, and the experimental part. During the theoretical phase, in addition to the literature review and data collection, it was necessary to introduce a market analysis on graphene to understand which market segments and the most promising products are. Downstream of this, a clearer picture has emerged on the possible developments of a graphene prototype in architecture, excluding materials and design paths that would not have made significant progress in scientific research. In this regard, the framing action of the most encouraging field of action has shown that the target market segment is related to green building. Environmental sustainability in architecture is a collateral theme to research that will be given more space during the material development of the experimental application. A hypothesis of approaching the objectives of environmental sustainability in architecture is to put the relationship between design and material back at the center, in which the performance of the materials acquires a priority value.

Downstream of a methodological approach made up of a first review of the main literature on the use of graphene in architecture, market and feasibility analyses, and the involvement of experts and interlocutors from different disciplines, such as chemistry and materials engineering, research has focused on the hypothesis of improving the performance of existing building material. Based on the degree of technological advancement of graphene recorded up to now in architecture, the choice of the "killer" application fell on the use of graphene as an additive in addition to raw earth as a building material. The resultant of this experimental approach will give birth to a new raw earth-based material with enhanced characteristics compared to the starting material. Based on the initial predictions of the stakeholders involved, the addition of graphene to the raw earth will enhance the physical properties of the raw earth by virtue of a performance improvement. A special water-based dispersion of graphene will be verified and tested together with three types of raw earth - ABS, T2 and TC - the most common types used today, to obtain the optimal compositional mix in terms of expected results. The tests will be carried out at the Department of Chemistry, Materials and Chemical Engineering of the Politecnico di Milano, under Prof. Giovanni Dotelli's guide and with the cooperation of the expert in clay, Prof. Sergio Sabbadini - both Professors affiliated with the Politecnico di Milano. - while the graphene masterbatch was produced by the graphene producer, European leader in the sector, GrapheneUp, strategic partner of the present research. As an expert in nanotechnology and graphene, GrapheneUp supports the research activity through its knowledge of various graphene applications in different sectors. His recent experience in the construction sector supports the idea that already from the first tests, it will be possible to obtain quantifiable performance benefits. Preliminary tests have already started at the end of February 2022 and concern standard test protocols for new additives and soil characterization. While from March onwards, a series of tests will begin, mainly concerning the performance investigation of some physical properties. The phase of execution of the tests will be followed by a phase of evaluation of the results from which the limits of the research and the consequent purposes will be established. Once the framing of the material evaluation has been completed, the type of graphene material product developed will be exhaustively defined. At the same time, a set of tools and a methodology are emerging as a keystone for critical reading of the experimental project. The introduction of the design-driven research approach, together with the activity of prototyping architectural design, will be the key to interpreting a valuable contribution to research. Some of the tests that will be performed in the laboratory are exploratory tests, such as the one on electromagnetic shielding, which arise spontaneously from the pure scientific spirit of the researchers involved. We do not yet know if some evidence will be decisive or crucial; however, the research topic offers the opportunity to investigate new frontiers and open new food for thought. As suggested by the book “The new architecture of science: learning from Graphene” (Kostya S. Novoselov, Albena Yaneva. 2020), the discovery of graphene has ignited the enthusiasm of researchers, encouraging them to push beyond the limits known and studied so far.

In conclusion, the research activity, through the study of graphene, aims to achieve the following objectives:

• contribute to the development of scientific research on the use of graphene in building construction;
• develop an industrial, architectural prototype with graphene;
• create an unpublished compendium on graphene and architecture;

Concerning the experimental part of the research, a further objective is also closely linked to the impacts of developing an application to graphene in architecture. In other words, the research study also wants to encourage a more conscious use of non-renewable resources in construction, to favor a rethinking of the entire supply chain of raw materials for the sustenance of the construction industry, but above all to urge a return to use of “poor” construction materials, in this case, raw earth, to offer a contemporary interpretation by rethinking it as a precious resource.