Green and Sustainable Chemistry

What is green and sustainable chemistry (GSC)? Immediately one thinks of polymers, pollution, recycling, packaging, solvents, aquatic life, toxicity, PFAPs, and many more topics, including the twelve principles of green chemistry developed by Paul Anastas and John Warner in 1998. These principles guide decisions made by chemists to engineer “chemical products and processes that reduce or eliminate the use and generation of hazardous substances”(https://greenchemistry.yale.edu/about/principles-green-chemistry). Hazardous not only to humans, but to the planet as well. So, shall students memorize the twelve steps and other related facts to learn green chemistry? No, but perhaps what we know about learning science can assist us with this new adventure.


If we are attempting to guide novices to think like experts, we must have students use their knowledge in similar ways experts do. When we think about science education, we want students to use their knowledge to predict and explain phenomena—the objective of science. GSC uses scientific principles to weigh constrains and benefits, which aligns with engineering more than science. Therefore, we could re-conceptualize GSC education to involve students using their knowledge to make decisions about the reactants, products, and processes involved in a chemical synthesis. These decisions will be impacted by the phenomenon under review and reflect the constraints and goals of the stakeholders. Of course, the phenomenon is not necessarily green, but the decisions about those phenomena will be.
Why incorporate that into a curriculum? Well, our world is on fire, and if we want the next generation of scientists and citizens to make informed decisions regarding the safety of our planet when engaging in chemistry, then preparing students to make those decisions should be a part of our curriculum.


So how do you incorporate a complex socio-scientific issue, such as PFAS exposure, into a curriculum? Well generating a causal mechanistic explanation for such phenomenon is inherently difficult given the context. The molecular-level chemistry may be hidden beneath the many layers that a real-world example brings to the explanatory ‘table’ (Pazicni and Flynn 2019). Furthermore, the context in which student knowledge is activated has implications for what knowledge gets activated and how that activated knowledges gets acted upon. (Hammer et al. 2005)
Scaffolding student activities may be one way to support students in activating knowledge that is productive for the given context. Prior scholarship has shown that scaffolding does impact activation of knowledge, however we do not understand nor have evidence of how scaffolding will impact student knowledge within the context of socio-scientific issues. I am sure some instructors assume that students are incapable of reasoning about such complex issues. However, I disagree.

Before we can support students in developing casual mechanistic explanations, first we must ask, do you need to have students generate a causal mechanistic explanation to make decisions about the greenness of a synthesis? One could have students use an online tool to generate a report about the greenness of specific reactants, solvents, etc., then determine which is greener, all without thinking about the underlying scientific principles at play (Reyes et al. 2023). While such information may be useful, it depends on the subsequent use of and application of the knowledge gained through those online tools. If causal explanations are not formed, then the holistic view of the socio-scientific issues would not be obtained, arguably the main reason for introducing socio-scientific phenomenon. Such a holistic view is often labeled as systems thinking. What is systems thinking? Well, there is no agreed upon definition (Orgill et al. 2019). However, it lies in contrast to a reductionist perspective often taken in the natural sciences. The general idea is to think about all the parts of the phenomenon: the chemical, the social, the legal, the ethical, the cultural. Therefore, I believe that to engage in GSC, one has to engage in systems thinking.


What does that look like? I have no clue.


References


Hammer, D., Elby, A., Scherr, R. E., & Redish, E. F. (2005). Resources, framing, and transfer. In J. P. Mestre (Ed) Transfer of Learning from a Modern Multidisciplinary Perspective., 26.


Orgill, M., York, S., & MacKellar, J. (2019). Introduction to Systems Thinking for the Chemistry Education Community. Journal of Chemical Education, 96(12), 2720–2729. https://doi.org/10.1021/acs.jchemed.9b00169


Pazicni, S.; Flynn, A. B. Systems Thinking in Chemistry Education: Theoretical Challenges and Opportunities. J. Chem. Educ. 2019, 96 (12), 2752–2763. https://doi.org/10.1021/acs.jchemed.9b00416.


Reyes, K. M. D., Bruce, K., & Shetranjiwalla, S. (2023). Green Chemistry, Life Cycle Assessment, and Systems Thinking: An Integrated Comparative-Complementary Chemical Decision-Making Approach. Journal of Chemical Education, 100(1), 209–220. https://doi.org/10.1021/acs.jchemed.2c00647