Designing and Incorporating Green Chemistry Courses at a Liberal

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Designing and Incorporating Green Chemistry Courses at a Liberal Arts College To Increase Students’ Awareness and Interdisciplinary Collaborative Work Renuka Manchanayakage* Department of Chemistry, Susquehanna University, Selinsgrove, Pennsylvania 17870, United States S Supporting Information *

ABSTRACT: Two green chemistry courses have been introduced into the liberal arts curriculum at Susquehanna University. Green chemistry was integrated into an existing course, Chemical Concepts, and offered as Green Chemical Concepts for nonscience majors. This course is designed to instill an appreciation for green chemistry in a large and diverse group of students. The course follows a separate interactive lecture and laboratory format, consists of an atom economy workshop, and ends with students’ collaborative group presentations on “life cycle assessment of a greener product”. A chemistry elective, Green Chemistry, was also developed and offered to science majors. It is important that students from various areas of science be exposed to green chemistry, as many innovative science discoveries are made today through interdisciplinary collaborative work. This course follows a unique workshop style, integrating lectures with laboratory activities, and ends with student proposal presentations on “designing a greener product or process”. These courses will help students in all areas make intelligent decisions in the future and explore solutions based on green chemistry principles, which will eventually serve a greater community, thereby supporting the liberal arts mission. KEYWORDS: Curriculum, Green Chemistry, Student-Centered Learning, First-Year Undergraduate/General, Upper-Division Undergraduate, Inquiry-Based/Discovery Learning

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INTRODUCTION Liberal arts education provides students with a broad knowledge of the wider world (e.g., science, culture, and society), as well as in-depth study in a specific area of interest. Integrating green chemistry across the liberal arts curriculum may increase the level of communication and awareness among students from different majors about growing environmental and global issues. Current students and ultimately future scientists, policy makers, and members of the general public may then be motivated and feel responsible to protect our resources so future generations are not compromised by today’s actions. This supports the liberal arts mission, which requires students to develop a sense of social responsibility. Many institutions have introduced green chemistry into the chemistry curriculum.1−3 Two green chemistry courses have been introduced at Susquehanna University. Green chemistry was integrated into the existing 100-level, general education chemistry course Chemical Concepts and offered as Green Chemical Concepts for nonscience majors. A 300-level workshop-style chemistry elective, Green Chemistry, was developed and offered to science majors.

the needs of the present without compromising the ability of future generations to meet their own needs”.4 Green Chemical Concepts covers sustainability from a chemistry perspective. This course illustrates how chemistry plays a central role in developing the knowledge and tools for society not only to meet our basic needs for food, clean water, and medicine but also to address growing challenges such as clean energy, environmental pollution, and global warming. Green Chemical Concepts is designed to instill an appreciation for green chemistry in a large and diverse group of students who may make ethical, policy, or business decisions regarding our health or environment. Regardless of their specialization area, students in the course Green Chemical Concepts can learn to become more informed citizens, thereby supporting the liberal arts mission. Course Format

Green chemistry elements are integrated into the existing general education chemistry course, Chemical Concepts, and offered as Green Chemical Concepts. This is a 100-level, 14week course offered for nonscience majors who are required to complete a four-credit science course. The course consists of separate lecture and laboratory format, and laboratories meet once a week. The basic chemical principles are introduced using interactive lecture format, and green concepts and applications

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GREEN CHEMICAL CONCEPTS: A COURSE FOR NONSCIENCE MAJORS Many students today are concerned about the sustainability and well-being of our planet. Sustainability is defined as “meeting © XXXX American Chemical Society and Division of Chemical Education, Inc.

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Collaborative Group Projects: Life Cycle Assessment of a Greener Product or Process. The collaborative group project was developed on the basis of the concept of life cycle assessment.15,16 The project is intended to make students aware of the health and environmental impacts of products, and processes, and enhance oral presentation skills and team work abilities. In this assignment, each team of three students selects a greener product or process already existing in the market. Throughout the semester, the students study the life cycle assessment of the greener product or process, comparing it with that of the conventional product. At the end of the semester, the results are presented to the class using PowerPoint group presentations. The presentation is 30 min long followed by 10− 15 min for questions. The presentation should include an introduction of the green product or process and its applications, along with a complete life cycle assessment. The impact of the greener product on the environment, human health, and economy should be addressed. The presentation should end by discussing any challenges associated with the long-term viability of the greener product or process. Each group presentation is evaluated by the instructor and students using presentation evaluation forms based on motivation, preparation, organization, content, depth of analysis, quality of visual aids, delivery, transition and coherence, and ability to answer questions. It is worth noting that the student comments and evaluations on the green chemical concepts course were extremely positive and encouraging. The outcome of green chemical concepts was a motivation to design and offer a new green chemistry course as an elective for upper-level science majors.

are then integrated into each topic throughout the semester (Table 1).5,6 After each green chemistry topic has been Table 1. Lecture Format for Green Chemical Concepts Lecture Topics overview and introduction chemical accounting chemicals and materials

Chemical Concepts introduction to chemical principles, properties of matter, atomic structure, and chemical bonding chemical reactions and acid base chemistry introduction to organic chemistry

polymers and plastics energy applications of chemistry

introduction to fossil fuels and nuclear chemistry chemistry of air pollution introduction to biochemistry and enzymes chemicals used in everyday life

Green Concepts (Documentary Film DVDs Used in Discussions)10 introduction to green chemistry (Human Footprint) atom economy: how much do we waste? greener methods in organic synthesis and life cycle assessment biodegradable plastics (Addicted to Plastic) renewable energy (Solar Energy) cleaning up the air (Global Warming) using enzymes to achieve sustainability going green at home and garden (Silent Spring)

introduced, student viewpoints and perspectives are explored through class discussions. Supplemental materials such as journal articles and documentary film DVDs on some green chemistry concepts are used to facilitate their discussions.7−10 The small class size helps all students to participate in weekly discussions. The laboratory experiments are part of the course and used to illustrate some of the concepts, reactions, and sustainable methods presented in lecture. Students learn to perform basic laboratory techniques correctly and to use modern equipment and instrumentation. They maintain a comprehensive notebook throughout the semester and critically evaluate and present scientific data through completed worksheets. Students are assessed by their lab performance, lab notebook, and worksheets.

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GREEN CHEMISTRY: A COURSE FOR SCIENCE MAJORS This course was introduced with the purpose of integrating green chemistry across the science disciplines: chemistry, biochemistry, biology, ecology, and earth and environmental science. Today, many innovative science studies and discoveries are made through interdisciplinary collaborative work.17 The knowledge of green chemistry may allow today’s students, and ultimately the scientific community of tomorrow, to collaboratively develop the technologies that are necessary to achieve the goals of a sustainable world. Students from various areas of science will be made aware of major issues associated with current industrial processes. They may be motivated to develop solutions based on green chemistry principles in an interdisciplinary environment, which will eventually serve a greater community, thereby supporting the liberal arts mission.

Course Activities

Atom Economy Workshop. As part of the lab series, an atom economy workshop was introduced. Atom economy means maximizing the incorporation of material from the starting compounds or reagents into the final product, thereby reducing the amount of waste.11 The concept of atom economy was first introduced by Barry Trost, and several different atom economy workshops and modules have been reported.12,13 The main objective of this workshop is to open students’ minds about the importance of the prevention of pollution at the molecular level. The activity starts in the computer lab where students use ChemDraw to draw and study the atom economy of various reactions, including the reaction for the synthesis of aspirin. Students then synthesize aspirin in the chemistry lab using salicylic acid and acetic anhydride and calculate the percentage yield for the synthesis.14 At the end, students compare and discuss their percentage yields and the percentage atom economy, keeping green chemistry as the focus. The comparison of two metrics such as percentage yield (widely used to measure the reaction efficiency) and percentage atom economy makes students aware that even an efficient synthetic procedure may have unintended negative environmental consequences.

Course Format

The Green Chemistry course is an upper-level chemistry elective designed for science students who already have some knowledge of general chemistry and organic chemistry. This is a 14-week course with a 2 h class period, twice a week. The course is offered in a unique workshop style, integrating class work with lab activities. The classes are lecture-only, lab-only, or a combination of lecture and lab. Some lecture topics are readily applied in a lab exercise, and this approach allows the development of green chemistry concepts to move smoothly between lecture and laboratory activities. Then, the green chemistry concepts are further discussed using laboratory results and pre- and postlab questionnaires. These discussions give an opportunity to the students from different science majors (chemistry, biochemistry, biology, ecology, and earth B

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The laboratory experiments were adapted from the recent literature as indicated in the discussion below. New sets of pre- and postlab questionnaires were developed to discuss some lab experiments and can be found in the Supporting Information.

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(5) renewable resources and emerging greener technologies (6) application of green chemistry

(4) catalysis for green synthesis

uses of solvents in chemical industry, organic solvents and volatile organic components, Solventless chemistry: Aldol and Michael addition reactions. Infrared and nuclear magnetic solvent-free systems, water as a reaction solvent, supercritical fluids, ionic liquids resonance analysis of the products. heterogeneous catalysis, homogeneous catalysis, phase-transfer catalysis, biocatalysis, Biocatalysis: Reduction of ethyl acetoacetate using Baker’s yeast. The results are discussed photocatalysis comparing with the noncatalytic pathway. energy, polymers, and other chemicals from renewable feedstocks; photochemical Electrosynthesis: Electrochemical reductive coupling reaction in room-temperature ionic liquids. reactions; microwave chemistry; sonochemistry; electrochemical synthesis The synthesis is performed and discussed in comparison with the metal-mediated pathway. Students develop a proposal on “designing a greener product or process” and present to the class.

Topics Section

Table 2. Workshop Format for the Green Chemistry Science Major Elective Course

Lab Experimentsa

Section 1: Introduction to Green Chemistry. In this section, the foundation for green chemistry is built by discussing the 12 principles of green chemistry in detail and giving special attention to atom economy. This section is coupled with a laboratory activity in which students assess the environmental impact of a chemical reaction using green chemistry metrics. Students are divided into three groups and perform three different bromination reactions of transstilbene.21 Each method is evaluated to identify hazardous materials used with the help of material safety data sheets prior to the experiment. After the synthesis, the percentage yield, atom economy, e-factor, and effective mass yield are calculated for each method and used in measuring the efficiency and environmental impact of each reaction. Another important aspect of this activity is to identify some challenges and issues that are encountered in applying metrics to evaluate the “greenness” of a reaction. Section 2: Environmental Impact of Chemical Processes and Products. Section 2 mainly focuses on waste production and prevention, life cycle assessment, and environmental management systems. This section is merged into the lab where students use the process flow sheet (PFS) method to analyze the waste-minimizing approaches for a two-step synthesis. During the development of a multistep synthesis, it is important to visualize the whole process through the PFS to minimize waste and avoid inefficient procedures.22 This twostep synthesis involves the preparation of substituted chalcones (aromatic enones), followed by green epoxidation of chalcones.23 Students thoroughly analyze the synthesis using the PFS and identify steps that need to be improved. The modifications are proposed and discussed to improve the environmental compatibility of this synthesis. Section 3: Alternative Reaction Media. This section explores the organic solvents used in the chemical industry and introduces volatile organic components. A detailed discussion of alternative solvent systems, including solvent-free systems, water, supercritical fluids, and ionic liquids, follows. This section is integrated with a lab activity in which students use solventless chemistry in chemical synthesis. Sequential solventless aldol and Michael addition reactions are conducted using the “grinding method” to prepare a 1,5-diketone, and the product is analyzed by nuclear magnetic resonance and infrared (IR) spectroscopy.24 Section 4: Catalysis. In this section, heterogeneous catalysis and homogeneous catalysis are discussed in detail, and students are also introduced to phase-transfer catalysis, biocatalysis, and photocatalysis. The biocatalysis section is migrated to the lab where students study the effect of a biocatalyst on a chemical reaction. The experiment involves the reduction of ethyl acetoacetate using Baker’s yeast, followed by IR and polarimetry analysis of the product.25 The discussion of biocatalysis continues through postlab questions. Students identify the environmental benefits and challenges encountered when using a biocatalyst such as Baker’s yeast in a chemical reaction. They also discuss the advantages and disadvantages of

waste production and prevention, life cycle assessment, environmental management systems

Course Components

“Greening up” the bromination: Three different bromination reactions are performed, analyzed, and compared using various green chemistry metrics. Synthesis of chalcones and green epoxidation of synthesized chalcones: The synthesis is analyzed by the process flow sheet method.

this course are divided into five coupled with a laboratory activity

12 principles of green chemistry, atom economic and uneconomic reactions

to gain a deep understanding of while sharing their expertise,

(1) introduction to green chemistry (2) environmental impact of chemical processes and products (3) alternative reaction media

and environmental science) green chemistry concepts comments, and opinions. The materials covered in sections, and each section is (Table 2).18−20

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improve their critical-thinking, problem-solving, oral presentation, and teamwork skills, which are important elements in liberal arts education.

using whole cell organisms, such as yeast, over isolated enzymes in chemical synthesis. Section 5: Renewable Resources and Emerging Greener Technologies. Through green chemistry education, it is important that students are made aware of not only concepts and methods that aid in the development of more sustainable products and processes but also technology aspects that can lead to improved process and energy efficiency, as well as process cost reduction. This section is focused on the applications of renewable feedstock as a source for energy, polymers, and other chemicals, such as lubricants, surfactants, solvents, and agrochemicals. A detailed discussion of energyefficient emerging technologies, including photochemical reactions, microwave chemistry, sonochemistry, and electrochemical synthesis, follows. The electrochemical synthesis portion of this section is further explored using a laboratory activity developed by our research group.26 In this lab, students as a group perform an electrochemical reductive-coupling reaction in room-temperature ionic liquids. Students discuss advantages and challenges of electrochemical synthesis compared to the samarium(II) iodide-mediated chemical method, keeping green chemistry as the focus.27 They also use the knowledge obtained from Section 3: Alternative Reaction Media to discuss the advantages of using an ionic liquid as the reaction medium in this experiment. Section 6: Application of Green Chemistry: Design of a Greener Product or Process. This project, first introduced by Marteel-Parrish,1 provides students with the opportunity to apply their knowledge of green chemistry. In this section, each student is supposed to develop an original proposal to design a greener product or process and present the proposal to the class. As the class is represented by a diverse group of science students, each student is encouraged to identify a problem significant to his or her major and come up with a solution using green chemistry concepts learned in the class. The proposal should employ one or more of the 12 principles of green chemistry. Students are also encouraged to visit the Web site for presidential green chemistry challenge award to learn about outstanding achievements.28 The individual proposals should be presented to the class as a 20−25 min PowerPoint presentation followed by 10−15 min for questions and discussion. Both the content of the proposal and the presentation style are evaluated by the instructor and students using presentation evaluation forms.

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ASSOCIATED CONTENT

S Supporting Information *

Detailed laboratory activities, pre- and postlab questionnaires, the worksheet for the atom economy workshop, the list of topics covered in collaborative group projects and individual proposals, and presentation evaluation forms. This material is available via the Internet at http://pubs.acs.org.

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AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. Notes

The authors declare no competing financial interest.

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REFERENCES

(1) Marteel-Parrish, A. E. Toward the Greening of Our Minds: A New Special Topics Course. J. Chem. Educ. 2007, 84, 245−247. (2) Collins, T. J. Introducing Green Chemistry in Teaching and Research. J. Chem. Educ. 1995, 72, 965−966. (3) Green Chemistry at the University of Oregon (http:// greenchem.uoregon.edu/) (accessed August 2013). (4) Report of the World Commission on Environment and Development (http://www.un-documents.net/ocf-02.htm) (accessed August 2013). (5) Hill, J.; McCreary, T.; Kolb, D. Chemistry for Changing Times; Prentice Hall: Upper Saddle River, NJ, 2009. (6) Anastas, P. T.; Warner, J. C. Green Chemistry Theory and Practice; Oxford University Press: New York, 1998. (7) Cann, M. C.; Connelly, M. E. Real-World Cases in Green Chemistry; American Chemical Society: Washington, DC, 2000. (8) Anastas, P.; Lankey, R. Life Cycle Assessment and Green Chemistry: The Yin and Yang of Industrial Ecology. Green Chem. 2000, 2, 289−295. (9) Thayer, A. M. Biocatalysts. Chem. Eng. News 2001, 79, 27−34. (10) (a) Human Footprint (DVD); Clive Maltby, Director; NGHT, Inc., 2008. (b) Addicted to Plastic (DVD); Ian Connacher, Author; Bullfrog Films, 2008. (c) Solar Energy (DVD); Steven Latham, Director; WGBH Boston Video, 2007. (d) Global Warming (DVD); Jon Palfreman, Director; WGBH Boston Video, 2000. (e) Silent Spring (DVD); Neil Goodwin, Producer; WGBH Boston Video, 2007. (11) Trost, B. M. The Atom EconomyA Search for Synthetic Efficiency. Science 1991, 254, 1471−1477. (12) A Green Chemistry Module (http://cann.scrantonfaculty.com/ organicmodule.html) (accessed August 2013). (13) Witzel, J. E. Lego Stoichiometry. J. Chem. Educ. 2002, 79, 352A−352B. (14) Brown, D. B.; Friedman, L. B. The Aspirin ProjectLaboratory Experiments for Introductory Chemistry. J. Chem. Educ. 1973, 50, 214−215. (15) Mercer, S. M.; Andraos, J.; Jessop, P. G. Choosing the Greenest Synthesis: A Multivariate Metric Green Chemistry Exercise. J. Chem. Educ. 2012, 89, 215−220. (16) Life Cycle Assessment (http://www.epa.gov/nrmrl/std/lca/lca. html) (accessed August 2013). (17) Porter, L. A. Chemical Nanotechnology: A Liberal Arts Approach to a Basic Course in Emerging Interdisciplinary Science and Technology. J. Chem. Educ. 2007, 84, 259−264. (18) Lancaster, M. Green Chemistry: An Introductory Text; Royal Society of Chemistry: Cambridge, U.K., 2002. (19) Stevens, E. S. Green Plastics: An Introduction to the New Science of Biodegradable Plastics; Princeton University Press: Princeton, NJ, 2002.

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SUMMARY Green chemistry has been integrated into the liberal arts education at this institution through two courses: Green Chemical Concepts for nonscience majors and Green Chemistry for science majors. The course Green Chemical Concepts consists of a separate lecture and laboratory format, and the lecture discussions are facilitated by a series of documentary film DVDs and journal articles. Students also complete an atom economy workshop and a collaborative group project. The Green Chemistry elective is offered for science majors with a unique workshop style integrating class work with laboratory activities. This approach allows the development of green chemistry concepts to move smoothly between lecture and laboratory activities, and the green chemistry concepts are further discussed using laboratory results and pre- and postlab questionnaires. These courses provide students the opportunity to explore the connection between green chemistry and their local environment and to D

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(20) Tester, J. W.; Drake, E. M.; Driscoll, M. J.; Golay, M. W.; Peters, W. A. Sustainable Energy: Choosing Among Options; MIT Press: Cambridge, MA, 2005. (21) McKenzie, L. C.; Huffman, L. M.; Hutchison, J. E. The Evolution of a Green Chemistry Laboratory Experiment: Greener Brominations of Stilbene. J. Chem. Educ. 2005, 82, 306−310. (22) Van Arnum, S. D. An Approach Towards Teaching Green Chemistry Fundamentals. J. Chem. Educ. 2005, 82, 1689−1692. (23) Pavia, D. L.; Lampman, G. M.; Kriz, G. S.; Engel, R. G. A Microscale Approach to Organic Laboratory Techniques; Brooks Cole: Belmont, CA, 2012; pp 551−559. (24) Cave, G. W. V.; Raston, C. L. Green Chemistry Laboratory: Benign Synthesis of 4,6-Diphenyl[2,2′]bipyridine via Sequential Solventless Aldol and Michael Addition Reactions. J. Chem. Educ. 2005, 82, 468−469. (25) Besse, P.; Bolte, J.; Veschambre, H. Bakers’ Yeast Reduction of α-Diketones. J. Chem. Educ. 1995, 72, 277−278. (26) Jones, A.; Kronenwetter, H.; Manchanayakage, R. Electrochemical Reductive Coupling of 2-cyclohexen-1-one in a Mixture of Ionic Liquid and Water. Electrochem. Commun. 2012, 25, 8−10. (27) Inanga, J.; Handa, Y.; Tabuchi, T.; Otsubo, K.; Yamaguchi, M.; Hanamoto, T. A Facile Reductive Dimerization of Conjugated Acid Derivatives with Samarium Diiodide. Tetrahedron Lett. 1991, 32, 6557−6558. (28) Presidential Green Chemistry Challenge Home Page (http:// www.epa.gov/gcc/pubs/pgcc/presgcc.html) (accessed August 2013).

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