%20(1).png)
JUNE 20 - 23, 2023
Sustainability, the Great Lakes, and Chemistry for the Future
Wednesday Morning Session Details
June 21, 2023
S1. Circular Economy for Plastics: Challenges and Opportunities
M. Bouguettaya, L. Wang, Organizers, Presiding
Salon I
8:30 AM
Introductory Remarks
8:40 AM
Enabling novel circular economy processes utilizing mass balance in chemical processes Mass Balance (MB) is a proven chain of custody methodology that enables new or novell recycling processes to get started utilizing existing supply chains. This provides a relatively low risk, low barrier to entry pathway to start developing circular processes until economies of scale allow segregated supply chains to be justified. Few know the details of how MB works, especially in highly complex value chains found in the chemical industry. This talk will cover the basics on what MB is, how it works, why it's used and the value it brings in developing circular pathways for end of life materials.
Thomas McKay, thomas.mckay@basf.com. BASF Corp, Florham Park, New Jersey, United States
9:10 AM
Microscopy supports on circular economy in BASF North America BASF has set up aggressive goals on sustainability. Analytical North America (ANA) is the key component of global efforts on Circular Economy, and biodegradation & microplastics center of excellence. Feedstocks, R&D samples, and commercialized materials are frequently needed to be characterized and tested for assuring materials quality, facilitating formulation/processing development, and meeting regulatory requirements. In this presentation, microscopy technologies used in characterizing samples in CE are discussed and application examples are demonstrated to show the importance of analytical supports.
Keqing Fa, keqing.fa@basf.com. BASF, Wyandotte, Michigan, United States
9:40 AM
Break
9:50 AM
Evolving industrial analytics for the plastics circular economy Industrial innovations to generate a plastics circular economy, a cradle-to-cradle model for polymers that prevents the generation of plastic waste and improves carbon footprint, are developing at a fast pace. As a result, new categories of chemical and physical analytics must continuously grow and evolve in industry to support these emerging needs. From evaluation of biodegradable polymeric products, to understanding chemical recycling and improved mechanical recyclability, analytical methods must generate reliable, robust results for increasingly complex chemistries. This seminar will focus on emerging and growing analytics for biodegradable chemistries, microplastics, chemical recycling, and odor analysis as relevant to the chemical industry. It will also include an overview of the new Analytical Center for Microplastics & Biodegradation at BASF’s Corporate Analytical & Material Science North America and provide a window into how industry tackles complex challenges in developing a polymeric circular economy.
Jeanne Hankett, jeanne.hankett@basf.com. Analytical & Material Science North America, BASF Corporation, Wyandotte, Michigan, United States
10:20 AM
Circular upcycling approach to sustainable silicone polymers This presentation will showcase our recent work on the development of circular methodologies for siloxane-based elastomers and resins to demonstrate the potential industrial feasibility of silicone recycling/upcycling. We have developed an efficient methodology to depolymerize polysiloxanes of various forms and cross-link densities to cyclic siloxanes of D 4 , D 5 , and D 6 with an emphasis towards D 4 development and then demonstrate their repolymerization back to polysiloxane structures. The depolymerization processes are conducted using a cocktail of fluoride ions from tetrabutylammonium fluoride or from photoreleasable flourides from phenacyl photocages in THF or MEK and other intermediate high swell solvents. The reactions are highly efficient with conversion to cyclomers taking place in as little as 30 min through an equilibration process, with quenching by CaCl 2 to remove active fluoride ions and lock the cyclic structures. The conversion to cyclomers are verified by 29 Si NMR and GCMS spectroscopic techniques. Traditional methods such as triflic acid initiated polymerization have shown effective repolymerization to polysiloxanes containing M w up to 8600 Da. We also demonstrate methods for the mechanochemical transformation of siloxane polymers to cyclic compounds and also the conversion of siloxanes directly to alkoxysilanes via catalytic processes. Lastly, we will show how the incorporation of light responsive cross-linkers into siloxane systems can enable dynamic re-processible polymeric systems by losing and then restoring mechanical properties for adhesives and self-healable materials.
Joseph C. Furgal, furgalj@bgsu.edu, Kalani D. Edirisinghe, Herenia Espitia Armenta, Ethan Chandler, Cory B. Sims, Buddhima Rupasinghe, Chemistry, Bowling Green State University, Bowling Green, Ohio, United States
S2. Education in Chemistry
D. N. Maxwell, Organizer, Presiding
Salon II
8:30 AM
Opening Remarks
8:35 AM
Sense of belonging of students from historically excluded groups in general chemistry courses Students with a strong sense of course belonging tend to have higher course level academic achievement and persist in STEM. Systemic racism and sexism in STEM fields may lead to a lower sense of belonging and higher belonging uncertainty in students from historically excluded groups. A survey on sense of belonging was conducted in all general chemistry courses during autumn 2022 at a large research institution in the Midwest. From this survey, we will examine students’ sense of belonging and belonging uncertainty with respect to course progress. Data on sense of belonging will be disaggregated by self-reported demographic information. The role of intersectionality will be examined. The ways in which various course aspects such as recitation, lab, homework, and exams relate to sense of belonging will be explored.
Nicole M. Karn, karn.38@osu.edu, Jennifer Collins, Luka Medvedovic, Makda Berhe, Sarah Ogrin-Cotarlan. Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States
8:55 AM
Implementation of a vertical and interdisciplinary curriculum-based research experience in organic chemistry courses Creating opportunities for learners to explore research projects in their undergraduate curriculum is critical to 1) enhance problem solving skills, 2) master laboratory skills in synthesis, and 3) become creative in designing future research. More importantly, this approach can assist in creating a more equitable experience for non-traditional learners. A team of faculty members at University of Detroit Mercy has been designing a module of vertical research projects to incorporate the synthesis and characterization of organometallic ferrocene hybrids using a combination of experimental conditions and coupling reagents. The project is also aimed to incorporate biochemical and electrochemical investigations to simulate interdisciplinary work in chemistry. Through a set of laboratory courses, the faculty members expanded on the implementation and modifications of ferrocene syntheses and worked to create a community of learners who contribute to a common goal of expanding knowledge about successful syntheses. This presentation will address the design and implementation of a two-year vertical CURE and will include students' perspectives of their learning experiences. Faculty members are interested in assessing students' responses to determine whether multi-module exposures enhanced their attitudes towards research and to identify challenges in implementing vertical CUREs in chemistry. Additional modifications and examples of students facing resources will be shared.
Marwa Abdel Latif (1), abdellmk@udmercy.edu, Mara Livezey (1), livezemr@udmercy.edu, Steven Scribner (1)(2), scribnsl@udmercy.edu, Eleni Geragosian (1), Maryam Yousif (1), Courtney Profley (1). (1) Chemistry and Biochemistry, University of Detroit Mercy, Detroit, Michigan, United States (2) University of Michigan Dearborn Office of Metropolitan
Impact, Dearborn, Michigan, United States
9:15 AM
Navigating the hidden curriculum of academia: Critical approach to understanding the racial and science identity formation of Latine undergraduate students The narrative that science is objective, value-free, acultural, and rooted within a system of meritocracy constrains the representation and advancement of minoritized groups in science. Although there are initiatives to improve the representation of non-majority groups in STEM, much of this effort focuses on achieving racial or ethnic diversity rather than recognizing students’ diverse worldviews and identities in the classroom. To understand how students learn science, we need to understand how students engage with science and how this influences their personal and science identities. This study aims to understand how Latine undergraduate students at Hispanic-Serving Institutions (HSIs) develop science identities and how racialized experiences may influence this formation. In this study we use multiple theories of identity, a critical epistemological perspective, and qualitative research methods to build a conceptual framework and describe the salient experiences of our participants. We interviewed 18 Latine third- and fourth-year undergraduate students at three HSIs in the southwestern United States. Our analysis indicates that Latine students use a variety of racialized identity resources to negotiate the formation of their science identities. Positive or negative experiences with these resources can greatly influence their science identity formation. Specifically, Latine students have complex access and interactions with relational and material resources that influence their sense of belonging and science identity formation. The results of this study provide insights into how Latine students engage with the culture of science and advance our understanding of how to best support Latine students throughout their undergraduate science education. Furthermore, this study demonstrates the need for more Latine instructors and culturally responsive curriculum development in higher education.
Danielle N. Maxwell (1), maxweldn@umich.edu, Jorge L. Rivera-Colon (2) , Kathryn Hosbein (3), Paulette Vincent-Ruz (4), Ginger V. Szymczak Shultz (1). (1) University of Michigan, Ann Arbor, Michigan, United States (2) University of Wisconsin-Madison, Madison, Wisconsin, United States (3) Middle Tennessee State University, Murfreesboro, Tennessee, United States (4) New Mexico State University, Las Cruces, New Mexico, United States
9:35 AM
Intermission
9:50 AM
Student perspectives to transform the general chemistry learning environment at predominantly white institutions The general chemistry course, especially at Predominantly White Institutions (PWI), is confirmed to be a gatekeeper to science and engineering degrees. Acknowledging this reality, research focused on understanding student perceptions of the learning environment and the barriers to success in general chemistry is extremely critical to shape efforts to advance systemic change in chemistry education. Student perceptions is especially critical as they are arguably the most critical stakeholders of higher education. Given this, this research study qualitatively and quantitatively examines student perspectives on the general chemistry environment with respect teaching practices, faculty and teaching assistant interactions, curriculum, and courses policies. Students in the study are enrolled at a research intensive PWI, and a research-based survey was administered to gather student perspectives in Autumn 2022. Preliminary results from 1637 general chemistry course 1 students indicate complex and multidimensional perceptions largely related to course difficulty, fast pace of the course, and unsupportive instructional behaviors and practices. Findings imply systemic change efforts should place considerable attention to course structural and curriculum reform, to ultimately advance student success and racial equity in general chemistry.
Jennifer Collins, collins.1711@osu.edu, Nicole M. Karn, Makda Berhe, Sarah Ogrin-Cotarlan, Luka Medvedovic. Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States
10:10 AM
Utilizing student-generated Mathematica demonstrations in general chemistry courses The Compute-to-Learn (C2L) Pedagogy is a semester-long, project-based learning experience in which students collaborate within a peer-led studio environment to code Mathematica demonstrations of abstract course concepts that can be illuminated by dynamic computation. During this experience, students learn key programming skills that they apply within the context of physical chemistry. At the end of the semester, the student demonstrations undergo external peer-review and are published on the Wolfram Demonstrations Project website. The C2L pedagogy was originally designed for introductory physical chemistry courses at a large midwestern research university. However, parameters for pedagogy design and implementation vary across different types of institutions. The strategies and solutions for implementing the C2L pedagogy in both advanced and introductory courses at an undergraduate liberal arts college are described here. In particular, the effect of utilizing student demonstrations created by upper-level physical chemistry students is investigated within a general chemistry course.
Heidi P. Hendrickson (1), hendrihe@lafayette.edu, Theresa Chua (1), Vedit Venkatesh (1), Tracie Addy (2) . (1) Chemistry, Lafayette College, Easton, Pennsylvania, United States (2) Center for the Integration of Teaching, Learning, and Scholarship, Lafayette College, Easton, Pennsylvania, United States
10:30 AM
Utilizing the 'Student Interaction Discourse Moves' (SIDM) framework to characterize student discourse in a chemistry POGIL session It is important to understand how students' interact with scientific literature and chemistry that is relevant to their lives. Process oriented guided-inquiry learning (POGIL) sessions are one way to have students' interact with new knowledge in group discursive settings. Herein, a POGIL sessions was implemented into a general chemistry course at the University of Michigan. The POGIL activity was created based on scientific literature and involved data relevant to students' perceptions of the Arctic. As part of the data collection, audio recordings of groups' dialogue was collected. This presentation seeks to utilize the Student Interaction Discourse moves (SIDM) framework to analyze these audio recordings. Our goal is to implement this framework and characterize students' discourse moves in a chemistry POGIL activity. As part of this analysis, we aim to investigate the nuances associated with the structure of POGIL activities, and instructor facilitation on students collaborative discourse.
Archer Harrold, Aharrold@umich.edu, Danielle N. Maxwell. Chemistry, University of Michigan, Ann Arbor, Michigan, United States
S6. Organic
D. B. Lawson, Organizer, Presiding
Salon III
8:30 AM
Macrocyclic resorcinarene salts as sensors for bioanalytes Synthetic materials that interact with biological target molecules are of paramount importance for the development of various biotechnological applications. Cyclophanes are macrocyclic supramolecular hosts famous for their ability to bind atomic or molecular guests via noncovalent interactions within their well-defined cavities. In this talk, I will present recent results on the design, formation, and host-guest properties of cationic macrocyclic resorcinarenes receptors and biological anions (chloride and pyrophosphate), and kynurenic acid, a bio-relevant analyte.
Ngong K. Beyeh, beyeh@oakland.edu. Chemistry, Oakland University, Rochester, Michigan, United States
8:50 AM
Formal cross-coupling of amines and carboxylic acids to form sp3–sp2 carbon–carbon bonds Amines and carboxylic acids are abundant synthetic building blocks that are classically united to form an amide bond. To access new pockets of chemical space we are interested in the development of amine–acid coupling reactions that complement the amide coupling. In particular, the formation of carbon–carbon bonds by formal deamination and decarboxylation would be an impactful addition to the synthesis toolbox. Here we report a formal cross-coupling of alkyl amines and aryl carboxylic acids to form C(sp3)–C(sp2) bonds following pre-activation of the amine–acid building blocks as a pyridinium salt and N-acyl-glutarimide respectively. Under nickel-catalyzed reductive cross-coupling conditions, a diversity of simple and complex substrates are united in good to excellent yield, and numerous pharmaceuticals are successfully diversified. High-throughput experimentation was leveraged in the development of the reaction, and to the discovery of performance-enhancing additives such as phthalimide, RuCl3 and GaCl3. Computational and experimental mechanistic investigations suggest phthalimide may play a role in stabilizing productive Ni complexes rather than being involved in oxidative addition of the N-acyl-imide and that RuCl3 supports the decarbonylation event, improving reaction selectivity.
James L. Douthwaite (1), jdouth@umich.edu, Ruheng Zhao (1), Eunjae Shim (2), Babak A. Mahjour(1), Paul M. Zimmerman(2), Tim Cernak (1)(2). (1) Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan, United States(2) Department of Chemistry, University of Michigan, Ann Arbor, Michigan, United States
9:10 AM
Carbenes and carbazoles: Elucidating solution-state behavior with non-traditional hydrogen bonding Since the discovery of isolable singlet carbenes there has been a concerted effort to probe these unique molecules across a range of chemistry disciplines. Two of the most well-developed classes of isolable carbenes, N-heterocyclic carbenes (NHCs) and cyclic (alkyl)(amino)carbenes (CAACs), have been of interest due to their contrasting reactivities. NHCs are generally considered to be both weak nucleophiles and bases; while CAACs exhibit both increased nucleophilicity and basicity in comparison to NHCs. While studies on metal–carbene complexes, from both a photophysical and structural perspective, are well known, examples employing metal-free systems are still relatively unexplored. Our research efforts have been to modulate the properties, both photophysical and structural, of NH-containing fluorophores. The focus of this seminar is to look at the interactions of NHCs and carbazoles, wherein we find the emission of the fluorophore is quenched at elevated concentrate, but returns to its emissive state upon dilution. Further investigation reveals the defining characteristic of these products is a non-traditional hydrogen bond between the carbazole NH and the carbenic carbon of the NHC. With this as our foundation, we posit that oligomeric carbazoles can form hydrogen bonded adducts with NHCs, ultimately imparting geometric constraints on these disordered foldamers.
Zacharias Kinney, kinney@oakland.edu. Chemistry, Oakland University, Rochester, Michigan, United States
9:30 AM
Break
9:40 AM
New developments in interrupted carbonyl-olefin metathesis reactions Carbonyl and olefin functionalities can undergo carbon-carbon bond-forming reactions through carbonyl-ene or Prins pathways upon activation with Lewis or Brønsted acids. Both pathways are accessible from similar substrates, depending on the choice of catalyst and conditions. Carbonyl-ene reactions result in the formation of homoallylic alcohols upon addition of an electrophilic carbonyl to an alkene with concomitant transfer of an allylic hydrogen atom. In comparison, the Prins reaction proceeds through an intermediate carbocation that is subsequently captured by an exogenous nucleophile to result in the corresponding alcohols. Our recently reported catalytic carbonyl-olefin metathesis reaction represents a third reactivity mode between carbonyl and alkene functionalities that proceeds via intermediate oxetanes and results in cyclic alkene products. As part of our efforts in developing new cycloaddition reactions between carbonyls and olefins, we discovered a fourth reactivity mode between these two functional groups that similarly proceeds under Brønsted or Lewis acid-catalysis. This transformation resembles the carbonyl-olefin metathesis reaction in that it also relies on intermediate oxetanes, however the ultimate products formed are tetrahydrofluorenes. We herein report new developments in this area of interrupted carbonyl-olefin metathesis reactions relying on aliphatic ketones as substrates to form valuable carbocyclic building blocks in a single transformation.
Sean Burns, seanbur@umich.edu. University of Michigan, Ann Arbor, Michigan, United States
10:00 AM
Kinetics of chlorine reactions with RNA: A step toward predicting viral inactivation during water treatment Chlorine treatment is commonly used to inactivate viruses. Chlorine inactivates viruses by reacting with their biomolecules, including their genomes. Understanding viral genome reaction mechanisms, and identifying the biological significance of reaction products, can help us predict the fate of newly emerging viruses during treatment. However, reaction mechanisms and reaction products of viral genomes with chlorine are poorly characterized. Further, genome inactivation kinetics have been predominantly measured using polymerase chain reaction (PCR)-based assays, which can underestimate degradation rates, and bias observed reaction kinetics. To address this, we exposed the genome of bacteriophage MS2, a commonly used surrogate for viruses in water treatment scenarios to chlorine. After exposure, we digested the genome enzymatically into individual nucleosides, and measured decay and product formation using an Orbitrap ion mass analyzer. We found that reaction kinetics of nucleosides incorporated in the MS2 genome differed from those observed for unincorporated nucleosides, and the reaction kinetics of the MS2 genome measured using the Orbitrap ion mass analyzer differed compared to reaction kinetics measured using PCR based assays. The results of this study will help us predict the fate of emerging viruses during treatment, and help us identify the biological significance of viral genome disinfection products.
Alex Szczuka, aszczuka@umich.edu. Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, United States
10:20 AM
Alkene aminoarylation via N-centered radical reactivity of sulfinamides Reported is an alternative strategy for accessing arylethylamines from ubiquitous starting materials. Careful modulation of the pKa properties of the N-H bonds found in sulfinamides allows for single electron transfer (SET) pathways to be exploited under photocatalytic conditions to participate in Smiles-Truce rearrangement with arylsulfinamides and unactivated alkenes. Our group has successfully established a system wherein generation of arylsulfinamide radicals can be achieved under basic conditions and can be adjoined with alkenes to make new C-N bonds yielding intermediate carbon centered radicals that undergo Smiles-Truce rearrangement. Using this method, we have shown that pharmaceutically relevant building blocks can be accessed and with high regio- and diasterocontrol. The nature of these rearrangements lends itself not only to 1,2-aminoarylation, but also as a viable methodology to access nitrogen-centered radicals (NCRs). More work to explore use of these NCRs is currently underway in our group.
Mark Glossbrenner, mglossbr@umich.edu. Chemistry, University of Michigan, Ann Arbor, Michigan, United States
S3. Expanding Green Chemistry in the Undergraduate Curriculum and Research Experiences
N. Kingsley, J. L. Tischler, Organizers, Presiding
Salon V
8:30 AM
Introductory Remarks
8:35 AM
Development and assessing the impact of student-generated videos, infographics, and open education resources related to sustainability and green chemistry Scaffolded semester-long projects were organized into phases and designed to promote the goals of teaching students about green chemistry and sustainability concepts while simultaneously creating case study videos, infographics, and open educational resources for future students. Learning objectives for these activities are two-fold. The first includes students connecting organic chemistry topics, green chemistry principles, planetary boundaries, and the UN sustainable development goals. The second refers to professional skills such as information literacy, communication, and peer review. Thorough evaluation of the impact of these curriculum innovations on student learning was conducted using high-quality assessment techniques, including sets of multiple-choice questions, student assessment of learning gains, open-ended questions that asked students to explain their reasoning about “greener” chemical reactions, and questionnaires. Overall, positive learning gains on chemistry knowledge and skills were observed and students viewed the projects favorably, with most indicating a desire for similar assignments in future courses.
Alexey Leontyev, alexey.leontyev@ndsu.edu, Krystal D. Grieger. Chemistry, North Dakota State University, Fargo, North Dakota, United States
8:55 AM
Undergraduate research and green chemistry: Exploring applications within analytical chemistry Often times, the concept of green chemistry is associated with the synthesis of new compounds or the toxicological and environmental impacts of chemical processes. This can leave easily accessible opportunities for green chemistry to be integrated into other areas of chemistry. As chemistry programs across the nation look to introduce their students to more sustainable and green material, one option that remains an exciting opportunity is through undergraduate research. This presentation will focus on the use of electrochemical methods and their application to assessing the quality of frying oils for restaurants and snack-food manufactures. In order to move these techniques to industry, a greener solvent system needed to be identified. The tenants and current outcomes of this research, in addition to how this project provides a platform for introducing undergraduate students to green chemistry will be presented.
Matthew J. Fhaner, fhaner@umich.edu. Natural Sciences, University of Michigan-Flint, Flint, Michigan, United States
9:15 AM
Using environmental justice to explore scientific ethics, chemical literature, and presentation skills in a seminar course In 2017 UM-Flint became the 38th signer of the Green Chemistry Commitment. Part of that pledge is the incorporation of Green Chemistry principles across the curriculum. This talk will describe a poster assignment in our Junior Seminar course that asks students to explain a green chemistry solution to an environmental injustice. This assignment seeks to teach scientific ethics by exploring the social impacts of chemistry with the social responsibility we have as scientists.
Jessica L. Tischler, jtisch@umich.edu. Natural Science, University of Michigan-Flint, Flint, Michigan, United States
9:35 AM
Break
9:45 AM
What do our students need to know about green and sustainable chemistry?: Panel discussion with industrial chemists In this session, we will host a panel discussion with speakers from BASF and Dow to discuss the incorporation of green and sustainable chemistry into industrial practices and corporate vision. We will explore how we as educators can better prepare our students to meet the challenges of today’s industrial careers and their companies’ sustainability goals.
Jessica L. Tischler, jtisch@umich.edu. Natural Science, University of Michigan-Flint, Flint, Michigan, United States
10:05 AM
Seed to oil, bench and beyond: Medicinal and aromatic plant course Aromatic plants have bioactive components which contribute to their therapeutic, aesthetic, and medicinal uses. Due to increasing interest, use and commercial promise of natural products, we created a novel course on isolation and characterization of natural products, with a focus on essential oils. The course attracts students interested in integrative medicine, cannabis, small business, medical anthropology and pharmacognosy research. In Medicinal and Aromatic Plants BCHM 413, advanced students couple their knowledge of biochemistry with biology, analytical and organic techniques and skills in applied projects. Students chose specific aromatic plants to study and extract oils or other plant products. Purification and characterization methods included solvent extraction and distillation (glass and copper alembics), while products and standards were compared using UV/Vis analysis, Gas Chromatography/Mass Spectrometry (GC/MS) and bacterial testing (contamination and resistance). Each student created a prototype product after researching the plant, selecting a type of consumer product, choosing an appropriate method to create a safe and chemically stable product, and designing the product literature.
Marilee A. Benore, marilee@umich.edu, Simona Marincean. Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan, United States
10:25 AM
30-minute panel discussion
S4. f-Block Extravaganza: The Best Symposium at CERM
M. Rashid, S. White, Organizers, Presiding
Salon VI
8:30 AM
Opening Remarks
8:40 AM
Controlling the kinetics of oxidation of EuII relevant to imaging hypoxia in vivo with magnetic resonance imaging Divalent europium is isoelectronic with trivalent gadolinium, which is used in clinical settings as a contrast agent for magnetic resonance imaging. The divalent oxidation state of europium changes to the trivalent state in normoxic conditions, completely changing the ability of the ion to enhance contrast. Because of the stark change in contrast enhancing ability in response to oxidation, the europium ion is an outstanding candidate for use in imaging of hypoxia. However, control of the switch in oxidation state is the key challenge to the use of europium for responsive imaging of hypoxia. I will share efforts to use chemistry to slow the rate of oxidation of EuII. I will also share in-vivo examples of the use of the ion to delineate hypoxic and normoxic regions of tissue using magnetic resonance imaging.
Md Mamunur Rashid (1), Andrea Batchev (1), Md Abul Hassan Samee (2), Robia Pautler (2), Matthew J. Allen (1), mallen@chem.wayne.edu. (1) Wayne State University, Detroit, Michigan, United States, (2) Baylor College of Medicine, Houston, Texas, United States
9:05 AM
Investigating the influence of alkyl substituents on the ability of β-carbonylphopshine oxide compounds to sensitize lanthanide luminescence Our group has been studying the ability of ligands containing the β-carbonylphopshine oxide group to sensitize the luminescence of lanthanide(III) metals. This presentation will describe systematic variations to the aromatic groups on these ligands, and how the changes affect metal binding in solution. We will also discuss the characterization of these ligands' complexes with Eu(3+), Tb(3+), Dy(3+) and Sm(3+) with regard to their luminescence lifetimes, quantum yields and triplet state energies.
Shannon M. Biros, biross@gvsu.edu. Chemistry, Grand Valley State University, Allendale, Michigan, United States
9:30 AM
Density functional study of binding mechanism of rare-earth elements with Bis(ethylhexyl)amido diethylenetriaminepentaacetic acid Bis(ethylhexyl)amido diethylenetriaminepentaacetic acid, denoted as modified DTPA here, has recently emerged as an outstanding ligand for extracting rare-earth elements on a solid-phase media, while the microscopic mechanism for the binding between rare-earth elements and the modified DTPA is still unknown. In this work, we fill this knowledge gap by employing first-principles density functional theory to study the binding mechanism of rare-earth elements with the modified DTPA at different pH values. We first compute the pKa values of the modified DTPA and study the binding between hydrated cations of rare-earth elements and the dominating modified DTPA species at different pH values. Our calculations of the Gibbs free energy explain the qualitative trends observed experimentally in the extraction of rare-earth elements. Our study provides insight into the thermodynamics of binding and separation of rare-earth elements using such materials and guides the future design of ligands for the extraction of rare-earth elements.
Timothy Quainoo, gw3083@wayne.edu, Zhenfei Liu. Chemistry, Wayne State University College of Liberal Arts and Sciences, Detroit, Michigan, United States
9:55 AM
Break
10:05 AM
MR responsive and theranostic probes: Where are we headed? We report a new series of MR contrast agents for tracking gene therapy in vivo and to ultimately treat monogenic diseases. With mean survival rate of 5 years (and most cases are fatal) lysomal storage diseases (LSD) are among the most dismal of prognosis in all of medicine. LSD’s represent a large number of monogenetic diseases and while rare the prevalence is to hemophilia. As monogenetic diseases with clearly defined genotype-phenotype relations, lysosomal storage diseases are excellent candidates for gene therapy. The transformative results documented in an adeno-associated virus (AAV) gene therapy clinical trial in infants affected by spinal muscular atrophy demonstrated unequivocally the potential of in vivo gene transfer to treat monogenic neurological disorders. To date there is a lack of non- invasive ways to determine biodistribution or activity levels of these AAV therapies in patients. This is a significant hinderance, leaving investigators guessing which organs or structures are effectively treated and, due to the lag time associated with clinical disease progression, this limitation ultimately impacts the evolution of treatment modalities. In order to overcome these limitations, we have developed a new class of bioresponsive MR imaging agents to track enzymatic activity in any organ, peripheral nervous system (PNS), or central nervous system (CNS) over time. MR imaging is an ideal technique for the study of neurological disorders.
Thomas J. Meade, tmeade@northwestern.edu. Departments of Chemistry, Northwestern University, Evanston, Illinois, United States
S5. Materials and Surface Chemistry
D. B. Lawson, Organizer, Presiding
Salon VII
8:30 AM
Do functional coatings work for solar panel dust mitigation? As one of the sustainable energy sources, solar energy is the ultimate replacement for fossil fuels. More than 3% of worldwide electricity demand is satisfied by solar photovoltaic (PV) and the number keeps increasing. However, apart from the inherent low efficiency, environmental factors such as hail, humidity, dust, and temperature have a significant influence on the effectiveness and practicality of the PV module. Where the weather is dry and sandy, in the Middle East for instance, mitigating against the effects of high temperature and dust are the main issues. Although some type of functional-coating-based, self-cleaning technology is proposed as the most effective approach towards dust mitigation (DM) in the literature, no report on a cost analysis comparing the practicality of such technologies with conventional methods such as manual cleaning and tractor-mounted brush cleaning has been undertaken. For this work, we performed a detailed techno-economic analysis on three different DM approaches using the outdoor testing data generated at installations in Rumah, Saudi Arabia, and Inner Mongolia, China, respectively. The results reveal that a durable superhydrophilic transparent coating is the most economical way of cleaning solar panels due to the 3% increase in annual generated power compared to an uncoated, regularly-cleaned solar farm. Moreover, the return on investment is 15 months at the PV electricity-selling price of 0.07 $/kW-hr.
Tayirjan T. Isimjan, Tayiris@gmail.com, David West. Saudi Basic Industries Corp, Riyadh, Saudi Arabia
8:50 AM
Laser-induced graphene interdigitated electrodes modified with gold nanoparticles for non-faradaic impedimetric detection of cortisol Wearable biosensors have received a lot of attention for their promising applications in personalized medicine. Cortisol is a biomarker for various diseases and plays an important role in metabolism, blood pressure regulation, and glucose levels. In this study, we fabricated laser-induced graphene interdigitated electrodes (LIG-IDE) for the non-faradaic impedimetric detection of cortisol in sweat. A direct laser writing technique was used to produce the LIG-IDE. Gold nanoparticles (AuNPs) were electrochemically deposited onto the surface to enhance impedance response. A self-assembled monolayer (SAM) was formed with on the AuNPs via MPA thiol chemistry. The carboxylic acid (-COOH) groups of the MPA were activated using EDC/NHS chemistry. Following activation, anti-cortisol antibodies were immobilized on the surface. Lastly, the IDE-LIG was incubated in the blocking agent bovine serum albumin (BSA) to avoid unwanted detection. Surface characterization of the LIG was performed at each step of modification by Electrochemical impedance spectroscopy (EIS) in a phosphate buffered saline (PBS) solution containing a 5 mM [Fe(CN)6]3-/4- (1:1) redox couple. Further characterization of the modified LIG electrode was achieved through Fourier transform infrared (FTIR) spectroscopy, surface-enhanced Raman spectroscopy (SERS), and X-ray diffraction (XRD). The detection experiment using EIS was carried out in increasing concentrations in cortisol (0.1 pM-100 nM) in PBS. A decrease in ZMod was found for increasing cortisol concentrations, verifying its ability to detect cortisol. The performance of the LIG-IDE were further examined by selectivity, reproducibility, and sensitivity experiments. The developed immunosensor shows excellent performance such as lower limit of detection, high selectivity, and good stability, and has great potential for development in point-of-care diagnostics in the future.
Kyle Duke, kcduke@student.ysu.edu, Prakrit i Dhungana, Kyle Preusser, Byung-Wook Park. Youngstown State University, Youngstown, Ohio, United States
9:10 AM
Ligand-associated adsorbents for selective recovery/extraction of rare-earth elements: Role of solid supports Rare-earth elements (REE) have been used in increasing quantities for applications ranging from automobile parts to satellites in recent years. It is estimated that demand for REE usage will grow by 7 times by 2040. It is also expected that the supply-demand gap will further accelerate with current geo-political tensions, which will increase focus on REE recovery and extraction from wastes for domestic sources. There have been various techniques used for REE recovery/separation such as precipitation, liquid-liquid extraction, and ion exchange resins as sorbent/ solid supports for solid-liquid extraction of REE. Due to the high cost of making resins, the need for more economic sorbents or solid supports has been explored recently. In this study, the diethylenetriaminepentaacetic acid (DTPA) ligand was modified by attaching hydrophobic chains and grafted on commercially available solid supports, including organosilica (O), sol-gel activated/synthesized organosilica (D), pyrolyzed coconut shell (C) and Amberlite resin (A). The resultant media were used in absorption studies to see the selectivity and recovery of 17 elements (REE + Sc+ Y+ Th) under various conditions such as pH, dosage, kinetics, and isotherms. O-DTPA media showed the highest sorption capacity (22 mg/g) and strong selectivity toward Sc and Th between pH 3 and 4. Sorption of REEs onto coconut-based media indicates the DTPA ligand is not attached to the solid support (coconut shell carbon), possibly indicating the insufficient presence of key functional groups. There was no significant selectivity and recovery of REEs onto A-DTPA (13 mg/g) at pH 2.
Sai Praneeth (1), hl9199@wayne.edu, Preetom K.Roy (1), Mohammed Dardona (1), Ahmed K.Sakr (1), Chandra Mouli Tummala (1), Matthew J. Allen (2), Timothy M. Dittrich (1). (1) Civil and Environmental Engineering, Wayne State University, Detroit, Michigan, United States (2) Department of Chemistry, Wayne State University, Detroit, Michigan, United States
9:30 AM
Break
9:45 AM
Self-assembly controlled at the level of individual functional groups Molecular self-assembly is a process that occurs when component molecules spontaneously organize into a specific arrangement due to the intermolecular interactions between them. These interactions are influenced by the functional groups present on the component molecules. By understanding the effects that different functional groups have on the self-assembly process, we can predict and control it. To do this, we study "families" of molecules that have a common backbone but differ in the functional groups they possess. We use a combination of experimental techniques, such as pulse deposition for scanning tunneling microscopy (STM), and a variety of computational methods to investigate the changes in self-assembly behavior that result from small modifications to the functional groups. In this talk/poster, I will present our work on a family of molecules with an indole backbone, including indol carboxylic acids, multiple isatin derivatives, and proline. By studying these molecules, we are able to gain a deeper understanding of the various intermolecular interactions that drive self-assembly in these systems.
Benjamin Heiner, benheiner7@gmail.com, S. Alex Kandel, Alexander M. Pittsford. Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, United States
10:05 AM
Iron-coated waste nutshells to recycle the lost phosphate and its potential application as a slow-release fertilizer for agriculture Direct application of phosphate fertilizer in agricultural fields can lead to >15% loss of total phosphate via agriculture runoff. Runoff containing excess phosphate fertilizer can create eutrophication in receiving waters, which has been linked to low dissolved oxygen, toxic compounds, and other problems. Slow-release phosphate fertilizers can be a potential solution to prevent this loss. In this study we have coated iron onto the surface of waste pistachio and walnut shells to synthesize biowaste adsorbent material, which has been shown to recover the phosphates from the water system. We have conducted laboratory scale experiments to understand the phosphate uptake capacity, kinetics and demonstrate its potential slow-release application as an agricultural fertilizer. XRD analysis have shown the iron coating process led to the formation of hematite particles on the surface of the waste nutshells. Batch studies have shown both iron coated shells follow pseudo second order kinetics and agree with the Freundlich isotherm model. Column studies have shown that the maximum uptake capacity of the iron coated pistachio and walnut shells is 12.63 mg/g and 9.25 mg/g, respectively. Experiments to validate the slow release of phosphorus under soil-relevant conditions are in progress to determine if this biodegradable waste material can be used as potential slow-release fertilizers in the agricultural fields
Chandra Mouli Tummala (1), gs4273@wayne.edu, Sanjay K. Mohanty (2), Timothy M. Dittrich (1). (1) Civil and Environmental Engineering, Wayne State University College of Engineering, Detroit, Michigan, United States (2) Civil and Environmental Engineering, University of California Los Angeles, Los Angeles, California, United States
10:25 AM
STM investigations into the role of chirality on molecular self-assembly The study of chiral molecular self-assembly is key for many fields, such as enantioselective heterogeneous catalysis and 2D chiral crystal engineering. However, the fundamental role of chirality in crystal formation is not well understood. This study aims to investigate the role that molecular chirality plays in the 2D crystallization, using scanning tunneling microscopy (STM) to study the self-assembly of enantiopure molecules and compare them to achiral analogues. Clusters of the chiral molecule S-indoline-2-carboxylic acid (S-ICA) are extremely similar to clusters of its achiral analogue, indole-2-carboxylic acid. Both molecules form chiral pinwheel pentamers that are present on the surface in a racemic mixture. These results suggest that the molecular chiral center of S-ICA does not drive the chirality of crystallization.