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Development of a Teaching Platform about Plasmonics based on the Color Perception of Colloidal Gold

JOURNAL OF CHEMICAL EDUCATION 2021年第8期98卷 2566-2573页

作者： Aftenieva, Olha Schletz, Daniel Meyer, Antonia Kuehne, Tino Schmalzriedt, Sierk Niethammer, Manuela Koenig, Tobias A. F. Leibniz Inst Polymerforsch Dresden eV IPF D-01069 Dresden Germany Tech Univ Dresden Ctr Adv Elect Dresden Cfaed D-01069 Dresden Germany Martin Andersen Nexo Gymnasium D-01309 Dresden Germany Tech Univ Bergakad Freiberg D-09599 Freiberg Germany Tech Univ Dresden Berufl Fachrichtung Lab & Prozesstech D-01217 Dresden Germany Tech Univ Dresden Didakt Chem D-01217 Dresden Germany Studio Fluffy Gesell Kunst & Angew Math UG D-76131 Karlsruhe Germany

In contrast to a macroscopic solid, the color and spectroscopic properties of gold nanoparticles change with size. Here, we propose a teaching platform for high school students (hereafter defined as students, attending secondary school in Europe, preparatory high schools in the US, or any educational institution of a comparable level) that explains the relationship between the perceived color of colloidal solutions and their physicochemical properties. For this aim, an open-source code, based on Mie theory and colorimetry, was developed to link the perceived colors to the plasmonic effects. Moreover, a set of such nanoparticles, varied in diameter, was created to support the theoretical description. The employed seed-mediated synthesis approach provides sufficient spherical roundness that is crucial for color matching. The proposed teaching platform is available online and can be linked to an outreach activity or practical laboratory course. Furthermore, we illustrate the linkage of nanoscience concepts to real-world examples (e.g., stained church glass), which can be used for promoting the potential of nanotechnology in other fields, including electronics, optics, and biomedicine adding to the interdisciplinarity of the teaching platform.

关键词： High School/Introductory Chemistry First-Year Undergraduate/General Physical Chemistry computer-based learning Aqueous Solution Chemistry Colloids Spectroscopy Nanotechnology

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Connecting Chemistry to Mathematics by Establishing the Relationship between Conductivity and Concentration in an Interdisciplinary, computer-based Project for High School Chemistry Students

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JOURNAL OF CHEMICAL EDUCATION 2021年第3期98卷 796-804页

作者： Shang, Hao Zhejiang Jiashan Middle Sch Jiashan 314100 Zhejiang Peoples R China

Here, we present an interdisciplinary educational project intended for high school chemistry that is focused on the establishment of a mathematical model to describe the relationship between conductivity and concentration, while linking chemistry to mathematics with the help of computer software. The project was designed to help high school students engage in methods and comprehend advanced topics beyond the typical high school chemistry curriculum, as well as to resolve a problem that no single disciplinary perspective is able to solve. This project provided students with a simple method to build mathematical models, which could be used to help them discover the relationship between discrete experimental data and mathematical equations. A postinstructional survey showed that, after completing the project, more students knew how to construct mathematical equations that fit discrete data.

关键词： High School/Introductory Chemistry Interdisciplinary/Multidisciplinary Inquiry-based/Discovery learning Problem Solving/Decision Making Mathematics/Symbolic Mathematics computer-based learning Conductivity

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Course on the Use of DFT Calculations to Improve Understanding of Phase Diagrams in Solid-State Chemistry

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JOURNAL OF CHEMICAL EDUCATION 2021年第10期98卷 3207-3217页

作者： Beck, Horst P. Zhou, Meijuan Hasanovic, Pamela Giesselmann, Elias Springborg, Michael Saarland Univ Inst Phys & Theoret Chem D-66041 Saarbrucken Germany Saarland Univ Inst Inorgan & Analyt Chem D-66041 Saarbrucken Germany

In this work, we venture to show how careful use of a program for quantum chemical calculations (such as VASP) may enrich teaching in solid-state chemistry and how principles of thermodynamics contribute to a validation of phase diagrams and reaction pathways using the quasiternary system Li2O-Al2O3-SiO2 as an example. We show how to calculate formation and reaction energies, we discuss the stability of compounds with respect to their decomposition by introducing the convex hull principle, and we compare the relative stability of polymorphs as well. In a final sum-up, we treat the problem of triangulation in ternary phase diagrams. We show how such a practical course can refer to earlier preparatory courses on thermodynamics, crystallography, and quantum chemistry, and how the results of different tasks distributed among several groups of students can merge to an overall picture and help to solve many problems in understanding solid-state chemistry.

关键词： Graduate Education/Research Collaborative/Cooperative learning computer-based learning Solids Theoretical Chemistry Physical Chemistry

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Effects of the COVID-19 Pandemic on Student Engagement in a General Chemistry Course

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JOURNAL OF CHEMICAL EDUCATION 2021年第12期98卷 3633-3642页

作者： Wu, Fan Teets, Thomas S. Univ Houston Dept Chem Houston TX 77204 USA Univ Houston Off Provost Houston TX 77204 USA

In response to the COVID-19 pandemic, many colleges and universities transitioned their face-to-face courses to emergency remote online courses during the spring of 2020. This study, conducted at a large, urban, diverse public university in the United States, answers the questions of how the sudden switch to emergency remote online instruction and the encompassing events of the pandemic changed student learning and engagement in a college-level introductory chemistry course. The research addresses the demographic and lifestyle factors that determine the magnitude of these changes. The mixed-methods approach uses a 19-item Pandemic Online Student Engagement (POSE) scale to quantitatively evaluate changes in student engagement and combines it with a qualitative analysis of student essay responses. The results reveal a decrease in student engagement, with underrepresented people of color (URPOC) students particularly affected and reporting significantly greater decreases in three of the four engagement components: skills engagement, participation engagement, and performance engagement. The decreases in motivation and self-regulation occurred in part because the historic pandemic event made it more difficult to focus on studies, and because students' home environments were not conducive to self-regulated learning. This study provides unique insights for chemistry instructors and college administrators into how the sudden changes in instructional dynamics affected students while the pandemic unfolded. Studies like this are necessary to prevent widening achievement gaps if the current pandemic lingers or if future threats dictate another widespread adoption of emergency remote online learning in general chemistry.

关键词： General Public Chemical Education Research Interdisciplinary computer-based learning Distance learning/Self Instruction Administrative Issues learning Theories Minorities in Chemistry

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Using NCBI Entrez Direct (EDirect) for Small Molecule Chemical Information Searching in a Unix Terminal

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JOURNAL OF CHEMICAL EDUCATION 2021年第12期98卷 3904-3914页

作者： Scalfani, Vincent F. Univ Alabama Rodgers Lib Sci & Engn Univ Lib Tuscaloosa AL 35487 USA

The National Center for Biotechnology Informa-tion Entrez Direct (EDirect) software facilitates programmatic access to numerous biomedical, chemical, and literature databases from within a Unix terminal. EDirect has traditionally been used for command line access to NCBI data within the fields of computational biology and bioinformatics. This Article describes how EDirect can be used for programmatic retrieval of small molecule and related chemical information from the PubChem and PubMed databases, useful for the chemical and cheminformatics communities. Several use cases are presented that demonstrate using EDirect in applications such as retrieving small molecule chemical property information, compound bibliometric data, and literature references. In addition, more advanced use cases are discussed that demonstrate how to incorporate EDirect searches into reproducible data analysis workflows, for example, with data visualization programs and cheminformatics toolkits. Since EDirect is a collection of command line programs, the syntax to perform programmatic search queries and related operations is simplified and suitable for beginners. This is in contrast to common approaches of programmatic chemical information searching using computational notebooks that may require additional training and computer programming skills. As a result of the more beginner friendly learning curve, EDirect may be particularly useful for chemical information professionals that often teach one time workshops where there is limited time to introduce programming concepts to students. This Article concludes with an example implementation of teaching EDirect and a review of the limitations. Approximately 20 EDirect scripts useful for programmatic small molecule chemical information searching are included in this Article and in the Supporting Information. All EDirect scripts shared have a permissible open source license, and educators are highly encouraged to adapt the scripts and workflows as

关键词： Upper-Division Undergraduate Graduate Education Research Chemoinformatics computer-based learning Chemometrics

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Developing a Simple and Cost-Effective Markerless Augmented Reality Tool for Chemistry Education

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JOURNAL OF CHEMICAL EDUCATION 2021年第5期98卷 1783-1788页

作者： Abdinejad, Maryam Ferrag, Celia Qorbani, Hossain S. Dalili, Shadi Univ Toronto Scarborough Dept Phys & Environm Sci Toronto ON M1C 1A4 Canada Carleton Univ Sch Informat Technol Ottawa ON K1S 5B6 Canada

Traditional visualization methods have a limited capacity to enhance students' understanding of 3D molecular structure and reactivity. Studies have shown that 3D visualization tools can play an essential role in improving students' learning. Augmented reality (AR) is a technology that merges virtual objects with real-world images seamlessly. We have previously developed a "marker-based" AR app (ARchemy) for Android devices to help students visualize molecular structures in 3D. Using recent technological advancements, to avoid the limitation of using a printed marker, we have successfully developed a simple and low-cost "markerless" AR app, which can be used for both Android and iOS devices. Students who used the AR app saw a significant increase in understanding of the complexity of molecular structures compared to those who used traditional molecular modeling kits. This unique technology will not only help teachers create more interactive and engaging lessons but also benefit students by making it more accessible and cost-effective to access the resources from any place and at any time.

关键词： computer-based learning Molecular Mechanics/Dynamics Molecular Modeling Molecular Properties/Structure Organic Chemistry/Online learning

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Quantification of Nitrite in Food and Water Samples Using the Griess Assay and Digital Images Acquired Using a Desktop Scanner

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JOURNAL OF CHEMICAL EDUCATION 2021年第10期98卷 3303-3311页

作者： Filgueiras, Matheus Fernandes de Jesus, Paulo Cesar Borges, Endler Marcel Fundacao Univ Reg Blumenau FURB Dept Quim BR-89012900 Blumenau SC Brazil

The Griess assay is widely used by regulation agencies as an official method for nitrite quantification in water and food samples. In Brazil, the official method, which has been used to determine nitrite in food, was described by Instituto Adolfo Lutz (283/IV) in 1984. It uses 8 mL of reactants and provides 50 mL (reactants plus sample) of waste per sample analyzed. Here, students scaled down the official method 50 times and quantified nitrite in water and food samples by using just 0.2 mL of the Griess reactant and 1 mL of sample. Quantitative analysis was carried out using absorbance measured at 540 nm (standard method) and 96-well-plate images (proposed method) obtained with a desktop scanner. The nitrite was extracted from solid food samples by heating it in a water bath. After heating, sample color and turbidity were eliminated by addition of K-4[Fe(CN)(6)] and ZnSO4 solutions and filtering. During samples preparation, students evaluate the heating time effect in nitrite extraction from sausage samples using hypothesis tests. Students did a series of matrix matched samples to observe the matrix effect. Students also calculated the detection limit (DL) and the quantification limit (QL) for the proposed method (1.35 and 4.1 mu mol/L nitrite, respectively) and for the standard method (1.1 and 3.4 mu mol/L nitrite, respectively). DL and QL were determined using the standard deviation of the lowest concentration point on the standard curve. The major pedagogical value of this laboratory class was to scale down the official method and use it to prepare and analyze a solid food sample. As a learning model, finding real water samples, which have nitrite concentrations larger than method QL, was a hard task, but all sausage samples analyzed had larger nitrate concentrations than the method QL and nitrite quantification in sausages was a good learning model.

关键词： Second-Year Undergraduate Analytical Chemistry Laboratory Instruction computer-based learning Instrumental Methods UV-Vis Spectroscopy Hands-On learning/Manipulatives Calibration

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Mimicking Students' Behavior during a Titration Experiment: Designing a Digital Student-Centered Experimental Environment

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JOURNAL OF CHEMICAL EDUCATION 2021年第6期98卷 1919-1927页

作者： Groos, Lukas Maass, Kai Graulich, Nicole Justus Liebig Univ Giessen Inst Chem Educ D-35392 Giessen Germany

More than ever, there is an increasing need for digital experimental learning environments in chemistry. The variety of digital learning approaches provided to students range from simple videos showing experiments to highly interactive virtual laboratories. Regardless of which approach is chosen, a digital learning environment should be adapted to students' authentic behavior in the laboratory. A special focus should be placed on their experimental skills to ensure that they are adequately prepared for the laboratory. Herein, we report how we designed a student-centered experimental environment on the basis of our observations of students' authentic behavior and their actions in the laboratory during a titration. Our work is based on three quality factors: individuality, interactivity, and realism. Therefore, the derived digital environment mimics students' decisions in the laboratory and allows a high degree of student-centeredness. In this article, we describe three aspects of the study: (I) how to convert students' actions into decision trees, (II) how to set up the titration digitally, and (III) how the targeted cohort of students rated the usability.

关键词： computer-based learning First-Year Undergraduate/General Laboratory Instruction Multimedia-based learning Qualitative Analysis Titration/Volumetric Analysis

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Designing and Implementing VR²E²C, a Virtual Reality Remote Education for Experimental Chemistry System

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JOURNAL OF CHEMICAL EDUCATION 2021年第8期98卷 2720-2725页

作者： Lu, Yihua Xu, Yao Zhu, Xi Chinese Univ Hong Kong Shenzhen Inst Artificial Intelligence & Robot Soc Shenzhen 518172 Guangdong Peoples R China

In this work, we introduce the (VREC)-E-2-C-2 system for Virtual Reality Remote Education for Experimental Chemistry. It aims to increase scientific literacy about remote education of theoretical and experimental chemistry among the public and high school students. It provides a laboratory option for students with disabilities who are keen on chemistry experiments but have limited mobility. (VREC)-E-2-C-2 provides three modes to accomplish the training: users can choose to control the intelligent robot to finish the experimental operations by instruction or choose to watch the experiments automatically conducted by (VREC)-E-2-C-2. The experimental results can be delivered to users in real time or later. This system provides remote education for safe and high fault-tolerant experimental topics, demonstrating how the latest VR and robotics technology could benefit traditional chemical education.

关键词： Graduate Education/Research Chemical Education Research Laboratory Instruction computer-based learning Spectroscopy Inorganic Chemistry

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Implementing Project-based learning as an Effective Alternative Approach for Chemistry Practical Courses Online

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JOURNAL OF CHEMICAL EDUCATION 2021年第11期98卷 3502-3508页

作者： Vergara-Castaneda, Arely Chavez-Miyauchi, Tomas-Eduardo Benitez-Rico, Adriana Ogando-Justo, Ana-Belen Univ La Salle Mexico Invest Ciudad De Mexico 06140 Mexico Univ La Salle Mexico Fac Ciencias Quim Ciudad De Mexico 06140 Mexico

Actions taken to control the propagation of COVID-19 forced most activities to switch into an online environment. Education was no exception. In most of the cases the transition turned out well, and online education proved to be a good alternative to the traditional model. However, in the case of practical courses, the situation is quite different because students do not acquire the abilities they would obtain by practical experience. A project-based learning (PBL) approach has been evaluated at the Chemical Sciences Department of Universidad La Salle Mexico as an alternative to practical courses. Two different experiences are depicted. Their structure and implications are explained, as well as the student and teachers' appreciation. It was observed that the strategy showed good results, by demonstrating qualitatively that students appropriated the knowledge of the courses, and although students struggled to adapt to the work, they were motivated. PBL was demonstrated to be effective in developing soft skills such as communication, teamwork, and problem and conflict solving. Although this approach may not substitute for the practical experience, it proved to be a good alternative to instill students with abilities that are necessary in the practical field.

关键词： computer-based learning Distance learning/Self Instruction Problem Solving/Decision Making Collaborative/Cooperative learning

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