Journal of Chemical Education最新文献

Artificial intelligence (AI) and automation techniques have promoted the rapid development of scientific fields such as chemistry, biomedicine, and materials science, where multiple variables and tremendous data collection are required in experiments. By incorporating machine learning (ML), an independently devised digital control system, and integrating custom-developed software into the sucrose hydrolysis experiment, intelligent identification of the polarimeter’s field of view and automatic data acquisition of the sucrose hydrolysis reaction are achieved. This innovation revolutionizes traditional experimental practices by replacing manual recognition and operation with automated processes, effectively addressing the inherent time-consuming and labor-intensive nature of conventional methods and thereby significantly improving experimental efficiency and accuracy. This novel, portable, and economical ML-based optical rotation measurement device will promote innovation in chemical experiment teaching models in the era of AI.

This paper outlines the development of a final examination for a first-semester general chemistry lab course that incorporates elements of the emerging assessment style ‘Specifications Grading’. Conducted across three semesters (Spring, Summer, and Fall 2022) at Southern Illinois University Edwardsville, the study gradually incorporated key elements, including early rubric access, skill evaluation at multiple checkpoints, pass/fail grading (eliminating partial credit), and an additional attempt for students who did not pass on their first try. In Fall 2022, supplementary initiatives such as manual modifications and practice lab final activities were introduced. Analyses of student performance and survey data indicate that semesters incorporating more Specifications Grading components were associated with higher pass rates and an improved perception of glassware proficiency in students. Students’ self-reported data revealed common student mistakes that may be informative to General Chemistry instructors, while teaching assistant surveys identified potential issues with implementing such an examination. Due to smaller sample sizes (<20) in the Spring and Summer and limitations on statistical rigor from confounding variables, our findings are best interpreted as an implementation report rather than generalizable educational research.

Everyday objects are often sources of inspiration for the study of materials. When aspiring scientists and engineers begin asking questions about the materials that comprise the objects around them─such as why different metal alloys have distinct colors or why jewelry often contains multiple precious metal elements─they are taking the first steps in discovering core concepts in Materials Science and Engineering. Here, we describe a laboratory at the intersection of art (jewelry making) and materials science that inspires students to investigate the processing and colorimetry of jewelry made from metal clays. Here, we focus on exploring key MSE concepts through (1) the use of accessible materials such as metal clays, (2) process design of the sintering stage through use of binary phase diagrams, and (3) metal alloy color design through empirical modeling using the CIELAB color space. Students ultimately design their own custom Cu–Ag alloy color and then fabricate a piece of jewelry that meets their color design specifications. We also highlight possible extensions for this laboratory, including mechanical characterization or patination. In addition, this laboratory is designed to be adapted for educational outreach and has been implemented in Chicago area secondary schools and with summer high school teachers through NIST- and NSF-supported programming.

This paper describes the implementation of a course-based undergraduate research experience focused on the design and evaluation of laboratory activities for students with visual impairment. In the project, students have demonstrated considerable initiative and creativity, designing a range of experiments and resources including olfactory and auditory titrations, use of nonstandard color indicators, tactile markings on standard laboratory equipment, and tactile models to explain chemistry concepts. Student perceptions of completing this CURE were gathered using interviews (N = 10) and analyzed using thematic analysis. Students perceived the project to enhance their transferable skills to a greater extent than other types of CUREs they had completed, particularly communication, teamwork, and problem-solving skills, likely due to a feeling that the projects were more autonomous. A significant proportion of students reported that the project had impacted decisions about future education or career directions. The projects were transformative in terms of shifting students’ perspective on inclusivity and increasing empathy for those whose experience of chemistry laboratories is very different from their own.

Carbon quantum dots (CQDs) are a prominent research topic in the fields of chemistry and interdisciplinary sciences. This paper presents a simple synthesis method for CQDs, aimed at introducing students to the preparation and application of nanomaterials. Through the use of nitrogen-doped CQDs, the experiment enables a systematic understanding of their structure, fluorescence mechanism, and potential applications in interdisciplinary fields, based on a comprehensive literature review. The fluorescence quantum yield of the CQDs was accurately determined using the reference method and characterized in detail using UV–vis, TEM, and XPS techniques. The innovation of this experiment lies in the combination of synthesized CQDs with poly(lactic acid) (PLA) powder, which, after drying, yields a white powder with prominent fluorescence properties. This material was then successfully used in 3D printing to produce a model of the “Lilac I” small satellite, demonstrating the potential application of CQDs in the field of 3D printing. The study further explores the prospects of this material in biomedical applications, particularly in the 3D printing of fluorescent probes. By integrating cutting-edge nanotechnology with traditional experimental teaching, this experiment not only enhances students’ engagement but also fosters their innovative thinking and comprehensive experimental skills.

Nanomaterial-based enzyme mimics, known as nanozymes, are extensively applied in chemical sensing and biomedical fields due to their low cost, high stability, and tunable catalytic activity. However, conventional synthesis methods employing hazardous chemicals limit their promotion in undergraduate laboratory training. Herein, an eco-friendly and simple green approach is proposed that utilizes plant extracts as natural reducing agents for nanozyme synthesis. Iron oxide nanozymes (Fe₃O₄ NZs) were synthesized using lemon peel extract, and their structures and properties were analyzed via SEM, XRD, XPS, and FT-IR. The peroxidase-like activity of Fe₃O₄ NZs was evaluated using a chromogenic substrate in the presence of H₂O₂. Additionally, their effectiveness in developing nanozyme-glucose oxidase (GOx) cascade colorimetric sensors for glucose detection was also demonstrated. These experiments have been successfully conducted at various undergraduate levels and have received positive feedback. Experimental assessments indicated that students’ understanding of green chemistry, catalytic mechanisms, and interdisciplinary applications of nanozymes had improved. Moreover, the flexible design of the experiment allows instructors to modify it based on students’ backgrounds, available equipment, and teaching objectives, making it applicable to multiple fields such as chemistry, materials science, and biology. This experiment provides a generalizable case for integrating cutting-edge technology into undergraduate education.

We describe an interdisciplinary medicinal plant course that integrates chemistry, botany, and cultural history in an immersive, study-abroad setting. By examining phytochemicals within their botanical and ecological contexts, students connect molecular science to real-world applications, enhancing their engagement and accessibility. Study-abroad experiences further enrich learning through hands-on exploration and interdisciplinary collaboration. As global citizenship gains emphasis in higher education, this model offers a compelling framework for integrating science with cultural perspectives, benefiting both students and faculty.

An experiment designed to teach principles of continuous flow technologies for photocatalysis is described as a part of a two-week summer camp program for high school students. Students learned about green chemistry, photocatalysis, flow chemistry, and the role of 3D printing in the design and production of custom millifluidic reactors. Students examined reactor designs that differed in terms of residence times and mixing capabilities. Such evaluation was based on the combination of blue and yellow dyes, followed by running a photocatalytic thiol–ene reaction on a gram-scale.

Nearly every high school and college introductory chemistry course features a treatment of Planck’s constant. This naturally arises in the context of studying the Bohr model of the atom and the nature of the electron─Planck’s constant is key to explaining atomic emission/absorption spectra, which provide evidence for the quantized energy levels for electrons. In this study, we sought to implement an interactive demonstration that provides a simple, straightforward determination of Planck’s constant by showing how the energy of a photon correlates with its frequency. The class demonstration used a hand-held module that facilitated the measurement of band gap voltage for several differently colored LEDs. The demonstration is best suited for high school and first-year college chemistry students and can be performed in approximately half an hour.

This study presents an innovative blended instructional model that integrates problem-based learning (PBL) and flipped classroom (FC) methodologies into the physical chemistry laboratory course at Hainan University, China. It specifically addresses the limitations of traditional instruction, such as passive learning, and insufficient individualized feedback. Grounded in outcome-based education (OBE) theory and facilitated through the “Wisdom Tree” online platform, this model aims to enhance students’ understanding of both fundamental principles and practical techniques in physical chemistry laboratory course, while simultaneously fostering their higher-order cognitive skills. Over 90% of the students reported increased essential problem-solving and analytical skills crucial for experimental work, while fostering effective teamwork ─key learning outcomes that align with contemporary priorities in chemistry education. To implement this model, we developed and introduced a series of self-designed instructional materials, including instructional videos, presentation slides, and problem sets, for implementation across three engineering disciplines at the second-year undergraduate level. The implementation process and assessment methodology are described in detail. The postintervention assessment indicated that the teaching method effectively supported students in achieving learning objectives across three key areas: instrument operation, adherence to rigorous scientific integrity, and data processing competence. However, the evaluations also highlighted that higher-order cognitive skills─specifically in teamwork and communication skills, as well as in analysis and experimental evaluation─ remained a relative weakness, necessitating further development.