Chemical Experiments Research Articles

“I Feel Like a Real Chemist Right Now”: Epistemic Affect as a Fundamental Driver of Inquiry in the Chemistry Laboratory

ABSTRACTAffect and emotions matter to science learning. They also matter because they are integral to science identity formation and sense of belonging. This study aims to foreground the epistemic and affective character of laboratory work in higher science education by conceptualizing it as epistemic practice, in which students activate their body and mind in discursive processes of proposing, communicating, and evaluating knowledge. On this conceptualization is an emerging construct, “epistemic affect,” which refers to how one feels when engaging with epistemic practices. Several methods were used to provide triangulated evidence for student learning processes and lived experiences in the chemistry laboratory. Students were observed and interviewed using custom protocols based on previously validated works. The empirical materials consist of audio recordings and transcripts of focus group interviews, audio and video recordings of students doing an experiment in analytical chemistry, verbatim transcripts of utterances and non‐verbal cues, as well as instructional artifacts (laboratory manuals, textbooks, and reports). Key findings from the study reveal a range of epistemic emotions experienced by students, including curiosity, frustration, and joy, which are intertwined with their engagement in experimental work and exploration of scientific principles. The study also identifies affective constructs such as confidence, pride, and humility, which contribute to students’ identity development within the context of laboratory‐related epistemic practices. These affective experiences are situated in the embodied nature of laboratory work, where failures and mistakes are common, but also serve as opportunities for learning. The research underscores the importance of recognizing and addressing the affective dimensions of learning in the chemistry laboratory. It suggests that fostering positive epistemic emotions and resolving negative ones can enhance students’ learning experiences and engagement with science. The study calls for a more holistic approach to chemistry education that acknowledges the role of emotion in laboratory‐related epistemic practices.

In-Situ Photoreaction Quantum Yield Measurements and Red-Light Actinometry Using Methylene Blue and Ascorbic Acid: Experiments for Analytical and Physical Chemistry

In-Situ Photoreaction Quantum Yield Measurements and Red-Light Actinometry Using Methylene Blue and Ascorbic Acid: Experiments for Analytical and Physical Chemistry

Cavity induced modulation of intramolecular vibrational energy flow pathways.

Recent experiments in polariton chemistry indicate that reaction rates can be significantly enhanced or suppressed inside an optical cavity. One possible explanation for the rate modulation involves the cavity mode altering the intramolecular vibrational energy redistribution (IVR) pathways by coupling to specific molecular vibrations in the vibrational strong coupling (VSC) regime. However, the mechanism for such a cavity-mediated modulation of IVR is yet to be understood. In a recent study, Ahn et al. [Science 380, 1165 (2023)] observed that the rate of alcoholysis of phenyl isocyanate (PHI) is considerably suppressed when the cavity mode is tuned to be resonant with the isocyanate (NCO) stretching mode of PHI. Here, we analyze the quantum and classical IVR dynamics of a model effective Hamiltonian for PHI involving the high-frequency NCO-stretch mode and two of the key low-frequency phenyl ring modes. We compute various indicators of the extent of IVR in the cavity-molecule system and show that tuning the cavity frequency to the NCO-stretching mode strongly perturbs the cavity-free IVR pathways. Subsequent IVR dynamics involving the cavity and the molecular anharmonic resonances lead to efficient scrambling of an initial NCO-stretching overtone state over the molecular quantum number space. We also show that the hybrid light-matter states of the effective Hamiltonian undergo a localization-delocalization transition in the VSC regime.

ORGANA: A robotic assistant for automated chemistry experimentation and characterization

ORGANA: A robotic assistant for automated chemistry experimentation and characterization

Comprehensive undergraduate experiment: determination of phenylurea herbicide in tea by magnetic solid-phase extraction-high performance liquid chromatography

Against the backdrop of the Ministry of Education's promotion of new agricultural science construction and interdisciplinary integration, a comprehensive chemistry experiment to enhance the practical skills of students in preparing biomass functional materials and detecting pesticide residues was designed. Natural loofah was utilized as a precursor in synthesizing nitrogen-doped magnetic porous carbon materials, which were then applied in a magnetic solid-phase extraction (MSPE) technique. Subsequently, high performance liquid chromatography (HPLC) was employed to analyze and detect the phenylurea herbicide monuron in tea. The experimental process included material synthesis, characterization, optimization of the MSPE conditions, adsorption performance studies, and HPLC, reflecting its scientific, systematic nature and providing a comprehensive learning platform for students. It not only deepens student understanding of the relationship between material characterization and application, but also improves their experimental design and problem-solving capacities. Moreover, by integrating cutting-edge science, ideological and political education, and experimental training, it not only stimulates student interest in scientific research and cultivates innovative thinking and practical skills, but also strengthens their feelings of social responsibility and historical mission. This approach realizes the comprehensive educational goals of experimental training and lays the foundation for nurturing high-quality talent with a global perspective and sense of social responsibility.

A mitochondrial redox switch licenses the onset of morphogenesis in animals.

Embryos undergo pre-gastrulation cleavage cycles to generate a critical cell mass before transitioning to morphogenesis. The molecular underpinnings of this transition have traditionally centered on zygotic chromatin remodeling and genome activation1,2, as their repression can prevent downstream processes of differentiation and organogenesis. Despite precedents that oxygen depletion can similarly suspend development in early embryos3-6, hinting at a pivotal role for oxygen metabolism in this transition, whether there is a bona fide chemical switch that licenses the onset of morphogenesis remains unknown. Here we discover that a mitochondrial oxidant acts as a metabolic switch to license the onset of animal morphogenesis. Concomitant with the instatement of mitochondrial membrane potential, we found a burst-like accumulation of mitochondrial superoxide (O2 -) during fly blastoderm formation. In vivo chemistry experiments revealed that an electron leak from site IIIQo at ETC Complex III is responsible for O2 - production. Importantly, depleting mitochondrial O2 - fully mimics anoxic conditions and, like anoxia, induces suspended animation prior to morphogenesis, but not after. Specifically, H2O2, and not ONOO-, NO, or HO•, can single-handedly account for this mtROS-based response. We demonstrate that depleting mitochondrial O2 - similarly prevents the onset of morphogenetic events in vertebrate embryos and ichthyosporea, close relatives of animals. We postulate that such redox-based metabolic licensing of morphogenesis is an ancient trait of holozoans that couples the availability of oxygen to development, conserved from early-diverging animal relatives to vertebrates.

The rebirth of home chemistry experiments: An international perspective and the Ukrainian context

The use of home chemistry experiments has experienced a resurgence in recent years, particularly in light of the COVID-19 pandemic and the need for remote learning solutions. This perspective article examines the rebirth of home chemistry experiments from an international viewpoint, with a specific focus on the Ukrainian context. We differentiate between household and home chemistry experiments, discussing their advantages and challenges based on the work of Ukrainian educator Andrii Kyrylovych Hrabovyi and recent studies. The impact of home chemistry experiments on chemistry education is explored through international case studies from the United States, Finland, South Africa, and Brazil. We argue that even with the return to normal learning conditions in Ukrainian schools, home chemistry experiments should occupy a leading position among the means of teaching chemistry due to their ability to develop design and research skills, foster a caring attitude towards nature, and promote interest in studying chemistry. The experience of Luis Eduardo Doná in developing a home chemistry laboratory kit using affordable and accessible materials is highlighted as an example of how such initiatives can bridge the gap between theoretical learning and practical applications. We conclude that while home chemistry experiments remain a necessity in Ukraine, a review of their role in chemical education worldwide can be a significant step towards improving the quality of chemistry education.

Investigating the vertical extent of the 2023 summer Canadian wildfire impacts with satellite observations

Abstract. Pyrocumulonimbus clouds (pyroCbs) generated by intense wildfires can serve as a direct pathway for the injection of aerosols and gaseous pollutants into the lower stratosphere, resulting in significant chemical, radiative, and dynamical changes. Canada experienced an extremely severe wildfire season in 2023, with a total area burned that substantially exceeded those of previous events known to have impacted the stratosphere (such as the 2020 Australian fires). This season also had record-high pyroCb activity, which raises the question of whether the 2023 Canadian event resulted in significant stratospheric perturbations. Here, we investigate this anomalous wildfire season using retrievals from multiple satellite instruments, ACE-FTS (Atmospheric Chemistry Experiment – Fourier transform spectrometer), OMPS LP (Ozone Mapping and Profiler Suite Limb Profiler), and MLS (Microwave Limb Sounder), to determine the vertical extents of the wildfire smoke along with chemical signatures of biomass burning. These data show that smoke primarily reached the upper troposphere, and only a nominal amount managed to penetrate the tropopause. Only a few ACE-FTS occultations captured elevated abundances of biomass-burning products in the lowermost stratosphere. OMPS LP aerosol measurements also indicate that any smoke that made it past the tropopause did not last long enough or reach high enough to significantly perturb stratospheric composition. While this work focuses on Canadian wildfires given the extensive burned area, pyroCbs at other longitudes (e.g., Siberia) are also captured in the compositional analysis. These results highlight that despite the formation of many pyroCbs in major wildfires, those capable of penetrating the tropopause are extremely rare; this in turn means that even a massive area burned is not necessarily an indicator of stratospheric effects.

Sulfur dioxide sources in the stratosphere

Version 5.2 SO2 data from the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) in low Earth orbit are used to determine global altitude–latitude abundance distributions. This new data set has SO2 volume mixing ratios (VMRs) from 11.5 to 39.5 km in altitude from February 2004 to July 2023. The average background SO2 abundance is plotted along with the abundance for four different seasons. These distributions show that there is a stratospheric source of SO2 that comes from the decline in sulfate aerosol abundance with increasing altitude. The visible and near-infrared photolysis of sulfuric acid (H2SO4) is the primary source of SO2 in the middle stratosphere. There is also a source of SO2 in the upper stratosphere and mesosphere. The Brewer-Dobson circulation enhances SO2 at higher altitudes, particularly by descent near the winter pole. The elevated abundance of SO2 near the poles originates from meteoric sources as well as UV photolysis of H2SO4 in the mesosphere. Large volcanic eruptions release sulfur dioxide (SO2) into the lower stratosphere, where it persists for several months.

The first satellite measurements of HFC-125 by the ACE-FTS: Long-term trends and distribution in the Earth’s upper troposphere and lower stratosphere

HFC-125 (CF3CHF2, pentafluoroethane) volume mixing ratios (VMRs) have been determined for the first time using infrared absorption spectra from the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) from 2004 to 2024. These VMRs provide global altitude-latitude VMR distributions. A VMR time series for HFC-125 has also been calculated and compared to values from in situ discrete flask measurements conducted by the National Oceanic and Atmospheric Administration Earth System Research Laboratory. The abundance of HFC-125 is currently experiencing exponential growth. ACE data shows a growth rate of 3.47 ± 0.05 ppt/year in the past six years.

A virtual 3D Chemistry Escape Room for Exam Preparations

Chemistry can be incredibly captivating. However, learning the theory can often be challenging and less appealing for students. Providing them with hands-on methods in their learning process is beneficial and also helps to lower the barrier for understanding theory. In a gamified approach, the "ChemScape" virtual 3D chemistry escape room, designed as a realistic laboratory with various equipment and hidden chemical tasks, can help solidify chemical knowledge and prepare students for chemistry exams. In 2023, as part of an e-learning project, the foundation of such a chemistry escape room was established, and several chemical questions were incorporated as escape room tasks. The objective is to discover hidden questions within the laboratory, utilize different instruments (such as scales), conduct virtual chemistry experiments, and solve various chemistry questions using theoretical knowledge (such as nomenclature and understanding of pH) in a game-based setting (utilizing multiple-choice, drag and drop, connecting cables, solving color codes, etc.). Typically, a code (comprising numbers, letters, signs, etc.) needs to be obtained for progression. To solve the chemistry tasks, approximately 10 different door-openers have been developed. Initial user tests have been conducted, and adjustments were made based on the feedback received, which was satisfactory and positive. In 2024, the "ChemScape" escape room will evolve from a game with a fixed set of tasks to a dynamic escape room game with a dynamic database that allows for the creation of new questions at the same stations, significantly expanding learning opportunities. A virtual chemistry laboratory rat provides hints if a participant gets stuck and requires assistance. Furthermore, "ChemScape" will be trialed in chemistry lectures and potentially utilized as an additional attraction at events held at the University of Applied Sciences.

Видео експериментът в обучението модел за приложението му при изучаване на химия и опазване на околната среда

In this paper, the focus is on the video experiment in learning. Its application in the teaching of Chemistry and Environmental Protection is justified. A model for the planning and implementation of video experiments in education is developed and presented through its main components in their interrelation and conditioning. The guiding idea on which the proposed model is based is the development of interest in the study of chemical science and the creation of conditions for the development of key competencies in science. The model is concretized and tested in the practice of organic chemistry education. On the basis of the proposed model 11 educational videos have been created, the applicability of which has been established by expert evaluation. For the implementation of the expertise, requirements for the virtual chemistry experiments have been defined, which can be used for both formative (in-process) and final assessment.

In Situ Growth of COFs within Cork for Oil–Water Separation: A Comprehensive Chemistry Experiment for Undergraduates

In Situ Growth of COFs within Cork for Oil–Water Separation: A Comprehensive Chemistry Experiment for Undergraduates

A Trend Analysis of Project-based Learning in Chemistry Experiment: A Bibliometric Analysis

Project-based learning is a global trend, widely adopted across countries. Project-based learning has developed diversely by emphasizing interdisciplinary, cross-domain, and regional collaboration. To provide in-depth resources for researchers and educators on project-based learning in chemistry experiments, this study aims to make a bibliometric analysis on the topic of project-based learning globally using publication characteristics analysis. The database used in this study used Scopus and obtained 5900 articles from 2018-2023. Bibliometric analysis was analyzed using VOSviewer and Microsoft Excel. The results of the bibliometric analysis show that Boone, C.D. is the author with the highest number of citations on the research topic, Project-based learning in a chemistry experiment. The United States is the most productive country in researching this topic, with 1351 articles. The most influential journal with the highest number of articles is the Journal of Physics Conference Series, with 243 articles. The major contextualized learning literatures in this study tend to fall into broad groups such as Project-based Learning, Education, and STEM Education. These findings suggest the need for multidisciplinary and cross-disciplinary studies on project-based learning research on chemistry learning and advocate for the inclusion of project-based learning research in education from a broader geographical context.

An Automated Electrochemical Flow Platform to Accelerate Library Synthesis and Reaction Optimization

Automated batch and flow reactors are well‐established for high throughput experimentation in both thermal chemistry and photochemistry. However, the development of automated electrochemical platforms is hindered by cell miniaturization challenges in batch and difficulties in designing effective single‐pass flow systems. In order to address these issues, we have designed and implemented a new, slug‐based automated electrochemical flow platform. This platform was successfully demonstrated for electrochemical C‐N cross‐couplings of E3 ligase binders with diverse amines (44 examples), which were subsequently transferred to a continuous‐flow mode for confirmation and isolation, showing its applicability for medicinal chemistry purposes. To further validate the versatility of the platform, Design of Experiments (DoE) optimization was performed for an unsuccessful library target. This optimization process, fully automated by the platform, resulted in a remarkable 6‐fold increase in reaction yield.

An Automated Electrochemical Flow Platform to Accelerate Library Synthesis and Reaction Optimization.

Automated batch and flow setups are well-established for high throughput experimentation in both thermal chemistry and photochemistry. However, the development of automated electrochemical platforms is hindered by cell miniaturization challenges in batch and difficulties in designing effective single-pass flow systems. In order to address these issues, we have designed and implemented a new, slug-based automated electrochemical flow platform. This platform was successfully demonstrated for electrochemical C-N cross-couplings of E3 ligase binders with diverse amines (44 examples), which were subsequently transferred to a continuous-flow mode for confirmation and isolation, showing its applicability for medicinal chemistry purposes. To further validate the versatility of the platform, Design of Experiments (DoE) optimization was performed for an unsuccessful library target. This optimization process, fully automated by the platform, resulted in a remarkable 6-fold increase in reaction yield.

TIMM9 as a prognostic biomarker in multiple cancers and its associated biological processes

TIMM9 has been identified as a mediator of essential functions in mitochondria, but its association with pan-cancer is poorly understood. We herein employed bioinformatics, computational chemistry techniques and experiments to investigate the role of TIMM9 in pan-cancer. Our analysis revealed that overexpression of TIMM9 was significantly associated with tumorigenesis, pathological stage progression, and metastasis. Missense mutations (particularly the S49L variant), copy number variations (CNV) and methylation alterations in TIMM9 were found to be associated with poor cancer prognosis. Moreover, TIMM9 was positively related with cell cycle progression, mitochondrial and ribosomal function, oxidative phosphorylation, TCA cycle activity, innate and adaptive immunity. Additionally, we discovered that TIMM9 could be regulated by cancer-associated signaling pathways, such as the mTOR pathway. Using molecular simulations, we identified ITFG1 as the protein that has the strongest physical association with TIMM9, which show a promising structural complement.

Atmospheric pressure atomic layer deposition for in-channel surface modification of PDMS microfluidic chips

Polydimethylsiloxane (PDMS) is one of the materials of choice for the fabrication of microfluidic chips. However, its broad application is constrained by its incompatibility with common organic solvents and the absence of surface anchoring groups for surface functionalization. Current solutions involving bulk-, ex-situ surface-, and in-situ liquid phase modifications are limited and practically demanding. In this work, we present a simple, novel strategy to deposit a metal oxide nano-layer on the inside of bonded PDMS microfluidic channels using atmospheric pressure atomic layer deposition (AP-ALD). Using three important classes of microfluidic experiments, i.e., (i) the production of micron-sized particles, (ii) the cultivation of biological cells, and (iii) the photocatalytic degradation in continuous flow chemistry, we demonstrate that the metal oxide nano-layer offers a higher resistance against organic solvent swelling, higher hydrophilicity, and a higher degree of further functionalization of the wall. We demonstrate the versatility of the approach by not only depositing SiOx nano-layers, but also TiOx nano-layers, which in the case of the flow chemistry experiment were further functionalized with gold nanoparticles through the use of AP-ALD. This study demonstrates AP-ALD as a tool to broaden the applicability of PDMS devices.

Research on Teaching Reform of Chemistry Experimental Course under New Engineering Background

With the proposal of new engineering education concept, new challenges are posed to the teaching reform of chemical experiment course. This study aims to explore the teaching reform path of chemistry experiment course under the new engineering background, so as to improve the students' practical ability and innovation ability. As an important part of engineering education, the teaching objectives of chemistry experiment should be consistent with the new engineering education concept, and pay attention to cultivating students' ability to solve practical problems and teamwork spirit. At present, there are some problems in chemistry experiment teaching, such as outdated curriculum system, too theoretical experiment content, lack of combination with engineering practice, and low participation of students. These problems restrict the improvement of teaching quality, and can not meet the needs of new engineering education for talent training. Therefore, the primary task of the reform is to update the experimental curriculum system and integrate more experimental projects with engineering background and cutting-edge technology, in order to improve the practicality and challenge of the experiment. In terms of reform strategies, it is suggested to implement the "student-centered" teaching mode, and encourage students to take the initiative to explore and innovate through project-driven and problem-oriented teaching methods. At the same time, strengthen the integration of experimental teaching and theoretical teaching, so that students can deepen the understanding of theoretical knowledge in the experiment, and use theoretical knowledge to solve practical problems. In addition, the information level of experimental teaching should be improved, and virtual simulation and other technologies should be used to expand the space-time dimension of experimental teaching and improve the teaching effect. The change of the role of teachers is also the key. Teachers should change from the teacher of knowledge to the guide and collaborator of students' learning. By building an open and interactive classroom environment, stimulate students' interest in learning and innovative thinking. At the same time, the establishment of a diversified evaluation system, in addition to the investigation of students' experimental skills, but also should pay attention to the evaluation of their innovative thinking, teamwork and solving practical problems. To sum up, the teaching reform of chemistry experimental curriculum under the background of new engineering should focus on the update of curriculum content, the transformation of teaching mode, the integration of teaching resources and the reform of evaluation system. Through the implementation of these strategies, it aims to build an experimental teaching system that can not only meet the needs of new engineering education, but also cultivate high-quality chemical engineering talents. Such reform is of great significance to enhance the competitiveness of chemical engineering education in China.

Correction to “Shrimp-Shell-Derived Carbon Dots for Quantitative Detection by Fluorometry and Colorimetry: A New Analytic Chemistry Experiment for University Education”

Correction to “Shrimp-Shell-Derived Carbon Dots for Quantitative Detection by Fluorometry and Colorimetry: A New Analytic Chemistry Experiment for University Education”