Pub Date : 2023-02-07DOI: 10.5923/j.jlce.20231101.01
Omar A. El Seoud, Nicolas Keppeler, Maria Helena Zambelli
{"title":"Sustainable Fuels for High School Students: Synthesis of Biodiesel from an Amazon Region Oil (Babassu)","authors":"Omar A. El Seoud, Nicolas Keppeler, Maria Helena Zambelli","doi":"10.5923/j.jlce.20231101.01","DOIUrl":"https://doi.org/10.5923/j.jlce.20231101.01","url":null,"abstract":"","PeriodicalId":91121,"journal":{"name":"Journal of laboratory chemical education","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72685195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-22DOI: 10.5923/j.jlce.20210903.02
Nicolas Keppeler, Matheus Costa Lourenço, Omar A. El Seoud
{"title":"Distance Teaching of the Undergraduate Laboratory During Pandemic Time: Dissolution of Cellulose in Mixtures of Ionic Liquids and Dimethyl Sulfoxide and Biopolymer Regeneration as Films","authors":"Nicolas Keppeler, Matheus Costa Lourenço, Omar A. El Seoud","doi":"10.5923/j.jlce.20210903.02","DOIUrl":"https://doi.org/10.5923/j.jlce.20210903.02","url":null,"abstract":"","PeriodicalId":91121,"journal":{"name":"Journal of laboratory chemical education","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77683877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-31DOI: 10.5923/j.jlce.20200801.03
O. A. Seoud, Nicolas Keppeler
We introduced an undergraduate chemistry project within the framework of education for sustainable development (ESD). The objective of the first part was to demonstrate the efficiency of an ionic liquid (IL)- 1-(n-butyl)-3-methylimidazolium acetate (BuMeImAcO)- as solvent for the dissolution, and subsequent regeneration of cellulose as fiber. Under mechanical stirring, the students dissolved microcrystalline cellulose in a mixture of BuMeImAcO-dimethyl sulfoxide (DMSO) at 80°C. Subsequently, they dyed the dissolved cellulose with a reactive dye, and regenerated (pink) colored fibers by injecting the resulting biopolymer solution into water (a non-solvent for cellulose). The objective of the second experiment was to show the potential application of BuMeImAcO-DMSO for the chemical recycling of the cellulosic component of polycotton (cellulose: polyethylene terephthalate; PET). Cellulose dissolves under the above-mentioned experimental conditions, leaving a mat of PET. The students dyed the dissolved cellulose, and then regenerated the biopolymer as fiber. This project fits the following aspects of ESD: fiber production from renewable sources other than cotton (wood-based cellulose); recycling of cellulose from its blends with synthetic polymers, when their reuse is not feasible. We recommend this project for senior science students of, e.g., chemistry, engineering and pharmacy, because of its simplicity, safety and socioeconomic relevance.
{"title":"Education for Sustainable Development: An Undergraduate Chemistry Project on Cellulose Dissolution, Regeneration, and Chemical Recycling of Polycotton","authors":"O. A. Seoud, Nicolas Keppeler","doi":"10.5923/j.jlce.20200801.03","DOIUrl":"https://doi.org/10.5923/j.jlce.20200801.03","url":null,"abstract":"We introduced an undergraduate chemistry project within the framework of education for sustainable development (ESD). The objective of the first part was to demonstrate the efficiency of an ionic liquid (IL)- 1-(n-butyl)-3-methylimidazolium acetate (BuMeImAcO)- as solvent for the dissolution, and subsequent regeneration of cellulose as fiber. Under mechanical stirring, the students dissolved microcrystalline cellulose in a mixture of BuMeImAcO-dimethyl sulfoxide (DMSO) at 80°C. Subsequently, they dyed the dissolved cellulose with a reactive dye, and regenerated (pink) colored fibers by injecting the resulting biopolymer solution into water (a non-solvent for cellulose). The objective of the second experiment was to show the potential application of BuMeImAcO-DMSO for the chemical recycling of the cellulosic component of polycotton (cellulose: polyethylene terephthalate; PET). Cellulose dissolves under the above-mentioned experimental conditions, leaving a mat of PET. The students dyed the dissolved cellulose, and then regenerated the biopolymer as fiber. This project fits the following aspects of ESD: fiber production from renewable sources other than cotton (wood-based cellulose); recycling of cellulose from its blends with synthetic polymers, when their reuse is not feasible. We recommend this project for senior science students of, e.g., chemistry, engineering and pharmacy, because of its simplicity, safety and socioeconomic relevance.","PeriodicalId":91121,"journal":{"name":"Journal of laboratory chemical education","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90901812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-15DOI: 10.5923/j.jlce.20200802.03
O. A. Seoud, L. Novaki, Nicolas Keppeler, A. M. Chinelatto, S. S. Santos, Vânia Silva
Guarana is a tropical fruit that grows in the Amazon basin and the northeastern part of Brazil, from which a popular soft drink is manufactured. The main methylxanthine (MX) in the guarana powder is caffeine (CF); theobromine (TB) and theophylline (TP) are also present in much lower concentrations. Because of the popularity of this soft drink, and the stimulating effects of MXs, we introduced an undergraduate chemistry project on their extraction from guarana powder and subsequent analysis. A literature survey showed that there is some variation in the values of λmax and emax of the three MXs. Using purified authentic samples, we showed that values of λmax and emax of CF, TB and TP are very close. Consequently, their concentrations in guarana extract cannot be calculated using a single technique (UV-Vis). After discussing this problem with the students, the following project was carried out: (i) guarana powder was extracted with acidified aqueous ethanol under different experimental conditions (alcohol volume fraction in the binary solvent mixture, ; powder extraction time, t); (ii) the apparent CF concentration was calculated from the absorbance of the extract at λmax = 272.5 nm; (iii) the extracts were analyzed by high performance liquid chromatography; the three MXs were identified in the chromatograms using internal standards, and the true [CF] calculated. Stage (i) involved use of chemometrics to optimize powder extraction, and to get information on the relative importance of the experimental variables ( is more important than t). Stage (ii) was a straightforward application of Beer’s law. Stage (iii) demonstrated the power of using tandem techniques to solve complex, everyday situation, namely the separation and analysis of biologically active components in consumer products (soft- and energy drinks).
{"title":"Application of Chemometrics and Tandem Techniques in the Chemistry of Beverages: Analysis of Methylxanthines in Guaraná Powder Extract","authors":"O. A. Seoud, L. Novaki, Nicolas Keppeler, A. M. Chinelatto, S. S. Santos, Vânia Silva","doi":"10.5923/j.jlce.20200802.03","DOIUrl":"https://doi.org/10.5923/j.jlce.20200802.03","url":null,"abstract":"Guarana is a tropical fruit that grows in the Amazon basin and the northeastern part of Brazil, from which a popular soft drink is manufactured. The main methylxanthine (MX) in the guarana powder is caffeine (CF); theobromine (TB) and theophylline (TP) are also present in much lower concentrations. Because of the popularity of this soft drink, and the stimulating effects of MXs, we introduced an undergraduate chemistry project on their extraction from guarana powder and subsequent analysis. A literature survey showed that there is some variation in the values of λmax and emax of the three MXs. Using purified authentic samples, we showed that values of λmax and emax of CF, TB and TP are very close. Consequently, their concentrations in guarana extract cannot be calculated using a single technique (UV-Vis). After discussing this problem with the students, the following project was carried out: (i) guarana powder was extracted with acidified aqueous ethanol under different experimental conditions (alcohol volume fraction in the binary solvent mixture, ; powder extraction time, t); (ii) the apparent CF concentration was calculated from the absorbance of the extract at λmax = 272.5 nm; (iii) the extracts were analyzed by high performance liquid chromatography; the three MXs were identified in the chromatograms using internal standards, and the true [CF] calculated. Stage (i) involved use of chemometrics to optimize powder extraction, and to get information on the relative importance of the experimental variables ( is more important than t). Stage (ii) was a straightforward application of Beer’s law. Stage (iii) demonstrated the power of using tandem techniques to solve complex, everyday situation, namely the separation and analysis of biologically active components in consumer products (soft- and energy drinks).","PeriodicalId":91121,"journal":{"name":"Journal of laboratory chemical education","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85336438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Christina Lee, Nay Chi P Naing, Daisy Herrera, Gerardo Aguirre, Brandon Rodriguez, Jared Ashcroft
Understanding molecular structure and its influence on chemical reactivity is a fundamental component in Chemistry curriculum. For example, acidic protons ionize, or ionic solids dissociate to form charge, inducing electrolyte properties depending on molecular structure. An active learning lab is designed to demonstrate connection between electrolyte behavior and structure of various molecules. Experiments are shared to show interdisciplinary aspect of electrolytes within biology and chemistry. Specifically, how biomolecules exhibit electrolyte behavior due to chemical composition.
{"title":"Light up My Life: An Active Learning Lab to Elucidate Conductive Properties of Electrolytes.","authors":"Christina Lee, Nay Chi P Naing, Daisy Herrera, Gerardo Aguirre, Brandon Rodriguez, Jared Ashcroft","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Understanding molecular structure and its influence on chemical reactivity is a fundamental component in Chemistry curriculum. For example, acidic protons ionize, or ionic solids dissociate to form charge, inducing electrolyte properties depending on molecular structure. An active learning lab is designed to demonstrate connection between electrolyte behavior and structure of various molecules. Experiments are shared to show interdisciplinary aspect of electrolytes within biology and chemistry. Specifically, how biomolecules exhibit electrolyte behavior due to chemical composition.</p>","PeriodicalId":91121,"journal":{"name":"Journal of laboratory chemical education","volume":"7 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9395145/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40721031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-31DOI: 10.5923/j.jlce.20180601.03
O. A. Seoud, L. Novaki, S. Possidonio, A. M. Chinelatto, Maria J. L. d’Almeida e Silva, Paula P. Brotero
Among soft drinks commercialized in Brazil, the one from guarana seeds (Paullinia cupana) is very popular, ranking second in volume of consumption. Guarana has the highest caffeine concentration in plants; its extraction with chloroform from aqueous solution is feasible using a relatively simple experimental protocol. Because of the commercial importance of this soft drink, and the health-related aspect of (stimulant) caffeine, we developed a project for high-school students on the extraction and analysis of caffeine from guarana powder. In this three-step project, the students did- in their school- a literature survey on the presence of caffeine in beverages, foods and other consumer products. In the second step, they visited the laboratories of the Institute of Chemistry of the University of Sao Paulo (ChemUSP) where they extracted caffeine with CHCl3 from the aqueous solution obtained by treatment of guarana powder with HCl, followed by filtration and alkalization. Using melting point and thin-layer chromatography, they checked the purity of the isolated caffeine. Finally, they determined its concentration by Uv-Vis spectroscopy. We used this simple, safe and low cost experiment to discuss several important concepts, e.g., acids and bases, solvent extraction, purity determination by simple physical method, and quantitative analysis by spectroscopy. The students evaluated this project positively.
{"title":"The Chemistry of Beverages for High School Students: A Project on Extraction and Analysis of Caffeine from Guaraná Powder","authors":"O. A. Seoud, L. Novaki, S. Possidonio, A. M. Chinelatto, Maria J. L. d’Almeida e Silva, Paula P. Brotero","doi":"10.5923/j.jlce.20180601.03","DOIUrl":"https://doi.org/10.5923/j.jlce.20180601.03","url":null,"abstract":"Among soft drinks commercialized in Brazil, the one from guarana seeds (Paullinia cupana) is very popular, ranking second in volume of consumption. Guarana has the highest caffeine concentration in plants; its extraction with chloroform from aqueous solution is feasible using a relatively simple experimental protocol. Because of the commercial importance of this soft drink, and the health-related aspect of (stimulant) caffeine, we developed a project for high-school students on the extraction and analysis of caffeine from guarana powder. In this three-step project, the students did- in their school- a literature survey on the presence of caffeine in beverages, foods and other consumer products. In the second step, they visited the laboratories of the Institute of Chemistry of the University of Sao Paulo (ChemUSP) where they extracted caffeine with CHCl3 from the aqueous solution obtained by treatment of guarana powder with HCl, followed by filtration and alkalization. Using melting point and thin-layer chromatography, they checked the purity of the isolated caffeine. Finally, they determined its concentration by Uv-Vis spectroscopy. We used this simple, safe and low cost experiment to discuss several important concepts, e.g., acids and bases, solvent extraction, purity determination by simple physical method, and quantitative analysis by spectroscopy. The students evaluated this project positively.","PeriodicalId":91121,"journal":{"name":"Journal of laboratory chemical education","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80116739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-01DOI: 10.5923/J.JLCE.20180605.01
Zhongde Dai, Gøril Flatberg, H. Preisig, Liyuan Deng
Chemical reaction engineering is one of the core courses for chemical engineering students. Laboratory exercise is an essential part of this course. The goal of this laboratory exercise is to demonstrate the possibility of using an in-situ spectroscopic method (UV-VIS spectroscopy) to investigate reaction kinetics. A solution of naphthol blue black (NBB) is oxidized by H2O2 through a Fenton oxidation process. In this exercise, the concentration of NBB was monitored by the UV-VIS spectroscopy, while the concentrations of H2O2, FeSO4 and different pH levels may be adjusted to enable students to obtain a wide range of reaction kinetic data. The reaction rate constant, kapp, can be estimated with a pseudo-first-order kinetic model. In addition, the reaction temperature was adjusted to investigate the decomposition activation energy (Ea), which exhibited a value of 56.0±7 kJ mol-1.
{"title":"Kinetic Studies of Fenton Oxidation Reaction by UV-VIS Spectroscopy","authors":"Zhongde Dai, Gøril Flatberg, H. Preisig, Liyuan Deng","doi":"10.5923/J.JLCE.20180605.01","DOIUrl":"https://doi.org/10.5923/J.JLCE.20180605.01","url":null,"abstract":"Chemical reaction engineering is one of the core courses for chemical engineering students. Laboratory exercise is an essential part of this course. The goal of this laboratory exercise is to demonstrate the possibility of using an in-situ spectroscopic method (UV-VIS spectroscopy) to investigate reaction kinetics. A solution of naphthol blue black (NBB) is oxidized by H2O2 through a Fenton oxidation process. In this exercise, the concentration of NBB was monitored by the UV-VIS spectroscopy, while the concentrations of H2O2, FeSO4 and different pH levels may be adjusted to enable students to obtain a wide range of reaction kinetic data. The reaction rate constant, kapp, can be estimated with a pseudo-first-order kinetic model. In addition, the reaction temperature was adjusted to investigate the decomposition activation energy (Ea), which exhibited a value of 56.0±7 kJ mol-1.","PeriodicalId":91121,"journal":{"name":"Journal of laboratory chemical education","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85421073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jared M Ashcroft, Ashley Min, Isabel Bojanini, Melanie Hacopian, Kristine Schroeder, Atilla O Cakmak, Brandon Rodriguez
In a series of activities/labs, designed in a building block approach, whereas each subsequent lab builds into the next, students will explore the reactivity and production of oxygen in various biological and chemical systems. Through student-constructed analyses, participants will optimize oxygen-generating systems for the colonization of Mars, wherein their system will be used as part of a narrative to construct a livable habitat for future astronauts. Use of remote access technology to a Scanning Electron Microscope (SEM) with elemental analysis capabilities allows students to investigate their oxygen reaction via formation of iron oxide, resulting in rich multidimensional and contextualized scientific exploration in the chemistry classroom.
{"title":"Cultivating Mars: A Project-Based Learning Lab Analyzing an Oxygen Based Redox Reaction in Order to Design an Oxygen-Rich Environment on the Red Planet.","authors":"Jared M Ashcroft, Ashley Min, Isabel Bojanini, Melanie Hacopian, Kristine Schroeder, Atilla O Cakmak, Brandon Rodriguez","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>In a series of activities/labs, designed in a building block approach, whereas each subsequent lab builds into the next, students will explore the reactivity and production of oxygen in various biological and chemical systems. Through student-constructed analyses, participants will optimize oxygen-generating systems for the colonization of Mars, wherein their system will be used as part of a narrative to construct a livable habitat for future astronauts. Use of remote access technology to a Scanning Electron Microscope (SEM) with elemental analysis capabilities allows students to investigate their oxygen reaction via formation of iron oxide, resulting in rich multidimensional and contextualized scientific exploration in the chemistry classroom.</p>","PeriodicalId":91121,"journal":{"name":"Journal of laboratory chemical education","volume":"6 1","pages":"4-11"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8863174/pdf/nihms-1056512.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39823827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-31DOI: 10.5923/j.jlce.20150301.01
O. A. Seoud, P. A. R. Pires, Edgar O. Moraes, J. Pedrotti, H. Nawaz
We present an interdisciplinary project (physical- and organic chemistry/spectroscopy) on the kinetics of the pH-independent hydrolysis of bis(2,4-dinitrophenyl) carbonate in mixtures of water and acetonitrile or dimethoxyethane. In order to increase the students' interest in the project, we used the following constructivist teaching approach: we stated the problem (studying the kinetics of ester hydrolysis), and then challenged the students to define an experimental protocol. The students did the experiment and presented their data, namely the dependence of rate constants and activation parameters on water concentration and temperature. We then linked theory to experiment by discussing the mechanistic use of isosbestic points and activation parameters; the determination of the partial kinetic orders with respect to the reactants (ester and water), and emphasized the question of obtaining quality kinetics data. We suggest this project for science students in general, because the experiment is safe, low-cost, and can be used to teach theory.
{"title":"An Undergraduate Project “For all Seasons”: The pH-Independent Hydrolysis of bis(2,4-dinitrophenyl) Carbonate in Aqueous Solvents","authors":"O. A. Seoud, P. A. R. Pires, Edgar O. Moraes, J. Pedrotti, H. Nawaz","doi":"10.5923/j.jlce.20150301.01","DOIUrl":"https://doi.org/10.5923/j.jlce.20150301.01","url":null,"abstract":"We present an interdisciplinary project (physical- and organic chemistry/spectroscopy) on the kinetics of the pH-independent hydrolysis of bis(2,4-dinitrophenyl) carbonate in mixtures of water and acetonitrile or dimethoxyethane. In order to increase the students' interest in the project, we used the following constructivist teaching approach: we stated the problem (studying the kinetics of ester hydrolysis), and then challenged the students to define an experimental protocol. The students did the experiment and presented their data, namely the dependence of rate constants and activation parameters on water concentration and temperature. We then linked theory to experiment by discussing the mechanistic use of isosbestic points and activation parameters; the determination of the partial kinetic orders with respect to the reactants (ester and water), and emphasized the question of obtaining quality kinetics data. We suggest this project for science students in general, because the experiment is safe, low-cost, and can be used to teach theory.","PeriodicalId":91121,"journal":{"name":"Journal of laboratory chemical education","volume":"106 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75673325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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