| 1. |
- Broman, Karolina, 1969-
(författare)
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Chemistry: content, context and choices : towards students' higher order problem solving in upper secondary school
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chemistry is often claimed to be difficult, irrelevant, and uninteresting to school students. Even students who enjoy doing science often have problems seeing themselves as being scientists. This thesis explores and challenges the negative perception of chemistry by investigating upper secondary students’ views on the subject. Based on students’ ideas for improving chemistry education to make the subject more interesting and meaningful, new learning approaches rooted in context-based learning (CBL) are presented. CBL approaches are applied in several countries to enhance interest, de-emphasise rote learning, and improve students’ higher order thinking.Students’ views on upper secondary school chemistry classes in combination with their problem- solving strategies and application of chemistry content knowledge when solving context-based chemistry tasks were investigated using a mixed methods approach. Questionnaire responses, written solutions to chemistry problems, classroom observations, and think-aloud interviews with upper secondary students at the Natural Science Programme and with experts working on context- based chemistry tasks were analysed to obtain a general overview and explore specific issues in detail.Several students were identified who had positive feelings about chemistry, found it interesting, and chose to continue with it beyond the compulsory level, mainly with the aim of future university studies or simply because they enjoyed it. Their suggestions for improving school chemistry by connecting it to everyday life prompted an exploration of CBL approaches. Studies on the cognitive learning outcomes arising from the students’ work on context-based tasks revealed that school chemistry heavily emphasises the recall of memorised facts. However, there is evidence of higher order thinking when students’ problem-solving processes are scaffolded using hints based on the Model of Hierarchical Complexity in Chemistry (MHC-C). In addition, the contextualisation of problems is identified as something that supports learning rather than distracting students.To conclude, the students in this thesis are interested in chemistry and enjoy chemistry education, and their motives for choosing to study chemistry at the post-compulsory level are related to their aspirations; students’ identity formation is important for their choices. Because students are accustomed to recalling facts and solving chemistry problems that have “one single correct answer”, they find more open problems that demand higher order thinking (e.g. knowledge transfer) unfamiliar and complex, suggesting that such processes should be practiced more often in school chemistry.
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| 2. |
- Broman, Karolina, 1969-, et al.
(författare)
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Chemistry in crisis? : Perspectives on teaching and learning chemistry in Swedish upper secondary schools
- 2011
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Ingår i: NorDiNa. - Oslo : Naturfagsentret. - 1504-4556 .- 1894-1257. ; 7:1, s. 43-60
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Tidskriftsartikel (refereegranskat)abstract
- Explanations for a decline in the number of students studying chemistry at advanced level all over the world have been sought for quite some time. Many students do not find chemistry relevant and meaningful and there have been difficulties in developing school chemistry courses that engage students sufficiently and tempt them to further studies in the field. In this study, Swedish upper secondary school students (Ns=372) and their teachers (Nt=18) answered a questionnaire on their experiences of the content and the working methods of their chemistry course. They were also given the opportunity to express ideas on how to make chemistry courses more interesting and meaningful. The results point out some subject areas as both easy and interesting, e.g. atomic structure; while other areas are hard to understand but still interesting, e.g. biochemistry. The students find chemistry lessons teacher-centred, something they appreciate. When teachers and students gave suggestions on how to improve the relevance of chemistry education at upper secondary level, more laboratory work and connections to everyday life were the most common proposals. But on the whole, these students seem quite satisfied with their chemistry courses.
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| 3. |
- Broman, Karolina, Universitetslektor, 1969-, et al.
(författare)
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Engineering students going “flipped” : a new teaching approach in organic chemistry to increase students’ interest and value
- 2019
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Ingår i: 7:e utvecklingskonferensen för Sveriges ingenjörsutbildningar. - : Luleå tekniska universitet.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a longitudinal design-based research study where a university organic chemistry course has changed teaching and learning focus, from more conventional teaching into flipped teaching. Engineering students have been followed with surveys, observations, interviews and analysis of how the teaching material was used; results on students’ perceived interest and value are discussed. The project shows that flipped learning with peer instruction is an applicable way to increase students’ interest in organic chemistry and perceived value of the problem-solving process and peer instruction when learning chemistry. Moreover, the paper also discusses the design-based aspect, and how researchers and practitioners can collaborate to develop university teaching with an aim to enhance students’ higher-order thinking and deep learning.
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| 4. |
- Broman, Karolina, Universitetslektor, 1969-, et al.
(författare)
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Flipped Learning as a New Approach for University Organic Chemistry
- 2018
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Ingår i: 14th European Conference on Research in Chemical Education. ; , s. 20-20
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Konferensbidrag (refereegranskat)abstract
- Flipped learning approaches have emerged since the beginning of the 21st century to make students’ learning environments more active and thereby improve learning outcomes as well as student engagement [1]. In the US, several flipped projects have focused on university chemistry courses, normally the student groups are large, from hundreds up to thousands of students [2], while some research also is found on smaller groups [3]. Here we study an organic chemistry university course both quantitatively and qualitatively during two years when changing from a more traditional teaching method to a new pedagogical approach (i.e., flipped learning), for empirical data see Table 1. In Sweden, flipped learning approaches are uncommon compared to the US and a Swedish university chemistry department had intentions improve students’ learning outcomes and increase students’ engagement in chemistry. The organic course has been perceived difficult and, according to previous course evaluations, also been ascribed as having bad quality in general. Therefore, a change was requested both from students and teachers.From the empirical data we will elaborate on students’ opinions when meeting a new teaching and learning approach. Students’ challenges with the organic chemistry course are discussed relating to their opinions about chemistry in general and flipped learning in specific. How students used the different learning material and how they made use of each other through peer interaction when solving problems in class will be discussed according to both constructivist and socio-cultural perspectives. Furthermore, students’ own perception of how they used the course material related to an exact analysis of how the material actually was adapted will be presented together to explore how flipped learning have been applied within the course.
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| 5. |
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| 6. |
- Broman, Karolina, 1969-, et al.
(författare)
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Flipping the class : university chemistry students' experiences from a new teaching approach
- 2017
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Ingår i: Universitetspedagogiska konferensen 2017. - Umeå : Universitetspedagogik och lärandestöd (UPL), Umeå universitet. ; , s. 14-18
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Konferensbidrag (refereegranskat)abstract
- University chemistry courses have for a long time had a similar approach to teaching, with chemistry professors lecturing in a traditional manner. Today, flipped learning approaches have found their ways into higher education and positive results from for example the US have been spread and made Swedish university chemistry teachers interested and curious to develop their courses. The rationale of flipped learning is to incorporate an active learning approach in the lecture halls and thereby hopefully both increase student engagement and learning outcomes. In this study, an implementation project where an organic chemistry course has changed focus from traditional teaching to flipped learning will be presented. The focus will be on students’ experiences when meeting a new teaching and learning approach.
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| 7. |
- Broman, Karolina, Universitetslektor, 1969-, et al.
(författare)
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Flipping the class : University chemistry students' experiences from a new teaching and learning approach
- 2019
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Ingår i: Chemistry Teacher International. - : De Gruyter Open. - 2569-3263. ; 1:1
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Tidskriftsartikel (refereegranskat)abstract
- University chemistry courses have for a long time had a similar conventional approach to teaching, with chem- istry professors lecturing in a traditional manner. Today, flipped learning approaches have found their ways into higher education with positive results. In particular, US innovations in this area have made positive im- pressions on Swedish university chemistry educators, resulting in an interest and curiosity in integrating a flipped model into the course curricula. The rationale behind flipped learning is to incorporate an active learn- ing approach into lecture, thereby increasing both student engagement and learning outcomes. In this paper, an implementation project where an organic chemistry course has changed focus from traditional teaching to flipped learning, will be presented. The focus in this mixed-methods study will be on students’ cognitive and affective responses when meeting a new teaching and learning approach. Through following a project where a conventional approach to an organic chemistry course is changed into a more student-active focus, we elaborate on implications for course development of chemistry curricula.
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| 8. |
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| 9. |
- Broman, Karolina, Universitetslektor, 1969-, et al.
(författare)
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Spatial Ability in Organic Chemistry : Can Virtual and Augmented Reality be Valuable?
- 2019
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Ingår i: 7:e Utvecklingskonferensen för Sveriges ingenjörsutbildningar. - : Luleå tekniska universitet.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, the roles of digital technologies as Virtual Reality (VR), and Augmented Reality (AR), are discussed to explore how biotechnology engineering students develop their spatial ability in organic chemistry. We have, through stereochemistry workshops, followed how students, in specific, visualise and rotate molecular representations and how the use of digital tools influences the students’ interest.
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| 10. |
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| 11. |
- Broman, Karolina, 1969-, et al.
(författare)
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To flip or not to flip : Students’ use of the learning material in a flipped university organic chemistry course
- 2017
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- University chemistry courses have had a similar approach to teaching for a long time, with chemistry professors lecturing in a traditional manner. Today, flipped learning approaches have found their ways into higher education and positive results from for example the US have been spread and made Swedish university chemistry teachers interested and curious to develop their courses. The rationale of flipped learning is to incorporate an active learning approach in the lecture halls and thereby hopefully both increase student engagement and learning outcomes. In this presentation, an implementation project where an organic chemistry course has changed focus from traditional teaching to flipped learning will be presented.
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| 12. |
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| 13. |
- Gromov, SP, et al.
(författare)
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Novel supramolecular charge-transfer systems based on bis(18-crown-6)stilbene and viologen analogues bearing two ammonioalkyl groups
- 2005
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Ingår i: NEW JOURNAL OF CHEMISTRY. - : Royal Society of Chemistry (RSC). - 1144-0546 .- 1369-9261. ; 29:7, s. 881-94
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Tidskriftsartikel (refereegranskat)abstract
- A series of new viologen analogues bearing two ammonioalkyl groups (2-4) were synthesized in order to study their complexation with bis(18-crown-6)stilbene (1b). Electronic spectroscopy and H-1 NMR measurements show that in acetonitrile, bis( crown) stilbene 1b forms highly stable 1 : 1 and 2 : 1 charge-transfer (CT) complexes with pi-acceptors 2-4 owing to host-guest bonding. The influence of geometric and electronic factors on the complex formation constants are discussed. The structures of the supramolecular CT complexes are analyzed on the basis of H-1 and C-13 NMR data obtained in solution and in the solid state. X-Ray diffraction data for 1b and for model tetramethoxystilbene are also reported.
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| 14. |
- Gromov, Sergey P, et al.
(författare)
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Novel Photoswitchable Receptors: Synthesis and Cation-Induced Self-Assembly into Dimeric Complexes Leading to Stereospecific [2+2]-Photocycloaddition of Styryl Dyes Containing a 15-Crown-5 Ether Unit
- 2003
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Ingår i: The Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 68:16, s. 6115-25
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Tidskriftsartikel (refereegranskat)abstract
- Styryl dyes 4a-e containing a 15-crown-5 ether unit and a quinoline residue with a sulfonatoalkyl or sulfonatobenzyl N-substituent were synthesized. The relationship between the photochemical behavior of these dyes and their aggregates derived from complexation with Mg2+ in MeCN was studied using 1H NMR and absorption spectroscopy. The E-isomers of 4a-e were shown to form highly stable dimeric (2:2) complexes with Mg2+. Upon irradiation with visible light, the dimeric complexes undergo two competing photoreactions, viz., geometric E Z isomerization, resulting in an anion-capped 1:1 complex of the Z-isomer with Mg2+ and stereospecific syn-head-to-tail [2+2]-cycloaddition, affording a single isomer of bis-crown-containing cyclobutane. The N-substituent in the dye has a dramatic effect on the photochemical behavior of the dimeric complex. Molecular dynamics and semiempirical quantum-chemical calculations were carried out to interpret the observed photocycloaddition in the dimer. Conformational equilibria for the dimer of (E)-4b were analyzed using 1H NMR spectroscopy.
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| 15. |
- Gromov, S P, et al.
(författare)
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Self-assembly of a (benzothiazolyl)ethenylbenzocrown ether into a sandwich complex and stereoselective [2+2] photocycloaddition
- 2005
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Ingår i: RUSSIAN CHEMICAL BULLETIN. - : Springer Science and Business Media LLC. - 1066-5285 .- 1573-9171. ; 54:7, s. 1569-79
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Tidskriftsartikel (refereegranskat)abstract
- In the presence of Ba2+ ions, (benzothiazolyl)ethenylbenzocrown ether forms the stable sandwich complex 2L center dot Ba2+ with an unusual structure, in which the benzothiazole fragments are arranged one above the other. Irradiation of the sandwich complex with visible light induces stereoselective [2+2] cycloaddition giving rise to two "head-to-head" isomers of biscrown-cyclobutane. The addition of dibasic dicarboxylic acids that additionally stabilize the sandwich complex in a favorable conformation affects the isomer ratio of the cyclobutanes formed. The conformational equilibria for the sandwich complex and cyclobutanes were studied by H-1 N MR spectroscopy.
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| 16. |
- Hedenström, Mattias, et al.
(författare)
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Characterization of Hydrogenated Fullerenes by NMR Spectroscopy
- 2010
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Ingår i: Fulleranes. - Dordrecht : Springer Netherlands. - 9781402098864 - 9781402098871 ; , s. 171-202
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- NMR spectroscopy is so far the only analytical technique that has been used to get a detailed structural characterization of hydrogenated fullerenes. A substantial amount of information derived from different NMR experiments can thus be found in the literature for a number of fullerenes hydrogenated to various degrees. These studies have benefitted from the fact that chemical shifts of H-1 and C-13 and in some cases also He-3 can be used to obtain structural information of these compounds. Such results, together with discussions about different NMR experiments and general considerations regarding sample preparations, are summarized in this chapter. The unique information, both structural and physicochemical, that can be derived from different NMR experiments ensures that this technique will continue to be of central importance in characterization of hydrogenated fullerenes.
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| 17. |
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| 18. |
- Mercier, Guillaume, et al.
(författare)
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Porous Graphene Oxide/Diboronic Acid Materials : Structure and Hydrogen Sorption
- 2015
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 119:49, s. 27179-27191
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Tidskriftsartikel (refereegranskat)abstract
- Solvothermal reaction of graphite oxide (GO) with benzene-1,4-diboronic acid (DBA) was reported previously to result in formation of graphene oxide framework (GOP) materials. The theoretical structure of GOFs consists of graphene layers separated by benzene-diboronic "pillars" with similar to 1 nm slit pores thus providing the opportunity to use it as a model material to verify the effect of a small pore size on hydrogen adsorption. A set of samples with specific surface area (SSA) in the range of similar to 50-1000 m(2)/g were prepared using variations of synthesis conditions and GO/DBA proportions. Hydrogen storage properties of GOF samples evaluated at 293 and 77 K were found to be similar to other nanocarbon trends in relation to SSA values. Structural characterization of GO/DBA samples showed all typical features reported as evidence for formation of a framework structure such as expanded interlayer distance, increased temperature of thermal exfoliation, typical features in FTIR spectra, etc. However, the samples also exhibited reversible swelling in polar solvents which is not compatible with the idealized GOF structure linked by benzenediboronic molecular pillars. Therefore, possible alternative nonframework models of structures with pillars parallel and perpendicular to GO planes are considered.
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| 19. |
- Persson, Per-Axel, et al.
(författare)
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High-pressure polymerized C60
- 1996
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Ingår i: Extended Abstracts of Carbon´96, European Carbon Conference, Newcastle-upon-Tyne 1996, volume 2. - : The British Carbon Group. ; , s. 746-747, s. 746-747
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 20. |
- Persson, Per-Axel, et al.
(författare)
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NMR and Raman characterization of pressure polymerized C-60
- 1996
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 258:5-6, s. 540-546
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Tidskriftsartikel (refereegranskat)abstract
- Bulk C60 has been treated at 1.1 GPa and 550–585 K, producing a dense insoluble material which on heating to above 600 K reverts to normal C60. Raman and IR studies on modified material show a large number of new lines, and the Raman pentagon pinch mode shifts from 1469 to 1458 cm−1 as on photopolymerization. MAS NMR shows one broadened line at the original C60 shift 144 ppm and a small peak at about 77 ppm due to the bridging carbons. None of the new resonances observed for C60 polymerized by other methods were observed. The results verify previously suggested polymeric structures where the fullerence cages are connected by four-membered rings.
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| 21. |
- Persson, Per-Axel, et al.
(författare)
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Physical properties of pressure polymerized C60
- 1996
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Ingår i: High Pressure Science and Technology. - Singapore : World Scientific. - 9810225474 ; , s. 716-718
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Konferensbidrag (refereegranskat)abstract
- The properties of C60 have been studied after treatment at high temperature and high pressure (1.1 GPa and 565 K for 2 h). The treated material is insoluble in organic solvents. We present results obtained in NMR and Raman studies and measured data for the specific heat and the thermal expansion. Our results show clearly that there are no covalent bonds and no molecular rotation, but suggest that the molecules are slightly deformed and held together by weak pi-type bonds.
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| 22. |
- Röding, Robert, et al.
(författare)
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Structural and vibrational properties of Li- and Na-doped fullerene polymers
- 2004
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Ingår i: Fullerenes, Nanotubes and Carbon Nanostructures vol. 12. - London : Taylor & Francis. ; , s. 319-25
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Konferensbidrag (refereegranskat)abstract
- We have studied tetragonal C60 and C60-based polymers doped with Lithium and Sodium. We show that the intercalated phases Li4C60 and Na4C60 both form two-dimensional polymers. X-ray diffraction diagrams for Li4C60 and tetragonal C60 can be accurately indexed assuming tetragonal structures, but for Na4C60 a monoclinic quasi-tetragonal structure is found. We conclude that in Li4C60 the covalent bonds are formed by (2 + 2) cycloadditions, in the same way as in the tetragonal polymer produced by treating pure C60 at high temperature and high pressure, while single C-C bonds connect the fullerene molecules in Na4C60.
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| 23. |
- Soldatov, Alexander, et al.
(författare)
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Pressure polymerized C60 : Raman and NMR studies
- 1996
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Ingår i: Fullerenes and Fullerene Nanostructures. - Singapore : World Scientific. - 9810228538 ; , s. 344-348
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Konferensbidrag (refereegranskat)abstract
- The properties of bulk C60 have been studied after treatment at 1.1 GPa and 550-585 K. The treated material is insoluble in both toluene and 1,2-dichlorobenzene. Raman spectroscopy on modified aterial shows a large number of new lines, and the Raman pentagon pinch mode (Ag2) shifts from 1469 to 1458 /cm as on photopolymerization. MAS NMR shows one broadened line at the original C60 shift 144 ppm and a small peak at about 77 ppm due to the bridging carbons. The results verify previous suggested polymeric structures where the fullerene cages are connected by four-membered rings.
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| 24. |
- Soldatov, Alexander, et al.
(författare)
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Topochemical polymerization of C70 controlled by monomer crystal packing
- 2001
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Ingår i: Science. - : American Association for the Advanement of Science. - 0036-8075 .- 1095-9203. ; 293:5530, s. 680-683
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Tidskriftsartikel (refereegranskat)abstract
- Polymeric forms of C60 are now well known, but numerous attempts to obtain C70 in a polymeric state have yielded only dimers. Polymeric C70 has now been synthesized by treatment of hexagonally packed C70 single crystals under moderate hydrostatic pressure (2 gigapascals) at elevated temperature (300°C), which confirms predictions from our modeling of polymeric structures of C70. Single-crystal x-ray diffraction shows that the molecules are bridged into polymeric zigzag chains that extend along the c axis of the parent structure. Solid-state nuclear magnetic resonance and Raman data provide evidence for covalent chemical bonding between the C70 cages.
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| 25. |
- Sundqvist, Bertil, et al.
(författare)
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Physical properties of pressure polymerized C60
- 1996
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Ingår i: Fullerenes: Recent Advances in the Chemistry and Physics of Fullerenes and Related Materials, volume 3. - Pennington, NJ : The Electrochemical Society. - 1566771625 ; , s. 1014-1028
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Konferensbidrag (refereegranskat)abstract
- We present in this paper an overview of the physical properties of the high pressure polymerized C60 phase commonly known as "soft fcc". This phase has been studied by several methods over wide ranges in temperature T and/or pressure, p. We present here experimental information about the specific heat capacity, the thermal expansion coefficient, the lattice structure, and the thermal conductivity, and we also show results obtained by NMR and Raman spectroscopy. All data presented agree with the accepted model that the individual molecules in this phase are covalently bound to form linear molecular chains. In particular, the NMR data show clearly the presence of covalent bonds, and the Raman data exhibit several new lines at very low energies connected with chain vibrations. Thermal conductivity data obtained during polymerization show both the time dependence of the process and that polymerization occurs at lower p and T than observed previously for this phase.
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