Syftet med denna studie är att bidra med ökade kunskaper om hur mellanstadielärare undervisar om partikelmodellen. Datainsamlingsmetoden var kvalitativa semistrukturerade intervjuer och åtta lärare intervjuades. Resultatet visar att partikelmodellen får lite utrymme i dagens kemiundervisning på mellanstadiet. Lärarna anger flera idéer men gör det utan att presentera en holistisk modell. Likaså lyfter de fram ett begränsat undervisningsinnehåll kopplat till partikelmodellen som inte speglar dess användbarhet eller ger eleverna förutsättningar till att utveckla en helhetsförståelse för vad modellen innebär. Lärarna har dessutom lättare för att ange varför och vad de undervisar om partikelmodellen än när och hur. Detta tyder på att de saknar strategier för hur de kan undervisa om partikelmodellen med en genomtänkt progression. En slutsats är att lärarna är medvetna om att partikelmodellen är viktig, men att detta inte speglas i deras undervisningspraktik. / The purpose of this study is to contribute with increased knowledge of how primary school teachers teach about the particle model. The data collection method was qualitative semi-structured interviews and eight teachers were interviewed. The result shows that the particle model has a small place in today’s chemistry teaching for pupils in age 10 to 12 years. The teachers mention several ideas that pupils should learn but without presenting a holistic model. Similarly, they emphasized a limited teaching content linked to the particle model which does not reflect its usefulness or provide students with the conditions to develop a holistic understanding of what the model means. In addition, teachers can more easily tell why and what they teach about the particle model than when and how. This indicates that they lack strategies for how to teach about the particle model with a progression. One conclusion is that teachers are aware of the importance of the particle model, but this is not reflected in their teaching practice.

In this work, a study of a recent approach in the design of light-driven molecular motors is presented. The approach involves enabling part of the motor to obtain aromatic-like properties through photoexcitation, and is found to significantly facilitate the rotary motion by reducing the barriers normally present in the excited-state potential energy surfaces of rotary motors.

Atmospheric deposition has been suggested to be a major input pathway of perfluoroalkyl acids (PFAAs) to the Baltic Sea catchment area and to the Baltic Sea itself. However, the sources of PFAAs to the atmosphere are not well characterized. In this study we investigated if waste incineration plants in Sweden could be a source of PFAAs to the atmosphere and to the environment in general. Samples of the end products from waste incineration were collected at four different incineration plants. The plants differed in size and technical advancement and were considered to be representative for the majority of waste incineration plants in Sweden. The collected samples were slag from the furnaces, fly ash from the flue gases, “bambergkaka” (a mix of fly ash and sludge from wastewater treatment) as well as condensate and wastewater from the cleaning process of the flue gases. Two methods were developed, one for analysis of PFAAs in solid samples and one for water samples. Method validation showed good performance for both methods in terms of precision and accuracy, despite low recoveries obtained for the method for solid samples. The results from sample analysis revealed that PFAAs were present in all solid samples at concentrations in the low to sub ng/g range and in all but one condensate and wastewater samples at concentrations in the low to sub ng/L range. The quantified concentrations were used to estimate the potential annual discharges of PFAAs from waste incineration plants to the environment. Emission scenarios via landfills, via wastewater treatment plants and to the atmosphere were considered. The main conclusion of this study is that waste incineration in Sweden is not a significant source of PFAAs to the atmosphere or to the environment in general.

The aim with this essay is to analyze subject-specific concepts in three textbooks for chemistry for the chapter air. The study will examine how these subject-specific concepts are distributed and how they are represented. The representations used are analogy and metaphor, example, relation and nothing used. The following questions were studied and answered. - Which subject specific concepts are used? - In which frequency does the subject specific content appear? - How are these subject specific concepts used and presented in the text (with analogies, metaphors, examples or relation)? In order to answer the questions for the thesis and to fulfil the aim for this study, a quantitative analysis was done and used as a method. The gathered material was analyzed with Vygotskijs theory of development of concepts. Analysis was made in depth for the subject specific contents that were found in the chapter of air in all three textbooks; which were atmosphere, helium, nitrogen, air pressure, and oxygen. The frequencies of subject specific concepts align with Lindbergs theory (the margin of the amount of unknown words in textbooks has to be 5%) but does not align with Hipkiss theory (2%). Textbook “Utkik” has highest frequency of 4,5%, “PULS” 3,8% and “Boken om Fysik och Kemi” 3,1%. In textbook “Utkik” the most used representation of the common subject specific contents was “relation” with 35%. In textbooks “PULS” and “Boken om Fysik och Kemi”, the most occurring representation was “analogy and metaphor” with 100 % respectively 67%. The results show that the subject specific concepts used in each book were mostly different. The textbooks differ in information and the students will miss out on some knowledge depending upon which book that is studied in the classroom. The essay shows that there is a correlation between earlier studies such as Lindberg (et al. 2007), that in order to improve knowledge of the subject specific concepts, it is crucial to use representations such as “analogy and metaphor”. It is also evident that the teacher has a responsibility to evaluate the textbooks and, in some cases, complement the subject specific concepts in order to increase the students’ knowledge ability in natural science such as chemistry.

“Green” explosives are an important sub-family of explosives due to the banning of explosives based on heavy metals, such as lead azide and lead styphnate, according to the REACH list. A substitute to lead azide is potassium 4,6-dinitrobenzofuroxane (KDNBF) which is an alternative “green” explosive. Hence there is an upcoming need for analytical and quality control protocols for KDNBF. In this report is HPLC-UV/VIS, GC-FID and potentiometric titration evaluated for their suitability as methods for testing of KDNBF. The results implies that KDNBF can be analyzed by GC-FID, when dissolved in DMSO and caffeine is used as internal standard. To analyze KDNBF by HPLC-UV/VIS was isocratic mode used together with a porous graphitic carbon (PGC) (Hypercarb ®) column. However, degradation of the analyte was severe and quantitative results were not obtained. Potentiometric titration indicated that KDNBF equilibrate with four hydrogen ions during titration, instead of the one to one ratio with potassium and hydrogen ion, as in previously proposed theory. Despite this and with careful titration is potentiometric titration and GC-FID analysis combined suitable as a quality control protocol for KDNBF.

Chemical substances that are either produced by nature or by humankind have a consequence on the environment when they are accumulated to a great extent. One of nature’s major problem is that of the eutrophication of surface waters, which is caused by inorganic and organic phosphorus compounds and, in particular, from a group known as Inositol Phosphates. There are six different forms of these inositols and are commonly found in soil and sediment samples. The conducted project was aimed to develop an analytical method that could efficiently analyze and separate all six with repeatable results. As such, soil samples were collected two times from two forest locations and two crop field locations. The first time the soil samples were left overnight to dry in a drying oven while on the second time, the samples left to dry at room temperature. When the samples were considered dry enough, they processed to reach grain size and extracted with a mixture of NaOH and Titriplex® III. The extracted soil samples, the standard solutions containing inositols, and the spiked extracted soil samples with inositol solution were all analyzed with an instrumental combination of a Capillary Electrophoresis instrument coupled manually to an Electrospray mass spectrometer, where the first was operated at reversed mode and the second at negative mode. To achieve the best feasible separation, several background electrolyte solutions were created along with a large number of sheath liquids regulated by an LC pump, two Capillary Electrophoresis methods, and twenty-five distinct MS methods, all tested through extensive screening to obtain the best possible combination of parameters. Out of the obtained results from the runs, four background electrolyte solutions, two MS methods, one sheath liquid controlled by one specific flow rate, and one Capillary Electrophoresis method exhibited promising potentials with a satisfying outcome. However, the intense pulsation of the spray cone observed for many of the runs, the manual protrusion of the Capillary Electrophoresis fused silica capillary, and some random errors, the repeatability of the method is called into question.

År 2011 antogs en ny läroplan i Sverige, där större fokus lades på hållbar utveckling än i tidigare läroplaner i såväl skolan som helhet, men också bland annat ämnesplanerna för Kemi 1 & 2 (Skolverket, 2018; Skolverket, 2011). I anslutning till detta publicerades nya läromedel som skulle överensstämma med den nya läroplanen. Mot bakgrund av detta ämnade denna studie att undersöka hur hållbar utveckling behandlas i svenska läromedlen för Kemi på gymnasienivå. Detta gjordes genom att analysera fem på gymnasiet förekommande läromedel, varav två var ämnade för Kemi 1 medan övriga tre var ämnade för Kemi 2. Böckerna genomsöktes efter tillfällen då kopplingar till hållbar utveckling gjordes. Dessa tillfällen kategoriserades sedan efter längd, om de kom som en del av kapiteltexten eller som extraläsning samt efter vilka och hur många av hållbar utvecklings tre dimensioner (ekologiska, sociala och ekonomiska) de behandlar. Resultatet visar att hållbar utveckling får mycket lite utrymme i läromedlen för Kemi med få och ofta korta tillfällen då hållbar utveckling behandlas. En bok skiljde sig från de övriga med två kapitel som handlade om miljö och samhällsfrågor, men följde i övrigt samma mönster som övriga böcker. Det vanligaste var att en dimension behandlades åt gången, och den vanligaste dimensionen som lyftes var den ekologiska. Mycket få tillfällen behandlade alla tre dimensionerna tillsammans, även om alla dimensionerna i någon grad belystes i alla böckerna. Att läromedlen i låg omfattning belyser hållbar utveckling kan vara en orsak till att kemilärare har svårt att implementera hållbar utveckling i undervisningen. / In 2011, a new curriculum was adopted in Sweden, where a heavier focus was placed on sustainable development than in previous curricula in both school as a whole, but also in the specific subject plans for chemistry 1 & 2 (Skolverket, 2018; Swedish National Agency for Education, 2011). In conjuntion with this, new teaching materials were published that would be in line with the new curriculum. Considering this, this study aimed to investigate how sustainable development is treated in Swedish textbooks for chemistry at upper secondary level. This was done by analyzing five high school chemistry textbooks, two of which were intended for Chemistry 1, while the other three were intended for Chemistry 2. The books were scanned for the times when links to sustainable development were made. These occasions were then categorised by length, whether they came as an integral part of the chapter text or as extra reading and by which and how many of the three dimensions of sustainable development (ecological, social and economic) they deal with. The results show that sustainable development has very little space in the teaching materials for chemistry, with few and often short examples. One book differed from the others with two dedicated chapters dealing with environmental and social issues, but otherwise followed the same pattern as the other books. The most common situation was that a single dimension was treated at a time, and the most common dimension to be dealt with was the environmental one. Very few examples dealt with all three dimensions together, although all the dimensions were to some extent highlighted in all the books. The fact that textbooks are dealing with sustainable development on a low scale can be one reason why chemistry teachers have difficulties implementing sustainable development in teaching.

New psychoactive substances are becoming increasingly common in many parts of the world, and some of them are marketed as “legal highs” and are produced to circumvent the drug legislation, and they come in many unregulated forms. The aim of this research was to characterize the metabolites of a new psychoactive substance and hence provide the fundamental data needed for further research of toxicity and future drug testing. The synthetic cannabinoid 4-fluoro-CUMYL-5-fluoro-PICA was incubated in cryopreserved hepatocytes for 1, 3 and 5 hour and then the formed metabolites was analyzed with an LC-QTOF-MS method, data analysis was performed by using the software MassHunter Qualitative Analysis. For 4-fluoro-CUMYL-5-fluoro-PICA a total of ten metabolites were identified, with three hydroxylations, two oxidative defluorinations to carboxylation, three oxidative defluorination and two fluoropentyl dealkylation. The metabolite with the highest intensity was oxidative defluorination.

The selection of a representative sample is a delicate problem when drug seizures comprised of large number of units arrive at the Swedish National Forensic Centre (NFC). If deviating objects in the selected sample size are found, additional analyzes are required to investigate how representative the results are for the entire population. This generates further pressure on operational analysis flow. With the goal to provide a tool which forensic scientists at NFC can base their assessment of the representative nature of the selected sampling of large drug seizures on, this project investigated the possibilities of evaluating the level of homogeneity in drug seizures using near-infrared (NIR) hyperspectral imaging along with principal component analysis (PCA). A total of 27 sample groups (homogeneous, heterogeneous and seized sample groups) were analyzed and different predictive models were developed. The models were either based on quantifying the variation in NIR spectra or in PCA scores plots. It was shown that in the spectral range of 1300-2000 nm, using a pre-processing combination of area normalization, quadratic (second polynomial) detrending and mean centering, promising predictive abilities of the models in their evaluation of the level of homogeneity in drug seizures were achieved. A model where the approximated signal-dependent variation was related to the quotient of significant and noise explained variance given by PCA indicated most promising predictive abilities when quantifying the variation in NIR spectra. Similarly, a model where a rectangular area, defined by the maximum distances along PC1 and PC2, was related to the cumulative explained variance of the two PCs showed most promising predictive abilities when quantifying the variation in PCA scores plots. Different zones for which within sample groups are expected to appear based upon their degree of homogeneity could be established for both models. The two models differed in sensitivity. However, more comprehensive studies are required to evaluate the models applicability from an operational point-of-view.

Nanoparticles are very interesting components. Due to their very large specific surface area they possess properties in between molecules and macroscopic materials. In addition, a material built up of hierarchically assembled nanoparticles could obtain unique properties, not possessed by the nanoparticles themself. A very interesting group of nanoparticles is the cellulose nanofibrils. The fibrils are found in various renewable resources such as wood, bacteria and tunicates. In this work fibrils extracted from wood is studied. In wood the fibrils are the smallest fibrous component with the approximate dimensions; 4 nm in width and length in the micrometer range, providing a high aspect ratio. In addition, they have a crystallinity above 60% and, hence, a high stiffness. These fibrils are hierarchically ordered in the wood fiber to give it its unique combination of flexibility and strength. The properties of the fibrils make them very suitable to be used as reinforcement elements in composites and, due to their ability to closely pack, to make films with excellent gas barrier properties. The key aspect to design materials, efficiently utilizing the properties of the individual fibrils, is to control the arrangement of the fibrils in the final material. In order to do so, the interactions between fibrils have to be well characterized and controlled. In this thesis the interaction between fibrils in aqueous dispersions is studied, where the main interactions are attractive van der Waals forces and repulsive electrostatic forces. The electrostatic forces arise from carboxyl groups at the fibrils surface, which either are due to hemicelluloses at the fibrils surfaces or chemically introduced to the cellulose chain. This force is sensitive to the chemical environment. It decreases if the pH is reduced or if the salt concentration is increased. If it is strongly reduced the system aggregates. In dilute dispersions aggregation causes formation of multiple clusters, whereas in semi-dilute dispersions (above the overlap concentration) a volume filling network, i.e. a gel, is formed. The tendency of aggregation, i.e. the colloidal stability, can be predicted by using the DLVO theory. In this thesis DLVO predictions are compared to aggregation measurements conducted with dynamic light scattering. Good agreement between experiments and the designed theoretical model was found by including specific interactions between added counter-ions and the carboxyl groups of the fibrils in the model. Thus, the surface charge is both reduced by protonation and by specific interactions. This emphasizes a much larger effect of the counter-ions on the stability then generally thought. Hence, this work significantly improves the understanding of the interfibril interactions in aqueous media. As mentioned above, the fibrils can be physically cross-linked to form a gel. The gelation is an instant process, occurring at pH or salt levels causing the interfibril repulsion to decrease close to zero. If a well dispersed stationary dispersion is gelled, the homogenous and random distribution of the fibrils is preserved in the gel. These gels can be used as templates to produce composites by allowing monomers or polymers to enter the network by diffusion. In an effort to mimic processes occurring in the tree, producing materials with fibrils aligned in a preferred direction, the ability to form gels with controlled fibril orientation were studied. Such networks were successfully produced by applying strain to the system prior or past gelation. Orientation prior gelation was obtained by subjecting the dispersion to elongational flow and freezing the orientation by “turning off” the electrostatic repulsion. Orienting the fibrils after gelation was achieved by applying shear strain. Due to the physical nature of the crosslinks, rotation in the fibril-fibril joints can occur, enabling the fibrils to align in the shear direction. This alignment significantly increased the stiffness of the gels in the shear direction. / QC 20111205