Today, paper and paperboard is an important part of the packaging industry, as well as natural part of our daily lives. The alternatives to paper and paperboard is often produced from nonrenewable sources such as petroleum and as demands on sustainability increase in the packaging sector, it gives paper a desirable advantage over plastics. To increase the use of paper, some of the limiting factors for paper needs to be overcome, such as its limited formability. One way to create a paper that can be formed in new ways is to imbibe the paper with an additive that makes its modulus changeable. This would make it possible to control the stiffness of the paper which would make it more formable. This have been the aim of this thesis. To create this formable paper four different approaches were used. Of these four, three included how paper can be treated with polyelectrolytes to be able to increase its modulus when stimuli are applied. The two first approaches were based on the layer-by-layer technique adsorbing alginate and cationic fibrils to form a layer that could be cross-linked, either on the surface of a film (the first approach) or in the network of fibres in a porous paper (the second approach). The last approach was to impregnate the papers with alginate. The results show that the first approach gave a too low adsorption of polyelectrolytes, why no difference could be detected. The second approach resulted in a higher adsorbed amount, but the effects were still too small. The third approach gave a paper which could, depending on the concentration of alginate, either increase or decrease its modulus when cross-linked. The last approach was to create a laminate, using unmodified fibers together with dialcohol cellulose fibres. This resulted in a paper that could be formed using heat and allowing the paper to cool down in the desirable form. In the curriculum for chemistry in Swedish high schools there is a paragraph that says that research in chemistry should be a part of the content the students learn. This is a challenge both to teachers and researchers. For teachers, to find research at an appropriate level and teach it in an understandable way. For researchers, to communicate the research so it is understandable for society. With this as a motivation, a second part of this thesis discuss the method flipped classroom in chemistry education at Swedish high schools. It was seen that from the teacher’s perspective, flipped classroom meant advantages that could be categorized into five categories. The categories that was found were Time to interact, Student responsibility, dialogue, laboratory work and understanding and using the language. / Pappers- och kartongindustrin är idag en viktig del av förpackningsindustrin. Alternativ till kartong är ofta producerat av icke-förnybara råvaror och idag när kraven på hållbarhet ökar ger detta kartong en fördel mot plast. För att öka användningsområdena för kartong så måste de begränsningar som materialet har idag övervinnas. Detta gäller till exempel formbarheten. Ett sätt att skapa kartong som kan bli format på nya sätt är att göra en additiv tillsats till papperet som har egenskapen att det kan variera sin styvhet. Detta skulle göra det möjligt att kontrollera papperets styvhet, vilket har varit målet för det här arbetet. Genom att använda fyra olika arbetssätt har denna egenskap försökts åstadkommas. Tre av arbetssätten har behandlat papper med polyelektrolyter vars E-modul kan ökas med hjälp av något stimuli. I de två första försöken applicerades polyelektrolyterna genom den så kallade lager-på-lager-tekniken, där alginat och katjoniska cellulosafibriller adsorberades, i första försöket på ytan av en film och i det andra på ytan av fibrerna i fibernätverket i ett poröst papper. I det tredje försöket impregnerades de orösa papperna med alginat. Resultatet från det första försöket var att adsorptionen inte gav någon effekt eftersom den absorberande mängden var för låg. I det andra försöket var adsorptionen högre men det påverkade inte de mekaniska egenskaperna nämnvärt. I det tredje försöket med impregnering så kunde en ändring av E-modulen observeras när systemet tvärbands. I det sista försöket användes en metod som byggde på laminering. Ett ark av modifierade fibrer guskades ihop med ett ark med dialkoholcellulosefibrer. De försök som gjordes tyder på att papperet kunde formas och kunde fås att behålla formen om det värmdes och kyldes i den önskade formen. I läroplanen för kemi på gymnasiet finns en paragraf som beskriver hur kemiundervisningen ska ha inslag av forskning. Detta är en utmaning för både lärare och forskare. Lärarnas utmaning består i att finna forskning på en bra nivå för eleverna och att förklara den på ett förståeligt sätt. För forskare består utmaningen i att kommunicera forskningen på ett förståeligt sätt till samhället. Med detta som motivering har detta arbete en utbildningsdel. I den har lärares perspektiv på metoden ”flipped classroom” i kemiklassrummet undersökts. Flipped classroom beskrevs ha styrkor och dessa kunde kategoriseras i fem kategorier. Kategorierna var tid för interaktion, elevens ansvar, dialog, laborationer och förstå och använda språket.

In an effort to produce new derivatives of cellulose for drug delivery applications, methods were developed to regioselectively modify C-6 halo cellulose esters to produce cationic derivatives via nucleophilic substitution. Reaction of C-6 substituted bromo and iodo cellulose with trialkylated amines and phosphines produced new cationic ammonium and phosphonium cellulose derivatives which can be explored as delivery agents for nucleic acids, proteins and other anionic drug molecules. It was anticipated that these new derivatives would not only be capable of complexing anionic drug molecules but would have greatly improved aqueous solubility compared to their precursors. The phosphonium derivatives described in this work are an obvious example of such improved solubility properties. Given the importance of cellulose derivatives in making amorphous dispersions with critical drugs, it has also been important to analyze commercially available polymers for the potential impact in oral drug delivery formulations. To do so pairwise blends of cellulosics and synthetic polymers commonly used as excipients were tested for miscibility using techniques such as DSC, mDSC, FTIR and film clarity. Miscible combinations highlight the potential to use combinations of polymers currently available commercially to provide drug delivery solutions for specific drug formulations. The use of melt extrusion in processing some of these drug/polymer dispersions provides a means of highlighting the capability for the use of these cellulosics in melt extruded amorphous dispersions. This solvent free, high pressure method significantly reduces cost and time and can be applied on a large scale. The analysis of long chain cellulose esters and ultimately the novel omega carboxy esters for melt processability significantly impacts the possibilities available for use of those excellent drug delivery agents on a much larger scale. / Ph. D.

[pt] Os mosquitos são os principais vetores de transmissão de doenças como zika, dengue e chikungunya, causando mais de 700 mil casos por ano. O uso de repelentes, principalmente formulações tópicas, é uma das melhores medidas de proteção para reduzir e/ou prevenir a transmissão de muitas doenças transmitidas por insetos. Neste trabalho, formulamos emulsões de DEET/óleo em água para liberação controlada de repelentes como estratégia para desenvolver formulações repelentes com tempo de proteção superior a 6 h. Investigamos os efeitos do valor de HLB na estabilidade e viscosidade das emulsões, usando uma mistura de surfactantes (Span 80 e Tween 80) para formular emulsões em uma faixa de HLB entre 4-14. Também avaliamos o tamanho das gotas, comportamento reológico, método de mistura e índice de estabilidade da emulsão. As emulsões de DEET-óleo-em-água desenvolvidas contendo N, N-dietil-3-metilbenzamida (DEET) foram estabilizadas usando dois nanomateriais carregados negative e positivamente, nanopartículas de sílica (SiNP) e nanofibrilas de celulose catiônica (CCNF), e uma mistura de surfactantes não iônicos de grau para evitar a precipitação por agregação eletrostática. Os resultados indicam que no HLB 10, esta mistura pode estabilizar as emulsões independentemente do tipo de óleo (mineral ou vegetal), e as emulsões apresentam comportamento newtoniano independentemente do método de mistura. As formulações foram estáveis por mais de quatro meses à temperatura ambiente, mostrando-se fortemente resistentes à desestabilização por estresse centrífugo e térmico quando se utiliza nanomateriais em combinação com surfactantes. O CCNF e o SiNP mantiveram a distribuição granulométrica estável devido ao aumento da viscosidade da fase contínua. A ação combinada desses materiais na estabilização da fase oleosa contendo DEET diminuiu significativamente a taxa de liberação do composto ativo em comparação com o DEET não emulsificado, produzindo uma liberação sustentada de DEET nas primeiras 6 h. / [en] Mosquitoes are the main vectors of transmission of diseases such as zika, dengue and chikungunya, causing more than 700,000 cases per year. The use of repellents, mainly topical formulations, is one of the best protective measures to reduce and/or prevent the transmission of many insect-borne diseases. In this work, we formulated DEET/oil-in-water emulsions for the controlled release of repellents as a strategy to develop repellent formulations with a protection time greater than 6 h. We investigated the effects of the HLB value on the stability and viscosity of the emulsions, using a blend of surfactants (Span 80 and Tween 80) to formulate emulsions in an HLB range between 4-14. We also evaluated droplet size, rheological behavior, mixing method and emulsion stability index. The developed DEET-oil-in-water emulsions containing N, N-diethyl-3-methylbenzamide (DEET) were stabilized using two positively and negative charged nanomaterials, silica nanoparticles (SiNP) and cationic cellulose nanofibrils (CCNF), and a blend of food-grade nonionic surfactants to prevent precipitation by electrostatic aggregation. The results indicate that at HLB 10, this mixture can stabilize the emulsions regardless of the type of oil (mineral or vegetable), and the emulsions present Newtonian behavior regardless of the mixing method. The formulations were stable for more than four months at room temperature, showing to be strongly resistant to destabilization by centrifugal and thermal stress when using nanomaterials in combination with surfactants. The CCNF and SiNP kept the droplet size distribution stable due to the increase in the viscosity of the continuous phase. The combined action of these materials in stabilizing the DEET-containing oil phase significantly decreased the rate of active compound release compared to non-emulsified DEET, producing a sustained release of DEET within the first 6 h.