This study investigates the swelling and liquid retention properties of cellulosic pulp from cotton waste, cotton linters and conventional dissolving wood pulp in both neutral (water) and alkaline (sodium hydroxide) conditions in regard to the first phase of the viscose process (mercerization). The swelling of single fibers is investigated by microscopic observation of the diameter increase during immersion in the liquids, which resulted in a logarithmic trend over time. The retention properties are investigated by water and lye retention values, and the latter was coupled to the pressability of mercerized pulp through observation of the trend in press factor with increasing pressing times. The different materials behaved similarly in neutral conditions regarding single fiber swelling and retention properties. Alkaline conditions, on the other hand, resulted in increased swelling and retention properties for all materials compared to neutral conditions, and the cotton-based pulps showed higher single fiber swelling and retention of lye, accompanied by impeded pressability. Thereafter, several material properties were investigated; morphological fiber properties (fiber width, cell wall thickness and fiber coarseness), fines content, carbohydrate monomer composition, and charge density. The results indicate that a thin cell wall and large lumen of the cotton waste fibers affect their higher swelling and retention properties, but further investigation of other morphological, chemical and physical properties of the fibers and fiber networks in pulp sheets is necessary. However, these insights on the behavior of different pulps can already help industries with the optimization of implementation of cotton waste pulps for viscose production.

In the past decades, substantial research efforts have been directed towards increasing the availability of renewable and recycled raw materials. Lignin, one of the most abundant natural polymers, constitutes a vast, renewable, and largely untapped source of aromatic structures. In addition, it is one of the most abundant renewable sources of carbon. Despite the countless research projects aimed at valorizing kraft lignin, the largest source of industrial lignin, relatively few commercial kraft lignin products have emerged. Simultaneously, lignosulfonates represent a commercially successful range of products with a steady and growing global market. This paper reviews the current outlook of technical lignin research, including common misunderstandings, and discusses various factors that have hampered the use of lignin as a renewable source of materials and chemicals.

In the manufacturing of cellulose derivatives, improving cellulose accessibility is essential for achieving a high product quality. In this study, endoglucanase enzyme treatment was applied prior to the cationization reaction to enhance the accessibility of hydroxyl groups for the production of cationized dialdehyde cellulose (CDAC). A range of enzyme dosages (0.09–45.00 ECU/g) was tested, and their effects on the swelling behavior and surface charge density of the final product were evaluated. The surface charge density of the ultimate cellulosic derivative confirmed its cationization and was proven to enhance the charge density of cationized dialdehyde cellulose (35% increase) compared to untreated pulp with enzyme. Additionally, the modified cellulose exhibited a significantly higher swelling capacity than regular pulps. These findings suggest that enzymatic pretreatment can enhance fiber reactivity and support a more sustainable and efficient production of cellulose-based derivatives, offering a promising potential for commercial applications.

Under vårterminen 2020 utbröt Coronapandemin och tre dagar innan en inplanerad salstentamenför en grundkurs i kemi kom besked om att alla examinationerskulle ske digitalt. Examinationsformen tentamen i skrivsal ändrades till en så kallad Open Book examination i form av endigital hemtenta med alla hjälpmedel tillåtna. Hemtentamen genomfördes under en vecka, och trots att den var avberäkningskaraktär var kravet att använda valfritt ordbehandlingsprogram och lämna in som PDF. Plagieringskontroll genomfördes för att öka rättssäkerheten.En enkät skickades ut till studenterna för att undersöka hur deras inlärning påverkades av den snabbt förändrade examinationsformen. Svarsfrekvensen var 81%. Alla som besvarade enkäten ansåg att upplägget hade fungerat mycket bra och 85% kände att examinationsformen gjorde att inlärningen i samband med examinationen ökade.

För ett utbildningsprogram finns nationella mål som beskriver deförmågor som studenterna ska ha efter avslutad utbildning.Utbildningen är uppbyggd av kurser, och för varje kurs finns enkursplan med de lärandemål som beskriver de förmågor och denkunskap studenterna ska ha efter avslutad kurs. Ombedömningskriteriet för godkänd kurs är procent av maximaltentamenspoäng kan en student få godkänt på kursen, men vilkaförmågor och vilken kunskap som studenten har är osäkert. I dennastudie analyseras och diskuteras problemet med procent av maximalapoängantalet som bedömningskriterium och ett alternativt sätt attexaminera presenteras.

Kurser inom teknik- och naturvetenskap innehåller traditionellt en eller flera laborationer. Laborationernas syfte måste på ett tydligt sätt kommuniceras till studenterna. Det är också viktigt att det finne en synlig koppling mellan kursens lärandemål och laborationerna.

För att få svar på hur studenterna upplever laborationernas syfte och mål i kemikurser, samt hur laborationerna kan bidra till studenternas lärande, har studenter besvarat enkäter och deltagit i samtal. Blan annat framkom att när studenterna fick samtala om sina beräkningar och resultat kunde de i diskussionen bekräfta sin kunskap. Många menade att också att diskussionerna bidrog till lärande.

Det är viktigt att universitetslärare sätter studenternas lärande i centrum. Om vi kan förstå hur olika undervisnings- och examinationsformer bidrar till studenternas lärande får vi möjlighet att designa våra kurser på bästa sätt.

Kurser inom teknik- och naturvetenskap innehåller av tradition ofta en eller flera laborationer. När en universitetslärare designar en kurs finns ett tydligt syfte med varje laboration och koppling till lärandemål. Men hur upplever studenterna laborationernas syfte och mål i våra kurser och hur kan de bidra till studenternas lärande? För att få svar har studenter svarat på enkäter och deltagit i samtal om hur laborationer bidrar till deras lärande på kurser. 

Från enkäter och samtal framkom att när studenterna fick samtala om sina beräkningar och resultat kunde de i diskussionen bekräfta sin kunskap. Många menade också att diskussionerna bidrog till inlärning. Ett annat sätt som visade sig bidra till ökat lärande var när studenterna rättade varandras protokoll.

Purposes of employing barrier coatings in packaging, and in particular food packaging, can be to increase the shelf life, preserve colour, odour, and taste, and to protect from a harmful environment in general. Barrier coatings can thus help to reduce food waste along the value chain until end use. Including both materials choice for packaging and the possible fates of the used package, even further steps to provide greater knowledge for decisions on choices of packaging solutions. To that end, we have conducted several experimental and transport modeling studies on oxygen barrier coatings performance. The coating system of choice    has been dispersion coatings of poly vinyl alcohol (PVOH), with additions of kaolin. Physical and chemical features of the coatings were characterized to obtain information on polymer crystallinity, free volume and filler orientation as these characteristics are influential to the oxygen mass transport performance. In turn, the oxygen mass transport was also measured, both in steady state and dynamically. In so doing, we obtained information    useful for developing a general model to describe the oxygen permeability taking into account the physical and chemical features, described above, of the coating layer. Attempts on describing the interdependence and impact, for instance between crystalline and amorphous polymer regions and moisture, was added to the model. The model showed agreement to experimental data for PVOH-kaolin coating in this particular case. However, the basic permeability model has been applied to  many different polymers.

To further explore the potential of these types of coating, which are technically possible to    produce in paperboard production, an economic-environmental impact comparison to other existing material solutions was made. Four barrier material alternatives – starch, polyethylene, ethyl vinyl alcohol (chosen as an alternative for PVOH, where data was difficult to obtain) and kaolin, and latex and kaolin, were analyzed with respect to cost and global warming potential. Weighting and comparing cost to environmental aspect, weighting    factors based on interviews with experts in the packaging value chain, starch emerges as the most sustainable alternative. However, previous coating and mass transport studies also shows how these renewable materials require some further technical development to be competitive.

The mass transport model can serve as a tool for customizing barrier coatings and to predict the barrier performance, as permeability is obtained and thus shelf-life estimation is    possible. The overall concept, the combination of assessment of structural performance and the environmental studies, can be employed to find sustainable food packaging solutions.

In this study oxygen permeability in dispersion barriers produced from poly(vinyl alcohol) (PVOH) and kaolin clay blends coated onto polymeric supports was investigated. To determine the oxygen permeability, two measurement methods were used: the oxygen transmission rate (OTR) and the ambient oxygen ingress rate (AOIR). It was found that with increasing kaolin content the oxygen permeability increased, up to about 5 wt% kaolin, whereafter the oxygen permeability decreased, as was expected. The increased (> 5%) kaolin loading lowered the diffusion because of an increased tortuosity. Structural information about the dispersion-barrier coatings, such as kaolin orientation and polymer crystallinity, was obtained from Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Kaolin orientation was influenced by the drying temperature, the thickness of the samples, and the kaolin concentration. The polymer crystallinity increased in thicker samples. The drying temperature did not show any clear effect on the crystallinity of thin samples, while for the thicker barriers, combined with a kaolin concentration lower than 20 wt%, a higher crystallinity was achieved at lower drying temperatures. This study demonstrates the strong influence of chemical and physical structures on the permeability of the investigated coatings.