In kraft pulping, one of the main issues is the extensive wood losses. With increasing prices ofwoody biomass an incentive towards minimizing the wood losses exists. Amongst the variousprocess steps, the impregnation of wood chips has shown to enhance the cooking by providinga homogeneous distribution of chemicals inside the chips. It is proven that a more proficientimpregnation phase can improve the overall yield in kraft pulping. However, there is a lack ofscientific research comparing different impregnation techniques for hardwood. Hence, thisthesis will attempt to clarify the impregnation of hardwood.The impregnation efficiency was studied by comparing three different impregnation methods:High Alkali Impregnation (HAI), Extended Impregnation (EI) using a low alkali level and aReference Impregnation (REF) to enable a comparison to the industrially establishedconditions. The cases were compared by analysing the yield, selectivity and homogeneity. Thecomparison was also made under cooking conditions with the objective to understand theimpact of impregnation on the subsequent cooking phase. The cooking procedure was assessedby analysing the degree of delignification, yield and reject content.In impregnation, most chemical consuming reactions occurred within the first 10-30 minutes,mainly contributed by deacetylation. HAI obtained the fastest homogeneous distribution of OH-(~60 min), but the fastest dissolution of wood. The effect was contributed by the high [OH-],providing fast diffusion of ions and rapid dissolution of xylan. In the contrary, EI attained thehighest impregnation yield after a given impregnation time but required a prolonged durationto obtain a chemical equilibrium between the free and bound liquor (~120 min). REF showeda higher yield than HAI and similar chemical equilibrium as EI. The hydrosulphide sorption inimpregnation was highest for EI due to the high initial sulphidity charge and similar for REFand HAI. For impregnations at 115°C, the HS- sorption was significantly increased for all cases,resulting from delignification. In the subsequent cooking phase, it was prevalent that impregnation of chips under EIconditions were easier delignified, leading to a reduced cooking time to reach the defibrationpoint. Birch was more prone to delignification than eucalyptus. In turn, eucalyptus also obtaineda higher defibration point. Highest total cooking yield at similar kappa numbers was achievedwith REF conditions, followed by HAI and lastly the EI conditions. The high yield of REF incontrast to HAI could be explained by an improved xylan yield due to an alleviated hydroxidelevel. The low yield of EI can be assigned to continues peeling due to the prolongedimpregnation and loss of xylan when removing black liquor after impregnation. In terms ofproduction rate, yield, energy and chemical consumption the REF is the most efficientimpregnation condition for birch kraft cooking in this batchwise laboratory kraft cookingprocedure. / Ett av de största problemen vid massaframställning med sulfatprocessen är de stora förlusterna av råmaterial. Med stigande priser på träbiomassa finns ett incitament att minimeraträförlusterna. Bland de olika processtegen har impregneringen av träflis visat sig förbättrakokningen genom att tillföra en homogen fördelning av kemikalier inuti flisen. Det är bevisatatt en väl genomförd impregneringsfas kan förbättra det totala utbytet vid massakokning. Dockfinns det en brist på vetenskaplig forskning som jämför olika impregneringstekniker för lövved. Därav kommer detta arbete att försöka förtydliga impregneringen av lövved. Impregneringseffektiviteten studerades genom att jämföra tre olika impregneringsmetoder:High Alkali Impregnation (HAI), Extended Impregnation (EI) med låg alkalinivå ochreferensimpregnering (REF) för att möjliggöra en jämförelse med de industriellt etableradeförhållandena. Impregneringsteknikerna jämfördes genom att analysera utbytet, selektivitetenoch homogeniteten. Jämförelsen utfördes även under kokningsförhållanden med målet att förståhur impregneringseffekten påverkar det efterföljande kokningssteget. Kokningen bedömdesgenom att analysera ligninnivån, utbytet och spetinnehållet. Under impregneringsförsöken inträffade de flesta kemikaliekonsumerande reaktionerna inom10–30 minuter, främst bidragen av deacetyleringsreaktioner. HAI erhöll den snabbastehomogena fördelningen av OH- (~ 60 min), dock med konsekvensen att snabbast upplösaträmaterialet. Effekten bidrogs av den höga [OH-], vilket gav snabb diffusion av joner och snabbupplösning av xylan. EI erhöll det högsta impregneringsutbytet efter en given impregneringstidmen krävde en förlängd uppehållstid för att erhålla en kemisk jämvikt mellan den fria ochbundna vätskan (~ 120 min). REF visade ett högre utbyte än HAI och liknande kemisk jämviktsom EI. Sorption av vätesulfidjoner vid impregnering var högst för EI på grund av den högainitiala svavelhalten följt av REF och till sist HAI. För impregnering vid 115°C ökade HSupptagetbetydligt för alla metoder, orsakad av delignifiering.I den efterföljande kokningsfasen var det framträdande att impregneringen av flis under EIförhållandenlättare delignifierades, vilket resulterade i en reducerad kokningstid för att nådefibreringspunkten. Björk var mer benägen att delignifieras än eukalyptus. I sin tur fickeukalyptus även en högre defibreringspunkt. Högsta totala kokningsutbytet vid snarlika kappataluppnåddes med REF-förhållandet, följt av HAI och slutligen EI. Det höga utbytet av REFjämfört med HAI kunde förklaras av ett förbättrat xylanutbyte på grund av den lägrehydroxidnivån. Det lägre utbytet av EI kan förklaras på grund en större utsträckning av peelingreaktionpå grund av den förlängda impregneringen och förlust av xylan vid avlägsnande avsvartlut efter impregneringen. Sammanfattningsvis, i termer av produktionshastighet, utbyte,energi och kemikalieförbruk var REF den mest effektiva impregneringsmetoden vidmassatillverkning av björk i denna studie.

Bone fractures are a commonly occurring injury, which in severe cases require internal fixation. The standard surgical procedure for fracture fixation is Open Reduction Internal Fixation (ORIF) with metal implants and screws. Frequent complications include infections and soft-tissue adhesions which could lead to a secondary removal operation. Decreasing the risk of these secondary operations would be in everyone’s interest as it could lower the burden it puts on both the patient and health-care system. Replacement of metal implants with polymer-based fixation technologies may reduce complications from soft-tissue adhesions, but the risk of infections till remains. This study focused on adding antibiotics into trizonetrione (TATO) thermosets and hydroxyapatite (HA) composite materials to give them antibacterial properties and then evaluating their mechanical and biological properties. Two antibiotics, novobiocin salt (NB) and ciprofloxacin (CIP), were used at 0,1, and 5 wt%. For the biological evaluation, the material samples were subjected to both acytotoxicity test and a disk diffusion test against two different bacteria strains, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Further-more, the samples were evaluated mechanically in a three-point bending test and FT-Raman spectroscopy was utilized to confirm the successful monomer conversion following the thiolene coupling (TEC) reaction, even with the incorporation of antibiotics. Results showed no cytotoxicity and materials containing antibiotics displayed antibacterial properties. However, antibiotics significantly decreased the mechanical properties of the thermoset; 1wt% of either NB or CIP reduced the flexural modulus from 2197 (81) to 1643 (508) and 1021 (59) MPa, respectively. The impact on materials was much lower for the composite material; 1wt% of NB or CIP decreased the flexural modulus from 6719 (274) to 6233 (128) and 6561 (305) MPa, respectively. In conclusion, the thermoset material could be used as a coating on metal implants to minimize soft-tissue adhesions and prevent infection, while the composite showed potential for use in low loadbearing bone fixation as well as infection prevention. / Benfrakturer är en vanligt förekommande skada, som i allvarliga fall kräver öppen reduktion och intern fixering med metallimplantat och skruvar. Vanliga förekommande komplikationer innefattar mjukvävnadsadhesion och infektioner som ofta leder till att en till operation måste utföras där implantatet tas bort. Detta kräver extra resurser från både samhället och patienten, varför en minskning av dessa komplikationer skulle vara till allas fördel. Polymerbaserade implantat kan lösa problemet med mjukvävnads adhesion, men risken för infektion finns kvar. Det här projektet utforskade möjligheten att addera antibiotika till en triazintrion baserad härdplast och en hydroxiapatit komposit för att ge dem antibakteriella egenskaper och se hur de mekaniska och biologiska egenskaperna påverkas. Två antibiotika, novobiocin salt (NB) och ciprofloxacin (CIP), och utvärderades vid 0, 1, och 5 vt%. I den biologiska utvärderingen utsattes materialproverna för både ett cytotoxicitetstest och ett disk diffusionstest mot två olika bakteriestammar, Escherichia coli (E. coli) och Staphylococcus aureus (S. aureus). De mekaniska egenskaperna utvärderades genom trepunktsböjning och FT-raman spekstroskopi användes för att bekräfta monomerkonversionen efter tiolen-kopplingsreaktionen, även med inkorporeringen av antibiotika. Inga av proverna uppvisade några uppenbara tecken på cytotoxicitet och både härdplasten och kompositmaterialen förvärvade antibakteriella egenskaper. Tillsatsen av antibiotika minskade de mekaniska egenskaperna hos härdplasten avsevärt; inkluderingen av 1 vt% av antingen NB eller CIP reducerade böjmodulen från 2197 (81) till 1643 (508) respektive 1021 (59) MPa. Inverkan av antibiotikan var mycket lägre för kompositmaterialet; inkluderandet av 1 vt% NB eller CIP minskade böjmodulen från 6719 (274) till 6233 (128) respektive 6561 (305) MPa. Sammanfattningsvis kan härdplasten användas som ett lim på metallimplantat för att minimera mjukvävnadsadhesion och förhindra infektion. Kompositen kan potentiellt användas vid frakturfixering för icke vikt-bärande skelett, såsom fingrar, så väl som att agera infektionsförebyggande.

Crystalline carbon nitride has been a hot topic for the last ten years because of reports claiming it could work as a photocatalyst for cheap water splitting, a catalyst for difficult reactions inorganic chemistry and the use as a potential two-dimensional semiconductor.The carbon nitride of interest in this project is poly(triazineimide) (PTI), which has a layered structure similar to graphite. Oneof the goals was to examine the synthesis parameters to try tounderstand what makes these crystallites grow. The material was primarily analyzed using scanning electron microscopy and powder x-ray diffraction. The other goal of this project was to examine the physical properties of dissolved PTI. It is currently not understood how PTI behaves in various solvents. The effect on how the freezing point depression varies in different solvents was, therefore, tested.No strong correlations of how the morphology of the produced PTIdiffered with different synthesis parameters. Freezing point measurements suggest that a solution of PTI follows Raoult's law and can be described as a true solution.

<p>Research in paper-based analytical devices has been increasing rapidly in recent years. Manyof these devices are used as low-cost alternatives for diagnostics and biosensing. In this work,two novel paper-based technologies were developed.</p> <p>The first paper-based technology achieved was measuring streaming potential on paper-based microfluidic devices. The streaming potential measurements were able to detect the presence of adsorbed polyvinylamine or potassium polyvinylsulfate in paper-based microfluidic channels.</p> <p>The measured streaming potential ranged from -80 mV to 80 mV and the polarity was sensitive to the adsorbed polymer. Furthermore, the measured streaming potential on paper treated with BSA showed a polarity switch when the pH was changed from below the pKa to above the pKa of BSA. Lastly, streaming potential measurements may provide an electronic interface for paperbased sensors.</p> <p>The second technology developed was a paper-based chromatographic pre-concentration device for biological and chemical applications. The device successfully concentrated a protein, streptavidin, via biotinylated microgels immobilized onto a selected area of the filter paper. The device was able to process a large volume of fluid with the incorporation of a passive pump made of superabsorbent polymer. The concentration factor achieved by the device was over 3000-fold. The flow dynamics through the paper was modeled using Darcy’s law. This technology could be an excellent low-cost alternative for biochemical analysis for samples thatrequire preconcentration, especially for the analysis of trace compounds in wastewater and drinking water.</p> / Master of Applied Science (MASc)

<p>Hot-melt adhesives have been commercially available for a long time and they are used in a wide range of applications. The adhesive performance is governed by the adhesive material property as well as the application conditions for each type of substrate. In order to achieve a good bond between the adhesive and the designated substrate, both wetting ability and open time of the adhesive material have to be considered. Three commercial hot-melts were used in this study in order to examine the relationship between the material property and the adhesive performance. The thermal properties of the materials were obtained through Differential Scanning Calorimetry while Dynamic Analysis (DA) described their viscoelastic behaviour, and the hysteresis loop helped to characterize the flow regime from which the application conditions for the adhesive could be chosen. The adhesive performance was evaluated in term of the force required to break the bond between the adhesive and the substrate through a series of standardized pull-off tests. The effect of the time-temperature trade-off on the adhesive performance by varying the application temperature as well as prolonging the available bond-formation time was also examined. In most cases, the adhesive performance improved with extended open time. However, improved adhesive performance was also shown to be the response of shorter Maxwell characteristic time which was evaluated from the DA data. By providing the characteristic time as a linkage, a relationship between the adhesive performance and the material properties could be established. These results also offer a basis for the formulation of adhesives using structure-property parameters derived from DA.</p> / Master of Applied Science (MASc)

<p>A systematic investigation of Polyvinylamine (PVAm) as a strength-enhancing polymer for wet paper was undertaken through the development of a new test method that simulates the influence of polymers on fibre-fibre bonding in paper. Pairs of wet regenerated cellulose membranes were laminated using the paper strength-enhancing polymer as the lamination adhesive. The resulting laminates served as a physical model for fibre-fibre bonds in paper and the wet laminate strength was determined by ninety degree peeling experiments. Key experimental parameters and sources of error were identified.</p> <p>The mechanism of PVAm paper wet strength enhancement was explored by the wet cellulose delamination procedure. Initial results showed that PVAm was a poor wet adhesive for cellulose unless the cellulose was lightly oxidized. The adhesion was found to be a strong function of the concentration of amine and of the cellulose oxidation products. This led to the hypothesis that there are two mechanism in action; the first being the well-accepted electrostatic bonding theories and the second being covalent bond formation between acetal/hemi-acetals/aldehydes and the amine.</p> <p>A thorough investigation of the surface chemistry and morphology was conducted to confirm the hypothesis of covalent bond formation between aldehydes and amines. Oxidized regenerated cellulose was laminated with PVAm and the peeled surfaces analyzed by X-ray Photoelectron Spectroscopy (XPS). It was shown that the wet delamination force correlated to the acetal/hemi-acetal/alehyde surface concentration. It was concluded that the delamination force would be increased by a cumulative strengthening of both the cellulose surface and adhesive interface.</p> / Doctor of Philosophy (PhD)

<p>The production of latex in a solvent-free process within a twin screw extruder is of great industrial interest given the associated reduction in environmental impact when compared to conventional solvent-based emulsification techniques. The ability to produce latex continuously is also advantageous, compared to batch-wise solvent-based processes.</p> <p>The process of solvent-free emulsification in a twin screw extruder is studied. An inline fiber optic spectroscopic system was installed in the extruder to study the residence time distribution profile of resin through the emulsification process. A design of experiment study was performed analyzing the response of latex particle size from screw speed and feed rate factors. Finally, scanning electron microscopy was used to determine the morphology of the poorly- emulsified and pre-emulsified resin.</p> <p>Experimental results demonstrate that the residence time distribution of the polymer within the extruder is largely invariant of screw speed; the system also demonstrated a very low degree of axial mixing – which was not expected but can be attributed to high degree-of-fill within the screw. The results of the design of experiments study show that the final latex particle size is more influenced by the feed rate of the polymer than the screw speed of the extruder. These results were found to be consistent with the literature based on both batch- phase inversion emulsification as well as continuous polymer blending of immiscible phases. Finally, results from a study on morphology provided evidence of water domains within the pre-inverted polymer domains, analogous to a ‘water-in-oil-in water’ dispersion. Evidence of a bicontinuous network of polymer and water was also found to exist. The summation of these experimental results leads to the hypothesis that the solvent-free emulsification process is a phase inversion-type emulsification mechanism as opposed to a direct emulsification mechanism.</p> / Master of Applied Science (MASc)

The design and synthesis of porous materials attracted great attention recently because of their potential use in many fields like clean energy and environmental protection. Herein, we introduced new synthetic approaches for the preparation for porous carbons and organic polymers for selective CO2 and iodine capture application. Regarding CO2 capture application, Two new series of porous carbons (PYDCs) and (TRI-Ps) were synthesized by thermally activating Pyrazole and Triazolo Pyridine monomers respectively using KOH as a catalyst, which leads to porous carbon. PYDCs exhibit high surface area according to Brunauer–Emmett–Tellertheory (SABET = 1266–2013 m2 g−1), high CO2 Isosetric heat Qst(33.2-37.1 kJ/mol) and significantly high CO2 uptakes 8.59mmol g−1 (1bar) at 273k. The reported porous carbons also show significantly high adsorption selectivity for CO2/N2 (128) and CO2/CH4 (13.4) according to Ideal adsorbed solution theory (IAST) calculation using pure gas isotherms at 298 K. TRI-Ps exhibit high surface area (SABET=1852- 2917 m2 g−1) with a combination of mesoporous and microporous pores. TRI-Ps exhibit CO2 capture capacity of 6.98mmol g−1 at 1 bar and 273K. The development of majority of microporous offered a high CO2 storage capacity to TRI-Ps. High CO2 uptake achieved as a result of preferable pore size, surface area, and high oxygen content and high Qst values. Based on IAST calculation, high CO2/N2 selectivity (113.9) at 298K was achieved. Regarding iodine capture application, two new series of porous organic polymers Benzamidizole Linked Polymers (BILPs) and nitrogen rich porous Polymers (NRPPs) were synthesized and tested. Iodine capture, sorption isotherm and kinetics of adsorption were studied. BILPs exhibit iodine uptake capacity of 227.8 wt.% and 202.8 wt. % for BILP-A and BILP-B respectively. BILP-A shows ability of releasing 95.8% of captured iodine, while, BILP-B released 82.22%. Sorption curves were fitted by Freundlich equation indicating a heterogeneity of adsorption process on the surface. NRPPs exhibit iodine capacity of 192.35 wt.% and 222.35 wt. % for NRPP-1 and NRPP-2 respectively. NRPPs shows ability of releasing the majority of adsorbed Iodine. Sorption curves were fitted by Langmuir equation indicating a heterogeneity of adsorption process on the surface.

To be able to effectively study blood platelets in different environments adevelopment of an in vitro model of a microfluidic system for plateletproduction was started. The purpose of this thesis was to fabricate systemsand then characterize them and visualize the flow. The system consists of twochannels, one in the middle and the other one enclosing it. They are connectedthrough pores where Megakaryocytes can protrude through and produce platelets.The designs were produced in PDMS. This was done by first transfer the designsas structures onto a silicon wafer through UV lithography. The wafer served asa mould for casting PDMS that later was bonded to glass. The systems were thenstudied with three different methods. Computer simulations, flow tests andultimately tests with cells. From the results new designs were made andfabricated. The new designs were then tested the same ways as the first ones.The systems can most probably produce platelets with some optimisation of thetest parameters. No definite results were gathered to prove plateletproduction. Different flow speeds were tested and the flow profile atdifferent flow rates was visualised. The full capability of the new designscould not be fully studied due to unforeseen debris of PDMS clogging thechannels. A few things need to be done to achieve better results and establishfor sure if this method of producing platelets is possible. This thesis is agood ground for future work to stand on.

The aim of the thesis, industrial product design PPU304, is to develop a new product that will reduce food waste of dairy products in households. The main objective is that the product will be able to measure and signal when the milk has expired.The thesis is a start to find the solution to some of the food waste in households which is a major environmental issue in today's society. The goal is to develop a flexible expiration date that can reduce food wastage. With today's sensor technology bacterial levels can be calculated from the milk and that can increase the time a pack of milk can be used. The greater knowledge and awareness humanity have for environmental issues the better world we will live in. To understand the question, “what is it that makes the milk unfit for consumption?” A part of the work has gone into researching the technological aspect. In consumer ready milk there is different bacteria that will grow over time and eventually spoil the milk, how this process works varies depending on what or which bacteria manage to grow the most. Therefore, the most appropriate technique is to measure bacteria in the milk and identify at which level the milk passes its actual expiration date.The design of the product has been guided by two major factors, the predetermined dimensions of the circuit board and the adaptation to the size of the milk carton. The shape of the product is an oblong rear part with a spherical body at the front. The edges are rounded to give a pleasantand smooth feeling to the hand using the product.The thesis in industrial product design resulted in a final concept. The product analyses the amount of bacteria in the milk through sensors that measure bacterial metabolism. The data gets interpreted and displayed through the use of LEDs. To save energy the concept is equipped with a photo resistor that deactivates the LEDs when the fridge is closed and dark. The conclusion of the thesis, performed at Millcroft AB is at a conceptual level. To go from idea to product, is a process that takes a long time to complete and often involves many different moments. The timeframe during this study is considered too short to cover all parts of the product and therefore the boundaries set and the focus has been on constructing a design that fits the estimated technology as well as consumer needs. Some suggestions are that more research in the technical aspect of the product should be concluded. Further testing of dairy sustainability should be conducted on a larger scale and further development of the technology to send data.