Subcutaneous administration of biological drugs has become highly attractive as it offers the possibility for patient self-administration. Coacervates as a subcutaneous drug delivery system provide a way to decrease injection volumes thereby reducing the risk of injection site pain. The aim with this thesis was to investigate possible coacervation between polyelectrolytes and peptide drugs under various physicochemical conditions. In this project, hyaluronic acid (HA) and carboxymethylcellulose (CMC) and their ability to coacervate with polymyxin B (PB) and vancomycin (VA) was studied. Furthermore, the release of these peptide drugs from the formulations into a release medium mimicking the subcutaneous environment was studied using UV spectroscopy. Studies showed successful coacervation between VA-CMC, PB-CMC and PB-HA. VA-CMC and PB-CMC coacervates were formed at higher peptide-polyelectrolyte charge ratios and lower ionic strengths at pH 7. The increase in charge ratio seemed to eliminate steric effects caused by the polyelectrolyte chains that most likely hindered coacervation. Furthermore, PB-CMC and PB-HA formed gel-like coacervates in the pH range of 11.73-11.84 at 1:1 charge ratio and ionic strengths 0-70mM. At such high pH values, the obtained formulations were most likely a result of PB-PB aggregation or charge regulation. From drug release studies one could conclude that VA-CMC exhibits direct release followed by a slower prolonged release profile. PB-CMC coacervates, liquid and gel, showed a sustained release profile while the PB-HA gel formulation resulted in direct release. Unfortunately, due to limitations with the experimental release rate set-up, the conclusions drawn can not be considered 100% reliable.

The interactions between the divalent salts CaCl2, MnCl2 and NiCl2 with the carboxylicacid groups in an arachidic acid Langmuir monolayer are studied using vibrational sumfrequency spectroscopy (VSFS). At low salt concentrations the charging of the monolayer is shown to behave in accordance with classical theories of the electrical doublelayer. However, deviations from classical theories are readily apparent at concentrations starting from 1 μM and shown to differ depending on the nature of the cation, indicating an ion specific effect. From the analysis of the carboxylate symmetric vibration at least two different types of ion pair interactions between the divalent cations and the carboxylicacid moiety are detected: a solvent-separated and two (or more) possible contact ion-pairs and/or complexes. By using different VSFS polarization schemes the molecular orientation of the vibration is elucidated and further insight into the state of the carboxylic acidis gained. The ordering of water molecules in the diffuse layer as a result of the surfacepotential of the charged monolayer is also probed and found, at low ionic strengths, to bein agreement with the behaviour predicted by the Gouy-Chapman model. At high concentrations the hydration within the Stern layer can be detected and found to differ with the nature of the electrolyte. Additionally, the importance of the purity grade of the salts used for correctly interpreting the results is shown theoretically and verified experimentally,where trivalent ions affect the surface at concentrations several orders of magnitude below those from mono and divalent ions. Finally, diffusion is shown to play a major rolein the kinetics of deprotonation of the monolayer at submicromolar concentrations, while higher valency cations are also shown to deprotonate the surface at a quicker rate through electroflux.

The wet-end of the centre ply of the paperboard machine n˚ 2 (“Kartongmaskin 2” or KM2) inIggesund was simulated to obtain both qualitative and quantitative results on its start-up dynamics andits variation damping capacity. The accuracy of the model was controlled by comparing the simulationresults with data from the real production process. Furthermore, alternative strategies with theobjective of reducing the time needed for start-ups and grade changes were evaluated.The modeling was done using the Paperfront simulation software. Variables such as layout for themixing system, retention level and amplitude and period of inlet concentration were used asparameters. As alternative operation strategies for start-up and grade change, increased flowrate in theearly phase of a start-up and the temporary overdosing during the beginning of a stock change wereevaluated.The results indicate a strong control of the mixing system over the short circulation both in dynamicsat start-up and in general operation with a time constant for the machine close to 35 minutes. Inaddition, variations in consistency are more easily controlled by a double-chest mixing system and, ingeneral, variations are more easily damped the higher the active volume in the mixing system. Finally,times needed for start-up and composition changes could be reduced by as much as 50% by using amore proactive approach.

The strive for cutting out of a fossil-fuels dependence of countries' economies has driven the global research into developing more sustainable powersources with the ultimate target to completely liberate from coal-red and nuclear power plants. Shifting energy policies to renewable energy resourcesundoubtedly carries many benecial features, but also poses a range of technical challenges, such as the necessity to overcome large uctuations in the energy output from wind or photo-voltaic farms.One solution to this problem proposed in the 1970's is to integrate a large-scale energy storage device such as redox- ow batteries into the electrical grid. The thesis rst presents a brief overview of ow battery technology and applications. Next, a one-dimensional, steady-state, macrohomogeneous mathematical model of a hydrogen-bromine ow battery is developed, described and solved. The results are in good agreement with existing experimental data. Moreover, a parametric study is performed to examine the impact of selected parameters on the overall performance of a single cell. A complete set of eld variable plots is explicitly presented.

In this thesis project, treatment of municipal wastewater using ultrafiltration is evaluated to investigate ways to prevent or minimize fouling from occurring. The aim of this project is to examine which factors play a significant role in causing different types of fouling, in order to minimize the resulting effect and thereby increase the efficiency and lifetime of the membrane. The project started with a broad literature study, which researched which methods are currently used to treat wastewater on an industrial level and other state-of-the-art solutions that are available. This was then used to form an experimental plan where two membranes were tested using a pilot plant constructed at IVL’s research facility Hammarby Sjöstadsverk. Firstly, a polymeric membrane was tested using different pressures to see the influence on the membrane flux. The results indicated that although a higher pressure lead to higher flux, there is an upper limit for the flux that was achieved at 5 bar, since similar flux values were found at 5 bar, 7 bar and 9 bar. Also, though a higher flux did lead to a more rapid decrease in flux initially, all curves plateaued after approximately 40 minutes. An average recovery of the membrane flux capacity was 88.7%, where the highest one was achieved with a pressure of 7 bar. Secondly, a ceramic membrane was tested using a factorial design with three parameters, each having a low and high setting. The parameters that were tested were the total operating time, the pressure and the cleaning time of the membrane, with the aim to investigate how each parameter influenced the fouling and the removal of organic compounds from the wastewater. The fouling was analyzed by measuring the flux across the membrane and showed mixed results. Fouling could be removed and the flux often had a recovery of 100% or more, however, no clear conclusion could be drawn to which parameter was the most influential for this high removal percentage. As for the removal of organic compounds, an average removal of 66.9% was achieved and it was determined that the cleaning time was the most influential parameter, and the interaction between running time and pressure being the second most influential.

Pretreatment of biomass plays an important role in IGCC processes. Optimized operating conditions improve overall process eciency, product diversity and producergas composition. This project focuses on the pretreatment of spruce woodbiomass using high pressure superheated steam in a packed bed reactor with heated walls. The objective is to optimize the operation for ecient energy consumption and uniform thermal treatment of wood particles along the reactor. For this purpose,two models have been developed: Single-phase superheated steam in porous media where local thermal nonequilibrium condition prevails, Multi-phase ow in porous media.The rst model investigates the essential parameters to be taken into accountto ensure a uniform thermal treatment as the pyrolytic agent i.e. steam exchanges heat with solid particles. It is found that solid matrix and steam reach thermalequilibrium at early stages of the process however, sharp decrease in uid temperatureis observed. This trend is believed to be aected mostly by uid inlet velocity and solid initial temperature. The model suggests that the initial solid temperaturedoes not play an important role compared to the uid inlet velocity.The focus of the second model is optimization of reactor heat source to avoidthe complications attributed by a two-phase ow. The model can predict the phasesaturation of uid in the porous media along with the pressure and velocity prolesfor a given inlet ow condition and reactor heating power. A reactor with heatsource localized at the inlet is recommended to satisfy the thermal requirements ofthe system.Steam treatment of biomass at elevated pressures is a novel technology whichis believed to bring about many advantages for IGCC process. However, detailed optimization is necessary to benet from these advantages.

In this study, the development of a cellulose-based membrane for use in Vanadium Redox Flow Cell Batteries (VRFBs) was investigated. Cellulose is the most abundant biopolymer on earth and due to its versatility it finds multiple applications. However, cellulose and its derivatives can be easily hydrolyzed in the amorphous regions, under acidic conditions. In order to bypass this problem and use this tough material in the highly acidic and oxidative environment of a VRFB, two approaches were utilized. First, cellulose nanocrystals (CNCs) were employed, which basically lack amorphous regions, to minimize the effect of hydrolysis. An additional advantage is that CNCs can create films with specific stereochemistry, as they pack closely, in helical structures. Second, the surface of the CNCs was modified with the use of trichloro(1H,1H,2H,2H- perfluorooctyl)silane (TCPOS). This molecule has a long fluorocarbon chain, which acts protectively towards hydrolysis of the CNCs. The choice of silane was made in order to produce a material that can resemble Nafion, the most popular copolymer used in VRFBs. Nafion has a fluorocarbon, Teflon-like, backbone and a hydrophilic side chain that consists of a sulfonic acid groups. The first step was to make a material that is stable under the VRFB conditions. The membranes were characterized with AFM imaging, FTIR spectroscopy, contact angle measurements, and tensile testing. With the use of the product of alkoxylation of TCPOS (TMPOS), hydrophobic membranes were produced that exhibit contact angle with water larger than that of Nafion. Young’s modulus of the membranes with TMPOS was larger compared to the one of CNC membranes without TMPOS. To determine stability against acidic conditions, Dynamic Light Scattering (DLS) was used. Additionally, stability of the membranes after acid and Vanadium solution treatment was performed with gravimetric measurements. From the results, 67% of the samples tested remained intact under high ionic strength and acidic conditions. In addition, the effect of the amount of silane on the membranes was evaluated. The results of this study are promising and encourages further research on this direction. / I denna studie undersöktes utvecklingen av ett cellulosabaserat membran för användning i Vanadin redoxflödesbatterier (VRFB, en.). Cellulosa är den mest förekommande biopolymeren på jorden och med dess mångsidighet finns många tillämpningar. Cellulosa, och dess derivat, kan dessvärre enkelt hydrolyseras i amorfa regioner under sura förhållanden. För att kringgå detta problem och för att kunna använda materialet i den sura och oxidativa miljö som förekommer i ett VRFB, användes två tillvägagångssätt. Först användes cellulosananokristaller (CNC, en.) för att minimera effekten av hydrolys, då de huvudsakligen saknar amorfa regioner. Ytterligare en fördel är att man med CNC kan skapa filmer med specifik stereokemi, då de packas tätt i spiralformade strukturer. Det andra tillvägagångssättet var att modifiera CNC-ytan med hjälp av trikloro(1H,1H,2H,2H-perfluoroktyl)silan (TCPOS, en.). Denna molekyl har en lång fluorvätekedja, som skyddar mot hydrolys av CNC. Silan valdes för att skapa ett material som liknar Nafion, som är den vanligaste co-polymeren i VRFB. Nafion har en huvudkedja av fluorväte, liknande Teflon, och en hydrofil sidokedja bestående av sulfonsyragrupper. Det första steget var att göra ett material som är stabilt under de förhållanden som råder i ett VRFB. Membranen karaktäriserades med hjälp av AFM, FTIR-spektroskopi, kontaktvinkelmätningar och dragprov. Alkoxyleringsprodukten som erhölls ifrån TCPOS- behandlingen användes för att tillverka hydrofoba membran med en kontaktvinkel mot vatten som är större än för Nafion. Youngs modul för membran med TMPOS var större än för CNC- membran utan TMPOS. För att klarlägga stabiliteten under sura förhållanden ändvändes DLS. Dessutom testades membranens stabilitet efter syra- och vanadinlösningsbehandling genom olika gravimetriska mätningar. Resultaten visade att 67 % av de testade proverna förblev intakta under förhållanden med hög jonstyrka och surhet. Effekten av mängden använt silan i membranen utvärderades också. Resultaten från denna studie är lovande och uppmuntrar till vidare forskning i denna riktning.

Polymer electrolyte fuel cells (PEMFC) convert chemical energy into electrical energy with high energy efficiency. Air-breathing PEMFC is a type of fuel cell suited for portable application owing to certain properties such as light weight and low operating temperature. The performance of the fuel cells can be improved by optimizing the temperature and pressure. Temperature directly influences the water management and the rate of oxygen reduction, whereas pressure, due to clamping of the cell, acts as one of the main dominant characters in the performance of the cell in the case of air-breathing PEMFC. The main goal of this thesis was to study the effect on performance of using different geometrical areas of the GDL (electrode area).The polarization results for the entire set of cells showed an increasing trend with higher electrode areas. The effect of clamping pressure was observed to be one of the dominant parameters when the performance curve was plotted for potential vs current density. This might be due gas distribution along the surface of the electrodes. The choice of gasket thickness in the cell assembly also showed a performance difference for cells of same electrode area

Förgasning av biomassa är en åtråvärd process då det erbjuder en mängd olika slutprodukter såsom; värme, kraft, biometan, väte etc. Dessa fås från de bildade produkterna från förgasningen, dvs. H2, CO, CO2, CH4 och H2O(g). Det är emellertid även känt att processen producerar orenheter under förgasningssteget såsom NH3, H2S, HCl, tjära och partiklar. En lösning för att avlägsna tjära är genom katalytisk tjärsprickning som sker under höga temperaturer direkt efter förgasaren. Huvudproblemet med detta är att den katalysator som används är känslig gentemot H2S ty gasen deaktiverar katalysatorn. På grund av detta bör H2S avlägsnas före den katalytiska tjärsprickningen. Då förgasaren och den katalytiska tjärsprickningen sker under höga temperaturer, är det önskvärt att avlägsna H2S vid höga temperaturer. Syftet med denna uppsats är att utveckla en experimentelluppställning för avlägsnandet av H2S vid 800°C. Utöver detta, genomfördes det även en dimensionell analys för att förstå hur olika parametrar påverkar omvandlingshastigheten hos metalloxiden, samt utseendet på genombrottskurvan.Från resultaten visade sig att det var möjligt att utveckla en experimentelluppställning för avlägsnande av H2S vid 800°C. Dock bör parametrar som påverkar tryckfallet tas i beaktning för framtida experiment. Dessa parametrar är; bredd på reaktorn, läng på sorbentbädden, partikelstorlek samt magnituden på flödet. Det fattade beslutet för denna studie var att minska på flödet samt öka partikelstorleken. När det kommer till den dimensionella analysen av omvandlingshastigheten, visade det sig att en ökning av kontrollparametern 𝜑 ledde till en ökning av omvandlingshastigheten vilket skedde vi ökande temperatur, partikelstorlek och koncentration av gasreaktanten. Därtill visades det även att diffusion var det fenomen som var hastighetsstyrande. Detta bekräftar SCM, och innebär att den kemiska reaktionen kan försummas vid den dimensionella analysen av genombrottskurvan. Från denna analys visade det sig att när kontrollparametern 𝛽 ökades, minskades diffusionsbegränsningarna och den givna genombrottskurvan blev mer idealiskt. Därför minskade 𝛽 vid ökande Mn-innehåll då det ökar diffusionsbegränsningarna. Dock hade detta ingen signifikant effekt på 𝛽. För de kurvor som hade 𝛽~1, var både konvektion och diffusion är hastighetsstyrande

Wastewater treatment plants (WWT P ) are often the cause of malodor. The com-pounds which are the main causes of the odor is hydrogen sulfide (H2S), ammonia (NH3), mercaptans (RSH) and volatile organic compounds (V OC) [1]. The odorous air can be analyzed to determine the concentration of the odorants. The odorous can also be analyzed by measuring the odor. The odor is measured, a test panel of people smells the odorous air and determines how many times greater the concentration of the odorants is compared to the odor threshold which is the concentration at which a compound or a mixture is detectable by smell [3].Measurements were done at three systems for air purification at three different locations, the Vimmerby WWT P , the Alvim WWT P and Renova’s biological waste treatment facility in Gothenburg. The odor was measured at the inlet and the outlet and the concentration of H2S and ozone (O3) were measured at all the sampling points of the systems. The system at Vimmerby consisted of three CIF s followed by an UV-reactor and an AC-reactor. In Alvim there were two system which used UV and AC. The system at Renova consisted of a barrier filter followed by UV and AC.The system at the Vimmerby WWT P had a conversion rate between 87-97% of H2S. The CIF s had conversions between 50-64% of the H2S. H2S was not detected at any of the other systems. O3 was only detected at Renova where ground level O3 was present at the inlet, 0.16 ppm. The concentration increased to 0.20 ppm after the UV-reactor. The activated carbon could adsorb all the incoming O3.The odor at the Vimmerby WWT P was determined to 27500 Ou/m3 at the inlet and 19071 Ou/m3 at the outlet. The odor conversion over the system was 31%. The odor conversion at the Alvim WWTP was 99.8%. With an odor of 5490 Ou/m3 at the inlet and 11 Ou/m3 at the outlet. The ingoing air at the system at Renova had an odor of 434 Ou/m3 and was reduced to 36 Ou/m3 at outlet. The odor conversion at Renova was 92%.To increase the accuracy of the measurements he time between the sampling and measurements should have been minimized. The test panels should also have been larger and the panelists should have been screened in advance, so results from panelists which were over and under sensitive to odors were not included in the final results.