Processes where a molecule absorbs visible light and then converts the solar energy into chemical energy are important in many biological systems, such as photosynthesis and also in many technical applications e.g. photovoltaics. This thesis describes a part of a multidisciplinary project, aiming at a functional mimic of the natural photosynthesis, with the overall goal of production of a renewable fuel from sun and water. More specific, the thesis is focused on design and photophysical characterization of new photosensitizers, i.e. light absorbers that should be capable of transferring electrons to an acceptor and be suitable building blocks for supramolecular rod-like donor-photosensitizer-acceptor arrays. The excited state lifetime, the excited state energy and the geometry are important properties for a photosensitizer. The work presented here describes a new strategy to obtain longer excited state lifetimes of the geometrically favorable Ru(II)-bistridentate type complexes, without a concomitant substantial decrease in excited state energy. The basic idea is that a more octahedral coordination around the Ru will lead to longer excited state lifetimes. In the first generation of new photosensitizers a 50-fold increase of the excited state lifetime was observed, going from 0.25 ns for the model complex to 15 ns for the best photosensitizer. The second generation goes another step forward, to an excited state lifetime of 810 ns. Furthermore, the third generation of new photosensitizers show excited state lifetimes in the 0.45 - 5.5 microsecond region at room temperature, a significant improvement. In addition, the third generation of photosensitizers are suitable for further symmetric attachment of electron donor and acceptor motifs, and it is shown that the favorable properties are maintained upon the attachment of anchoring groups. The reactivity of the excited state towards light-induced reactions is proved and the photostability is sufficient so the new design strategy has proven successful.

Iron oxyhydroxide (FeOOH) mineral plays an important role in a variety of atmospheric, terrestrial and technological settings. Molecular resolution of reactions involving these minerals is thereby required to develop a fundamental understanding of their contributions in processes taking place in the atmosphere, Earth’s upper crust as well as the hydrosphere. This study resolves interactions involving four different types of synthetic FeOOH particles with distinct and well-defined surfaces, namely lath- and rod-shaped lepidocrocite (γ), goethite (α) and akaganéite (β). The surface and bulk reactivities of these particles are controlled by their distinct structures. When exposed to ambient atmospheric or aqueous conditions their surfaces are populated with different types of (hydr)oxo functional groups acting as reaction centers. These sites consist of hydroxyl groups that can be singly- (≡FeOH, -OH), doubly- (≡Fe2OH, μ-OH), or triply-coordinated (≡Fe3OH, μ3-OH) with underlying Fe atoms. Moreover, these sites exhibit different types, densities, distributions, as well as hydrogen bonding patterns on different crystal planes for each mineral. Knowledge of the types and distributions of hydroxyl groups on minerals with different surface structures is fundamental for building a molecular-scale understanding of processes taking place at FeOOH particle surfaces. In this thesis, Fourier transform infrared (FTIR) spectroscopy was used to resolve the interactions between (hydr)oxo groups of FeOOH particles with (in)organic acids, salts, water vapor as well as carbon dioxide. The focus on such compounds was justified by their importance in natural environments. This thesis is based on 9 articles and manuscripts that can be found in the appendices. FTIR spectroscopic signatures of hydroxyl groups in the bulk of well crystallized FeOOH minerals were characterized for structural differences and thermal stabilities. Those of akaganéite were particularly resolved for the variable bond strength of bulk hydroxyls induced by the incorporation of HCl through nanostructured channels at the terminations of the particles. FTIR bands of hydroxyl groups at all particle surfaces were monitored for responses to thermal gradients and proton loadings, providing experimental validation to previous theoretical accounts on surface site reactivity. This site reactivity was resolved further in the fluoride (F-) and phosphate (PO43-) ions adsorption study to follow the site selectivity for ligand-exchange reactions. These efforts showed that singly-coordinated groups are the primary adsorption centers for ligands, doubly-coordinated groups can only be exchanged at substantially higher ligand loadings, while triply coordinated groups are largely resilient to any ligand-exchange reaction. These findings helped consolidate fundamental knowledge that can be used in investigating sorption processes involving atmospherically and geochemically important gases. The latter parts of this thesis were therefore focused on water vapor and carbon dioxide interactions with these FeOOH particles. These efforts showed how surface structure and speciation affect sorption loadings and configurations, as well as how water diffused into and through the akaganéite bulk. Hydrogen bonding is one of the most important forms of interactions between gas phase and minerals. It plays a crucial role in the formation of thin water films and in stabilizing surface (bi)carbonate species. The affinity of surface hydroxyl groups for water and carbon dioxide is strongly dependent on their abilities to form hydrogen bonds. These are controlled by coordination number and site accessibility/steric constraints. In agreement with the aforementioned ligand-exchange studies, surfaces dominated by singly coordinated groups have stronger ability to accumulate water layers than the ones terminated by groups of larger coordination number. Collectively, these efforts consolidate further the concept for structure-controlled reactivities in iron oxyhydroxides, and pave the way for new studies along such lines.

The great tunability of structure and electronic properties of π-conjugated organic molecules/polymers combined with other advantages such as light weight and flexibility etc., have made organic-based electronics the focus of an exciting still-growing field of physics and chemistry for more than half a century. The application of organic electronics has led to the appearance of wide range of organic electronic devices mainly including organic light emitting diodes (OLED), organic field effect transistors (OFET) and organic solar cells (OSC). The application of the organic electronic devices mainly is limited by two dominant parameters, i.e., their performance and stability. Up to date, OLED has been successfully commercialized in the market while the OSC are still on the way to commercialization hindered by low efficiency and inferior stability. Understanding the energy levels of organic materials and energy level alignment of the devices is crucial to control the efficiency and stability of the OSC. In this thesis, energy levels measured by different methods are studied to explore their relationship with device properties, and the strategies on how to design efficient and stable OSC based on energy level diagrams are provided. Cyclic Voltammetry (CV) is a traditional and widely used method to probe the energy levels of organic materials, although there is little consensus on how to relate the oxidation/reduction potential ((Eox/Ered) to the vacuum level. Ultraviolet Photoelectron Spectroscopy (UPS) can be used to directly detect vertical ionization potential (IP) of organic materials. In this thesis, a linear relationship of IP and Eox was found, with a slope equal to unity. The relationship provides for easy conversion of values obtained by the two techniques, enabling complementarily use in designing and fabricating efficient and stable OSC. A popular rule of thumb is that the offset between the LUMO levels of donor and acceptor should be 0.3 eV, according to which a binary solar cell with the minimum voltage losses around 0.49 V was designed here. Introduction of the ternary blend as active layer is an efficient way to improve both efficiency and stability of the OSC. Based on our studied energy-level diagram within the integer charge transfer (ICT) model, we designed ternary solar cells with enhanced open circuit voltage for the first time and improved thermal stability compared to reference binary ones. The ternary solar cell with minimum voltage losses was developed by combining two donor materials with same ionization potential and positive ICT energy while featuring complementary optical absorption. Furthermore, the fullerene acceptor was chosen so that the energy of the positive ICT state of the two donor polymers is equal to the energy of negative ICT state of the fullerene, which can enhance dissociation of all polymer donor and fullerene acceptor excitons and suppress bimolecular and trap-assistant recombination. Rapid development of non-fullerene acceptors in the last two years affords more recipes of designing both efficient and stabile OSC. We show in this thesis how non-fullerene acceptors successfully can be used to design ternary solar cells with both enhanced efficiency and thermal stability. Besides improving the efficiency of the devices, understanding of the stability and degradation mechanism is another key issue. The degradation of conjugated molecules/polymers often follow many complicated pathways and at the same time many factors for degradation are coupled with each other. Therefore, the degradation of non-fullerene acceptors was investigated in darkness by photoelectron spectroscopy in this thesis with the in-situ method of controlling exposure of O2 and water vapor separately.

This thesis presents the results of computer simulation studies of the structure, dynamics, and deformation of cross-linked polymer gels. Obtaining a fundamental understanding of the interrelation between the detailed structure and the properties of polymer gels is a challenge and a key issue towards designing materials for specific purposes. A new off-lattice method for constructing a closed network is presented that is free from defects, such as looping chains and dangling ends. Using these model networks in Brownian dynamics simulations, I show results for the structure and dynamics of bulk gels and describe a novel approach using spherical boundary conditions as an alternative to the periodic boundary conditions commonly used in simulations. This algorithm was also applied for simulating the diffusion of tracer particles within a static and dynamic network, to illustrate the quantitative difference and importance of including network mobility for large particles, as dynamic chains facilitate the escape of particles that become entrapped. I further investigate two technologically relevant properties of polymer gels: their stimuli-responsive behaviour and their mechanical properties. The collapse of core-shell nanogels was studied for a range of parameters, including the cross-linking degree and shell thickness. Two distinct regimes of gel collapse could be observed, with a rapid formation of small clusters followed by a coarsening stage. It is shown that in some cases, a collapsing shell may lead to an inversion of the core-shell particle which exposes the core polymer chains to the environment. This thesis also explores the deformation of bimodal gels consisting of both short and long chains, subject to uniaxial elongation, with the aim to understand the role of both network composition as well as structural heterogeneity on the mechanical response and the reinforcement mechanism of these materials. It is shown that a bimodal molecular weight distribution alone is sufficient to strongly alter the mechanical properties of networks compared to the corresponding unimodal networks with the same number-average chain length. Furthermore, it is shown that heterogeneities in the form of high-density short-chain clusters affect the mechanical properties relative to a homogeneous network, primarily by providing extensibility.

The thesis presents work regarding amphiphilic molecules associated in aqueous solution or at the liquid/solid interface. Two main topics are included: the temperature-dependent behavior of micelles and the adsorption of dispersants on carbon nanotube (CNT) surfaces. Various NMR methods were used to analyze those systems, such as chemical shift detection, spectral intensity measurements, spin relaxation and, in particular, self-diffusion experiments. Besides this, small angle X-ray scattering (SAXS) was also applied for structural characterization.   A particular form of phase transition, core freezing, was detected as a function of temperature in micelles composed by a single sort of Brij-type surfactants. In mixed micelles, that phase transition still occurs accompanied by a reversible segregation of different surfactants into distinct aggregates. Adding a hydrophobic solubilizate shifts the core freezing point to a lower temperature. Upon lowering the temperature to the core freezing point, the solubilizate is released. The temperature course of the release curves with different initial solubilizate loadings is rationalized in terms of a temperature-dependent loading capacity.   The behavior of amphiphilic dispersant molecules in aqueous dispersions of carbon nanotubes (CNTs) has been investigated with a Pluronic-type block copolymer as frequent model dispersant. Detailed dispersion curves were recorded and the distribution of the dispersant among different available environments was analyzed. The amount of dispersed CNT was shown to be defined by a complex interplay of several factors during the dispersion process such as dispersant concentration, sonication time, centrifugation and CNT loading. In the dispersion process, high amphiphilic concentration is required because the pristine CNT surfaces made available by sonication must be rapidly covered by dispersants to avoid their re-attachment. In the prepared dispersions, the competitive adsorption of possible dispersants was investigated that provided information about the relative strength of the interaction of those with the nanotube surfaces. Anionic surfactants were found to have a strong tendency to replace Pluronics, which indicates a strong binding of those surfactants.   CNTs were dispersed in an epoxy resin to prepare nanotube-polymer composites. The molecular mobility of epoxy was investigated and the results demonstrated the presence of loosely associated CNT aggregates within which the molecular transport of epoxy is slow because of strong attractive intermolecular interactions between epoxy and the CNT surface. The rheological behavior is dominated by aggregate-aggregate jamming. / <p>QC 20180103</p>

Organic electrode materials represent an intriguing alternative to their inorganic counterparts due to their sustainable and environmental-friendly properties. Their plastic character allows for the realization of light-weight, versatile and disposable devices for energy storage. Conducting redox polymers (CRPs) are one type of the organic electrode materials involved, which consist of a π-conjugated polymer backbone and covalently attached redox units, the so-called pendant. The polymer backbone can provide conductivity while it is oxidized or reduced (i. e., p- or n-doped) and the concurrent redox chemistry of the pendant provides charge capacity. The combination of these two components enables CRPs to provide both high charge capacity and high power capability. This dyad polymeric framework provides a solution to the two main problems associated with organic electrode materials based on small molecules: the dissolution of the active material in the electrolyte, and the sluggish charge transport within the material. This thesis introduces a general synthetic strategy to obtain the monomeric CRPs building blocks, followed by electrochemical polymerization to afford the active CRPs material. The choice of pendant and of polymer backbone depends on the potential match between these two components, i.e. the redox reaction of the pendant and the doping of backbone occurring within the same potential region. In the thesis, terephthalate and polythiophene were selected as the pendant and polymer backbone respectively, to get access to low potential CRPs. It was found that the presence of a non-conjugated linker between polymer backbone and pendant is essential for the polymerizability of the monomers as well as for the preservation of individual redox activities. The resulting CRPs exhibited fast charge transport within the polymer film and low activation barriers for charge propagation. These low potential CRPs were designed as the anode materials for energy storage applications. The combination of redox active pendant as charge carrier and a conductive polymer backbone reveals new insights into the requirements of organic matter based electrical energy storage materials.

Vatten som har förorenats genom att det passerat genom en deponi kallas för lakvatten. Detta vatten behöver tas omhand för att undvika negativ påverkan på miljön. Lakvattnets karaktär beror till stor del på vilken typ av avfall som har deponerats. Deponin Tippa ska ta fram ett förslag på lokalt omhändertagande av sitt lakvatten. Tippas lakvatten har karaktäriserats utifrån 11 provtagningar tagna år 2009. Analysresultaten visar att de föroreningar som överskrider satta riktvärden är; organiskt material i form av BOD och COD, kväve i form av ammonium och totalkväve samt metallerna järn och koppar. För att kunna utforma en reningsprocess som skulle kunna hantera dessa föroreningar har en litteraturstudie utförts som ska ligga till grund för bedömning av vilken/vilka tekniker som lämpar sig för Tippas förutsättningar. Litteraturstudien består av en sammanställning av de konventionella reningstekniker som används för rening av lakvatten och driftserfarenheter samt processbeskrivningar från 18 Svenska deponier. Med litteraturstudien som grund har en kombination av teknikerna SBR (öppen) och Sandfilter bedömts som de bäst lämpade alternativen i en reningsprocess för Tippas lakvattensituation. Reningsprocessen är uppdelad i fyra efter varandra följande zoner. Zon 1 är ett utjämningsmagasin dimensionerat för att kunna hålla vattenvolymer motsvarande två månaders medelflöde. I Zon 2 sker luftning med fyra stycken ytluftare, och den har dimensionerats efter modellen för en totalomblandad tankreaktor. I Zon 3 tillsätts metanol vilket främjar denitrifikation, och vattnet leds slutligen till Zon 4 vilket är en sandfilterbädd dimensionerad efter nödvändig filterkapacitet för att klara lakvattenflödet. Investeringskostnaderna för reningsprocessen uppskattas till 13,4 Mkr. Till detta kommer driftskostnader som uppskattas ligga kring 0,4 Mkr per år. / Water that has been contaminated by passing through a landfill is called leachate. This water needs to be treated to avoid negative environmental effects on the surrounding area. The composition of the leachate varies widely depending on the type of waste deposited in the landfill. The landfill Tippa is making plans for a process to treat its leachate locally. Tippas leachate has been characterized through 11 leachate samples collected throughout the year 2009. The results from analyzing the leachate show that the contaminants that exceed the recommended limits are; organic matter as BOD and COD, nitrogen as Ammonia and total nitrogen, as well as iron and copper. A summary of conventional technology for wastewater treatment has been made with information from various literary sources. Together with a summary of process descriptions for the leachate treatment from 18 Swedish landfills this constitutes a basis of reference for how to design a process best suited for Tippa. Through a process of selection, a modified version of SBR and Sand filtration have been selected as the most suitable technologies for local leachate treatment. The process consists of four sequent zones. Zone 1 is a storage basin that can hold volumes of up to two months worth of average flow. Zone 2 is aerated through four surface aerators and has been designed after the model for a continuously stirred tank reactor. In Zone 3 methanol is added to promote denitrification. Zone 4 is a sand filter that has been designed based on the required filter capacity. The investments costs for this process have been estimated to 13,4 Mkr, and operation costs to 0,4 Mkr per year.

Executive summary Today, packaging has gained a significant role in the food industry as well as other industries. Paper substrates that have been coated in some ways are typically used to make packaging. The amount and type of pigment used in the formulation determine whether this coating is a pigment coating or a barrier coating. Critical pigment volume concentration (CPVC) is the optimum spot when the pigments are packed as densely as possible, and the binder fills the air gaps. When the amount of pigment in a coating is less than CPVC, a barrier coating is formed, although when the amount of pigment in the coating is greater than CPVC, a pigment coating is formed. Pigment coating adds optical properties to a package, such as improved printability. And chemical protection is primarily provided for water, water vapour, fats, and gases in the case of the barrier coating. Chemical protection against these substances means, for food packaging, that the shelf life of the product will be extended, among other things. The role of packaging in society is expected to grow as barrier coatings on packaging continue to improve. The use of nanoclay in barrier coatings is investigated in this laboratory study. Two latexes are tested with nanoclay, with latex chosen based on its glass transition temperature (Tg). The hypothesis was that a latex with a higher Tg would have more properties like brittleness and orderly structure in its amorphous structure than the other latex. Latex with a lower Tg, on the other hand, would have more elasticity, be more ductile, and have a lower degree of ordered structure in its amorphous structure. Latex with a higher Tg was referred to as Hard latex and was composed of Styrene-butadiene, while latex with a lower Tg was referred to as Soft latex and was composed of Polyolefin dispersion, although it is unorthodox to call it latex. Previous research has found that the addition of Bentonite nanoclay can improve the mechanical and barrier properties of barrier coatings. Bentonite was therefore chosen as the nanoclay for this study due to having a higher aspect ratio, is flaky and can improve desired properties. The coating was applied as a dispersion coating using a lab-scale rod coater. The substrate for this study was BillerudKorsnäs FibreForm with a grammage of 150 g/m2.In order to find the optimum rod for the coating, three different rods were tested during screening test 1. The rods tested were based on the desired coating weight and thickness, a red rod with a wet film thickness of 12 μm was chosen. The nanoclay content of the latex formulation was investigated to determine the optimal level for improved barrier properties. In screening test 2, the concentrations examined were 2/4/8 w/w% nanoclay in each latex, and 0 w/w% to compare the difference with Hard/Soft latex to see if there are any benefits of nanoclay. For both latexes, the addition of 2/4 w/w% nanoclay resulted in more pinholes as well as a poor water vapour transmission rate and permeability. The results of screening test 2 showed that adding 8 w/w% nanoclay to both latexes improved the water vapour transmission rate, water vapour permeability, and pinholes test when compared to the other concentrations of nanoclay. In the water vapour transmission rate and pinholes test, however, 0 percent nanoclay performed similarly 8 w/w% for each latex formulation. The selected formulation for further study was 8 w/w% nanoclay with Hard/Soft latex.  Water vapour was the most important barrier property to investigate since barrier coatings were intended for food packaging. For the intended food packaging, it was sought that the barrier could be stretched with 3.8/6.7/10.4%-stretch and then characterized by water vapour transmission rate to be able to see the differences before and after stretching. Stretching with tensile tester were performed on a barrier coated FibreForm, first in the machine direction (MD), then in cross-direction (CD). Hydroforming with shaped bubbles was used for the second method of stretching with various bubbles. Stretching in MD + CD, and hydroforming bubbles were done according to the desired %-stretching. Characterization of the coating was done by water vapour transmission rate (WVTR) for all coatings, pinholes test for hydroformed coatings, water vapour permeability (WVP) and scanning electron microscopy (SEM) on tensile-stretched coatings. The performance of Soft latex with an 8 w/w% formulation stretched in MD then CD and characterized by water vapour transmission rate was significantly unchanged despite stretching up to 10.4%. This is thought to be because nanoclay, as the literature suggests, has created a better barrier against water vapour. The mean WVTR of 10.4%-stretching in MD then CD was 5.5 g/m2/day, compared to 5.5 g/m2/day for the unstretched barrier.  SEM images of both stretched and non-stretched coatings show that the dispersion of nanoclay is poor, as there are islands of polymer and nanoclay bulk. The poor dispersion of nanoclay in the matrix was due to the lack of polar groups in the backbone of Soft latex (Polyolefin) and also being hydrophobic, as opposed to Bentonite, which is hydrophilic. Despite poor nanoclay dispersion and a stretch of 10.4% in MD + CD, resulting in reduced barrier thickness, WVP improved from 289 g* /m2/day (pre-stress) to 191 g* /m2/day (10.4%-stretch), giving the impression of some reorientation of nanoclay in the polymer matrix. A crack was also visible in SEM images, near the boundary layer between the barrier and the substrate, on an unstretched coating, which is thought to be caused by the difference in the boundary layer and adhesive forces, that has occurred during drying. Cracks are not visible on the stretched barriers, even though it was expected. With increased stretching of hydroforming substrates coated with Soft latex formulation, the performance of water vapour transmission rate was significantly worse. The reason for this is thought to be that the barrier was damaged during hydroforming due to friction during pressing and shaping, as the hydroforming was done on the barrier side. The pinhole test revealed clearly degraded performance with a large number of pinholes. This could indicate that the barrier has been stretched beyond its capacity or has been damaged. There was no correlation found between stretching in tensile tester and hydroforming.  Hard latex with an 8 w/w% formulation stretched in MD then CD and characterized by water vapour transmission rate could be stated to have significantly improved performance despite stretching up to 10.4%. The mean-WVTR of 10.4%-stretching in MD then CD was 11.3 g/m2/day, compared to 16.4 g/m2/day for the unstretched barrier. According to SEM images, the reason for this is that nanoclay was very well dispersed in the matrix and that there has seemingly been a slight reorientation of nanoclay with increased stretch. Furthermore, SEM images show that the thickness was reduced, yet despite this, mean-WVP improved from 1094 g* /m2/day (pre-stress) to 419 g* /m2/day (10.4%-stretch), indicating reorientation of nanoclay and thus improved stretchability.These SEM images show cracks at the boundary layer between the barrier and the substrate for both unstretched and 10.4%-stretched barriers in the Hard latex formulation. The cracks are seemingly stopped by nanoclay in the matrix, according to the stress concentration effect, where the crack moves around nanoclay and not through nanoclay. Hydroforming of barrier coated Hard latex formulation showed a deterioration of water vapour transmission rate with increased stretching. The mean WVTR of hydroforming with 10.4%-stretching was 30.6 g/m2/day. It is not thought that pressing during hydroforming damaged the Hard latex barrier as much, which can be confirmed by the pinholes test. Pinholes test demonstrated good performance and comparable to an unstretched barrier. Because comparisons between the different polymers were impractical, it was not possible to state if the glass transition temperature was important for the improvement seen by stretching in the tensile tester. But it can be argued that Hard latex has a more structured and rigid structure, allowing for a greater degree of reorientation. Soft latex, on the other hand, has less stiffness and thus less reorientation. The result of this study is that when stretching is done in both tensile testing and hydroforming, 8 w/w% nanoclay (bentonite) with Hard latex (styrene-butadiene) can be used advantageously in FibreForm packaging if stretchability is desired while maintaining barrier properties against water vapor. / Sammanfattning Idag har förpackningar fått en betydande roll i matindustrin såväl som andra industrier. Vid bestrykning på förpackningar och papperssubstrat så är det vanligt med pigment- eller barriärbestrykning. Vid pigmentbestrykning så tillförs optiska egenskaper till förpackningen, såsom exempelvis förbättrad tryckbarhet. Vid barriärbestrykning tillförs huvudsakligen kemisk skydd mot exempelvis vatten, vattenånga, fetter eller gaser, och innebär för matförpackningar bland annat att hållbarheten blir längre för livsmedlet. Genom fortsatt utveckling av barriärbestrykningar på förpackningar så förväntas även förpackningens roll i samhället att bli större. I denna laborativa studie undersöks möjligheterna kring töjbara barriärer på papperssubstrat, med fokus på vattenångaresistans.  De formuleringar som togs fram bestod av en latex med låg glasövergångstemperatur (Tg), kallad Soft latex med implementerad nanolera samt en latex med en Tg kallad Hard latex med implementerad nanolera. Soft latex var en Polyolefin dispersion med Tg -30°C, och Hard latex var en Styren-butadien latex med Tg = 0°C. 8 w/w% nanolera var den halt som bedömdes ge förbättringar i de mekaniska samt barriäregenskaper som eftersöktes för de båda latex. För denna studie valdes Bentonit som nanolera, på grund av dess plana samt dess fjälliga (flaky) struktur.  Töjbarheten hos de framtagna barriärformuleringarna testades med töjning i dragprov först i maskin-riktning (MD) och sedan tvär-riktning (CD) samt töjning med hydroforming, med töjning på 3,8/6,7/10,4% för respektive metod. Efter töjning av respektive metod bestämdes överföringshastigheten av vattenångpermabilitet (WVTR) genom barriären. En jämförelse gjordes mellan töjning i dragprov och hydroforming för att få en ökad förståelse kring WVTR-prestationen beroende på metod av töjning.  Soft latex visade en oförändrad vattenångaresistans efter 10,4%-töjning i dragprovaren. Detta tros bero på att nanoleran försvårar vattenångan att genomträngas trots töjning. Vid elektronmikroskop (SEM) kunde det ses att dispersionen av nanolera med Soft latex inte var bra, och därför var inte förbättringarna lika tydliga. Den sämre dispersionen av nanolera i matrisen beror på att Polyolefin saknar polära grupper i dess ryggrad (backbone) samt är väldigt hydrofobt, till skillnad från Bentonit som är hydrofilt. Trots sämre dispersion av nanolera och en töjning på 10,4% i MD + CD, så förbättrades vattenånga permeabiliteten (WVP).För hydroforming var prestationen av Soft latexformuleringen gällande WVTR dåliga, och vid Pinholes test fanns det uppenbara pinholes.  Hard latex visade en tydlig förbättring av WVTR efter 10,4%-töjning i dragprovaren, som tros bero på en omorientering av nanoleran i polymer matrisen vid töjning, vilket kan bekräftas av elektronmikroskop (SEM) där viss omorientering är synlig. Dessutom sågs en tydlig förbättring i WVP trots en lägre barriärtjocklek.För hydroforming var WVTR-värdena liknande till endast Hard latex och 0% nanolera.  Vid töjning var jämförelser beroende på de olika glasövergångstemperaturerna hos polymererna inte möjlig, och därför inte heller möjligt att konstatera ifall glasövergångstemperaturen var viktig för den förbättring som setts trots töjning i dragprovare. Men det kan hävdas att Hard latex har en mer strukturerad och stel struktur, vilket möjliggör en större grad av omorientering. Soft latex däremot, är mindre styvt och mindre ordnat, därav åstadkoms en mindre omorientering.  Resultaten av denna studie är att när stretching görs i både dragprovning och hydroformning, kan 8 w/w% nanoclay (bentonit) med Hard latex (styren-butadien) vara fördelaktig i FibreForm-förpackning om töjbarhet önskas samtidigt som barriäregenskaperna mot vattenånga bibehålls.

The dynamic (ac) Stark effect refers to the energy shifting of electronic states induced by an oscillating electric field. Conveniently, the magnitude of the ac Stark shift scales with the square of the electric field amplitude, i.e. with light intensity. Using this fundamental effect to reshape molecular potentials, and steer the course of chemical reactions, is known as dynamic Stark control. The aim of this study was to investigate the dynamic Stark effect on the photodissociation of molecular oxygen (O2) in the Schumann-Runge continuum, SRC (130–175 nm). Absorption in the SRC leads to dissociation via the so-called B state, yielding O(1D) + O(3P), or the J state, forming O(3P) + O(3P). Both of these dissociative excited states may be well-described in terms of mixed valence and Rydberg state character, in which each of the two states are strongly coupled to a Rydberg state of similar symmetry. Due to the mixed character of the B and J states, simulations predict that dynamic Stark shifting of the coupled Rydberg states leads to a dramatic change in dissociation channel branching ratio, as well as a red-shift of the absorption spectrum. This study aimed at experimentally testing this theoretical prediction. A 400-nm femtosecond laser pulse was employed as a combined pump and control field, simultaneously inducing a three-photon transition into the SRC and ac Stark shifting the potentials. A detection scheme to detect the changes in absorption of the B channel with pump pulse intensity was devised and implemented. The chosen detection scheme, in which emission at 762 nm from the O2(b−X) transition is measured, in principle monitors O(1D) from the B channel via an energy transfer reaction. The experimental results overall show consistency between simulations and experiment. The measured 762-nm emission exhibited a pump pulse intensity-dependence that likely reflects the dynamic Stark reshaping of the excited state potentials. However, saturation is clearly present in the data, complicating data interpretation. Furthermore, deviations between experiment and simulations are large at high pulse intensities, indicating that O(1D) is additionally generated by absorption into higher excited states. Finally, structured features that deviate from the simulations at low pulse intensities may possibly be assigned to vibrational resonances to high-lying Rydberg states by four-photon absorption. / Den dynamiska (ac) Starkeffekten beskriver energiskiftet för elektroniska tillstånd som induceras av ett oscillerande elektriskt fält. Storleken på detta skift ökar med kvadraten av den elektriska fältstyrkan, det vill säga med ljusintensitet. Tillämpningen av denna fundamentala effekt i syfte att omforma molekylära potentialer, och därmed styra kemiska reaktioner, kallas för dynamisk Starkkontroll. Syftet med denna studie var att undersöka hur den dynamiska Starkeffekten påverkar den fotoinducerade dissociationen av molekylärt syre (O2) inom Schumann-Runge kontinuumet, SRC (130–175 nm). Absorption i SRC resulterar i dissociation via det så kallade B-tillståndet, som bildar O  (1D) + O(3P), eller via J-tillståndet, som leder till bildandet av O(3P) + O(3P). Båda dessa dissociativa tillstånd har en karaktär som kan beskrivas som en blandning av ett valenstillstånd och ett Rydbergstillstånd.  Simuleringar antyder att, till följd av valens- och Rydbergskaraktären hos B och J-tillståndet, leder dynamisk Starkskiftning av de kopplade Rydbergstillstånden till en dramatisk ändring i det relativa utbytet för de två dissociationskanalerna, samt till ett röd- skift av absorptionsspektrumet. Denna studie hade som ändamål att experimentellt testa denna teoretiska förutsägelse. En femtosekundslaser vid 400 nm användes som kombinerat excitations- och kontrollfält, vilket parallellt inducerar en trefoton-övergång in i SRC och ac Starkskiftar potentialerna. En detektionsmetod som mäter variationer i absorptionen för B-kanalen som funktion av pulsintensitet designades och implementerades. I den valda metoden detekteras emission vid 762 nm från O2(b − X)-övergången, vilket i sin tur ger en mätning av O(1D) som genereras från B- kanalen via en energiöverföringsreaktion. De experimentella resultaten stämmer relativt väl överens med simuleringarna. Den uppmätta emissionen vid 762 nm uppvisar ett intensitetsberoende som i stora drag reflekterar ac Stark- skiftningen av potentialerna. Utöver detta finns dock ett stort bidrag från mättnad, vilket försvårar tolkningen av datan. Vi-dare avviker den experimentella datan betydligt vid höga pulsintensiteter, vilket sannolikt tyder på att O(1D) även genereras genom absorption till högre exciterade tillstånd. Slutligen ob-serveras mindre, men tydliga avvikelser vid låga pulsintensiteter. Dessa kan möjligen tillordnas vibrationsresonanser med högre Rydbergstillstånd genom fyrfoton-absorption. ​

Laddningsbeteendet hos amingruppen vid ytgränsskiktet mellan vatten och luft har studerats under ändring av vattenfasens pH och NaCl-koncentration via den ickelinjära laserspektroskopiska tekniken, vibrationssumfrekvensspektroskopi (VSFS). Modellen som användes för ytan bestod av ett Langmuirmonolager av 1-docosanamin, en icke-löslig fettkedjeamin med NH2-gruppen riktad mot vattenfasen. En av de huvudsakliga syftena med projektet var att bestämma det skenbara samt yt-pKa:t för amingruppen, såväl som att testa gränserna för de klassiska Poisson-Boltzmann-formuleringarna av teorin för det elektriska dubbellagret. Molekylär information av laddningsbeteendet hos aminen erhölls från VSFS-spektra genom att följa NH-, OH- och CH-sträckningsvibrationsmoderna. Specifikt så identifierades de spektrala dragen från den neutrala formen (R-NH2) och den laddade formen (R-NH3+) av aminen, vilka direkt korrelerades med monolagrets ytladdning. Intensiteten hos OH-banden från vattenmolekylerna i det diffusa dubbellagret kunde länkas till ytpotentialen och CH-vibrationerna från alkylkedjan av amino-tensiden kopplades slutligen till packningstätheten hos monolagret. Ytterligare experiment utfördes med en deutererad vattenfas (D2O) för att bekräfta sträckningsvibrationsmoderna hos NH3+, vilka aldrig tidigare har rapporterats. Resultaten visar på att fettkedjeaminen får ett avsevärt lägre yt- och skenbart pKa jämfört med bulken (∼ 4 jämfört med 10,5). Detta är i enlighet med vad Gouy-Chapmann-modellen av det elektriska dubbellagret förutser. Dessutom så indikerar datat att det inneboende pKa:t hos aminen också blir lägre vid ytan än för bulken (9,7±0,7 jämfört med 10,5), vilket kan beskrivas som en effekt av begränsningen i frihetsgrader hos den ytbundna aminen. Dock, så hindrades en mer utförlig kvantitativ jämförelse mot teorin av ett sämre val av det experimentella referensvärdet som användes för att jämföra data mellan olika dagar. Dessutom så var anpassningsrutinen för datat begränsad på grund av spektrala vibrationsöverlapp mellan de relativt svaga aminbanden och de mycket starkare vatten- och alkylsträckningssignalerna. Intressant nog, för högre pH-värden, då aminen är helt oladdad, bevisade sumfrekvensspektra att hydroxidjonen föredrar att adsorbera till ytan genom att monolagret fick en negativ nettoladdning. Överlag så förbättrar studierna som presenteras i denna master-projektuppsats vår molekylära förståelse kring hur den biofysiskt betydande amingruppen beter sig vid ytgränsskikt. / The charging behaviour of the amine moiety at the water-air interface upon changes in the aqueous subphase pH and NaCl concentration has been studied using  the non-linear laser spectroscopy technique, Vibrational Sum Frequency Spectroscopy (VSFS).  The model surface consisted of a Langmuir monolayer of 1-docosaneamine, an insoluble fatty amine that exposes its NH2  group to solution. One of the main purposes of the project is to determine the surface, and the apparent pKa of the amine moiety, as well as testing the limits of validity of classical formulations of the electrical double layer theory within the Poisson-Boltzmann formalism. Molecular information of the charging behaviour was obtained from the VSFS spectra by targeting the NH, OH and CH stretching modes. Specifically, spectral features from the neutral amine (i.e. R-NH2) and charged (R-NH3+) groups could be identified and directly correlated to the surface charge of the monolayer. The intensity of the  OH bands from water molecules in the diffuse double layer, were linked to the surface potential, and finally, the CH modes from the surfactant alkyl chain gave information of the packing density in the monolayer. Additional experiments were also carried out in D2O to help confirm the assignment of the NH3+ stretching modes that had not been previously reported. The results show that as predicted from the Gouy-Chapman electric double layer model, the apparent pKa of the fatty amine monolayer is significantly lower than in the bulk  (∼ 4 compared with 10.5) . However, the data show indication that the intrinsic pKa at the surface is also lower than in the bulk (9.7+/- 0.7, compared to 10.5), an effect that is ascribed to the 2D molecular confinement in the monolayer. A more quantitative comparison with the theoretical predictions was nonetheless hampered by a poor selection of the experimental reference for comparing data collected in different days, and the limitations in the fitting routines due spectral overlap of the relatively weak amine bands with the OH and CH stretching modes. Interestingly, at high pH when the fatty amine is fully uncharged, the sum frequency spectra show evidence that OH- ion preferentially adsorbed to the surface, making it effectively net negatively charged. Overall, the studies presented in this master thesis, improve our molecular understanding of the behaviour of the biophysically relevant amine-functionality at interfaces.