Electrostatic interactions such as halogen bonding and pnictogen bonding interactions have gained a lot of interest in the field of crystal engineering and pharmaceutical science. In the first part of this thesis, we expand our knowledge on anion coordinated halogen bonded cocrystals by looking at a series of cocrystals made from 3-iodoethynyl pyridine and 3-iodoethynylbenzoic acid. We utilize the power of mechanochemistry to create the new cocrystals made with phosphonium salts and use multinuclear solid-state nuclear magnetic resonance spectroscopy and X-ray diffraction and characterize them. We found that mechanochemistry is a fast and powerful tool to explore and synthesize new halogen bonded cocrystals and ³¹P solid-state NMR is a rapid way to identify the formation of a cocrystal. In the second part, we look at the versatility of the pnictogen atom, specifically antimony, as a pnictogen bond donor and a halogen bond acceptor. We evaluate these electrostatic interactions with nuclear quadrupolar resonance and found that nuclear quadrupole resonance is a strong spectroscopy tool to probe these types of electrostatic interactions.

Produktion av nya energetiska material är dyrt. Målet med detta arbete är att utveckla en metod som uppskattar Chapman-Jouget detonationstrycket och detonationshastigheten hos nya CHNO-sprängämnen. En sådan metod möjliggör valet att bara syntetisera och testa de mest lovande kandidaterna som nya energetiska material, därmed undviks resursslösande arbete. Den här metoden använder sig av density functional theory (DFT) och den elektrostatiska potentialen till att uppskatta bildningsentalpier och kristalldensiteter. Beräkningarna gjordes på traditionella sprängämnen och de beräknade detonationstrycken och detonatioshastigheterna visade bra överensstämmelse med experimentell data. Detonationstrycken hamnade inom ±10% och detonatioshastigheterna inom ±5% av experimentell data. / Producing new energetic materials is expensive. This work aims to develop a method of estimating the Chapman-Jouget detonation pressure and the detonation velocity of potential new CHNO explosives. This would allow choosing the most promising candidates for synthesis and testing thus avoiding wasting resources. This method utilizes density functional theory (DFT) and the electrostatic potential to estimate heats of formation and crystal densities. The calculations were performed on traditionally used explosives and the calculated detonation pressures and detonation velocities showed good accordance with experimental data. The calculated detonation pressures fell within ±10% and the detonation velocities within ±5% of experimental data.

The removal of electrostatic precipitator (ESP) ash by solving the ash in water constitutes an environmental problem if heavy metals, such as cadmium, present in the ash remain in the outgoing effluent streams. The ESP ash solution is alkaline, meaning cadmium is present as the insoluble salt Cd(OH)2, cadmium hydroxide. The aim of this work is to reduce the amount of cadmium released to water recipients from pulp mills by investigating different precipitation mechanisms in ESP ash/ water solutions. Solutions with different concentrations, pH and added process chemicals were prepared and the Cd content in the supernatant measured with atomic absorption spectroscopy. The Cd removal through precipitation reached the highest values when ESP ash concentrations were >150 g/l, pH was above 11.5 and the ash solution was allowed to precipitate for 24h. The addition of polymers was found to reduce needed precipitation time. The effect of concentration on Cd removal could be caused by maximum solubility for the Cd2+ ion being reached at roughly 100 g/l ash concentration. The need for higher pH values could be caused by Cd forming complex ions with other solutions at pH<11 and theoretical maximum Cd2+ ion concentration decreasing from pH 10 to pH 13. / Uttag av elfilteraska där askan löses i vatten utgör ett miljöproblem om tungmetaller i elfilteraskan, till exempel kadmium, finns kvar i det avloppsvatten som lämnar systemet. Elfilteraskan är basisk, vilket innebär att kadmium bildar det olösliga saltet kadmiumhydroxid, Cd(OH)2 när askan löses i vatten. Målet med detta examensarbete är att reducera mängden kadmium som släpps ut till vattenrecipienter från massabruk genom att undersöka fällningsmekanismer i vattenlösningar av elfilteraska. Lösningar med olika koncentration, pH och fällningstid förbereddes och kadmiumhalten i klarfasen mättes genom atomabsorptionsspektroskopi. Avskiljningsgraden för kadmium var som störst när koncentrationen >150 g/l, pH var över 11,5 och fällningstiden för hydroxidsalterna var 24h. Polymertillsats visades reducera nödvändig fällningstid. Koncentrationens påverkan på kadmiumhalt i klarfasen kan tänkas bero på att maximal koncentration för Cd2+-jonen nås vid ungefär 100 g/l koncentration. Högre pH-värden kan leda till att komplexbildning med andra joner i asklösningen, vilket sker vid pH<11, undviks. Den teoretiskt maximala lösligheten för Cd2+-jonen minskar från pH 10 till pH 13, vilket kan förbättra avskiljningsgraden.

[pt] A aplicação de espumas na indústria de petróleo ganhou interesse significativo nos últimos anos, demandando espumas estáveis nas condições da aplicação. Neste trabalho, foi realizado um estudo sistemático envolvendo surfactantes de diferentes naturezas químicas (aniônico, catiônico, não iônico e zwitteriônico) para formular espumas de N2 e CO2 em salmouras. Altas concentrações de sais promoveram a precipitação dos surfactantes aniônicos, especialmente com cátions bivalentes (Ca2+ e Mg2+). O coarsening foi significativamente mais intenso nas espumas de CO2, devido à sua grande solubilidade na fase aquosa. Posteriormente, três surfactantes e duas nanopartículas (NPs) de óxidos (SiO2 e Al2O3) foram usados em combinações de cargas similares ou opostas para estabilizar espumas de CO2 em salmoura com formulação complexa (DSW). Experimentos de tensão superficial, viscosidade, potencial zeta e tamanho hidrodinâmico permitiram a análise da estabilidade da espuma de CO2 com base no impacto das interações surfactante/NP nas propriedades em bulk e interfaciais. Sistemas com cargas opostas aumentaram a estabilidade da espuma; no entanto, maior concentração de NPs foi necessária para surfactantes de alta eficiência de adsorção em interface. Tanto a viscosidade quanto a rigidez dos filmes interfaciais aumentaram nesses sistemas, reduzindo a drenagem. Os resultados desta tese mostraram que ouso de NPs deve ser adaptado ao surfactante escolhido, considerandoas condições de salinidade e o pH do meio, para alcançar a interação entre propriedades interfaciais e reológicas capazes de reduzir a drenagem em aplicações envolvendo espuma de CO2 em salmoura. / [en] The application of foams in the petroleum industry has gained significant interest in the past few years, demanding stable foams under applications conditions. In this work, a systematic screening study was carried out using surfactants of different chemical natures (anionic, cationic, non-ionic, and zwitterionic) to formulate N2- and CO2-foams in different brines. High concentrations of salts, especially bivalent cations (Ca2+ and Mg2+), led to a decrease in foam stability of anionic surfactants due to precipitation. In addition, coarsening dominated the foam destruction mechanisms of CO2-foams, due to the large gas solubility in the aqueous phase, compared to N2. Subsequently, three ionic surfactants and two oxide nanoparticles (NPs) (SiO2 and Al2O3) were used in combinations of similar or opposite charges to stabilize CO2 foams in a complex brine, typical of injection fluids (desulfated seawater - DSW). Surface tension, viscosity, zeta potential and hydrodynamic size experiments allowed the analysis of CO2 foam stability based on the impact of surfactant/NP interactions on bulk and interfacial properties. All oppositely charged systems improved the foam half-life; however, a higher NP concentration was required for surfactants with high interface adsorption efficiency. Both bulk viscosity and rigidity of the interfacial films drastically increased in these systems, reducing foam drainage. The results from this thesis showed that the use of NPs should be tailored to the surfactant of choice, considering the conditions of salinity and pH of the medium, to achieve an interplay of interfacial and rheological properties able to reduce foam drainage in applications involving CO2 foam in brine.

No description available.

No description available.

No description available.

DNA is the substance that encodes the genetic information that cells need to replicate and to produce proteins. The detection of DNA sequences is of great importance in a broad range of areas including genetics, pathology, criminology, pharmacogenetics, public health, food safety, civil defense, and environmental monitoring. However, the established techniques suffer from a number of problems such as the bulky size, high equipment costs, and time-consuming algorithms so that they are limited to research laboratories and cannot be applied for in-vivo situations. In our research, we developed a novel sensing scheme for DNA sequence detection, featuring sequence specificity, cost efficiency, speed, and ease of use. Without the need for labels or indicators, it may be ideal for direct in-cell application. The principle is simple. With capture DNA immobilized onto the probe by layer-by-layer selfassembly, the hybridization of a complementary strand of target DNA increases the optical thickness of the probe. Three kinds of sensors were developed. The optical fiber tip sensor has been demonstrated with good specificity and high sensitivity for target DNA quantities as small as 1.7 ng. To demonstrate the potential of this structure for practical applications, tularemia bacteria were tested. Two other micrometric structures were designed with specific advantages for different applications. The micro-fiber Bragg grating interferometer (Micro-FBGI) has the intrinsic temperature compensation capability. The micro-intrinsic Fabry-Perot interferometer (Micro-IFPI)features simple signal processing due to its simple configuration. Successful DNA immobilization and hybridization have been demonstrated onto the 25μm Micro-IFPI. Both structures have great potential for nanometric protrusion, allowing future in-cell DNA direct detection. In addition, its quick response time leads to the potential for express diagnosis. What's more, the idea of nanoscale probe has a broad impact in scanning near-field optical microscopy (SNOM), intracellular surgery in cell sensing, manipulation, and injection. / Ph. D.

This dissertation demonstrates the feasibility of using novel electrostatic self-assembly (ESA) methods to fabricate linear and nonlinear optical thin films and components. The ESA process involves the layer-by-layer alternate adsorption of anionic and cationic complexes from aqueous solutions. Selection of the molecules in each layer, their orientation at the molecular level, and the order in which the layers are assembled determine the film's bulk optical, electronic, magnetic, thermal, mechanical and other properties. In this work, the capability of nanoscale control over film optical properties allowed the fabrication of complicated refractive index profiles required for linear optical interference filters. The inherent ordered nature of ESA films yielded extremely stable noncentrosymmetric thin films for second-order nonlinear optical applications. The ESA technique offers numerous advantages over conventional thin film fabrication methods and offers great potential in commercial applications such as reflectance and AR filters, EO waveguides and modulators and other optoelectronic devices. The structure of each monolayer in ESA films is dependent on the processing parameters, producing subsequent variations in bulk film properties both intentionally and incidentally. As this method is still in its infancy, variations in ESA processing methods, including process automation, are considered first in this document. These results allowed carefully controlled refractive index experiments and the synthesis of both step and graded index structures, several microns thick. Dielectric stack, Rugate, and antireflection optical interference filters were designed, synthesized and demonstrated. c(2) films of both commercially available polymer dyes and novel polymers designed specifically for the ESA process were demonstrated using second harmonic generation. UV/vis spectroscopy, ellipsometry and atomic force microscopy analysis are presented. / Ph. D.

Background: Pulmonary Embolism (PE) is a potentially life-threatening condition that is characterized by one or several blood clots blocking the arteries in the lungs. The existing diagnostic tools for PE have their shortcomings, highlighting the importance of investigating new diagnostic methods. The development of non-invasive methods to collect microparticles from exhaled breath has opened possibilities to explore new potential biomarkers. SensAbues® is a sampling device that utilizes electrostatic filters to capture microparticles from the exhaled breath. The objective of this project was twofold: firstly, to assess the suitability of SensAbues® sampling device for a future proteomics study where the goal is to identify biomarkers for PE; and secondly, to evaluate the efficacy of various extraction solutions in retrieving proteins from the electrostatic filters. Materials and methods: Samples were collected from three healthy volunteers using the SensAbues® device. The electrostatic filters were then extracted using either PBS or 15% ethanol and the protein content was then estimated using a modified Bradford method. Additionally, two blank SensAbues® filter extracts, from PBS and 15% ethanol were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results: The attempts to evaluate extraction solutions using the Bradford method were unsuccessful, as all the samples yielded negative values. The filter-blank extracts analyzed with LC-MS/MS contained a significant amount of polyethylene glycols of varying sizes. Conclusion: The polyethylene glycols from the SensAbues® filters may have interfered with the Bradford method. Polyethylene glycols can also interfere with proteins, making the SensAbues® sampling device unsuitable for the prospective proteomics study.