Corrosion protection performance of a completely soluble polyaniline-dodecylbenzenesulfonic acid salt (PANI-DBSA) on C45 steel has been studied with electrochemical impedance and potentiodynamic measurements. Chloroform is the most suitable solvent to process the pristine PANI-DBSA because of negligible interaction of the solvent with the polyaniline (PANI) backbone. An anodic shift in the corrosion potential (<img src="http://scitation.aip.org/stockgif3/Dgr.gif" alt="Delta" align="bottom" border="0"><i>E</i>=~70&nbsp;&nbsp;mV), a decrease in the corrosion current and a significant increase in the charge transfer resistance indicate a significant anti-corrosion performance of the soluble PANI deposited on the protected steel surface. Corrosion protection follows the mechanism of formation of a passive oxide layer on the surface of C45 steel. In situ UV-Vis spectroscopy was used to investigate the differences in permeability of aqueous anions into PANI-DBSA. Preliminary results of electron diffraction studies show that PANI-DBSA possesses an orthorhombic type of crystal structure. An increase in the feed ratio of DBSA to aniline increases the tendency of aggregation of spherical particles of PANI obvious in transmission electron microscopy. PANI-DBSA slowly loses its electrochemical activity in acid free electrolyte without undergoing degradation.

This diploma thesis is focused on the charge exchange processes between projectile and target studied by the Low Energy Ion Scattering (LEIS) technique. Basic premise to investigate charge exchange processes is correct cleaning processes and proper settings of experimental instrument Qtac 100 placed in the Central European Institute of Technology (CEITEC) in Brno. Ion fraction expresses neutralization rate of the projectile. The parametr is investigated for clean and oxidized polycrystalline copper. Oxygen presence performs a significant part of reionization of backscattered neutralized projectiles.

Plume-spacecraft interactions play an important role in the performance and integrity of spacecraft during their missions in space. The study encompasses a thruster’s plume simulation and its impact on spacecraft geometries to understand and predict the effects and consequences of the impingement on spacecraft surfaces, such as erosion, contamination, forces, and torques. The initial focus of the thesis is to simulate an electric thruster current density for both space and vacuum chamber measurements. This estimates the artificial broadening of the plume produced by low-pressure background air particles inside a vacuum chamber. Subsequently, the study adopts a conservative approach by considering a current density obtained from vacuum chamber measurements, which allowed for an evaluation of the potential effects on spacecraft surfaces, thus delivering insights into erosion, contamination, as well as the distribution of forces and torques. The results highlight the importance of considering spacecraft charging in plume interactions, as the surface potential significantly affects the impact of the thruster’s plume on spacecraft surfaces. The outcome obtained throughout this project suggests that the effects of particle impingement on erosion, contamination, forces, and torques in plume-spacecraft interactions are influenced by the thruster location and the spacecraft’s surface potential. It is important to note that additional factors, including thermal effects, radiation, and magnetic fields, which were not addressed in this thesis, may also pose potential threats to spacecraft performance and should be considered in future investigations. / Interaktioner mellan plym och rymdfarkoster spelar en viktig roll i rymdfarkosternas prestanda och integritet under deras uppdrag i rymden. Studien omfattar simulering av en raketmotors plym och dess inverkan på rymdfarkostens geometrier för att förstå och förutsäga effekterna och konsekvenserna av kollisionen på rymdfarkostens ytor, såsom erosion, förorening, krafter och vridmoment. Avhandlingens initiala fokus är att simulera strömtäthet i plymen från en elektrisk raketmotor för både rymd- och vakuumkammarmätningar. Detta uppskattar den artificiella expansionen av plymen som produceras av de molekyler som närvarar i det låga trycket inuti en vakuumkammare. Därefter antar studien ett konservativt tillvägagångssätt genom att överväga en strömtäthet erhållen från vakuumkammarmätningar, vilket möjliggjorde en utvärdering av de potentiella effekterna på ytorna på en rymdfarkost, och därmed leverera insikter om erosion, förorening, såväl som fördelningen av krafter och vridmoment. Resultaten understryker vikten av att överväga laddning av rymdfarkoster i plyminteraktioner, eftersom ytpotentialen signifikant påverkar raketmotorplymens påverkan på rymdfarkostens ytor. Resultatet som erhållits genom hela detta projekt tyder på att effekterna av partikelkollision på erosion, förorening, krafter och vridmoment i växelverkan mellan plym och rymdfarkoster påverkas av raketmotorns placering och rymdfarkostens ytpotential.

Corrosion protection performance of a completely soluble polyaniline-dodecylbenzenesulfonic acid salt (PANI-DBSA) on C45 steel has been studied with electrochemical impedance and potentiodynamic measurements. Chloroform is the most suitable solvent to process the pristine PANI-DBSA because of negligible interaction of the solvent with the polyaniline (PANI) backbone. An anodic shift in the corrosion potential (<img src="http://scitation.aip.org/stockgif3/Dgr.gif" alt="Delta" align="bottom" border="0"><i>E</i>=~70&nbsp;&nbsp;mV), a decrease in the corrosion current and a significant increase in the charge transfer resistance indicate a significant anti-corrosion performance of the soluble PANI deposited on the protected steel surface. Corrosion protection follows the mechanism of formation of a passive oxide layer on the surface of C45 steel. In situ UV-Vis spectroscopy was used to investigate the differences in permeability of aqueous anions into PANI-DBSA. Preliminary results of electron diffraction studies show that PANI-DBSA possesses an orthorhombic type of crystal structure. An increase in the feed ratio of DBSA to aniline increases the tendency of aggregation of spherical particles of PANI obvious in transmission electron microscopy. PANI-DBSA slowly loses its electrochemical activity in acid free electrolyte without undergoing degradation.

Graphene-directed two-dimensional (2D) nitrogen-doped porous carbon frameworks (GPF) as the hosts for sulfur were constructed via the ionothermal polymerization of 1,4-dicyanobenzene directed by the polyacrylonitrile functionalized graphene nanosheets. As cathodes for lithium–sulfur (Li–S) batteries, the prepared GPF/sulfur nanocomposites exhibited a high capacity up to 962 mA h g⁻¹ after 120 cycles at 2 A g⁻¹. A high reversible capacity of 591 mA h g⁻¹ was still retained even at an extremely large current density of 20 A g⁻¹. Such impressive electrochemical performance of GPF should benefit from the 2D hierarchical porous architecture with an extremely high specific surface area, which could facilitate the efficient entrapment of sulfur and polysulfides and afford rapid charge transfer, fast electronic conduction as well as intimate contact between active materials and the electrolyte during cycling.