<p>Då marina enheter numera deltar i internationella missioner, kommer den nya miljön som enheterna opererar i att påverka bland annat deras sensorer.</p><p>Den här studien avhandlar några av de nu framtagna självsanerande ytbeläggningarna och ger en presentation av hur de fungerar på några marina elektrooptiska sensorers yttersta linser.</p><p>Studien försöker ge svar på ytbeläggningarnas transmittans och hur effektivt de kan sanera bort oönskade saltlager tillsammans med andra nedsmutsande partiklar från sensorlinserna samt den militära nyttan av att använda självsanerande ytbeläggning.</p> / <p>This study deals with now developed self-cleaning coatings and gives a presentation of how they work on some electro-optical sensor lenses used in the navy. The study also examines the coatings transmittance and how efficient they can clean the sensor lenses from undesired salt layers and other soiling particles.</p><p>After the introduction the study presents basic facts of the chosen sensors, nanotechnology, surface wettability and also salts and salinity. Thereafter the study describes current nano-research on self-cleaning coatings and possible results there of, when the coatings are applied on the different sensors.</p><p>In the study I give my opinion of the military benefit of using self-cleaning coatings, which from a general point of view is that there mostly are positive effects using such a coating, in a technical perspective.</p><p>The study ends with conclusions that there are self-cleaning coatings based on TiO₂-nanoparticles which can transmit within the visual spectra and also can clean undesired soiling particles. But can not confirm that these coatings have the desired effect on salt crystals, or transmit within wavelengths spectrum for IR-detectors and lasers.</p> / ChpT 08-10

Då marina enheter numera deltar i internationella missioner, kommer den nya miljön som enheterna opererar i att påverka bland annat deras sensorer. Den här studien avhandlar några av de nu framtagna självsanerande ytbeläggningarna och ger en presentation av hur de fungerar på några marina elektrooptiska sensorers yttersta linser. Studien försöker ge svar på ytbeläggningarnas transmittans och hur effektivt de kan sanera bort oönskade saltlager tillsammans med andra nedsmutsande partiklar från sensorlinserna samt den militära nyttan av att använda självsanerande ytbeläggning. / This study deals with now developed self-cleaning coatings and gives a presentation of how they work on some electro-optical sensor lenses used in the navy. The study also examines the coatings transmittance and how efficient they can clean the sensor lenses from undesired salt layers and other soiling particles. After the introduction the study presents basic facts of the chosen sensors, nanotechnology, surface wettability and also salts and salinity. Thereafter the study describes current nano-research on self-cleaning coatings and possible results there of, when the coatings are applied on the different sensors. In the study I give my opinion of the military benefit of using self-cleaning coatings, which from a general point of view is that there mostly are positive effects using such a coating, in a technical perspective. The study ends with conclusions that there are self-cleaning coatings based on TiO2-nanoparticles which can transmit within the visual spectra and also can clean undesired soiling particles. But can not confirm that these coatings have the desired effect on salt crystals, or transmit within wavelengths spectrum for IR-detectors and lasers. / ChpT 08-10

Biologically inspired design is used as an approach for sustainable engineering. Taking a biologically inspired approach, one abstracts ideas and principles from nature, an inherently sustainable system, and uses them in engineering applications with the goal of producing environmentally superior designs. One such biological idea with potential environmental benefits for engineering is microscale and nanoscale surface roughness found on the Lotus plant and many other surfaces in nature. These surfaces repel water and aid in contaminant removal; this self-cleaning phenomenon is called the "Lotus Effect," in honor of the plant first observed to exhibit it. The structures responsible for the Lotus Effect inspired research and development of many technologies capable of creating hydrophobic, self-cleaning surfaces, and many potential self-cleaning surface applications exist beyond nature's intended application of cleaning. While statements have been made about the environmental benefits of using a self-cleaning surface, only limited scientific data exist. Artificial self-cleaning surfaces are successfully cleaned using fog or mist. This shows that such surfaces can be cleaned with less energy and water intensive methods than the more conventional methods used to clean regular surfaces, such as spray or solvent cleaning. This research investigates the potential environmental burden reductions associated with using these surfaces on products. A life cycle assessment is performed to determine the environmental burdens associated with manufacturing a self-cleaning surface, for three production methods: a chemical coating, a laser ablated steel template, and an anodized aluminum template. The environmental benefits and burdens are quantified and compared to those of more conventional cleaning methods. The results indicate that self-cleaning surfaces are not necessarily the environmentally superior choice.

Poor indoor air quality is a source of adverse health effects. TiO2 coatings deposited on well-illuminated surfaces, such as window panes, can be used to fully mineralize indoor air pollutants by photocatalysis. In such applications it is important to ensure stable photocatalytic activity for a wide range of operating conditions, such as relative humidity and temperature, and to avoid deactivation of the catalyst. In this thesis photocatalytic removal of the indoor-pollutant acetaldehyde (CH3CHO) on nanostructured TiO2 films is investigated, and in particular it is proposed how such films can be modified and operated for maximum performance. Catalyst deactivation can be reduced by purposefully changing the surface acidity of TiO2 by covalently attaching SO4 to the surface. Moreover, the overall photocatalytic activity on anatase TiO2 films can be improved by increasing the fraction of exposed reactive {001} surfaces, which otherwise are dominated by {101} surfaces. In the first part of the thesis mode-resolved in-situ FTIR is used to elucidate the reaction kinetics of CH3CHO adsorption and photo-oxidation on the TiO2 and SO4 – modified TiO2 surfaces. Surface concentrations of main products and corresponding reaction rates were determined. Formate is the major reaction product, whose further oxidation limits the complete oxidation to gaseous species, and is responsible for photocatalyst deactivation by site inhibition. The oxidation reaction is characterized by two reaction pathways, which are associated with two types of surface reaction sites. On the sulfate modified TiO2 catalyst fewer intermediates are accumulated, and this catalyst resists deactivation much better than pure TiO2. A hitherto unknown intermediate – surface-bound acetaldehyde dimer with an adsorption band at 1643 cm−1 was discovered, using interplay between FTIR spectroscopy and DFT calculations. The second part of the thesis treats the effect of increasing the relative abundance of exposed {001} facets on the photocatalytic activity of anatase TiO2 films prepared by DC magnetron sputtering. A positive effect was observed both for liquid-phase photo-oxidation of methylene blue, and for gas-phase photocatalytic removal of CH3CHO. In both cases it was found that the exposed {001} surfaces were an order of magnitude more reactive, compared to the {101} ones. Furthermore, it was found that the reactive films were more resilient towards deactivation, and exhibited almost unchanged activity under varying reaction conditions. Finally, a synergetic effect of SO4 – modification and high fraction of exposed {001} surfaces was found, yielding photocatalysts with sustained high activity. The results presented here for facet controlled and chemically modified TiO2 films are of interest for applications in the built environment for indoor air purification and as self-cleaning surfaces. / GRINDOOR

Tenké vrstvy oxidu titaničitého byly imobilizovány na sodnovápenatá skla a skelný uhlík použitím jak techniky materiálového tisku tak metodou chemického napařování. Pro přípravu titaničitých solů byly použity metody sol-gelu a nebo hydrotermální syntézy. Struktura připravených vrstev byla zkoumána rastrovací elektronovou mikroskopií a mikroskopií atomárních sil. Krystalická struktura připravených TiO2 byla analyzovány pomocí XRD metody. Fotoindukováná superhidrofility pripravených vzorků byla charakterizována měřením kontaktních úhlů. Fotokatalytická aktivity připravených vzorků byla testována na fotokatalytické oxidaci 2,6-dichlorindofenolu a kyseliny mravenčí. V případě sol-gel vrstev byl zkoumán vliv množství naneseného TiO2 a množství PEG, který byl do solu přidán jako praskliny potlačující činidlo. V případě hydrotermálních vrstev byl zkoumán vliv času a teploty syntézy a množství vrstev na výslednou účinnost vzorku. U chemicky napařených vzorků byl zjišťován vliv intenzity záření. Byla porovnána fotokatalitická aktivita vrstev připravených materiálovým tiskem a chemickým napařováním a byl vyhodnocen nejaktivnější vzorek.