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The key requirement in manufacturing flexible organic lightemitting displays (OLEDs) is to protect the deposited electrodes and emitter materials from oxygen and moisture permeation. Multilayered organic/inorganic barrier films can get relatively thick and brittle, and thinner, intrinsically flexible barrier films need to be developed. In this study, we have investigated manufacturing multilayered sol-gel/atomic layer deposition (ALD) structures on poly(ethylene naphthalate) films. The results show improved surface morphology and promising shielding properties against water vapor and oxygen permeation.

Nonwovens are versatile material group suitable for various medical applications including. Properties of nonwoven materials can be adjusted by functionalization with various surface treatment and coating technologies. Printing methods e.g. can be used in functionalization of selected areas of nonwoven material. The foam coating technology enables application of thin functional coatings. Atomic layer deposition (ALD) and solgel techniques can be used to adjust surface properties with inorganic coatings also in nanoscale. In this presentation we will review some examples of nonwovens functionalization's with above mentioned technologies. We used screen printing method in order to prepare a medical cloth for application medical aids to skin. Cream transfer onto skin was tested and material showed promise e.g. for use for controlled dosage of medical creams. We used foam coating to make functional coating onto cellulosic fibre based nonwoven materials with polyvinyl alcohol (PVA)-nanofibrillated cellulose (NFC)-ZnO/TiO2 -solution. Coating increased the strength of nonwoven material compared to non-coated material most likely due to NFC and PVA, while metal oxides made it bacteriostatic. This kind of material could be used e.g. in wound care and bandage applications. Surface properties of nonwovens were adjusted by ALD and sol-gel coatings. Hydrophobicity of coated nonwovens depended on the used coating methods, material, coating thickness and surface roughness. Prospective applications for metal oxide functionalized textiles include with water, oil and soil repellent and antimicrobial medical textiles.

Composites and hybrid materials are new material combinations which can provide added value for existing products or create novel multifunctional properties. This thesis aimed at fabricating and modifying thin-film composites (TFC) by using various coating technologies. Moreover, the target was to tailor the permeability or to create anti-fouling performance. Inorganic, inorganic-organic and organic coating layers were made by atmospheric plasma deposition (APD), sol-gel (SG), atomic-layer-deposition (ALD) or polyvinyl alcohol (PVA) dispersion coating methods. Coatings were deposited using either roll-to-roll or batch process. APD method was used to create an inorganic silicon oxide (SiOx) coating layer on a low-density polyethylene (LDPE) coated board. In addition, atmospheric plasma was used for pre-treatment of LPDE surface prior SG coatings. The SiOx coatings did not show a significant improvement in barrier performance using the specific roll-to-roll process. Therefore, SG coating method was studied instead in order to form a barrier layer on LDPE-board by using the roll-to-roll process. SG coatings reduced the surface roughness and made the polymer surfaces either hydrophilic or hydrophobic. In addition, the coating chemistry had an effect on the oxygen and grease barrier performances. The highly cross-linked SG coating gave a better oxygen barrier performance, while the other SG coating revealed an enhancement in the grease barrier. Plasma activation of the LDPE surface enhanced the wettability and adhesion of both SG coatings. In addition, SG coating was applied on a polylactic acid (PLA) coated board. The SG coating created favourable, smooth and hydrophilic primer layer on PLA-board, which was further coated with an inorganic aluminium oxide (Al2O3) skin layer by using ALD. The particular TFC structure based on ALD and SG coatings gave a slightly better barrier performance compared to a plain ALD coating. PVA and ALD based antifouling coatings increased the hydrophilicity and surface polarity of the polyamide (PA) TFC membranes. All the coated membranes indicated an enhancement in bacteria-repellence. Indeed, the improvement in the bacterial anti-adhesion performance of coated membranes was due to an increase in surface polarity. The biocide-modified PVA coatings enhanced further the anti-fouling performance due to their antimicrobial activity. As expected, in comparison to the uncoated membrane, the PVA-coated membranes tend to increase the salt rejection and to reduce the water and salt permeability. However, the biocide-modified PVA coatings decreased the water permeability and showed also a minor decline on the salt rejection. The ALD coatings increased the water and salt permeability and furthermore, reduced the salt rejection.

Polystyrene was studied as a novel encapsulating polymer to reduce the release rates of biocides in coatings and so extend their useful life. PS microcapsules containing IPBC biocide were compared with 'free' IPBC and commercial microcapsules containing it. The experimental microcapsules were as effective as the commercial products, despite a slower biocide release rate. The hindered release of biocide is expected to provide a longer service life.

The current trend in packaging materials heads towards green chemistry using sustainable and renewable materials. A number of novel packaging coatings have been recently developed on paper, paperboard or bio-based plastic films in order to produce special and enhanced product properties as well as to improve the competitiveness of traditional industries such as forest and plastic. Especially new type of thin coating technologies such as atomic-layer-deposition (ALD) and sol-gel hybrid coatings have been tested by VTT for packaging purposes. The thin coatings have been applied, for example, on polylactic acid (PLA) films and coated paper and paperboard to improve the moisture, gas and grease barrier performance. In addition to new coating technologies VTT has recently developed coating processes for lab- and pilot-scale roll-to-roll processes. Thin hybrid coatings as well as many types of biopolymer based coatings and free-standing films have been produced. Coatings can be applied by flexo, soft bar, foam, curtain and spray coating methods, including optional pre-treatment by plasma or corona as well and post-treatment/curing by cold or hot air drying, IR-drying or UV-curing.

Recently, surface modification of reverse osmosis (RO) membranes has gained increasing attention. For example, some of the commercial thin-film-composite (TFC) polyamide (PA) membranes are coated to introduce hydroxyl groups to the PA surface. Among others hydrophilicity and low surface roughness are the key factors in the development of low-fouling surfaces for TFC-PA membranes. The main focus of the recent study was to develop and evaluate different thin coating technologies, which could have potentiality to introduce low-fouling performance on TFC-PA membrane surface. The selected thin coating technologies included inorganic atomic layer deposition (ALD) and antibacterial polyvinyl alcohol (PVA) based polymer films.

Two hybrid coatings synthesized by using alkoxysilanes as precursors in a sol–gel process, differing from each other in terms of the organic components in alkoxysilanes, have been developed to improve the water repellent properties of base paper. The sol–gel‐coated base paper samples were characterized by scanning electron microscopy, atomic force microscopy, confocal laser scanning microscopy, X‐ray photoelectron spectroscopy, time‐of‐flight secondary ion mass spectrometry, and contact angle measurements. The sol–gel coatings were found to clearly change the surface properties of base paper. Thin coating layers were formed on base paper surfaces. The topographical data indicated the formation of discontinuous thin films; the time‐of‐flight secondary ion mass spectrometry analyses confirmed that the coatings were covering the fibres but only partially covered the fibre–fibre intersections. Water and the subsequent heat treatment used as a reference treatment reduced the surface roughness and porosity and slightly changed the surface chemistry of the base paper. The wettability and absorptivity of base paper was clearly reduced by the applied coatings.

The VTT-Aalto-FIOH-IST joint RESCOAT (Novel Responsive Surfaces based on Active Hybrid Coatings Utilizing Encapsulation Technologies) project focuses on the development of novel active and responsive surfaces based on hybrid paint and thin coatings with encapsulated active agents. The developed polymeric or silica capsules are either slowly releasing or responsive to the external stimulus. The project aims to provide feasible functional solutions against e.g. biofouling, flare-up (delayed), wearing and scratches (self-healing) or ice nucleation. The developed coating and encapsulation technologies increase competitiveness of the products especially in the fields of construction, processing, electronic devices, machinery, infrastructure and transportation.

Among others hydrophilicity and low surface roughness are the key factors in the development of low-fouling surfaces for thin-film-composite reverse osmosis (TFC RO) membranes. The main focus of the recent study was to develop and evaluate different thin coating technologies which could have potentiality to introduce low-fouling performance on commercial TFC RO membrane surface. Furthermore, it was aimed to improve the mechanical and chemical resistance of the TFC RO membrane surface. The selected thin coating technologies, including inorganic-organic sol-gel and inorganic ALD (atomic layer deposition) thin films and also antibacterial polymer films, were studied. Typical sol-gel coating consisted of organically modified siloxanes whereas aluminium oxide (Al2O3) thin film was applied by the ALD method. In addition, different active agents, such as zinc oxide (ZnO) and carbon nanotube (CNT), were used to functionalise the polyvinyl alcohol (PVA) thin coatings. Commercial DOW LE membrane was used as a substrate for the coating applications. The coating thickness varied from 5 nm to 200 nm depending on the applied thin coating method. The surface chemistry and structure of the coated surfaces were characterised by using ATR-FTIR, AFM and SEM-EDS. Based on the surface analysis all the applied coatings decreased the roughness of the membrane surface. Contact angle measurement was used to determine the hydrophilicity and hydrophobicity as well as to calculate the surface energy of the coated surfaces. Some of the applied coatings were clearly more hydrophilic compared to the uncoated membrane surface. The bacteria attachment test with a flow was carried out to evaluate the anti-fouling performance of the surfaces. In the particular method the coated samples were contacted with Pseudomonas aeruginosa cells for 24 hours in modified standard seawater (ASTM D1141-98 (2008)) in room temperature (130 rpm orbital shaker) and after 24 h bacterial exposure the number of adhered cells on the surface was analysed. In general it was seen that less bacteria was attached to hydrophilic surface, but on the other hand it was noticed that the low surface roughness decreased the bacteria attachment even the surface was relatively hydrophobic. Furthermore it is suggest that some of the functional chemical groups also decrease the bacteria attachment. The flux and salt rejection test was performed for the selected samples to evaluate the membrane's filtration performance. As expected all the tested coatings showed lower flux compared to unmodified TFC RO membrane.

Sol-gel based inorganic-organic hybrid coatings were developed and coated on aeronautical parts including cadmium plated steel and magnesium alloy. The hybrid coatings were targeted to provide two kinds of solutions. Firstly, the aim was to protect the cadmium-plating against the corrosion initiated especially by runway de-icing chemicals (formiate and acetate based). Secondly, the hybrid coating approach was targeted to provide alternative coating solutions for cadmium plating as well as hexavalent chromium conversion coatings. In order to improve the corrosion resistance of the selected substances, the chemistry of the inorganic backbone of the hybrid coating was varied by using silane and aluminium alkoxides. Furthermore, the organic components of the hybrid coating were also varied. The corrosion performance of the coated specimens were investigated by using standardised runway de-icing corrosion test (AMS G-12) and salt spray test (ISO 9227). Based on the AMS G-12 test results, the use of the hybrid coatings improved the corrosion protection of cadmium plating against runway de-icing corrosion. The salt spray test showed that the corrosion protection performance of the hybrid coating on cadmium-plating was similar to uncoated cadmium plating. In the case of magnesium alloy, the hybrid coating showed also better corrosion protection in the both corrosion tests compared to Cr6 conversion coating.

In our current study non-woven materials such as polypropylene (PP) and polyester (PES), used in filtration application, were modified in terms of surface properties by using hybrid coatings synthesised by using sol-gel method. The hybrid coatings consisted of organically modified silanes with fluorocarbon functionality in order to increase the hydrophobicity of the non-woven surfaces. Furthermore, superhydrophobic property was aimed to obtain by mixing silica (SiO2) nanoparticles into the coating matrix. Surface chemistry and topography of the coated specimens were characterised by using FTIR, AFM and SEM methods. The water contact angle measurements were used to detect the hydrophobicity. It was revealed that the hybrid coating with SiO2 nanoparticles increased the initial water contact angle from 117o up to 140o for PP and respectively from 87o up to 126o for PES non-woven.

The traditional packaging film materials, non-polar polypropylene (PP) and polyethylene (PE) are used in several industrial packaging applications. Hydrolysis acts as a rapid initial reaction of the sol-gel process, where reactive alkoxide groups react with water molecules to form hydroxyl groups. RE plasma is based on a capacitive or inductive matching of the impedance in the system, with a time-varying magnetic field subsequently creating an electric ring field which excites the electrons and produces plasma. The sol-gel technique with atmospheric plasma pretreatment has proved to be a potential method to produce functional sol-gel thin films on reel-to-reel products. The oil and grease resistance of the specimens was studied by contact angle measurements with oleic acid. In addition, the effect of abrasive wear on the oil repellency was studied by a standard paint washing tester apparatus, where a brush was used as an abrasive material.

New functional packaging coatings on paper, paperboard or plastic films are used for special and enhanced properties in the field of paper converting. The ever-increasing demands for the product properties, e.g. gas and grease barrier, combined with simultaneously increased line speeds make it challenging to achieve the desired level of performance required for these coatings. When using non-polar plastics such as polypropylene or polyethylene as base material, increasing of surface energy by pre-treatment with e.g. plasma or corona is necessary for adhesion. To answer these challenges, methods for atmospheric plasma pre-treatment and deposition of the functional hybrid coatings on polyolefin substrates have been developed in this work. The target of the developed coatings was to obtain barrier (e.g. oxygen and grease) and antimicrobial properties for polyethylene coated paper. The applying of the hybrid coatings was performed with atmospheric plasma assisted on-line spray coating method at a reel-to-reel extrusion coating pilot line.

In this study novel and functional added value e.g. easy-to-clean, wear resistance and anti-ice was performed for aluminium surfaces by hybrid coatings prepared by sol-gel method. In addition, the potentiality of the developed sol-gel coatings to be used as a novel sealing method for anodized aluminium was investigated. The sol-gel coatings were targeted to perform a durable hydro- and oleophobic properties for the aluminium substrates. Furthermore, the effect of sol-gel chemistry on the repellence properties was studied. In addition, different additives and concepts were used to develop anti-ice coatings. The properties and performances were characterised with contact angle measurements, cleanability tests, wear tests, anti-ice tests and profilometer analysis. It was observed that a durable easy-to-clean property for the aluminium product was achieved by the developed coating. Furthermore, compared to easy-to-clean behaviour of the non-sealed aluminium, we noticed that the developed hybrid sol-gel coating improved substantially the cleanability of the non-sealed aluminium surface. The anti-ice coatings showed promising ice-repellent behaviour by decreasing the ice adhesion strength.

PUHTEET 2 ja 3 -projekteissa tutkittiin ohutkalvopinnoitteilla saavutettavaa lisäarvoa erilaisille metallimateriaaleille ja -tuotteille. Tavoiteltuja ominaisuuksia olivat muun muassa pitkäaikainen korroosion-, kulumisen ja naarmuuntumisenkesto, helpompi puhdistettavuus ja dekoratiiviset ominaisuudet. Lisäksi tutkittiin sooli-geelipinnoitteiden soveltuvuutta metalliohutlevyjen roll-to-roll-pinnoitukseen. Pinnoitekehityksessä on keskitytty tutkimaan erilaisten epäorgaanisten (esim. SiO2, Al2O3, ZrO2) ja orgaanisten (esim. vinyyli, akryyli, metakryyli, epoksi) komponenttien vaikutusta pinnoitteiden ominaisuuksiin. Lisäksi on tutkittu esimerkiksi korroosioinhibiittorien vaikutusta pinnoitteiden korroosiosuojausominaisuuksiin ja sopivien epäorgaanisten ja orgaanisten väriaineiden soveltuvuutta sooli-geelitekniikalla tuotettujen pintojen sävyttämiseen tai värjäämiseen. Sooli-geelipinnoitteiden prosessoitavuuden osalta on tutkittu erilaisten pinnoitustapojen sekä kovetusmenetelmien ja -prosessien vaikutusta pinnoitteiden ominaisuuksiin. Sooli-geelipinnoituksen esikäsittelystä tuotantomittakaavassa todettiin, että elektrolyyttista sähköpurkauskiillotusta (nk. PET-menetelmä) voidaan soveltaa myös jatkuvatoimisessa prosessissa käyttäen ympäristöystävällisiä suolaliuoksia elektrolyytteinä. Roll-to-roll-prosessista todettiin, että CO2-kuivajääpuhallus johtaa pinnoituksen kannalta riittävään laatuun, eli pinnoite saadaan kiinnitettyä riittävän hyvin. Em. menetelmä soveltuu erityisesti kupariseosten käsittelyyn. Roll-to-roll-pinnoitetulle nauhalle on tehty muovauskokeita yhdessä TKK:n materiaalien muokkauksen ja lämpökäsittelyn laboratorion kanssa. Kokeissa havaittiin, että pinnoitteet kestävät jossain määrin venytystä ja muovausta ilman merkittävää vaurioitumista. Kuitenkin vaativimpia muokkausparametreja kestävien pinnoitteiden osalta tarvitaan edelleen pinnoitteiden jatkokehitystä ja räätälöintiä. Pinnoitteiden ympäristöystävällisyydestä todettiin, että kaikki projektissa käytetyt pinnoitteet alittavat nykyiset, VOC-direktiivin (2004/42/EY) asettamat raja-arvot. Pitkäaikaisesta korroosionkestävyydestä ja lianhylkivyysominaisuuksista todettiin, että noin 500:n meriolosuhteissa toteutetun kenttäkoepäivän jälkeen pinnoitteista toimivat enää lähinnä kaikkein paksuimmat versiot (n. 30-50 µm). Ohuilla, nanotasolta muutamaan mikrometriin paksuilla sooli-geelipinnoitteilla tai kymmenien tai satojen nanometrien paksuisilla ALD/TiO2-pinnoitteilla ei kyetty suojaamaan perusmateriaaleja tyydyttävästi, erityisesti jos perusmateriaali oli anodinen. Näissä koeolosuhteissa edes pinnoittamaton EN 1.4301 -tyyppinen ruostumaton teräs ei selviytynyt koejaksosta ilman näkyviä vaurioita. Kuumasinkityksestä tehtiin kiinnostavia havaintoja, ja tutkitut sooli-geelipinnoitteet vaikuttavatkin soveltuvan erityisen hyvin kuumasinkityille pinnoille. Projektin kuluessa toteutettiin myös yrityshanke, jossa Millidynen ja VTT:n pinnoitteita sovellettiin Fläkt Woodsin ilmanvaihtoventtiilien pinnoituksessa. Pinnoitteen todettiin vähentävän ilmanvaihtoventtiilin likaantumista noin 40 % ja helpottavan puhdistusta moninkertaisesti. Lisäksi demonstroitiin sooli-geelipinnoitusta tuotanto-olosuhteissa Linjateräs Oy:n pinnoituslinjassa. Atomic Layer Deposition -menetelmän (ALD) toimivuutta demonstroidakseen Planar Oy pinnoitti myös Stala Oy:n tiskipöydän altaan ja valutusastian.

Corrosion, fouling and wearing of metal surfaces are the most common problems that are faced in industry as well as in environmental use. In particular, the maintenance of metal products and also the decrease in their value in use can cause major financial losses for example in construction, transportation, process and food industry. During the last ten years there has been a general interest to study the potential of nanoscale inorganic-organic hybrid sol-gel coatings and ALD coatings to improve the properties of metal surfaces. Sol-gel coatings are usually optically transparent reminding of very thin layers of varnish or lacquer. The main difference is that the sol-gel coatings consist of an inorganic network, which forms the backbone of the coating. By changing the organic and inorganic counterparts and varying their amounts, the properties of the coatings can be modified in a wide scale. TiO2-based or -doped coatings can be photocatalytically active and have self-cleaning properties under UV irradiation. This paper shows how the quality of metal products is improved by applying new thin coatings prepared with ALD or sol-gel techniques. TiO2-modified sol-gel and ALD coatings were used on stainless steel substrates (EN 1.4301, (AISI 304)) with the dry-brushed (2J) surface finish to enhance the soil resistance and cleanliness level of the material.

Tutkimuksen ensimmäisessä vaiheessa haettiin ja kehitettiin potentiaalisia esikäsittely- ja pinnoitusmenetelmiä tutkittaville metallimateriaaleille haluttujen ominaisuuksien kuten kulutuksen-, korroosion-, naarmuuntumisen- ja hapettumisenkeston tai lianhylkivyyden, parantamiseksi. Projektissa hyödynnettiin osin Tekesin "PINTA 2002-2006 - Likaantumattomat pinnat" -ohjelman aiemmissa projekteissa kehitettyjä pinnoitteita ja -menetelmiä. Materiaaliosaamisen lisäksi projektissa kiinnitettiin erityistä huomiota pinnoitteiden valmistettavuuteen sekä edelleen pinnoitettujen kappaleiden muodonantoon ja liittämiseen. Suoritettujen esikäsittelyjen vaikutusta pinnoitteen levittyvyyteen ja adheesioon sekä sooli-geelipinnoitteiden kemiallisten muuttujien ja pintatopografian vaikutusta pinnoitteen ominaisuuksiin tutkittiin myös projektin aikana tehdyissä opinnäytetöissä. Kokeiden tulosten perusteella valittiin parhaiten soveltuvat esikäsittelyt ja pinnoitteet yksityiskohtaisempiin jatkotutkimuksiin, joissa pinnoitettiin tutkittavia materiaaleja A4-kokoisina näytteinä. Jopa A4-kokoisia ALD-TiO2-pinnoitettuja näytteitä on tehtiin Planar Oy:ssä (nykyinen Beneq Oy). Pinnoitetuille materiaaleille suoritettiin pintaominaisuustestejä, fotokatalyyttisten ominaisuuksien määrityksiä, kemiallinen kestävyystesti ja pitkäaikainen korroosiotesti. Pinnoitteiden muodonmuutoskyvyn selvittämiseksi niiden murtumista ja kiinnipysymistä tutkittiin vetokokeilla. Muovaamisen vaikutusten lisäksi myös ALD- ja sooli-geelipinnoitettujen materiaalien käyttäytymistä liittämisessä selvitettiin hitsauskokeiden avulla. Yritys-case-tutkimuksessa VTT pinnoitti sooli-geelipinnoitteella AK-Tehtaalla (nykyinen Vaahto Roll Service) termisesti ruiskutettuja teloja. Stala Oy:n casen osalta suoritettiin ruostumattoman teräksen sooli-geelipinnoitusta käyttäen Millidyne Oy:n pinnoitetta. Lisäksi projektissa pinnitettiin mm. erilaisia Luvata Oy:n kuparituotteita, Rautaruukki Oy:n maalattuja coil coating tuotteita ja Outokumpu Stainless Oy:n erilaisia teräslaatuja. Muita projektiin osallistuneita yrityksiä olivat Kemira Pigments, Planar Systems ja Savcor. Projektin toisessa vaiheessa tutkitaan mahdollisuuksia pinnoittaa sooli-geeli- ja ALD-menetelmillä suuria kappaleita ja pintoja teollisessa mittakaavassa. Hankkeen tärkeimpänä tavoitteena on kehittää uusia, toimivia pinnoiteratkaisuja suomalaisen metalliteollisuuden tarpeisiin. Projektin toisen vaiheen hakemus on suunniteltu jätettävän Tekesin NewPro - Uusiutuva metalliteknologia - Uudet tuotteet 2004-2009 teknologiaohjelmaan, jonka tavoitteena on metallinjalostuksen erikoistuotteiden ja lisäarvopalveluiden merkittävä lisääminen.

Alumiinituotteiden pinnanlaatu on yksi tärkeimpiä tämän kevytmetallin laatukriteerejä. Pintaominaisuudet, kuten kulumiskestävyys, lianhylkivyys, kemiallinen kestävyys ja dekoratiivisuus, ovat alumiinituotteiden kannalta tärkeitä. Erityisesti kulumiskestävyys on alumiinilla heikompi kuin muilla konstruktiometalleilla. Alumiinipinnan naarmuuntuminen ja likaantuminen johtavat pahimmillaan korroosioon ja biofilmien muodostumiseen. Nämä aiheuttavat alumiinituotteiden käyttöarvon alenemista sekä myös kunnossapito- ja puhdistuskustannuksia. Julkaisu käsittelee yhteisrahoitteisen projektin Alumiinin pintaominaisuudet ja pintakäsittelyt keskeisimpiä havaintoja ja tutkimustuloksia. Projektissa kehitettiin ja tutkittiin prosessiparametrien vaikutusta alumiinituotteen mikrorakenteeseen, sooli-geelitekniikalla valmistettavia ohutpinnoitteita, anodisointimenetelmää, alumiinipintojen plasmaesikäsittelyä ja pinnoitettujen alumiinituotteiden käyttöominaisuuksia. Projektissa kehitettiin kolme alumiiniseosten sekä anodisoidun alumiinipinnan pinnoittamiseen soveltuvaa, kulumista kestävää ja likaantumattomuutta parantavaa sooli-geelipinnoitetta. Sooli-geelipinnoitteiden todettiin parantavan alumiinipintojen veden- ja rasvanhylkivyyttä. Sooli-geelipinnoitteet omasivat paremman kulutuskestävyyden anodisoidulla ja tiivistämättömällä pinnalla kuin anodisoidulla ja tiivistetyllä pinnalla. Yleishavaintona korroosiokokeissa on, että erityisesti hydrofobiset pinnoitteet antoivat hyvän korroosiosuojan alumiinille. Sooli-geelipinnoitteet näyttivät soveltuvan erityisesti anodisoinnin tiivistämiseen, jolloin saataisiin lisäarvoa tuotteille ja prosessivaiheita korvattua pinnoituksella. Lisäksi projektissa käytettiin etsaus- ja anodisointikäsittelyssä uutta pulssivirtamenetelmää, jota VTT on ollut mukana kehittämässä EU-Craft-projektissa. Uuden menetelmän etuja ovat mm. lyhemmät prosessointiajat, haitallisten kemikaalien käytön vähentäminen ja vähentynyt energiankulutus.

All surfaces are exposed to fouling, wearing and other degrading environmental effects during their lifetime.Continuous cleaning and repairing of surfaces causes financial losses and shutdowns in industrial processes.The aim of this study was to develop anti-fouling and scratch resistant hybrid sol-gel coatings for metal surfaces.Two different hybrid sol-gel coatings were prepared from modified solutions of silicon based alkoxides and coated on stainless steel by using spill and spray coating techniques.Anti-fouling properties were studied with contact angle measurements, fouling tests and FTIR scanning analysis.Abrasion properties were measured with pin-on-disk test and with an abrasive washing test (modified DIN 53778, Erichsen).Coatings were characterized with SEM and optical microscopy.According to performed anti-fouling tests, the cleanability of the anti-fouling sol-gel coated steel was enhanced compared to the uncoated steel surface.Measured water and oil contact angles were higher on the coated surface and the coated surface was not tainted.The abrasion tests showed that the scratch resistant coating abraded only slightly when the uncoated steel was abraded under the same load on a large scale.

Corrosion, fouling and wearing of metal surfaces are the most common problems that can cause a decrease in the use value of metal products and therefore financial losses in the metal industry.For this reason, nanoscale hybrid sol-gel coatings have been developed to protect metal surfaces.The aim of this research was to study the effects of chemical parameters and topography on the properties of the sol-gel coating developed by VTT.The inorganic-organic sol-gel coating was studied as such and as coated on stainless steel and copper substrates.The early-stage sol-gel reactions were examined with ATR-FTIR and with measurements of surface tension of the sol. FTIR and DSC were used to determine thermal curing processes.Topography of the sol-gel coating was studied by using profilometry and coating thickness measurements.In addition, surface properties of the sol-gel coating were examined.The sol-gel chemistry characterizations gave information about the phases of sol-gel reactions.Moreover, the topography measurements indicated changes in surface roughness of the thin film during the ageing process of the sol.On the basis of the important information obtained in this study, the protective properties of sol-gel coatings can be tailored for different purposes.