[pt] Superfícies superanfifóbicas poliméricas tem atraído grande interesse dentro da comunidade científica e da indústria por conseguirem combinar todas as características vantajosas dos polímeros, com propriedades de superfície únicas, como repelência à líquidos e autolimpeza. Uma variedade de polímeros possui potencial de uso em aplicações que requerem superfícies superanfifóbicas, dentre eles a poliamida (PA). Embora a repelência a água possa ser facilmente atingida, a produção de materiais repelentes a óleo é mais difícil por conta de sua baixa tensão superficial. Como qualquer avanço em pesquisa e inovação, o desenvolvimento de superfícies superanfifóbicas poliméricas requer sua caracterização. Uma maneira rápida de caracterizar a superfície superanfifóbica é por meio da medição do ângulo de contato por análise da forma da gota. Apesar dos progressos na computação e nos dispositivos ópticos, o uso de métodos ópticos para uma avaliação acurada, robusta e profunda das propriedades interfaciais ainda é restrito. Assim, o presente trabalho teve duas frentes de desenvolvimento: (i) construir um sistema de análise da forma da gota acessível, versátil e confiável para a avaliação de propriedades superficiais, e (ii) modificar a superfície da poliamida de modo que se obtenha uma superfície superanfifóbica por um método de fabricação/modificação simples e industrialmente viável. Em relação a primeira frente de trabalho, uma solução gratuita e completa para a investigação de gotas, chamada ZeDrop, foi criada. Em relação a segunda frente de trabalho, uma superfície anfifóbica na PA 6 foi alcançada por meio da combinação de uma rugosidade adequada, obtida pela aplicação de um revestimento formado por nanopartículas e ligante polimérico, e de uma baixa energia de superfície, resultante da ativação da superfície por UVO previamente a sua fluorosilanização. / [en] Polymeric superamphiphobic surfaces have attracted great interest within the scientific community and industry because they combine all the advantageous characteristics of polymers with unique surface properties, such as liquid repellency and self-cleaning. A variety of polymers have potential for use in applications that require superamphiphobic surfaces, among them polyamide (PA). Although water repellency can be easily achieved, the production of oil-repellent materials is more difficult due to oil low surface tension. Just like any advance in research and development, progress in polymeric superamphiphobic surfaces requires characterization. A fast way to characterize superamphiphobicity is measuring the contact angle of a drop shape in touch with the surface. Despite advances in computing and optical devices, the use of optical methods for an accurate, robust and in-depth evaluation of interfacial properties is still limited. Thus, the present work had two development fronts: (i) build an accessible, versatile and reliable droplet shape analysis system for the evaluation of surface properties, and (ii) modify the polyamide surface to reach superamphiphobicity by a simple and industrially viable fabrication/modification method. Regarding the first work front, a free and complete solution for drop research, called ZeDrop, was created. Regarding the second work front, an amphiphobic surface on PA 6 was achieved by combining an adequate roughness, obtained by the application of a coating formed by nanoparticles and polymeric binder, and a low surface energy, resulting from the activation of the surface by UVO prior to its fluorosilanization.

The increasing awareness of sustainability motivates the development of building materials from renewable resources. The requirements of wood-based products with improved durability, for example, an enhanced liquid repellence, is still a challenge. The aim of this thesis is to develop and study concepts to functionalize wood surfaces to obtain superhydrophobicity or superamphiphobicity, i.e. extreme liquid repellence of both water and oils. Birch and acetylated birch veneer samples were surface-modified by hydrophobized silicone nanofilaments. Specifically, birch samples surface-modified by fluorinated silicone nanofilaments (F-SMB) showed superamphiphobicity, which repelled water, ethylene glycol and hexadecane with static contact angles greater than 150° and roll-off angles lower than 10°. Birch and acetylated birch samples surface-modified by non-fluorinated silicone nanofilaments (SMB and SMAB) showed superhydrophobicity with static contact angles greater than 160° towards water, even for samples prepared using the shortest silicone nanofilaments reaction time of 1 h. In liquid uptake measurements submerging the F-SMB in water, ethylene glycol and hexadecane, a superamphiphobic plastron effect was observed which indicates that the wood surface was in Cassie-Baxter state. The plastron reduced the liquid uptake rate and extent depending on the interactions (diffusion and solubility) between the liquid and the silicone nanofilaments. The F-SMB showed good self-cleaning properties towards water and hexadecane. In multicycle Wilhelmy plate measurements, the SMB showed a lower water uptake than that of the acetylated samples, while the SMAB showed the lowest water uptake, i.e. a pronounced increased water resistance, due to a combined effect of acetylation and surface modification. In addition, the SMB exhibited more color change than the SMAB, which was caused by the release of hydrochloric acid during the surface modification process. / Den ökande medvetenheten kring hållbarsamhällsutvecklingmotiverarutveckling avbyggmaterial från förnybara resurser. Kraven på träbaserade produkter med förbättrad beständighet, exempelvisennödvändig vätskeavvisandeförmåga, är fortfarande en utmaning.Syftet med dennaavhandling äratt utveckla och studera koncept för attfunktionalisera träytorför att uppnåsuperhydrofobicitet ochsuperamfifobicitet, dvs en extrem vätskerepellerande egenskap för både vatten och oljor.Björk-och acetyleradebjörkfanérproverytmodifierades med hydrofobiserad silikon-nanofilament. Specifikt visade björk ytmodifierademedfluorerade silikon-nanofilament (F-SMB) superamfifobicitet, som repelleradevatten, etylenglykol och hexadekan med kontaktvinklar större än 150° och avrullningsvinklar lägre än 10°. Björk-och acetyleradebjörkproverytmodifierademedicke-fluorerade silikon-nanofilament (SMB och SMAB) visade superhydrofobicitet med kontaktvinklar större än 160° förvatten, även förprover framställda medkortast reaktionstid på 1 timme.Vid vätskeupptagningsmätningargenom att sänka F-SMB i vatten, etylenglykol och hexadekanobserverades en plastroneffekt som indikerade att träytan var i Cassie-Baxter-tillstånd. Plastronen minskade F-SMB vätskeupptagningshastighet och -nivåberoende på växelverkan(diffusion och löslighet) mellan vätskan och silikon-nanofilament. F-SMB uppvisadegoda självrengörande egenskaper förvatten och hexadekan.Vidmulticykel Wilhelmy-mätningarvisade SMB ett lägre vattenupptag än det acetylerade träet, medan SMAB visade denlägsta vattenupptagningen,det vill säga en mycketmärkbar ökad vattenavvisning, tack vareav en kombinerad effekt av acetylering och ytmodifiering. Dessutom uppvisade SMB en störrefärgförändring än SMAB, orsakad av frisättningen av saltsyra under ytmodifieringsprocessen. / <p>QC 20201113</p>