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Made available in DSpace on 2018-11-26T15:28:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) A simple and versatile route for the preparation of self-adhesive, corrosion-resistant and photochromic hybrid coatings is presented in this paper. The coatings are based on aliphatic poly(dimethylsiloxane)-derived hydroxyurethanes (PDMSUr), produced by the isocyanate-free route for inorganic substrates such as glass and metal alloys. This route involves the ring opening polymerization of a PDMS-derived bis(cyclic carbonate) (CCPDMS) with diamines and aminosilane. The cyclic carbonate was synthesized by cycloaddition of CO2 into a PDMS diglycidyl ether. The use of aminosilanes with CCPDMS enables hybrid organic-inorganic urethanic coatings to be obtained by the sol-gel process. The crystallinity of the coating can be easily controlled through the interplay of the ratio of monoamines and diamines in the formulation. The hybrid PDMSUr materials were tested as an adhesive/coating for metallic and glazed surfaces, presenting adhesion strengths of up to 7 MPa and a maximum usage temperature of 160 degrees C. The incorporation of phosphotungstic acid (PWA) produced a hard material (20-60 MPa) and the elastic modulus rose by more than a hundred times as the PWA content increased. The hybrid PDMSUr 2_35% PWA presented photochromic properties and is suitable as an adhesive and impact damping layer for laminated glass used for smart window production. Furthermore, these coatings are suitable for the protection of metallic substrates against corrosion in acidic, basic and seawater media. Univ Sao Paulo, Inst Chem Sao Carlos, BR-13563120 Sao Carlos, SP, Brazil Univ Fed Parana, Dept Phys, BR-81531980 Curitiba, PR, Brazil Univ Sao Paulo, Inst Phys Sao Carlos, BR-13566590 Sao Carlos, SP, Brazil State Univ Julio de Mesquita Filho, Engn Fac, Ilha Solteira, SP, Brazil Fraunhofer Inst Mfg Technol & Adv Mat IFAM, D-28359 Bremen, Germany State Univ Julio de Mesquita Filho, Engn Fac, Ilha Solteira, SP, Brazil FAPESP: 2011/06019-0 FAPESP: 2013/05279-3 FAPESP: 2011/08120-0 CAPES: 57060300

One of the major advantages of the Layer-by-Layer (LbL) deposition technique is the possible control of molecular architecture, not only to achieve optimized properties but also to seek synergy among different materials. In this study, LbL films containing nanoclusters of a Keggin type polyoxometalate, phosphotungstic acid (HPW), alternated with the polycation poly(allylamine hydrochloride) (PAH) were deposited on indium-tin oxide (ITO) substrates. The electrochemical properties of the hybrid LbL film investigated in acidic conditions indicated no significant desorption of HPW, when a layer of poly(dimethylsiloxane) terminated with 3-aminopropyl groups (PDMS) was previously deposited on the ITO substrate. Such effect occurred because PDMS prevents desorption of HPW from the hybrid film, as shown by X-ray Photoelectron Spectroscopy (XPS) analyses. The porous structures of the films were revealed by Fourier transform infrared reflection absorption spectroscopy, scanning electron microscopy and XPS. PDMS/PAH as a pre-coating allowed the HPW/PAH films to be sensitive to the electrochemical detection of the triazines atrazine and melamine. In conclusion, the precise control of the LbL films architecture is important to develop opportunities for new applications.