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Yayın Film formation from TiO2-polystyrene latex composite: a fluorescence study(Taylor & Francis Group, 2007-03-01) Uğur, Şaziye; Sunay Yapışkan, Münüre Selin; Tepehan, Fatma Zehra; Pekcan, Mehmet ÖnderThis work reports the use of the steady state fluorescence (SSF) technique for studying film formation from TiO2 covered polystyrene (PS) latex particles. The composite films were prepared from pyrene (P)-labeled PS particles by covering them with TiO2 at room temperature and then annealed at elevated temperatures in 10 min time interval above glass transition (T-g) temperature of polystyrene. Five different composite films were studied in various TiO2 layer contents. Fluorescence intensities Ip from P were measured after each annealing step to monitor the stages of film formation. Films showed considerable increase in Ip above the certain onset temperature called minimum film forming temperature, T-0. Void closure and interdiffusion stages were modeled and related activation energies were determined and found to be 23.12 and 92.80 kJ mol(-1), respectively.Yayın Dissolution of Al2O3-polystyrene latex composites: A fluorescence study(Taylor & Francis Ltd, 2005) Uǧur, Şaziye; Tepehan, Fatma Zehra; Pekcan, Mehmet ÖnderThis work reports the use of the steady state fluorescence (SSF) technique to study dissolution of a composite film formed from a mixture of Al 2O3 and polystyrene (PS) latex particles. The composite films were cast from dispersion of pyrene (P)-labeled PS particles in Al 2 O3 solution at room temperature and annealed at 280°C temperature for 10 min. Eight different composite films were studied in various latex contents. Toluene was used as dissolution agent. Fluorescence intensities Ip from P were monitored during dissolution. Fickian diffusion was employed to model the dissolution processes. Dissolution coefficients, D d, were measured and found to be increased at high PS content in the composite films.
