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Summary: Surface modification induced on poly(ethylene terephthalate) (PET) fibers by cold SF6 plasma treatment has been investigated systematically as a function of plasma device parameters. The observed wettability modifications of fibers plasma-treated under different operating conditions were correlated to their dyeability modifications and to the changes in surface chemical composition, determined by X-ray Photoelectron Spectroscopy (XPS), and topography, investigated by atomic force microscopy (AFM). Optical emission spectra from the SF6 plasma at different pressures gave information on its content of fluorine atoms. A striking transition was observed between the increased hydrophilicity and high dyeability, imparted by plasma treatment at low pressure (

Photochemical grafting of diallyl oxydiethylene dicarbonate onto cellulose (in the form of filter paper) was investigated kinetically at 20 ± 2 °C with 1,2-diphenyl-2,2-dimethoxyethanone as photoinitiator. Irradiations were carried out polychromatically with an incident radiation flux of (1.25 ± 0.07) × 10−7 einstein s−1 cm−2. The ratio R between the molar concentrations of photoinitiator and monomer was varied in the range 0.032–0.150 and the n/S value (n moles of monomer adsorbed per unit apparent surface S) was varied in the range 8.40–43.8 μmol cm−2. Two consecutive rate processes were shown by the kinetic curves, with quantum yields differing by about two orders of magnitude. Quantum yields Φ1 for the first, almost constant, rate period were measured as a function of R and n/S. Kinetic features of the grafting process of diallylic monomer are discussed in the light of a general mechanism proposed for grafting of diacrylates and the photochemical reactivity of the allylic vs. the acrylic function.

The geometrical photoisomerization reaction of the title molecule ( trans -I) has been studied in methanol/water 90/10 wt.% mixtures containing sulphuric or hydrochloric acid. Quantum yields of the process, measured under acidic conditions in the range 0.095 N + ] trans -I as a function of pH, experimental quantum yields have been interpreted in the light of prototropic equilibria in the excited state. Mechanistic models are proposed which are able to fit results obtained in the investigated experimental conditions.