Allyl bromide, CH2CHCH2Br, adsorbs both molecularly and dissociatively on Pt(111) at 95 K. The multilayer desorbs at 130 K and the monolayer at 156 K. At exposures >0.63 monolayers (ML), a broad high-temperature parent desorption peak appears, centered at ∼225 K. For exposures below 0.38 ML, complete decomposition occurs, and only H2 and HBr desorb when heated. For these exposures, high-resolution electron energy loss spectroscopy (HREELS) indicates complete C−Br bond cleavage and η3-allyl group, C(a)H2C(a)HC(a)H2, formation by 185 K, followed by rearrangement to propylidyne, C(a)CH2CH3, between 300 and 350 K. Higher exposures result in some hydrogenation of allyl groups to desorb a mixture of propane and propylene at ∼225 K and propylene at 320 K. HREELS suggests that π-bonded propylene may form from η3-allyl and lead to the 225 K propylene and propane desorption. H2 and D2 coadsorption experiments indicate that propane forms only in the presence of surface hydrogen. For these higher exposures, η-allyl (propenyl, C(a)H2CHCH2) fragments form and undergo reductive elimination to propylene at 320 K and reorient in a competing reaction to η3-allyl groups that subsequently rearrange to propylidyne between 320 and 350 K.

Contact angle measurements for water, glycerol, formamide, ethylene glycol, diiodomethane, α-bromonaphthalene, tricresyl phosphate, dimethylsulfoxide (DMSO), and bromoform on polymethyl methacrylate (PMMA) covered with adsorptive and gelatinized gelatin films were made. Adsorption was performed from solutions in the 0−25 g/L concentration range. A gelatinized gelatin film was created from solutions of 40−100 g/L concentrations. It was found that the biggest changes of the contact angles were up to monolayer coverage of the PMMA surface. For all liquids (besides water) the contact angle was almost constant above the gelatin concentration 50 g/L. Very high contact angles (∼134°) were obtained for water on a gelatinized gelatin film obtained from a solution of 100 g/L concentration. From the obtained contact angles, the Lifshitz−van der Waals components and the values of the electron−acceptor and electron−donor parameters of the acid−base components of the films were calculated for the glycerol−ethylene glycol−diiodomethane three-liquid system. It was found that the water contact angle strongly influenced the Lifshitz−van der Waals component and acid−base parameters of the gelatin film surface free energy. The systems involving water gave different results than those without water. It was found that the values of the gelatin film surface free energy components and parameters cannot be explained only on the basis of the functional group's orientation in gelatin molecules. To find an explanation, back-calculations of the contact angle for water, formamide, α-bromonaphthalene, tricresyl phosphate, dimethylsulfoxide, and bromoform were made. The authors found a good agreement between the calculated and measured values of the contact angle for all liquids studied, besides water and, partially, DMSO. To explain the obtained results of the measured contact angles, four models of hydratation of gelatin films were presented.