Bolesław Waligóra

Photo-oxidation of polystyrene film: 1. Photo-oxidation of polystyrene films with light absorbed by polymer

Abstract The photo-oxidation of polystyrene films irradiated with light absorbed by the polymer has been studied. The overall quantum yield of hydroperoxide as well as the relationship between the concentration of acetophenone-type carbonyl products and α,β-enone and diketone products were found. The spatial distribution of the different types of carbonyl products was investigated.

The effect of carbonyl compounds on photo-oxidation in polystyrene films

Abstract A group of twelve low-molecular-weight compounds was chosen to model the most likely carbonyl products of polystyrene photo-oxidation. Comparison of the rate of formation of long-chain photo-oxidation products was made between pure PS film and PS films containing model carbonyl compounds. The largest effect was observed for test films containing acetophenone and benzaldehyde. The rate of formation of high-molecular-weight carbonyl products is controlled by the rate of consumption of low-molecular-weight compounds.

Thermodynamic characteristics of anionic—cationic adsorption films based on a butler-type equation

Abstract It was stated that the simplified form of an integral adsorption isotherm based on the Butlers equation and derived previously (D. Goralczyk and B. Waligora J. Colloid Interface Sci. 82, 1 (1981)), describes satisfactorily the surface behavior of the solutions containing equimolar amounts of anionic and cationic surfactants with various surface ativity only within the range of great surface pressures. On the other hand, in the case of a small degree of surface coverage, deviation appear due to the presence of excess of ions with longer alkyl chain in the mixed adsorption film. The values of ΔG of adsorption for anionic—cationic surfactants are within the limits of experimental error equal to the sum of the values characteristic for single ionic substances being components of the mixture. The presence of adsorption film influences on the water structure in the surface layer which causes nonzero values of ΔGH2O.

Fluorescence quenching of polystyrene by oxygen

Abstract The fluorescence quenching of polystyrene by oxygen at room temperature was investigated. The diffusion coefficient of oxygen in polystyrene films was taken as 3.1 × 10 −7 cm 2 /sec; the energy migration coefficient of polystyrene in the excited singlet state was estimated as 6 × 10 −6 cm 2 /sec.

Electrical properties of the monolayers of p-phenol derivatives

Abstract The effective dipole moments of adsorbed molecules, functional groups, and water contained in the surface layer were determined using the Helmholtz equation. The calculations were done on the basis of surface excess values, obtained from surface tension measurements and surface potential changes of aqueous solutions of p-halogenphenols, p-methylphenol, and aniline.

Photo-oxidation of polystyrene film: 2. Photo-oxidation of polystyrene film with light absorbed by the polystyrene-oxygen complex

Abstract Photo-oxidation of polystyrene films prepared from carefully purified polymer, irradiated with light absorbed only by a polystyrene-oxygen complex has been studied. It was found that photo-oxidation of polystyrene under such conditions results in carbonyl compound and hydroperoxide formation. Photo-oxidation of polystyrene with light of a frequency abosrbed by the polystyrene-oxygen complex occurs throughout the whole volume of sample.

Surface orientation and effective dipole moments of some salicylic acid derivatives at the water/air interface

Abstract Surface tension (δσ) and electric surface potential (δV) measurements of aqueous solutions of salicylic, acetylsalicylic, and sulfosalicylic acid and salicylaldoxime were used for determination of the surface activity, orientation of molecules, the effective dipole moments, and standard free energy of adsorption.

Surface activity of p derivatives of phenol mixtures at the water/air interface

Abstract The coadsorption of two phenol derivatives, p-methylphenol and p-halogenphenol, at the free water surface was investigated. From measurements of surface tension the excesses of adsorbed molecules Γ of individual components at the water/air interface were determined. On the basis of the Butler isotherm equation the free enthalpy ΔG, enthalpy ΔH, and entropy ΔS of adsorption were estimated.