The heterogeneous nucleation of calcium phosphates on solid surfaces of poly(methyl methacrylate) (PMMA), poly-(tetrafluoroethylene-co-hexafluoropropylene) (FEP), silicone rubber, mica, and radiofrequency glow discharge (RFGD)-treated PMMA, FEP, and silicone rubber has been studied in solutions supersaturated with respect to hydroxyapatite. The surface properties of the substrates were characterized by contact angle measurements. For the RFGD-treated surfaces, the Lifshitz-Van der Waals surface tension component changes very little, but the Lewis acid-base surface tension parameters vary greatly depending upon the materials. With scanning electron microscopy, nucleation of calcium phosphates was observed only on the surfaces: mica, RFGD-treated PMMA and FEP, with relatively high values of the Lewis base surface tension parameter. The more hydrophobic surfaces having low Lewis acid-base surface tensions, untreated PMMA and FEP, silicone rubber, and even RFGD-treated silicone rubber showed no nucleation.

The surface composition and near-surface depth profiles of annealed films of poly(amide urethane) block copolymers were measured using angle-dependent electron spectroscopy for chemical analysis (ESCA). Segregation of the fluorinated polyamide soft segment to the surface was detected and quantified. The poly(amide urethane)s were made from amine-terminated polyamides with N-alkylated fluorinated side chains as well as fluorinated backbones, methylenebis(cyclohexandiyl diisocyanate) (H12MDI), and butanediol. The resulting copolymers display extremely low surface energy. A deconvolution program was utilized to obtain composition−depth profiles and to confirm phase segregation.

Time-of-flight secondary ion mass spectra were recorded from submonolayer thin films of aminopropyl end-capped poly(dimethylsiloxane) (PDMS) and from thick films (ca. 50 μm) of poly[(dimethylsiloxane)−urethane] (PU−DMS)-segmented copolymers. Ions detected and assigned to fragments in the low-mass range (m/z ≤ 300) provided structural information about the repeat units and the end groups. The high-mass spectrum of the PDMS homopolymer yielded a series of ions assigned to Ag+-cationized oligomers; this enabled determination of the molecular weight distribution in comparison with GPC measurement. In the high-mass (m/z = 800−3500) spectra of thick PU−DMS films, the peak series was assigned to a simple fragmentation process. That process would yield ions where the intact PDMS segment is present; it therefore can be used to evaluate the PDMS segment length distribution at the surface of the copolymer. It was found that the distribution of PDMS segment lengths segregated at the surface of the thick film was almost identical with that in the bulk for PU−DMS with PDMS nominal molecular weight of ca. 1000 Da. These results allow the development of an analysis of ion structure and a stepwise procedure for evaluating the segment length distributions in the near-surface region of siloxanes.