ABSTRACT Towards the validation of the atomic force microscopy-based approach to the determinatio... more ABSTRACT Towards the validation of the atomic force microscopy-based approach to the determination of surface energy at the nanometer scale, this paper explores the applicability of the technique by comparing atomic force microscopy-derived surface energy values with those from conventional contact angle measurements from a range of self-assembled organosilane structures ((3-aminopropyl)triethoxysilane, (3-glycidoxypropyl)trimethoxysilane, 3-(triethoxysilyl)propylsuccinic anhydride and trimethoxy(propyl)silane) and also from films of an ultra-low-surface-energy polymer, poly(1H,1H,2H,2H-perfluorodecyl methacrylate). The close agreement between the two sets of data indicates the validity of the AFM method, while unique attributes are indicated by the high resolution (ca. 1000 atoms) that is inherent to the approach and by the capability to study materials that are not compatible with the probing liquids used for goniometric determinations.
The synthesis and the detailed characterisation of poly(methylpropenoxy¯uoroalkylsiloxane)s, a cl... more The synthesis and the detailed characterisation of poly(methylpropenoxy¯uoroalkylsiloxane)s, a class of materials which are inherently resistant to bacterial colonisation, is described and discussed. #
The significance of the Liftshitz/van der Waals, Lewis-acid, and Lewis-base contributors to the t... more The significance of the Liftshitz/van der Waals, Lewis-acid, and Lewis-base contributors to the total surface energy of a homologous series of poly(perfluoroalkyl methacrylate)s is discussed in terms of the molecular design features and surface organization phenomena characterizing these polymeric compounds. The study suggests that, of the molecular design requirements for low-surface-energy polymers, a flexible backbone is not an essential feature.
Adhesion force mapping using atomic force microscopy has been used to investigate a phase-separat... more Adhesion force mapping using atomic force microscopy has been used to investigate a phase-separated blend of poly(methyl methacrylate) (PMMA) and poly(dodecyl methacrylate) (PDDMA). Comparison of the results from the blend with those from the pure constituent polymers showed that force mapping could identify PMMA-and PDDMA-rich areas in the blend. The adhesion maps produced were deconvoluted from sample topography and contrasted with data obtained from contact angle goniometry.
Good-quality coatings prepared from poly(methylpropenoxyfluoroalkylsiloxane)s or poly(perfluoroac... more Good-quality coatings prepared from poly(methylpropenoxyfluoroalkylsiloxane)s or poly(perfluoroacrylate)s are capable of inhibiting the bacterial colonisation of surfaces.
Using atomic force microscopy, adhesion force and indentation mapping have been combined with mea... more Using atomic force microscopy, adhesion force and indentation mapping have been combined with measurements of topography in mapping the hardness variations on the surface of a CaCO3-filled silicone coating material. The topographic image revealed a smooth surface with protruding features, matching the size of filler particles . Mapped indentation and adhesion force measurements showed that these features were associated with increased surface hardness and, also, a suppressed ability to develop adhesive interactions with the probing material (silicon nitride). Furthermore, the indentation images revealed that a boundary region of increased softness surrounded each protruding particle.
Poly(vinylidene fluoride) containing 10% dibutyl sebacate plasticizer, as used in the constructio... more Poly(vinylidene fluoride) containing 10% dibutyl sebacate plasticizer, as used in the construction of flexible oil and gas pipelines, has been exposed to raised temperatures for prolonged periods of time, to acid etching and to various tensile deformation regimes. The effects of these treatments on the crystallinity and surface properties of this material have been examined in the light of analytical data obtained by Fourier transform-infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, X-ray photoelectron spectroscopy, goniometry and a variety of microscopy techniques. The results have shown that the molecular organization of this material can be influenced by the adoption of appropriate preconditioning procedures. ᮊ
ABSTRACT Towards the validation of the atomic force microscopy-based approach to the determinatio... more ABSTRACT Towards the validation of the atomic force microscopy-based approach to the determination of surface energy at the nanometer scale, this paper explores the applicability of the technique by comparing atomic force microscopy-derived surface energy values with those from conventional contact angle measurements from a range of self-assembled organosilane structures ((3-aminopropyl)triethoxysilane, (3-glycidoxypropyl)trimethoxysilane, 3-(triethoxysilyl)propylsuccinic anhydride and trimethoxy(propyl)silane) and also from films of an ultra-low-surface-energy polymer, poly(1H,1H,2H,2H-perfluorodecyl methacrylate). The close agreement between the two sets of data indicates the validity of the AFM method, while unique attributes are indicated by the high resolution (ca. 1000 atoms) that is inherent to the approach and by the capability to study materials that are not compatible with the probing liquids used for goniometric determinations.
The synthesis and the detailed characterisation of poly(methylpropenoxy¯uoroalkylsiloxane)s, a cl... more The synthesis and the detailed characterisation of poly(methylpropenoxy¯uoroalkylsiloxane)s, a class of materials which are inherently resistant to bacterial colonisation, is described and discussed. #
The significance of the Liftshitz/van der Waals, Lewis-acid, and Lewis-base contributors to the t... more The significance of the Liftshitz/van der Waals, Lewis-acid, and Lewis-base contributors to the total surface energy of a homologous series of poly(perfluoroalkyl methacrylate)s is discussed in terms of the molecular design features and surface organization phenomena characterizing these polymeric compounds. The study suggests that, of the molecular design requirements for low-surface-energy polymers, a flexible backbone is not an essential feature.
Adhesion force mapping using atomic force microscopy has been used to investigate a phase-separat... more Adhesion force mapping using atomic force microscopy has been used to investigate a phase-separated blend of poly(methyl methacrylate) (PMMA) and poly(dodecyl methacrylate) (PDDMA). Comparison of the results from the blend with those from the pure constituent polymers showed that force mapping could identify PMMA-and PDDMA-rich areas in the blend. The adhesion maps produced were deconvoluted from sample topography and contrasted with data obtained from contact angle goniometry.
Good-quality coatings prepared from poly(methylpropenoxyfluoroalkylsiloxane)s or poly(perfluoroac... more Good-quality coatings prepared from poly(methylpropenoxyfluoroalkylsiloxane)s or poly(perfluoroacrylate)s are capable of inhibiting the bacterial colonisation of surfaces.
Using atomic force microscopy, adhesion force and indentation mapping have been combined with mea... more Using atomic force microscopy, adhesion force and indentation mapping have been combined with measurements of topography in mapping the hardness variations on the surface of a CaCO3-filled silicone coating material. The topographic image revealed a smooth surface with protruding features, matching the size of filler particles . Mapped indentation and adhesion force measurements showed that these features were associated with increased surface hardness and, also, a suppressed ability to develop adhesive interactions with the probing material (silicon nitride). Furthermore, the indentation images revealed that a boundary region of increased softness surrounded each protruding particle.
Poly(vinylidene fluoride) containing 10% dibutyl sebacate plasticizer, as used in the constructio... more Poly(vinylidene fluoride) containing 10% dibutyl sebacate plasticizer, as used in the construction of flexible oil and gas pipelines, has been exposed to raised temperatures for prolonged periods of time, to acid etching and to various tensile deformation regimes. The effects of these treatments on the crystallinity and surface properties of this material have been examined in the light of analytical data obtained by Fourier transform-infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, X-ray photoelectron spectroscopy, goniometry and a variety of microscopy techniques. The results have shown that the molecular organization of this material can be influenced by the adoption of appropriate preconditioning procedures. ᮊ
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