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We discuss the results of scanning probe microscopy studies of the surface morphology of ordered molecular films from organic low-molecular-mass and polymeric compounds. Films considered include: self-assembled monolayers, Langmuir-Blodgett films and composite molecular films fabricated from different organic compounds. Several aspects of these systems are revealed: their nanoscale surface morphology,...
Previous texture evolution experiments carried out on high-density polyethylene to an equivalent strain of e = 1.86 have indicated the development of a quasi-single-crystalline long-range coherence in the principal direction of molecular alignment parallel to the direction of extensional flow, in which the differentiation between crystalline and amorphous components is substantially weakened...
The morphology of syndiotactic polypropylene (s-PP), containing 91% racemic pentads, isothermally crystallized from the melt has been investigated by means of light microscopy, atomic force microscopy (AFM), and small-angle X-ray scattering (SAXS). Light microscopy shows a typical needle-like structure of crystalline entities at crystallization temperatures ranging from 115 to 150°C. Large bundles...
Atomic force microscopy (AFM) and Fourier transform infra-red spectroscopy (FTi.r.) were used to investigate the nature of poly(ethylene terephthalate) (PET) films formed on the surface of a highly oriented poly(tetrafluoroethylene) (PTFE) substrate mechanically deposited on silicon wafers. PTFE films have been previously shown to be highly effective substrates for the growth of oriented overlayers;...
Characterization of poly(p-oxybenzoate) (POBA) films epitaxially grown on mica and KBr single crystal substrates was performed by atomic force microscopy (AFM). For a thin POBA film sample prepared at 320 o C on a mica substrate, oligomer domains were found in the vicinity of the nuclei, forming an interfacial layer between the mica crystal and the homogeneous POBA film. The AFM study further...
Atomic force microscopy has been used to investigate the morphology of isotactic polystyrene lamellae growth from the melt in very thin films ( 50 nm in thickness). It is shown that atomic force microscopy can elucidate the crystal morphology and provide quantitative measurements of the step height (between successive crystal layers of a spiral overgrowth terrace) corresponding to the long spacing,...
Atomic force microscopy has been successfully used to observe morphologies and characterize polymer components of poly(styrene-block-ethylene/butylene-block-styrene) (SEBS) triblock copolymer surfaces. The surfaces exhibited characteristic topographies consisting of hills and valleys. The height difference between them increased with the polystyrene component, which is probably due to the stress...
The surface morphology and molecular arrangement of a Kevlar aramid fibre (coded Fibre A, from E. I. DuPont de Nemours and Co.) were studied by atomic force microscopy (AFM). Pleats parallel to the fibre axis have been observed. At nanometre scale, the polymer chains display several different arrangements from the reported crystalline structures for the bulk polymer especially in the polymer chain...
The processes of melting and crystallization of poly(ethylene oxide) are followed in real time at elevated temperature by atomic force microscopy using a simple hot stage apparatus. Hedritic development at a temperature of 57°C is monitored, including the process of lamellar splaying to yield a spherical morphology. Crystal growth kinetics are measured by monitoring the growth of individual lamellae...
The structure of thin crystallized films of a diblock or a triblock copolymer deposited on silicon has been investigated using atomic force microscopy (AFM). Non-contact mode AFM was used to investigate the topography of crystallites of poly(oxyethylene)/poly(oxybutylene) (E/B) block copolymers at room temperature, where E is crystallized and B is amorphous. The crystal thicknesses determined from...
Xanthan molecules derived from dilute and semi-dilute solutions which have been heated above the order–disorder melting temperature T m and thereafter cooled below T m were imaged by atomic force microscopy (AFM). A new method which avoids the drying step of the sample has been used to give images of individual xanthan molecules. It has also been possible to obtain images of aggregated...
The miscibility and surface crystalline structure of blends containing poly(vinylidene fluoride) (PVDF) composed of α and γ phases were investigated by atomic force microscopy (AFM) and differential scanning calorimeter (d.s.c.) measurements. It was found that the surface crystalline phase of PVDF and the degree of surface enrichment of a lower surface free energy component in a blend might strongly...
A new experimental setup designed to monitor by atomic force microscopy (AFM) the time evolution of a single micrometer-sized polymer spherulite during crystallization at elevated temperatures is presented. For the case of blends of poly(aryl-ether–ether–ketone), PEEK, with poly(ether–imide), PEI, it is shown how AFM can help visualizing the time sequence and space location of events occurring during...
Kevlar® fiber surface structure was primarily and directly observed in the filament configuration by the tapping mode atomic force microscopy (AFM). The microfibrils feature was observed with an average width of 500nm, composed of various types of periodical units of an average size 50nm in a pleating appearance. At the less crystalline spot on the Kevlar® fiber surface, the periodical organizations...
Monodispersed poly(styrene–maleic anhydride) alternating copolymer (SMA) is synthesized through radical polymerization, and characterized by GPC, DSC, FT-IR and 1H NMR spectra. The mole fraction, χ, of styrene in the copolymer is 0.51, determined from integrated 1H NMR spectrum, this value is consistent with the alternating structure. FT-IR spectra show that maleic anhydride moieties on the backbone...
Semicrystalline polymers exhibit different levels of microstructure: macromolecules, individual crystalline lamellae, stacks of lamellae separated by amorphous layers, spherulites. Due to such complexity, the understanding of their macroscopic mechanical behaviour requires study of the plastic deformation mechanisms which occur from the nanoscopic to the microscopic scale. We are interested here in...
Using atomic force microscopy we have examined the surface morphology of sequentially biaxially oriented polypropylene (BOPP) films. The surface was shown to be dominated by a nanometer-scale fiber-like network structure, the configuration of which was found to be determined by the relationship between the draw ratios used in the bi-directional stretching processes [machine draw (MD) and transverse...
Use of atomic force microscopy (AFM) together with light microscopy (LM) provides an ideal opportunity for studying the initial growth of wrinkles on polypyrrole films. In situ experiments, where continuous AFM image data acquisition was carried out during growth of thin polypyrrole films on indium–tin oxide (ITO) anodes, proved unsuccessful because the height changes occurring during the deposition...
Nafion ( R) is a commercially available perfluorosulphonate cation exchange membrane commonly used as a perm-selective separator in chlor-alkali electrolysers and as the electrolyte in solid polymer fuel cells. This usage arises because of its high mechanical, thermal and chemical stability coupled with its high conductivity and ionic selectivity, which depend strongly on the water content...
Atomic force microscopy (AFM) and wide angle X-ray scattering (WAXS) were used to examine the morphology of hard domains in flexible polyurethane foams and plaques based on slabstock formulations. In plaque samples that were uniaxially deformed to 50% elongation, WAXS was utilized to demonstrate transverse hard segment orientation relative to the axis of deformation. AFM was utilized to directly observe...
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