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Carboxylic acid terminated polystyrene and polybutylacrylate were grafted from melt onto a silicon substrate modified with the epoxysilane monolayer. The tethered layers fabricated from polymers of different molecular weights are smooth, uniform, mechanically stable, and cover homogeneously the modified silicon surface. Micromechanical properties of the dry glassy and rubbery brush layers were measured...
A poly(bisphenol A octane ether) (BA-C8) was synthesized. The isothermal spherulitic growth process was studied in situ using atomic force microscopy (AFM) at room temperature. For spherulites formed by homogeneous nucleation, the growth process includes the birth of a primary nucleus, the development of a founding lamella and the growth of the founding lamella into a spherulite. An embryo below a...
Approximately 30 years after their preparation, the nanoscale morphology of a series of ‘model’ segmented polyurethane elastomers has been further elucidated using the technique of tapping mode AFM. The materials investigated are based on 1,4-butanediol extended piperazine based hard segments and employ poly(tetramethylene oxide) soft segments. The chemistry of these polyurethanes was specifically...
The effects of the molecular weights (molecular weight of polystyrene, M w,PS , varying from 2.9 to 129k) on the surface morphologies of spin-coated and annealed polystyrene/poly (methyl methacrylate) (PS/PMMA=50/50, w/w) blend films were investigated by atomic force microscopy and X-ray photoelectron spectroscopy. For the spin-coated films, when the M w,PS varied from 2.9 to 129k,...
This work deals with the study of comb-like vs. arborescent grafted copolymers made of poly(chloroethyl vinyl ether)-g-polystyrene (PCEVE-g-PS). We describe how the molecular architecture of the branched polymers affects their nanoscale organization in thin films, as observed using atomic force microscopy. The results indicate that modifying the molecular architecture from a 'generation-zero' comb-like...
Four sets of propylene based random copolymers with co-units of ethylene, 1-butene, 1-hexene and 1-octene, and a total defect content up to ~9mol% (including co-unit and other defects), were studied after rapid and isothermal crystallization. Etched film surfaces and ultramicrotomed plaques were imaged so as to enhance contrast and minimize catalyst and co-catalyst residues. While increasing concentration...
The influence of the extent of hydrogen bonding in mediating the long-range connectivity and percolation of the hard segment phase in model tri-segment oligomeric polyurethanes (PU) was explored by using LiCl as a molecular probe. A 22wt% hard segment containing model PU plaque based on a mono-functional oligomeric polyether, 80:20 2,4:2,6 isomeric mixture of toluene diisocyanate, and water as a chain...
Both confocal Raman microspectroscopy and atomic force microscopy (AFM) have been undertaken to study the crystalline and the morphological aspects of cast PA 6 films at a sub-microscopic scale. The percentages of the different crystalline structures present within PA 6 cast films, i.e. the monoclinic α, the pseudo-hexagonal β, and the monoclinic γ, have been measured by confocal Raman microspectroscopy...
Spherulites with closely packed edge-on lamellae and lathlike flat-on crystals of melt crystallized isotactic poly(1-butene) in ultra-thin films at different temperatures were studied by AFM in taping mode. Starting from these different crystals, the melting processes of them after aging at room temperature for different periods of time were monitored. Through selective melting of the thermally less...
Polydimethylsiloxane (PDMS) materials show the unique phenomenon that when exposed to electrical discharge, such as corona discharge, their hydrophobic surface becomes hydrophilic. However, after a certain relaxation time they gradually regain their hydrophobicity. In this study the adhesive force obtained by AFM force distance measurements using a hydrophilic Si 3 N 4 probe is used...
A method for preparing open, sub-monolayer cellulose films on a silicon substrate is introduced, and the open films were quantified using the three-dimensional information from atomic force microscopy (AFM) height images. The preparation method is based on spin coating low concentrations of trimethylsilyl cellulose (TMSC) on silicon and hydrolysing the TMSC to cellulose using a vapour phase acid hydrolysis...
The growth behaviors of cross-hatched and lath-like lamellae of α-form spherulites and flat-on lamellae of β-form pherulites of isotactic polypropylene were studied with a high-temperature atomic force microscopy in situ and in real time. The growth rates of crystal lamellae in types I, II and mixed α-form spherulites and in β-form spherulites, as well as the spatial frequency of tangential branching,...
A nanoindentation technique using an atomic force microscope (AFM) was applied to characterize the mechanical behaviour of several isotactic polypropylene (iPP) samples. The samples were solidified from the melt with a CCT (continuous cooling transformation) procedure spanning a wide range of cooling rates thanks to a fast quenching apparatus developed by the authors. The influence of instrumental...
This work reports on morphological features of hydrogels, which have been used for the ultimate removal and recovery of nutrient and toxic anions from wastewater effluents. The sorbent used was crosslinked polyamine (PAA·HCl) polymeric hydrogels. The surface topography and morphology of these hydrogels were characterized by tapping mode atomic force microscopy. The change of the gel surface in response...
The solid-state structure–property behavior of highly branched segmented poly(urethane urea) (PUU) copolymers and their linear analog was investigated. A limited study of their solution rheological behavior was also undertaken. The linear PUUs were synthesized by the two-step prepolymer method, whereas the oligomeric A 2 +B 3 methodology was utilized to synthesize the highly branched...
The cyclic deformation of two polyurethane elastomers that differed in soft segment content and molecular weight was investigated. The microphase-separated morphology of the polyurethane with higher soft segment content consisted of hard segment domains dispersed in a soft segment matrix. In the polyurethane with lower soft segment content, the hard segment domains appeared to be partially cocontinuous...
Nanostructured films of poly(o-ethoxyaniline) (POEA) were studied by atomic force microscopy (AFM), which indicated a globular morphology for films containing one or more layers of POEA. Consistent with the nucleation and growth model for the adsorption process, the mean roughness and fractal dimension were found to increase with the time of adsorption and with the number of POEA layers in the initial...
Using Tapping Mode atomic force microscopy, we studied crystallization of polymers in confined cylindrical geometries of micro-phase separated asymmetric diblock copolymers, deposited in thin films onto solid substrates. We observed that in most cases crystallization occurs separately and independently in each cylinder of the mesophase pattern. We followed the kinetics of the crystallization process...
We investigated various stimuli-responsive poly(ferrocenylsilane) (PFS) polymers as model systems for the realization of molecular motors powered by a redox process. Covalently end-grafted PFS on gold, as well as PFS homopolymers and block copolymers in ultrathin films, were studied by AFM-based single molecule force spectroscopy (SMFS). Surface confined PFS macromolecules were chemically oxidized...
A method, which is called as ‘nanofishing’, enabled us to stretch a single polymer chain adsorbed on an Au(111) substrate with picking it at its two thiol-modified termini using atomic force microscope equipped with a gold-coated probe. A force–extension curve obtained for a single polystyrene chain in a Θ solvent (cyclohexane) showed a good agreement with a so-called worm-like chain model, and thus...
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