Carbon nanotubes (CNTs) were deposited on the surfaces of polyurethane (PUR) foams by electrophoretic deposition (EPD). The parameters of EPD were optimized in order to obtain homogeneous CNT coatings on PUR foams and adequate infiltration of the three-dimensional (3D) porous network. The microstructure of the composites was investigated by high-resolution scanning electron microscopy (HRSEM), revealing that optimal quality of the coatings was achieved by an EPD voltage of 20 V. The thermal properties of the CNT-coated specimens, determined by thermogravimetric analysis (TGA), were correlated to the foam microstructure. In vitro tests in concentrated simulated body fluid (1.5 SBF) were performed to study the influence of the presence of CNTs on the bioactivity of PUR-based scaffolds, assessed by the formation of calcium phosphate (CaP) compounds, e.g. hydroxyapatite (HA), on the foam surfaces. It was observed that CNTs accelerate the precipitation of CaP, which is thought to be due to the presence of more nucleation centres for crystal nucleation and growth, as compared with uncoated foams. Polyurethane foams with CNT coating have the potential to be used as bioactive scaffolds in bone tissue engineering due to their high interconnected porosity, bioactivity and nanostructured surface topography.

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Structure and properties of polyurethane/YAG:Tb 3+ nanocomposites with luminescence properties Summary-Elastic polyurethanes films with luminescent properties have attracted increasing attention, both as a subject of fundamental and applied research. In the present study, polyurethane nanocomposites containing 0.05 to 0.2 wt. % of nanofillers were prepared by in situ polymerization. These nanocomposites were subsequently used to investigate the influence of the nanoparticles' content on their structure and properties. PUR was synthesized using polycaprolactone diol (PCL diol) and dicyclohexylmethane-4,4'-diisocyanate (HMDI) with addition of diols as chains extenders. The nanofiller in the form of yttrium-aluminum-garnet (YAG) containing 10 wt. % of Tb 3+ was added and samples of composites were synthesized employing prepolymer fabrication route. Series of nanocomposites with exhibited high luminescence and intensity of emission. Microstructure of these composites was investigated using atomic force microscopy (AFM) in a tapping mode. The grain size analysis of nanofillers was performed with high resolution scanning electron microscopy (HRSEM) and high resolution transmission electron microscopy (HRTEM). The mechanical and optical properties of the specimens have been correlated to their microstructure.

This paper presents the results of studies on ZrO2 containing 10% Eu3+ as a nanofiller in polyurethane nanocomposites with luminescent properties. The nanocomposites, which are potential materials for electro-optical-electronic applications, were prepared by in-situ polymerization. Emission spectra, thermodegradation, thermal analysis and mechanical properties of polyurethane ZrO2/10% Eu3+ were investigated and the structure examined using HRSEM. The aim was to investigate the influence of the distribution of nanofillers in the composite and the structure of hard domains of polyurethanes on the relevant properties for opto-electronic applications.

In this research, we aimed to develop a new type of core-shell electrospun fiber, possessing “short” length (core) and “concentrated” polymer brush (shell). We prepared electrospun fibers with initiating moiety for surface-initiated atom transfer radical polymerization (SI-ATRP), one of living radical polymerizations. Then we grafted poly(sodium styrene sulfonate) (PSSNa) on the fibers by SI-ATRP. After the polymerization, we mechanically cut the electrospun fibers with a homogenizer, yielding regulated shortened fibers. Our ultimate goal is to make a novel shortened nanofibril biomaterial with concentrated brush as cell growth scaffolds. Therefore we expect that this unprecedented short nanofiber can be broadly applied as a biomaterial owing to the unique structures and properties of the concentrated brush. The details will be discussed.

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