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In this study, magnetic polyurethane rigid foam nanocomposites were synthesized by in situ polymerization of polyol and diisocyanate in the presence of ferroso-ferric oxide (Fe3O4)@silicon dioxide (SiO2)@urea magnetic core-shell nanoparticles (NPs). The structure of the Fe3O4@SiO2@urea NPs were confirmed by Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and energy-dispersive X-ray spectroscopy. The effect of the Fe3O4@SiO2@urea NPs on sound absorption characteristics, thermal stability, and mechanical property of the polyurethane (PU) foams was studied. The sound absorption coefficient was determined using the sound impedance tube method, and it was concluded that the coefficient of the composites was increased in comparison to the pure foam and previously reported magnesium hydroxide-3% and aluminum oxide-3% PU foams, over the entire frequency range.

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SbstractIron oxide magnetic nanoparticles (NP's) converted to the core-shell structres by reacting with by n-(2-aminoethyl)-3-aminopropyl trimethoxysilane (AEAP) incorporated in polyurethane flexible (PUF) foam formulations. Fourier transform spectra, thermal gravimetric analysis, scanning electron images, thermo-mechanical analysis and magnetic properties of the prepared nanocomposites were studied. Obtained data shown that by the increasing of the amine modified magnetic iron oxide NP's up to 3% in the polymer matrix, thermal and magnetic properties improved in comparison with pristine foams. In addition, due to the presence of functional groups on the magnetic NP's surface, hard phases formation decrease in the bulk polymer and cause decreasing of glass transition temperature.

Biofilm is a microbiome complex comprising different bacterial colonies that typically adhere to device surfaces in water, which causes serious medical issues such as indwelling infections and outbreaks. Here, we developed a non-nanoparticle, flexible antibiofilm hygiene coating consisting of lithocholic acid (LCA), zinc pyrithione (Zn), and cinnamaldehyde (Cn) (named as LCA-Zn-Cn) that largely prevents the bacteria adhesion to various water device surfaces such as stainless steel and glass through a synergistic mechanism. The existing chelated groups on LCA and Cn attract plenty of bacteria via hydrophobic interaction. Both the bactericidal reaction by grafting biocidal groups from both LCA and Cn and the bacteriostatic reaction by inhibiting cell division via zinc ions (Zn) lead to a largely improved bacteria/biofilm prevention. The antibacterial performance was assessed by using the JIS Z 2801/ISO 22196 method. The designed LCA-Zn-Cn coating displayed log 10 reduction of 4.23 (99.9% reduction) of E. coli and log 10 reduction of 3.51 (99.8% reduction) of E. faecalis on stainless steel, which are much higher than the control samples, demonstrating a promising colonization inhibition. In parallel, the polysulfone encapsulated beads also showed >99% reduction efficiency in batch and >97−98% reduction efficiency in continuous column tests using the Lake Michigan water. Due to the strong cross-linked configuration, the coating still showed >90.9% bacterial reduction after 3000 abrasion cycles and over 99.9% bacteria reduction after a high flow velocity of 1.99 m/s test, which confirmed the enhanced mechanical durability. By applying either spray or dip-coating, the designed polymer composite can be coated on a variety of irregular water devices with mass production using an auto-controlled robot arm.

Polyurethane rigid foam (PUR) nanocomposite contain of novel magnetic (MNPs) core-shell nanoparticles (Fe 3 O 4 /Silica/Urea-1 and 3wt%) was prepared by in situ polymerization method. The structure of nanoparticles was investigated by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The effect of the MNPs nanoparticles on morphology properties of PUR was studied.

Magnetic polyurethane rigid foam nanocomposites were synthesized by incorporation of surface functionalized iron oxide nanoparticles with 3‐aminopropyltriethoxysilane (APTS). Magnetite nanoparticles (MNPs) and Fe3O4@APTS were synthesized via co‐precipitation and sol–gel methods, respectively. The main purpose of the surface modification of MNPs was the formation of hydrogen bond between amino groups of Fe3O4@APTS with the urethane groups to improve magnetic and thermal properties of the nanocomposites. The effect of different amounts of Fe3O4@APTS on the thermal and magnetic behavior of resultant nanocomposite was investigated and the optimum percentage of nanostructure in foam formulation was defined. POLYM. COMPOS., 38:877–883, 2017. © 2015 Society of Plastics Engineers