Surface modification of polyurethane/HCNT nanocomposite with octavinyl polyhedral oligomeric silsesquioxane as a heart valve material

Fabrication of polyurethane – Heparinized carbon nanotubes composite for heart valves application

Submicron/nano-structured icephobic surfaces made from fluorinated polymethylsiloxane and octavinyl-POSS

In this study, it was aimed to investigate octavinyl‐polyhedral oligomeric silsesquioxane (OV‐POSS) incorporation into natural rubber (NR)/butadiene rubber (BR) elastomer blends as a potential compatibilizer. The effects of OV‐POSS loading levels on the thermal, mechanical, morphological, and dynamic‐mechanical properties of elastomer blends were explored. Fourier‐Transform Infrared Spectrometer (FTIR), Temperature Scanning Stress Relaxation (TSSR), and Differential Scanning Calorimetry (DSC) results revealed the conceivable effect of OV‐POSS nanoparticles in the vulcanization through reacting with sulfur and/or elastomers. Scanning Electron Microscope (SEM), X‐Ray Diffraction (XRD), and tensile test measurements supported the improvement of mechanical properties due to homogeneous dispersion at low loading levels. On the other hand, high amount of OV‐POSS incorporation (7 and 10 phr) resulted in a decrease in mechanical properties, owing to the agglomeration of nanoparticles. According to contact angle and Dynamic mechanical analysis (DMA) results, it could be concluded that OV‐POSS nanoparticles were localized at the interface of the elastomers and enabled the compatibilization of immiscible NR/BR blends.

Novel and eco-friendly hydrophobic treatment of cotton and polyester fabrics based-on octavinyl and aminopropylisobutyl polyhedral oligomeric silsesquioxanes (OL-POSS and AM-POSS)

UV-curable waterborne polyurethane acrylate (WPUA) modified with octavinyl polyhedral oligomeric silsesquioxane (OVPOSS) was prepared via photopolymerization between OVPOSS and WPUA. Structural and morphological features of WPUA/OVPOSS coatings were assessed using Fourier transform infrared spectroscopy, transmission electron microscopy and X-ray diffraction. Thermal properties of the WPUA/OVPOSS hybride coatings have been improved over the pure waterborne polyurethane acrylate analyzed by thermal gravimetric analysis. Performance of the coatings was also evaluated using water absorption, hardness, contact angle, X-ray photoelectron spectroscopy (XPS). The data showed that the WPUA/OVPOSS coatings possessed better water resistance and thermal oxidative stability in comparison with pure WPUA.

Compositing is an interesting strategy that has always been employed to introduce or enhance desired functionalities in material systems. In this paper, sponges containing polypropylene, lignin, and octavinyl-polyhedral oligomeric silsesquioxane (OV-POSS) were successfully prepared via an easy and elegant strategy called thermally induced phase separation (TIPS). To fully explore the behaviour of different components of prepared sponges, properties were characterized by a thermogravimetric analyser (TGA), differential scanning calorimetry (DSC), Fourier transform infrared measurement (FTIR), and scanning electron microscopy (SEM). Furthermore, wettability properties toward an organic liquid and oil were investigated. The FTIR analysis confirmed the chemical modification of the components. TGA and DSC measurements revealed thermal stability was much better with an increase in OV-POSS content. OV-POSS modified sponges exhibited ultra-hydrophobicity and high oleophilicity with water contact angles of more than 125°. The SEM revealed that POSS molecules acted as a support for reduced surface roughness. Moreover, OV-POSS-based blend sponges showed higher sorption capacities compared with other blend sponges without OV-POSS. The new blend sponges demonstrated a potential for use as sorbent engineering materials in water remediation.

In this study, the calcification and platelet adhesion resistance property of plasma-treated polyurethane/heparinised carbon nano tube (PU/HCNT) nanocomposite thin films as a candidate polymer for polymeric heart valve was investigated. The PU and HCNTs nanocomposite films (PU/HCNT) were prepared using the solvent casting technique. CNTs were heparinised to surpass the dispersal and calcification resistance of CNTs in the PU matrix. Dispersal of CNTs in the matrix of produced films was analysed with (TEM), and HCNTs were observed well distributed in the polymer matrix. Greater storage modulus and better calcification resistance were detected for the nanocomposite. DMTA used for determining nanocomposite properties, which showed that the modulus increased as modified CNTs added to the matrix. The composite films were exposed to oxygen plasma treatment. The modified surface was characterised using ATR-FTIR, SEM, EDXA, and water drop contact angle measurements. The results indicated that the treated PU/HCNT surface was more hydrophilic. Increased surface roughness for modified PU/HCNT surface observed in AFM images. In-vitro calcification test verified reduced calcification for the modified PU/HCNT surface. No cytotoxicity was observed for the modified polymeric films using L929 fibroblast cells. The platelet adhesion test showed that the modified films are more blood compatible than unmodified.

The widespread use of fluorinated silane coupling agents in hydrophobic textile coatings has raised increasing concerns due to their bioaccumulation and environmental persistence. In this study, a series of fluorine‐free, POSS‐based silane coupling agents were synthesized via hydrosilylation between octavinyl polyhedral oligomeric silsesquioxane (OV‐POSS) and two functional silanes—trimethoxyhydrosilane (MTMS) and bis(trimethylsiloxy)methylsilane (MDHM)—with tunable molar ratios. These hybrid silanes were applied to cotton fabric using a simple one‐step dip‐coating method. Among them, the POSS‐4MTMS‐4MDHM formulation, at a concentration of 0.2 wt%, imparted superhydrophobicity with a water contact angle (WCA) of 151° and a sliding angle (SA) of 8°. The modified fabric exhibited outstanding mechanical durability, maintaining a WCA of 147° after 100 abrasion cycles under 200 g loading, and retained excellent water repellency after ultrasonic washing and tape‐peeling tests. Furthermore, the coating demonstrated chemical resistance over a wide pH range, while preserving the inherent softness and improving the surface smoothness of the fabric. In oil–water separation tests, the coated fabric achieved a separation efficiency of 98.5% and an oil flux of 11.59 L m −2 s −1 , with efficiency remaining above 97% after 30 reuse cycles. This scalable, fluorine‐free strategy enables the fabrication of multifunctional, robust textile coatings with hydrophobic, antifouling, and separation properties.

Controllable synthesis of 3D superhydrophilic Cd(II) ion-imprinted polymer microspheres based on OV-POSS and bifunctional monomers synergy with superior selectivity for Cd(II) adsorption

Platelet adhesion onto segmented polyurethane film surfaces modified by addition and crosslinking of PEO-containing block copolymers

Vascular implant interventional medical catheter will contact with blood firstly after implantation. The anticoagulation and antibacterial functions of this device will determine the success or failure. Copper (Cu) has been verified to possess multi-biofunctions, but it was challenging to add the Cu metal to most materials. Take advantage of its functionality; Cu has been grafted on the material surface to improve the anticoagulation function and accelerate endothelialization. In this study, a Cu-bearing chitosan coating was prepared on the catheter to endow the anticoagulation and anti-infection functions. Besides, properties characterization and functional evaluation of the coated medical catheter were investigated. Dynamic blood clotting and platelet adhesion tests were carried out to evaluate the anticoagulation property. Besides this, the antibacterial test was used to estimate the anti-infection function. The surface energy and Cu ions release from the coating were detected and calculated by contact angles and immersion tests, respectively. The results of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) revealed that Cu ions were grafted in the chitosan coating. Thermogravimetric analysis (TA) result showed the concentration of Cu ions in the coating. The results of dynamic blood clotting, platelet adhesion, and antibacterial tests revealed that Cu grafted in chitosan would improve the blood compatibility and anti-infection property. The surface properties and Cu ions release behavior of Cu-bearing coating revealed the reasons for multi-biofunctions. This study indicated that the Cu-bearing chitosan coating could endow the vascular implant interventional device anticoagulation and anti-infection functions, which has excellent potential for clinical application.

Novel synthesis, structure characterization, DFT and investigation of the optical properties of cyanine dye/zinc oxide [4-CHMQI/ZnO]C nanocomposite thin film

Determination of physical properties of graphene doped ZnO (ZnO:Gr) nanocomposite thin films deposited by a thermionic vacuum arc technique

Enhancement of photoluminescence in Er-doped Ag–SiO 2 nanocomposite thin films: A post annealing study

Research was undertaken to determine the influence of the increased content of chromium in the outermost passive layer of magneto-electrochemically refined Co-Cr alloy L-605 surface on its hemocompatibility. The chemistry, roughness, surface energy, and wettability of conventionally electropolished (EP) and magnetoelectropolished (MEP) samples were studied with x-ray photoelectron spectroscopy (XPS), open circuit potential, atomic force microscopy, and contact angle meter. In vitro hemocompatibility of tested material surfaces was assessed using two important indicators of vascular responses to biomaterial, namely endothelialization and platelets adhesion. The endothelialization was assessed by seeding and incubating samples with human umbilical vein endothelial cells (HUVEC) for 3 days before counting and observing them under a fluorescent microscope. The platelet (rich plasma blood) adhesion and activation test on EP and MEP L-605 alloy surfaces was assessed using a laser scanning confocal microscope. The XPS analysis of MEP samples showed significant enrichment of the passive layer with Cr and O when compared with the EP one. The amount of other elements in the passive layer did not show a significant difference between EP and MEP treatments. The adhesion of HUVEC cells shows remarkable affinity to surfaces enriched in Cr (MEP) with almost 100% confluency. In addition, the number of platelets that adhered to standard EP surfaces was higher compared to the MEP surface. The present study shows that the chromium-enriched surface of cobalt-chromium alloy L-605 by the magnetoelectropolishing process tremendously improves surface hemocompatibility with regard to stent functionality by enhanced endothelialization and lower platelet adhesion and should be taken under consideration as an alternative surface of biodegradable polymer drug-eluting stents, polymer-free drug-eluting stents as well as bare-metal stents.