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Procedural sedation in patients with congenital heart disease (CHD) is associated with significant morbidity and mortality. It is vital for the practitioner to fully understand the complexity of lesions, their hemodynamics, and the impact of medications commonly used for procedural sedation on the stability of systemic vascular resistance and pulmonary flow. According to the literature, we explain the interaction of the systemic vascular resistance and pulmonary flow in such lesions and divide them into five categories outlined in this article: (1) CHDs with left-to-right shunt with normal pulmonary arterial pressure and resistance, (2) CHD with left-to-right shunt and moderate to severe elevation of pulmonary arterial pressure with near-normal pulmonary vascular resistance, (3) CHD with pulmonary flow dependent on systemic vascular resistance, (4) patients with congenital coronary stenosis and coronary anomalies, and 5) aortic obstructive lesions.

A polyurethane-based polymer, and a sustainable, natural resource in the form of chicken feather (keratin) fibers were combined to form a bio-composite via solvent-casting-evaporation at 0, 10, 20, 30, 40, 50, 60, and 70%·w/w. The thermo-mechanical properties of the composites were assessed using thermogravimetry, dynamic mechanical analysis, and stress-strain measurements with hysteresis loops. The uniformity of the dispersion of the feather fiber in the polyurethane matrix was investigated via macro-photography. Scanning electron microscopy of fracture surfaces was used to verify that the adhesion between fiber and polymer was effective. A molecular modeling visualization predicted the existence of hydrogen bonding between fibers and polyurethane molecules and this result was supported by Fourier transform infrared analysis of the final composites. Addition of chicken feather fibers to the polyurethane matrix was found to decrease the glass transition temperature, recovery strain and mass loss of the composites, but increase the elastic modulus, storage modulus and char level. The results demonstrate that keratin derived from what is currently a waste product from the poultry industry (with significant economic and environmental disposal costs) can effectively and cheaply improve the thermo-mechanical properties of composite materials, with potentially large environmental benefits.

Nanocomposites containing thermally reduced graphene (TRG) have been prepared with poly(trimethylene terephthalate) (PTT) plasticized with (bisphenol-A diglycidyl ether) (BADGE), a cross-linkable additive. Morphology of the PTT–BADGE blend was dependent on preference for interaction of TRG with PTT or BADGE and nucleation activity of TRG toward PTT. PTT-TRG and PTT-BADGE-TRG nanocomposites with different BADGE-TRG ratios were prepared by a melt mixing technique facilitated by miscibility of PTT and BADGE. The influence of TRG on crystallization nucleation, kinetics and morphology was measured using differential scanning calorimetry and wide-angle X-ray scattering. Crystallization of PTT caused phase separation of BADGE, though PTT–BADGE remained miscible in PTT amorphous regions. BADGE created increased flexibility of PTT though dynamic mechanical properties were moderated by TRG, both directly as a filler and as a result of enhanced crystallization. Synergistic improvement in modulus was observed at particular compositions attributed to a change in morphology of an immobilized zone consisting of BADGE and TRG within amorphous fractions of PTT. The results are of consequence for design of materials using a semi-crystalline polymer, for applications where simultaneous use of a processing aid, plasticizer and nano-reinforcement.

Carbon monoxide reduced graphene (CO-rG) was compounded with polyamide-6 (PA6) by melt-mixing to investigate the suitability of CO-rG as novel filler for enhanced mechanical properties in PA6-based composites. CO-rG was first exfoliated via probe ultrasonication in p-xylene prior to melt-mixing. Nanocomposites of differing compositions were then prepared and characterised for their elastic modulus (E), tensile yield strength (σyield), and strain at break (eb). Interactions between CO-rG and PA6 were characterised via Fourier-transform infrared (FTIR) spectroscopy and observed via scanning electron microscopy (SEM). Significantly enhanced mechanical properties were achieved even at low CO-rG content, with mechanical percolation observed at 1.0 %·w/w CO-rG. Beyond the mechanical percolation concentration, the addition of 6.0 %·w/w CO-rG resulted in overall enhancement in bulk composite properties with a measured E and σyield of 4107±225 MPa and 62±1 MPa, respectively. FTIR spectroscopy confirmed the existence of hydrogen bonding between CO-rG and PA6. SEM imaging indicated uniform dispersion of CO-rG in PA6.

Development of advanced magnetic carbon nano-materials has provided new dimensions in numerous research areas due to their multiple applications. In this study, novel magnetic carbon nano-composites were synthesised by integration of magnetic nanoparticle on novel graphene and renewable carbon materials from rice husk. Magnetic carbon nano-composites were fabricated by hydrothermal carbonization-coprecipitation (HTCC) and solvothermal carbonization-coprecipitation (STCC) routes that are easily scalable. The objective of this work is a comparative study of HTCC and STCC processed and their products. The experiments were conducted using different process variables including process temperatures (180,220 and 260 °C), process time (0.5,1 and 2 h) and solvents (water and ethanol). Chemical interaction of well-dispersed magnetic nano-particles of 5–20 nm size with carbonaceous material was confirmed. Magnetically recoverable nano-composite is highly suitable for use in multiple applications including catalysis, super-capacitance, biosensing devices, environmental remediation and enzymes immobilization and can establish various opportunities for industry in future.

The aim of this work was to prepare and characterize nanocomposites containing graphene from intercalated graphite. The graphene was produced by rapid thermal expansion using expandable graphite oxide or obtained commercially. The polymer used was poly(styrene-b-butadiene-b-styrene) (SBS). The SBS was dissolved in p-xylene and the graphene was ultrasonically suspended in the xylene solution. The morphology, dynamic mechanical, electrical, and thermal properties of composites were characterized. Graphene at 1% (w/w) (hydrogen atmosphere) was found to increase the storage modulus (68%) and loss modulus (147%) of the glassy state of polybutadiene in SBS. The damping factor of SBS was enhanced by 74% corresponding to the polystyrene phase of SBS using Cheap Tubes graphene. The composites were insulators at 1% (w/w). The styrene groups in SBS strongly adsorb onto the graphenes, preventing a percolation network that would enhance electrical permittivity. Graphene enhanced physical crosslinks of the polystyrene phase to increase the modulus at low concentration. Graphene dispersion using ultrasonic shear depended on π-π interactions between the aromatic rings of the solvent, graphene, and polystyrene. This is a simple, fast, cheap, and scalable way of making high-quality graphene and a new way of graphene dispersal in polymers.

Every year billion kilograms of unused feathers result from the poultry industry worldwide, which in effect impose a difficult disposal process to the environment. Chicken feathers are considered as a valuable and renewable keratin protein source, which could be used advantageously in a number of applications as alternatives to feather meal and feather disposal. Although the potential applications of keratin derived from chicken feathers have been investigated, the initial purification phase has not been fully described in the literature. Original chicken feathers contain many biological organisms along with other contaminants after plucking. Unprocessed chicken feathers are considered as potentially hazardous biological materials due to the presence of blood borne pathogens; therefore, the decontamination process is very important. The purpose of this work is to compare the effects of different purification techniques on chicken feathers prior to keratin isolation. These processes include surfactant washing, soxhlet extraction with ethanol, ozone, and sodium chlorite solutions. Thermogravimetric analysis, vibrational spectroscopy, and wide angle X-ray scattering were used to characterise the purified feathers prior to keratin extraction.

This article provides a comparative study of advanced single pot microwave versus conventional solvothermal co-precipitation synthesis for producing magnetic carbon nanocomposites and bio-oil from rice husk. The aim was to produce nanocomposites composed of magnetic nanoparticles and novel graphene on the surface of hydrochar improving the reaction efficiency. The experiments were conducted at two different temperatures (140 °C and 180 °C). The processing time was varied from 0.5 to 2 h. The main focus of the study was to investigate the effect of process parameters on the yield, thermal stability and morphology. Microwave-assisted solvothermal carbonisation (MSTC) provided a higher yield of bio-oil compared to solvothermal carbonisation (STC) due to more effective heat transfer to the core of the material. Microwave processing also resulted in less C C and C–H vibrations as measured by FTIR. Transmission electron microscopy confirmed the presence of well-dispersed nanoparticles, ranging in size from 5 to 20 nm in both MSTC and STC. Thermal stability of the nanocomposite materials was significantly higher for conventional solvothermal synthesis compared to the microwave system.