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In this work, we investigated the enhancement of corrosion resistance in a biodegradable Mg-0.7Zn-0.6Ca (wt. %) alloy (MgZnCa) by applying ZrO2 thin films deposited via reactive magnetron sputtering. We employed a fractional factorial experimental design to systematically examine the influence of the deposition power, deposition time, and O2 fraction on the effectiveness of the ZrO2 thin film in preventing corrosion of the Mg alloy. Our analysis revealed that the ZrO2 thin films exhibited a monoclinic crystal phase and maintained stoichiometry across various O2 fractions. Interestingly, we observed a 78% roughness reduction when using the lowest O2 fraction, while roughness increased with the deposition power and time. The corrosion response of bare and ZrO2-coated MgZnCa alloy was assessed by electrochemical techniques and detection of H2 production during the Mg corrosion via gas chromatography. The optimal set of deposition conditions, essential for enhancing the short-term corrosion resistance of magnetron-sputtered ZrO2 coatings, involves maximizing thickness through high power (400 W) and extended deposition time (90 min). It is crucial to balance these factors while maintaining an appropriate O2 fraction (20%) to ensure the formation of a stoichiometric film. Avoiding excess oxygen is imperative, as it can lead to undesirable intergranular porosity and surface roughness. This optimization resulted in a 46% reduction in the evolution of H2 gas compared to the bare MgZnCa alloy. Overall, this work sheds light on the potential of ZrO2 thin films as effective corrosion-resistant coatings for MgZnCa alloys, emphasizing the critical role of deposition parameters in achieving superior protection against corrosion. [ABSTRACT FROM AUTHOR]

Recent advances in the fabrication of neuromorphic electronic devices using biomaterials have received increasing attention for their prospect in biologically compatible and "green" electronic devices. Here, we proposed a novel electric-double-layer (EDL) synaptic transistor gated with Li-doped natural gelatin membranes, demonstrating larger capacitance at low frequency and extremely strong electrostatic modulation behavior. Experimental results have shown that a concentration of 2 wt. % Li-doping can obtain better electrical performance of EDL synaptic transistor. Ion/Ioff of 4.86 × 105 and threshold voltage of 0.68 V were obtained. Meanwhile, some important synaptic functions such as excitatory postsynaptic current, paired-pulse facilitation, and high-pass filtering characteristic have been successfully implemented. As a result, it can be inferred that the proposed gelatin-based natural polymer EDL electrolyte has demonstrated potential applications in "green" neuromorphic platforms. [ABSTRACT FROM AUTHOR]

This study investigated the potential of producing and upgrading bio-oil from plastic waste through a catalytic pyrolysis process. Plastic waste samples composed of polystyrene, polyethylene, and low-density polyethylene, shredded to sizes of 1.5–2.5 mm and blended in a ratio of 50/25/25, respectively, were pyrolyzed in a fluidized bed reactor at optimal conditions of 560–650 °C, a heating rate of 15 °C/min, and N2 gas flow rate of 100 ml/min in the presence of zeolite catalysts. The produced bio-oil was treated with fossil diesel, calcium hydroxide, and sodium sulfate to enhance its properties. The results showed that bio-oil production was increased to 65 wt. %, while char was reduced to 3.5 wt. %. Treatment with 20 wt. % diesel reduced bio-oil kinematic viscosity by 58% and improved stability from 20% to 50%. The addition of 16 g calcium hydroxide reduced the bio-oil acidity by 51% from a pH of 3.2–4.85. Furthermore, the bio-oil moisture content was reduced from 10 to 5.2 wt. % through the addition of 10 g of sodium sulfate, while the lower heating value was improved to 39.0 MJ/kg. Therefore, the catalytic pyrolysis of plastic waste in a fluidized bed reactor, and the various treatments performed on the generated bio-oil proved to be an effective technique to enhance the economic value of plastic waste and its environmental management at large. [ABSTRACT FROM AUTHOR]

Due to its high biocompatibility and biodegradability, supraparticles made from silk fibroin—produced from Bombyx mori (B. mori) cocoons—can find various applications in biomedical fields. The evaporation of Ouzo droplets by not requiring energy nor a surfactant is an environmentally friendly, easy, and cost-effective strategy to fabricate three-dimensional supraparticles, tackling the so-called "coffee ring effect" associated with droplet evaporation. Silk fibroins are dissolved into quaternary droplets, comprised of ultrapure water, ethanol, trans-anethole oil, and formic acid. The Ouzo droplet is able to form an oil ring that facilitates the droplet contraction to create a three-dimensional supraparticle. Using the Ouzo effect to fabricate these particles from silk fibroin results in consistent macro-porous structures with a high porosity. [ABSTRACT FROM AUTHOR]

Biodegradable plastics are thought to be the possible directions in managing plastic pollutions. Unfortunately, they are not recycled in most countries since they are designed to decompose even though recycling is a more pragmatic method than landfill or incineration. Thus, it is more constructive to develop methods to recycle biodegradable plastics or to develop biodegradable yet recyclable plastics. In this study, we used cutlery with a composite of poly(lactic acid) (PLA) and talc. The possibility to recycle it to make foams was studied even though it will have lowered mechanical strength from the recycling process as it is less significant for this product. Tensile properties of solid PLA and foams showed no significant decrease in the strength up to three processes of compression molding and foaming. We performed shear rheometry to determine the thermal stability and dependences of the complex viscosity on frequency and temperature. The magnitude of the complex viscosity dramatically increased with decreasing frequency and such an upturn increased with temperature, but time-temperature superposition was valid at high temperatures. The extensional rheometry showed no strain hardening, but physical foaming using supercritical carbon dioxide (CO2) could still occur, and the operating conditions to obtain various foamed structures were determined. We also compared the effects of one-directional against three-dimensional expansion. Overall, the concentration of CO2 in PLA and crystallinity of the foams are the two key variables to describe the bulkiness of foams. Surprisingly, the lower the CO2 concentration, the bulkier the foams at any sorption temperature and pressure. [ABSTRACT FROM AUTHOR]

The article provides resources for the upcoming total solar eclipse on April 8, 2024. It includes links to websites with information on the eclipse, citizen science opportunities, and lesson plans and activities for educators. The article also emphasizes the importance of safety during the eclipse, advising against looking directly at the sun and providing tips on how to view the eclipse safely. The author mentions the Harvard eclipse sonification project, which aims to provide a unique experience of the eclipse for the blind and visually impaired. [Extracted from the article]

Massive rotator cuff tears (MRCTs) remain a challenge in orthopedic shoulder surgery. The medical implant is a feasible and effective treatment option for MRCTs. However, the complications of implant migration usually occurred in clinical trials. To address this problem, biodegradable implants from poly(L, L-lactide-co-ε-caprolactone) (PLCL) copolymers were applied to treat MRCTs and presented major clinical effects in this study. The medical implants were designed in a dented shape to clad the head of the humerus, which could prevent the migration of implants and effectively improve shoulder function in a human specimen test. The structure was tested through finite element analysis and human specimen experimentation. The appropriate ratio of PLCL constituents was confirmed by examining the degradation of PLCL implants and measuring their mechanical, physical, chemical, and biological features. Samples were characterized using a scanning electron microscope, gel permeation chromatography, mechanical test, and transmission electron microscope. It was found that PLCL5050 (segment ratio PLA:PCL = 50:50) copolymer implants possess good processability and mechanical properties, as well as an appropriate degradation time of 177 days, which could satisfy the treatment requirements of MRCTs. [ABSTRACT FROM AUTHOR]

A chemical sensor was fabricated using indium-tin-oxide (ITO) films printed on biodegradable plastic substrates. The ITO layers were printed on polylactic acid (PLA) films. To optimize the printing procedure, the thermal properties of the PLA substrate were investigated using the differential scanning calorimetry method. The structural and electrical properties of the fabricated ITO films (P-ITO) were compared with commercial sputtered ITO films (S-ITO). X-ray diffraction and Hall effect measurements were used to estimate the grain size and the carrier transportation mechanism of the ITO films. The small grain size of P-ITO was attributed to its scattering mechanism. Grain boundary scattering was shown to be dominant in the P-ITO. The chemical sensing properties were also evaluated using a droplet of methanol (20 µl), indicating that the response rate of the P-ITO film was considerably higher (650%) than that of the S-ITO film. These results were attributed to the large surface area of the P-ITO film. [ABSTRACT FROM AUTHOR]

Design and analysis of a ceramic-filled bio-plastic composite sandwich structure is presented. This proposed high-dielectric structure is used as a substrate for patch antennas. A meandered-strip line-fed fractal-shape patch antenna is designed and fabricated on a copper-laminated sandwich-structured substrate. Measurement results of this antenna show 44% and 20% of bandwidths with maximum gains of 3.45 dBi and 5.87 dBi for the lower and upper bands, respectively. The half-power beam widths of 104° and 78° have been observed from the measured radiation pattern at the two resonance frequencies 0.9 GHz and 2.5 GHz. [ABSTRACT FROM AUTHOR]

To enhance the cytocompatibility of polycaprolactone (PCL), cell-adhesive gelatin is covalently immobilized onto the PCL film surface via two surface-modified approaches: a conventional chemical immobilization process and a surface-initiated atom transfer radical polymerization (ATRP) process. Kinetics studies reveal that the polymer chain growth from the PCL film using the ATRP process is formed in a controlled manner, and that the amount of immobilized gelatin increases with an increasing concentration of epoxide groups on the grafted P(GMA) brushes. In vitro cell adhesion and proliferation studies demonstrate that cell affinity and growth are significantly improved by the immobilization of gelatin on PCL film surfaces, and that this improvement is positively correlated to the amount of covalently immobilized gelatin. With the versatility of the ATRP process and tunable grafting efficacy of gelatin, this study offers a suitable methodology for the functionalization of biodegradable polyesters scaffolds to improve cell-material interactions. [ABSTRACT FROM AUTHOR]