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Due to the expansion in the global population, there is an increase in animal protein demand and waste generation. Currently, food waste derived from supermarkets, etc., which is used to produce biogas, is collected separately and can contain (micro)plastics deriving from food packaging, imposing potential risks to the environment. A possible solution to address protein, waste and plastic concerns can potentially be achieved by rearing black soldier fly (BSF) larvae on such substrates. In this study, we investigated the effect of polyvinyl chloride (PVC) (micro)plastics on the growth, survival, and bioconversion of BSF larvae. On the other hand, the impact of the larvae on the polymer structure and degradation was also assessed. This was carried out by rearing BSF larvae on artificial food waste spiked with micro-, meso-, and macroplastics, while measuring larval growth, survival, and bioconversion parameters. The remaining plastics were collected and analysed upon changes and degradation of their polymer structure. Generally, BSF larvae were not affected in terms of growth performance (179.9–210.4 mg), survival (77.1–87.3%), and bioconversion (FCR: 4.65–5.53) by the presence of (micro)plastics in the substrates. Furthermore, the larvae were also unable to significantly alter the polymer structure of the used plastic.

To tackle the challenge of bauxite residue (BR), generated during the alumina production, as well as to recover some of its metal content, three combinatory H2-based processes were utilized. Firstly, Greek BR was mixed with NaOH to produce water soluble Na-aluminates and was roasted under pure H2 gas in order to reduce the Fe+3 content. Then the first process combined water leaching and magnetic separation, the second water leaching and melting and the last included wet magnetic separation. The water media resulted in the dissolution of Na-aluminate phases and the production of Al, Na-ion rich leachates. From these, pregnant leaching solutions recovery of Al was 78%, 84% and for the third case it reached 91%. Concerning Na recovery, it could reach 94%. Both melting process and magnetic separation aimed for Fe recovery from the material. The former case however still needs to be optimized, here its concept is introduced. The magnetic fraction, after the dry magnetic separation, varied in Fe content from 31.57 wt.% to 38.50 wt.%, while after the wet magnetic separation it reached 31.85 wt.%.

A new zeolite, COK-24, which is an intergrowth of erionite (ERI) and chabazite (CHA), was successfully synthesized for the first time. This was realized via a mixed gel approach. The formation of an intergrowth was confirmed via XRD combined with advanced electron microscopy. The new zeolite intergrowth outperformed its individual counterparts in NH3-SCR reaction. ispartof: ACS Materials Letters vol:3 issue:5 pages:658-662 status: published

An approach to induce conductivity in immiscible polystyrene/polypropylene (PS/PP) blends is described using a percolated conducting polyaniline/polyamide (PANI/PA) filler combined with a polystyrene‐block‐poly(ethylene‐ran‐butylene)‐block‐polystyrene‐graft‐maleic anhydride compatibilizer. The approach is based on the ability of the compatibilizer to concomitantly stabilize the cocontinuous morphology and to improve the state of dispersion of the PANI/PA filler. Selective localization of PANI/PA in the PS phase with improved filler dispersion is achieved with the optimal master batch (MB) preparation technique followed by its optimized sequence addition to the blend components. This results in an increase in the dc conductivity by six decades as compared with that of the neat compatibilized blend at an effective 4.8‐wt % PANI concentration. An investigation of the effect of functionality and concentration of the filler and the compatibilizer on the filler connectivity in the blend is performed. The prevailing specific interactions are analyzed by Fourier transform infrared spectroscopy and thermogravimetric analysis of the MBs. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48433.

This study addresses the effect of plastic deformation on the dissolution corrosion behavior of a Type 316L austenitic stainless steel. Dissolution corrosion was promoted by low oxygen conditions in liquid lead-bismuth eutectic (LBE). Specimens with controlled degree of plastic deformation (20%, 40%, and 60%) and a non-deformed, solution-annealed specimen were simultaneously exposed for 1,000 h at 500°C to static LBE with low oxygen concentration ([O] < 10−11 mass%). The corroded specimens were analyzed by various material characterization techniques. All exposed specimens exhibited dissolution corrosion. The non-deformed steel showed the least dissolution attack (maximum depth: 36 μm), while the severity of attack increased with the degree of steel deformation (maximum depth in the 60% steel: 96 μm). It was, thus, concluded that increasing the amount of plastic deformation in a Type 316L stainless steel results in higher dissolution corrosion damages for steels exposed to low oxygen LBE conditions. Addit...

The mechanism governing the electrical properties for phase separating blends containing multiwall carbon nanotubes (MWNTs) is unravelled by tuning the compatibilization efficiency. Thereto, compatibilization by interfacially segregated block and random copolymers (cp) of poly(styrene-random/block-methyl methacrylate)(PS-r/b-PMMA) was achieved in phase separating blends of poly[(α-methyl styrene)-co-acrylonitrile]/poly(methylmethacrylate) (PαMSAN/PMMA) undergoing spinodal decomposition. A systematic study of the effects of copolymer architecture and molecular weight on the percolating network of selectively localized MWNTs is performed. Effective compatibilization is achieved with block cp irrespective of the ability of the blocks to entangle, whereas for random cp only long random cp having the ability to effectively entangle with the homopolymers are as efficient as long block cp. With increasing copolymer concentration, an increase and subsequent saturation of the electrical conductivity is attained. This originates from an increased connectivity and refinement of the MWNT laden PαMSAN phase, as confirmed by optical microscopy and the linear viscoelastic response of the blends. An effective compatibilizer led to an interfacial tension mediated suppression of an interfacial coarsening of the PαMSAN phase during phase separation, subsequently leading to percolation of MWNTs selectively localized in the PαMSAN phase. Furthermore, the copolymer having the ability to promote the development of a percolated network of MWNTs also allowed the network to be formed at a lower copolymer concentration as compared to that of blends with copolymers leading to restricted improvement in the connectivity of MWNTs. Our robust and simple procedure to tune the blend morphology via the efficiency of the compatibilizers can be used to achieve a synergistic increase in conducting properties.

This article reports on the development of thin films of p- and n-type bismuth telluride compounds which are suitable for microelectromechanical systems (MEMS) thermoelectric energy harvesters. Films were prepared by the pulsed laser deposition technique. It is shown that the thin films of binary Bi-Te alloys outperformed considerably their ternary counterparts. Furthermore, the highest thermoelectric figure of merit (ZT) was found to be 0.39 for the p-type Bi 32 Te 68 alloy, whereas the optimal n-type alloy was Bi 25 Te 75 , which was characterized by a relatively low stress gradient.

This work studies the possibility to treat plasma enhanced chemical vapor deposited (PECVD) silicon germanium (Si1−xGex) thin films grown at 400 °C or lower with a pulsed excimer laser for obtaining good MEMS structural layers. The main advantage of using PECVD is that a high growth rate (∼35 nm/min) can be achieved at low temperatures (≤370 °C). It is demonstrated that optimizing the pulse fluence, number and rate yields high quality films characterized by a low defect density (∼102 defect/cm2), large grains (∼300 nm), a low mean stress and a low stress gradient. Furthermore, the electrical resistivity of the as grown material, deposited at 210 °C, is reduced from 12 kΩ cm to 1.3 mΩ cm after laser annealing.

Cu pumping is the irreversible extrusion of Cu from Cu-filled through-silicon vias (TSVs) exposed to high temperatures during back-end of line (BEOL) processing. The distribution of Cu pumping values over the TSVs of a single wafer has a large intrinsic spread. As potential BEOL reliability issues due to Cu pumping will first occur at the highest pumping TSVs, they can be mitigated if the fundamental cause for this large intrinsic spread is known and under control. This paper describes a clear correlation between Cu pumping and TSV Cu microstructure based on the grain size at the top of 5×50 μm TSV, disregarding twin boundaries. For the mitigation of TSV Cu pumping the ideal microstructure was shown to consist of a single grain spanning the whole TSV cross section, bringing down the highest measured Cu pumping value from 248 nm to 73 nm. This effect was attributed to the absence of rapid diffusion paths and grain boundary sliding ability.

In this work stacked boron doped poly-crystalline Silicon-Germanium (poly-SiGe) layers, which can be applied as structural MEMS layers, were studied. A standard 1 µm base layer, deposited at 480 ºC chuck temperature, is stacked until the required thickness (e.g. 10 x for a 10 µm thick layer). This 1 µm base layer consists of a PECVD seed layer (+/− 75 nm), a CVD crystallization layer (+/− 135 nm) and a PECVD layer to achieve the required thickness with a high growth-rate. The top part of this PECVD layer can optionally be used for optimizing the stress gradient by a stress compensation layer. This approach resulted in 4 µm thick poly-SiGe MEMS structural layers with low tensile stress (50 MPa), low resistivity (2 mΩcm) and a low strain gradient (< 1*10−5/µm).