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Der gesamte Band ist unter der DOI 10.24405/14522 abrufbar.

Hierarchically porous synthetic bone grafts (scaffolds) are gaining attention in the clinical arena. Scaffolds should combine morphological (macro- and microporosity, pore interconnectivity), mechanical and biological (biocompatibility, degradation rate) properties to fit this specific use. Supercritical (sc-) foaming is a versatile scaffold processing technology. However, the selection of the optimum operating conditions to obtain a defined scaffold structure is hampered by the lack of a single characterization technique able to fully elucidate the porous features of the resulting scaffolds. In this work, the effect of soaking time (1, 3 and 5 h) on the preparation of poly(ε-caprolactone) (PCL, 50 kDa) scaffolds by sc-foaming was evaluated by a combined X-ray microtomography (μ-CT) and mercury intrusion porosimetry (MIP) 3D-morphological analysis. Mechanical tests and in silico modelling for cell penetration and water permeability of the scaffolds were also conducted. Results evidenced the relevance of μ-CT and MIP as a synergistic analytical duo to fully elucidate the morphology of the sc-foamed scaffolds and the soaking time effect.

Due to the lack of advanced methods to clean plastic waste from organic contaminants, this study aimed at evaluating supercritical extraction as a decontamination method. Oil-adhesive high-density polyethylene (HD-PE) oil containers were subjected to supercritical extraction using supercritical carbon dioxide. The extraction was conducted at 300 bar, applying various temperatures (i.e., 70, 80 and 90 &deg, C). The study assessed the impact of temperature on the decontamination efficiency. The variation in the samples&rsquo, quality was first analyzed using near infrared (NIR) spectroscopy. An analysis of the content of polycyclic aromatic hydrocarbons (PAHs) was followed. Samples treated at 70 and 80 &deg, C showed higher extraction efficiencies, in spite of the lower extraction temperatures. The NIR analysis showed that the plastic specimens did not experience degradation by the supercritical decontamination method. Moreover, the NIR spectra of the extracted oil showed the presence of a wide range of compounds, some of which are hazardous. This has been confirmed by a GC-MS analysis of the extracted oil. Based on the provided assessment, the quality of the decontaminated HD-PE plastic samples&mdash, from a contamination point of view&mdash, is enhanced in comparison to untreated samples. The level of PAHs contamination decreased to be within the allowed limits defined by the REACH regulation, and also met the specifications of the German Product Safety Committee. This study proved the effectiveness of the supercritical extraction using CO2 in extracting organic contaminants from plastics, while maintaining their quality.

The injection of sulfonated-modified water could be an attractive application as it results in the formation of a mechanically rigid oil-water interface, and hence, possible higher oil recovery in combination with polymer. Therefore, detailed experimental investigation and fluid-flow analysis into porous media are required to understand the possible recovery mechanisms taking place. This paper evaluates the potential influence of low-salt/sulfate-modified water injection in oil recovery using a cross-analyzed approach of coupled microfluidics data and core flooding experiments. Fluid characterization was achieved by detailed rheological characterization focusing on steady shear and in-situ viscosity. Moreover, single and two-phase micromodels and core floods experiments helped to define the behavior of different fluids. Overall, coupling microfluidics, with core flooding experiments, confirmed that fluid-fluid interfacial interaction and wettability alteration are both the key recovery mechanisms for modified-water/low-salt. Finally, a combination of sulfate-modified/low-salinity water, with polymer flood can lead to ~6% extra oil, compared to the combination of polymer flood with synthetic seawater (SSW). The results present an excellent way to make use of micromodels and core experiments as a supporting tool for EOR processes evaluations, assessing fluid-fluid and rock-fluid interactions.