Encapsulation of heavy metals by a nanoporous complex oxide 12CaO · 7Al₂ O₃

The nanoporous oxide 12CaO ⋅ 7Al2O3 (C12A7) offers the possibility of capturing large concentrations of environmentally damaging extra-framework species in its nanopores. Using density functional theory with a dispersion correction, we predict the structures and energetics of some heavy metals (Cr, Ni, Cu, Zn, Cd, Hg, and Pb) trapped by the stoichiometric and electride form of C12A7. In the stoichiometric form, while Zn, Cd, Hg, and Pb are encapsulated weakly, Cr, Ni, and Cu exhibit strong encapsulation energies. The electride form of C12A7 shows a significant enhancement in the encapsulation of Cr, Ni, Cu, and Pb. Successive encapsulation of multiple Cr, Ni, Cu, and Pb as single species in adjacent cages of C12A7 is also energetically favorable

Encapsulation performance of layer-by-layer microcapsules for proteins

This study reports on the encapsulation efficiency of proteins in dextran sulfate/poly-l-arginine-based microcapsules, fabricated via layer-by-layer assembly (LbL). For this purpose, radiolabeled proteins are entrapped in CaCO3 microparticles, followed by LbL coating of the CaCO3 cores and subsequent dissolving of the CaCO3 using EDTA. To allow to improve protein encapsulation in LbL microcapsules, we studied all steps in the preparation of the microcapsules where loss of protein load might occur. The encapsulation efficiency of proteins in LbL microcapsules turns out to be strongly dependent on both the charge and molecular weight of the protein as well as on the number of polyelectrolyte bilayers the microcapsules consist of

Mechanical analysis of encapsulated metal interconnects under transversal load

Novel insights regarding the ability of encapsulated metal interconnections to deform due to bending are presented. Encapsulated metal interconnections are used as electric conductor or measurement system within a wide range of applications fields, e.g. biomedical, wearable, textile applications. Nevertheless the mechanical analysis remains limited to reliability investigation of these configurations. Different papers and research groups claim that meander-shaped metal interconnections are predisposed for these applications fields due to their deformability while, to the author’s knowledge, no reports are found about this ability. An analysis based on the work needed to bend interconnections to a certain curvature will be used to compare different interconnection configurations with each other. The experimental as well as the simulation setup is based on PDMS encapsulated PI-enhanced Cu tracks. The results and conclusions are specific for this type of interconnections, but can be extended to a global conclusion about stretchable interconnections. From the obtained insights it is proven that periodically meander-shaped interconnections need significant less work, up to more than 10 times less, to bend the interconnection to the same curvature compared to straight interconnection lines. Furthermore it shows out, for the meander-shaped interconnection, that per increase of 250µm encapsulation thickness the work raises with a factor 2. For straight interconnection lines the work in function of the encapsulation thickness is limited to 20%/250µm. The bendability of the straight interconnection lines is determined by the shape of the interconnection, where for meandered tracks the encapsulation will determine this factor, for an encapsulation thickness of maximum 1mm. For encapsulations > 1mm, the encapsulation thickness will become the predominant factor which determines the deformability for both interconnection shapes

Applications of ethylene vinyl acetate as an encapsulation material for terrestrial photovoltaic modules

Terrestrial photovoltaic modules must undergo substantial reductions in cost in order to become economically attractive as practical devices for large scale production of electricity. Part of the cost reductions must be realized by the encapsulation materials that are used to package, protect, and support the solar cells, electrical interconnects, and other ancillary components. As many of the encapsulation materials are polymeric, cost reductions necessitate the use of low cost polymers. The performance and status of ethylene vinyl acetate, a low cost polymer that is being investigated as an encapsulation material for terrestrial photovoltaic modules, are described