Martin Depardieu

Nano-spots induced break of the chemical inertness of boron: a new route toward reversible hydrogen storage applications

Novel LiBH4–metal-loaded carbonaceous foams have been designed to trigger reversible hydrogen storage properties. The metallic nanoparticles favour preferential wetting of LiBH4 on their surface and subsequent nucleation and growth, a configuration in which borate formation is strongly minimized. A cooperative effect between lower boron oxidation and the presence of metallic particles bearing intrinsic high heat capacity (acting as high temperature nanospots) promotes a strong improvement toward the rehydrogenation process, where the chemical inertness of boron has been overcome in this way for the first time. Hence, the LiBH4–M@C-HIPE(25HF) hybrid macrocellular foams (with M = Pd or Au) facilitate a reversible hydrogen storage process with a remnant capacity of about 7.4 wt% H2 (related to LiBH4) after 5 desorption–absorption ) hybrid…” and throughout the article should “absorption” be changed to “adsorption”??>cycles.

A multiscale study of bacterial proliferation modes within novel E. coli@Si(HIPE) hybrid macrocellular living foams

For the first time the study at various length scales of E. coli proliferation modes within Si(HIPE) inorganic macrocellular foams is proposed. Both qualitatively and semi-quantitatively, bacterial proliferation within the foam is not homogeneous and is directly linked to the random distribution of Si(HIPE) macroscopic cells. When inoculated in a nutrient loaded Si(HIPE), the bacterial growth is enhanced within the Si(HIPE) matrices compared to the surrounding LB media. The bacterial growth kinetics tends to be faster and the concentration at saturation is roughly 100% times higher. In the case of a Si(HIPE) host free of nutrients, bacterial motion occurs as an infiltration wave; the peak of this propagation wave moves at a constant speed of 88 μm h-1, while bacterial concentrations within the Si(HIPE) host reach levels far above the ones reached in the presence of nutrients, suggesting a real synergetic relationship between the bacterial colony guests and the Si(HIPE) host. When a nutrient reservoir is present at the opposite position from which bacteria were inoculated, bacterial proliferation is associated with a coalescence process between the growing colonies that were rapidly established within the first hours. When the Si(HIPE) host was fully colonized we found out a specific distance between adjacent colonies of 5 and 15 μm in good correspondence with the repartition of the wall to wall distances of the Si(HIPE) macroscopic cells, meaning that bacterial repartition once colonization occurs is optimum. These results show that Si(HIPE) foams are outstanding candidates for strengthened bacterial proliferation without motion restriction imposed by conventional silica gels.

Polymer-Derived Silicoboron Carbonitride Foams for CO2 Capture: From Design to Application as Scaffolds for the in Situ Growth of Metal–Organic Frameworks

A template-assisted polymer-derived ceramic route is investigated for preparing a series of silicoboron carbonitride (Si/B/C/N) foams with a hierarchical pore size distribution and tailorable interconnected porosity. A boron-modified polycarbosilazane was selected to impregnate monolithic silica and carbonaceous templates and form after pyrolysis and template removal Si/B/C/N foams. By changing the hard template nature and controlling the quantity of polymer to be impregnated, controlled micropore/macropore distributions with mesoscopic cell windows are generated. Specific surface areas from 29 to 239 m(2)  g(-1) and porosities from 51 to 77 % are achieved. These foams combine a low density with a thermal insulation and a relatively good thermostructural stability. Their particular structure allowed the in situ growth of metal-organic frameworks (MOFs) directly within the open-cell structure. MOFs offered a microporosity feature to the resulting Si/B/C/N@MOF composite foams that allowed increasing the specific surface area to provide CO2 uptake of 2.2 %.

From compartmentalization of bacteria within inorganic macrocellular beads to the assembly of microbial onsortia.

Microorganisms are highly efficient biocatalysts. Yet making use of their capabilities for chemical transformations requiring synergistic interactions between different microbes is challenging as the competition for resources might reduce the diversity and ultimately disrupt the synergies. Here, a new method is proposed for constructing microbial consortia for the integration of multistep transformations. Bacteria are successively grown and trapped within semipermeable inorganic foams produced as millimeter‐sized beads. The beads function as efficient living biocatalysts is demonstrated. These living heterogeneous biocatalysts are manipulated to perform cycles of biochemical reactions and furthermore assembled to perform preprogrammed sequences of reactions. This new family of living advanced biocatalysts should find applications in a wide range of basic research and industrial systems where complex tasks have to be performed by controlled consortia of microorganisms.