Dislocation-loop-mediated smectic melting

We report the direct observation, using freeze-fracture transmission electron microscopy, of topological melting in a lyotropic system in the vicinity of a smectic-cholesteric (N*) phase transition. The proliferation of dislocations leads to at least one, and possibly two intermediate phases, characterised by orientational ordering of the dislocation loops and the subsequent unbinding of the screw-dislocation lines. PAC

Développement d'une aproche originale pour évaluer l'effet des surfactants, de la biomasse et des polluants sur l'extrapolation d'un réacteur biphasique

BACKGROUND: Two-phase partitioning bioreactors (TPPBs) are considered as a new technology for xenobiotic degradation in gaseous effluents. However, there is still a need for more knowledge on how to design and scale-up TPPBs. The partitioning of the two phases remains a misunderstood way of research. In particular, the impact of pollutant (isopropylbenzene), biomass and surfactant extract needs to be better evaluated. RESULTS:. An adaptated scale-down apparatus has been developed in order to quantify the speed of phase partitioning (SPP) into a plug flow section. Firstly, it was shown that isopropylbenzene (IPB) doesn’t destabilize more significantly the system. Secondly, respectively 0.5 g.L-1 and 0.05 g.L-1 of biomass and surfactant extract, separately or in mixture, were sufficient to ensure the stability of the two-phase system. Finally, a 100 m3 limit of scaling-up was suggested on the basis of the circulation time comparison. CONCLUSION: The scaling-up of an aqueous/silicone-oil TPPB was found to be definitely conceivable when the presence of biotic compounds were considered. However, further considerations are needed to verify our assumptions, in particular by taking into account the velocity field pattern in full-scale bioreactors and reproduce it in lab-scale apparatus

Thermo-Responsive Multi-Cargo Core Shell Particles

The synthesis of multi-compartment thermally sensitive capsules is proposed using Pickering-based double emulsions and sol-gel chemistry. As reported by Rénal Backov, Véronique Schmitt, and co-workers on page 62, a limited coalescence process allows the generation of size-controlled systems using a turbulent mixing device that makes and industrial transfer very easy. The release is provoked by an external thermal treatment, while the delivery temperature may be tuned for targeted application by the choice of the appropriate wax