We explore a bioinspired approach to design tailored functionalized capillary electrophoresis (CE) surfaces based on covalent grafting for biomolecules analysis. First, the approach aims to overcome well‐known common obstacles in CE protein analysis affecting considerably the CE performance (asymmetry, resolution, and repeatability) such as the unspecific adsorption on fused silica surface and the lack of control of electroosmotic flow (EOF). Then, our approach, which relies on new amino‐amide mimic hybrid precursors synthesized by silylation of amino‐amides (Si–AA) derivatives with 3‐isocyanatopropyltriethoxysilane, aims to recapitulate the diversity of protein–protein interactions (π–π stacking, ionic, Van der Waals…) found in physiological condition (bioinspired approach) to improve the performance of CE protein analysis (electrochromatography). As a proof of concept, these silylated Si–AA (tyrosinamide silylation, serinamide silylation, argininamide silylation, leucinamide silylation, and isoglutamine silylation acid) have been covalently grafted in physiological conditions in different amount on bare fused silica capillary giving rise to a biomimetic coating and allowing both the modulation of EOF and protein–surface interactions. The analytical performances of amino‐amide functionalized capillaries were assessed using lysozyme, cytochrome C and ribonuclease A and compared to traditional capillary coatings poly(ethylene oxide), poly(diallyldimethylammonium chloride), and sodium poly(styrenesulfonate). EOF, protein adsorption rate, protein retention factor k , and selectivity were determined for each coating. All results obtained showed this approach allowed to modulate the EOF, reduce unspecific adsorption, and generate specific interactions with proteins by varying the nature and the amount of Si–AA in the functionalization mixture.

Mesurer nécessite d'évaluer les incertitudes de mesure. Une mesure scientifique n'a de sens qu'accompagnée de son incertitude, ce qui permet de fixer le nombre de chiffres significatifs de sa valeur numérique. Ceci permet par exemple de vérifier la conformité d'une série de pièces usinées à un cahier des charges qualité.Les méthodes de calcul des incertitudes-types conformes aux recommandations internationales sont présentées progressivement, après avoir distingué les erreurs des incertitudes.Des vidéos d'expérience, accompagnées de cours et de nombreux exercices, devraient vous permettre d'exprimer correctement vos résultats de mesure, quelle que soit la grandeur mesurée et les appareils utilisés.https://socles3.unisciel.fr/course/view.php?id=555

Silica aerogels have many potential applications, including as host matrices for chemical species or nuclear waste storage. For these applications, the permeability is a key parameter and data show that the silica aerogels have poor permeability (~10-60 nm 2). In this chapter we review the method to measure the liquid and gas permeability in gels, aerogels and composite aerogels. Ideally, permeability does not depend on the type of pore fluid, therefore permeability measured using gas should be the same as that measured using water. We measured gas and water permeability in sets of nano composite silica aerogels. Experimental results show that gas permeability in aerogels was larger than water permeability by almost two orders of magnitude. The observed difference in gas and water permeability was analyzed from the point of view of the slip regime (Klinkenberg correction), and transition regime (Knudsen correction), the slip flow of gas at pore walls enhance the gas flow when pore sizes are small. This work addresses the problem of estimating permeability with high porosity materials such as aerogels. The effects of structural parameters of porous media (pore volume, tortuosity, fractal features) on the Klinkenberg and Knudsen corrections are discussed and the different models proposed in the literature are tested.

An experimental program is oriented to the mechanical behaviour of the Interfacial Transition Zone (ITZ) exposed to leaching, for a single mix. Leaching kinetics of the degraded depth, measured through grey level on cross sections, reveals a maximum gap of 10 % between ITZ and bulk cement paste. ITZ, with a main thickness of 15 µm suffers a significant decalcification, which is reflected on the mechanical properties of the bond. Grey level, Calcium/Silicon (Ca/Si) molar ratio and Young’s modulus in the degraded zone present similar evolution. Effect of ITZ causing cracking and then debonding is noticed, through chemical analysis, image observation and mechanical tests.