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International audience; The aim of this study is to extract brownmillerite from sulfate resisting Portland cement (SRPC) in order to determine its crystal chemistry and the effects of dissolution protocols. Brownmillerites (C4AF) from four SRPC were extracted and systematically studied by X-ray diffraction (XRD), electron probe microanalysis (EPMA) and X-ray fluorescence spectroscopy. Two extraction steps were used. The first is the SAM protocol that leaves a residue rich in ferrite, C3A and sulfates. Precipitated hydrated sulfate minerals are also observed for clinker with high molar SO3/Na2Oeq ratio. The second, developed in this paper, uses acetic acid (AcA) to dissolve C3A and sulfates. The Rietveld refinements showed that all brownmillerites of this study crystallize in Ibm2 space group. Two families of brownmillerite were identified by their aluminum content and cell parameters, related to the presence of C3A in the clinker. EPMA indicated that ferrites from SR0 and SR3 cements have Al/Fe ratios about 0.7 and 0.8-1.0 respectively. XRD allows to predict the (Al+Mg+Si)/Fe ratio in brownmillerite in good agreement with EPMA. The SAM protocol is the best way to study crystal chemistry of brownmillerite and the AcA protocol is recommended to dissolve sulfates and C3A for further reactivity studies.

International audience; Curcumin is a natural polyphenolic compound known for its numerous pharmacological properties. However, its low water solubility and instability at neutral pH are serious drawbacks preventing its use as an oral drug. Well‐defined amphiphilic poly(ethylene glycol)‐block‐poly(ethoxyethyl glycidyl ether) (PEG‐b‐PEEGE) block copolymers carrying acid‐labile acetal groups are synthesized by anionic ring‐opening polymerization and investigated as potential pH‐sensitive nano‐carriers for delivery of curcumin to cancer cells. The nanoparticles, resulting from copolymer self‐assembly in aqueous media, are characterized by dynamic light scattering and cryo‐transmission electron microscopy. The nanoparticles’ stabilities are evaluated in three different phosphate buffers (pH = 7.2, 6.4, and 5.3). The stability decreases at lower pH and a complete disappearance of the nanoparticles is noticed after 4 days at pH 5.3. Curcumin is encapsulated in hydrophobic core of mPEG40‐b‐PEEGE25 nanoparticles allowing significant enhancements of curcumin solubility in water and lifetime at neutral pH. In vitro curcumin release is studied at different pH by UV‐spectroscopy and high‐performance liquid chromatography (HPLC). The cytotoxicity of curcumin and curcumin encapsulated in micelles is evaluated by cell viability 3‐(4,5‐Dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT) assay on MDA‐MB‐231 human breast cancer cells