The variety of H bond (HB) interactions is a source of inspiration for bottom-up molecular engineering through self-aggregation. Non-conventional intermolecular HBs between N,N0disubstituted urea and thiourea are studied in detail by vibrational spectroscopies and ab initio calculations. Raman and IR mode assignments are given. We show that it is possible to study selectively the different intermolecular bifurcated intra-and inter-dimer HBs with the two types of HB acceptors. Through the ab initio calculation, the thioamide I mode, a specific marker of N-H … S=C HB interactions, is unambiguously identified.

Silica–wollastonite xerogel composites (xerocomposites) with different wollastonite filler content were obtained after classical drying of silica–wollastonite gels. Two different silica precursors were used, TEOS and colloidal LUDOX, for composites named TW and LW, respectively. We utilized SAXS experiments, N2 adsorption–desorption, and SEM techniques to determine the textural and structural properties of these porous materials. For both the TW and LW composites, it was shown that a macroporosity and a mesoporosity coexist. We argue that the proportion of macroporosity directly depends on the proportion of wollastonite fillers in the composite. We propose a unique two-stage drying mechanism to explain the formation of macropores. We additionally found that the surface of wollastonite fillers was covered by a dense multilayer packing of silica colloids in LUDOX LW xerocomposites. We believe that these surface-modified wollastonite fillers could improve the carbonation kinetics of wollastonite when used as a precursor for aqueous mineral carbonation, a promising route for safe and durable carbon sequestration.

Au-covered hollow urchin-like ZnO nanostructures were prepared with controlled size by combining nanosphere lithography (NSL), atomic layer deposition (ALD), electrodeposition, and electron beam (e-beam) evaporation. The optimal Au film thickness for sensing applications was determined by measuring the surface-enhanced Raman scattering (SERS) intensities of the substrates. Furthermore, the sensing performances of these hybrid nanostructures have been investigated by using chemical and biological molecules: thiophenol and adenine, respectively. Limits of detection (LOD) of 10 À8 M and 10 À6 M were found for the detection of thiophenol and adenine, respectively. Additionally, the excellent uniformity and batch-to-batch reproducibility of the substrates make them excellent candidates for reliable SERS sensing and biosensing.

Nano-porous two-dimensional molecular crystals, self-assembled on atomically flat host surfaces offer abroad range of possible applications, from molecular electronics to future nano-machines. Computerassisteddesigning of such complex structures requires numerically intensive modeling methods. Here wepresent the results of extensive, fully atomistic simulations of self-assembled monolayers of interdigitatedmolecules of 1,3,5-tristyrilbenzene substituted by C6 alkoxy peripheral chains (TSB3,5-C6), depositedonto highly-ordered pyrolytic graphite. Structural and electronic properties of the TSB3,5-C6 moleculeswere determined from ab initio calculations, then used in Molecular Dynamics simulations to analyze themechanism of formation, epitaxy, and stability of the TSB3,5-C6 nanoporous superlattice. We show thatthe monolayer disordering results from the competition between flexibility of the C6 chains and theirstabilization by interdigitation. The inclusion of guest molecules (benzene and pyrene) into superlatticenanopores stabilizes the monolayer. The alkoxy chain mobility and available pore space defines thesystems dynamics, essential for potential application.

Porphyrin nanorods were prepared by ion-association between free-base meso 5,10,15,20-tetrakis-(4-N-methylpyridinium)porphyrin cations and tetraphenylborate anions. The nanorods have variable lengths (up to a few micrometers long) and diameters (∼50–500 nm). Their structure at the molecular level was elucidated by combining multinuclear solid state NMR spectroscopy, synchrotron X-ray powder diffraction and DFT calculations.

The current challenge is to produce asphalt mixtures incorporating higher rates (>50%) of Re-claimed Asphalt (RA) while controlling the quality of the final mix. During the service life of a pavement properties change, mainly due to oxidation and need to be restored. The resulting mix must exhibit at least equivalent performances regarding the mechanical and durability properties compared to that from a mix without RA. Hence, recycling agents are sometimes employed to “rejuvenate” aged bitumen. In this study, three recycling agents were used on both RA and neat bitumens, displaying different compositions. The effects on unaged and aged blends were as-sessed through rheology tests using Dynamic Shear (DSR) and Bending Beam (BBR) Rheome-ters. Data from DSR obtained with 4mm and 8mm parallel plates allowed to calculate the Glov-er-Rowe criteria and to determine the crossover parameters whilst BBR measurements yield Tm, Ts and ΔTc parameters. The blends resulting from the two bitumens displayed a similar evolu-tion of behavior. This outcome suggests that these tests cannot discriminate the origin of the re-juvenation phenomenon since they only highlight the softening effect of the recycling agent and not its impact at the molecular level, i.e. on asphaltene and maltene compounds.