The purpose of this study was to control the fabrication of new labile supramolecular assemblies by formulating associations of DNA molecules with inorganic layered double hydroxides (LDHs). The ...results show that LDH/DNA hybrids synthesized by a coprecipitation route involving the in situ formation of LDHs around DNA molecules acting as templates were characterized by a lamellar organization, with DNA molecules sandwiched between hydroxide layers, exhibiting a regular spacing of 1.96 nm. Our results indicate that labile complexes resulting from the association of nucleic acids and inorganic materials can be obtained not only by anion exchange but also by a direct self-assembly route.
The article describes the synthesis and properties of new ionogels for ion transport. A new preparation process using an organic linker, bis(3-(trimethoxysilyl)propyl)amine (BTMSPA), yields stable ...organosilica matrix materials. The second ionogel component, the ionic liquid 1-methyl-3-(4-sulfobutyl)imidazolium 4-methylbenzenesulfonate, BmimSO
HPTS, can easily be prepared with near-quantitative yields. BmimSO
HPTS is the proton conducting species in the ionogel. By combining the stable organosilica matrix with the sulfonated ionic liquid, mechanically stable, and highly conductive ionogels with application potential in sensors or fuel cells can be prepared.
This work investigated in situ changes in the structure of the layered double hydroxides (LDH) during electrochemical processes as well as followed the ion motion related to the charge balancing ...process. Electrogravimetric measurements, using an electrochemical quartz crystal microbalance (EQCM), allowed one to monitor simultaneously changes in current and in microbalance frequency when electroactive films of Co2Al–NO3 LDH were subjected to voltammetry potential cycling in alkaline solutions (0.1 M COH, C = Li+, Na+, and K+). EQCM results showed a strong dependence of the electrochemical process on the nature of electrolyte cations. Operando X-ray diffraction measurements, carried out during potential cycling of Co2Al–NO3 films in KOH electrolyte, showed the diffusion of OH– species gradually replacing NO3 –. Total X-ray scattering experiments recorded ex situ on Co2Al–NO3 after successive oxidation and reduction revealed the presence of a high level of structural disorders even in the pristine material. A quantitative analysis of the local distribution of the cations by the analysis of the pair distribution functions highlighted the presence of different Co sites with distinct modification of Co–OH distances in the first coordination shells after oxidation/reduction.
Olive mill wastewater (OMW) is the aqueous waste derived from the production of virgin olive oil. OMW typically contains a wide range of phenol-type molecules, which are natural antioxidants and/or ...antibacterials. In order to exploit the bioactive molecules and simultaneously decrease the environmental impact of such a food waste stream, OMW has been intercalated into the host structure of ZnAl layered double hydroxide (LDH) and employed as an integrative filler for the preparation of poly(butylene succinate) (PBS) composites by in situ polymerization. From the view point of the polymer continuous phase as well as from the side of the hybrid filler, an investigation was performed in terms of molecular and morphological characteristics by gel permeation chromatography (GPC) and X-ray diffraction (XRD); also, the thermal and mechanical properties were evaluated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic thermomechanical analysis (DMTA). Antibacterial properties have been assessed against a Gram-positive and a Gram-negative bacterium,
and
, respectively, as representatives of potential agents of foodborne illnesses.
A new material testing reactor Jules Horowitz Reactor is under construction at CEA Cadarache. The materials to be irradiated will be placed into experimental devices around the reactor. Process and ...measurements of experimental devices will be carried out by command control. A data acquisition system having processing performances will be associated to the programmable logic controller. The challenge is to design and realize for twenty experiment devices a high availability data acquisition system architecture for 50 years of sustainability. The real time target will achieve 24/7 data acquisition and real time processing. This scalable architecture could be use as well for JHR experimental devices with high availability as for testbed. This architecture could be run on a standalone station for a measuring bench or deployed on cluster for high availability. CAREDAS’s design is modular and use proven widely used open source solutions. All parts are independent from each other and can be replaced with another technology with the same functionalities. This ensures sustainability and control of software sources.
A new luminescent composite film resulting from the dispersion of luminescent organic dyes in a single-layered hydroxide (SLH)-type inorganic matrix has been developed. Two fluorescent organic dyes ...emitting visible light upon blue LED excitation were investigated in this study: dicyanomethylene (DCM) and pyranine (HPTS). These dyes exhibit broad emission bands that cover a large part of the visible spectrum. The concept developed in our work consisted in keeping SLH in its wet form to ensure a good dispersion of the fluorescent dyes prior to immobilizing the hybrid materials in a silicone polymer to achieve luminescent composite films. We demonstrate that these coatings stacked upon each other and placed above a blue LED lead to white-light emission with suitable photometric parameters for applications in lighting or display devices: colour temperature of 5409 K and colour rendering index (CRI) of 81.
For many decorative applications like industrial and architectural paints, prevention of metal substrates from corrosion is a primary function of organic coatings. Triggered release of inhibitor ...species is generally accepted as a remedy for starting corrosion in case of coatings damage. A polyurethane based coating, doped with bola-amphiphiles of varying molecular weight but with a common head group motif that stems from ring-opened alkenyl succinic anhydride, enables passivation of the defect and mitigates cathodic delamination, if applied on cold rolled steel. An antagonistic effect results from the intercalation of the bola-amphiphiles into layered double hydroxide Zn
Al(OH)
and subsequent incorporation of the hybrid phase into the organic matrix. In particular higher molecular weight bola-amphiphiles get immobilized through alkaline degradation of the layered framework in the basic milieu at the cathode. By means of sediments from colloidal states it is demonstrated that in-situ formed zinc oxide encapsulates the hybrid phase, evidenced by impeded dissolution of the ZnO based shell into caustic soda. While inhibition of steel corrosion results from a Donnan barrier layer, impeded zinc oxide dissolution is rooted in zinc catalyzed bola-amphiphile hydrolysis and layered deposition of the crystalline spacer diol hydrogenated bisphenol-A.
The XAS/WAXS time-resolved method was applied for unraveling the complex mechanisms arising from the evolution of several metastable intermediates during the degradation of chlorine layered double ...hydroxide (LDH) upon heating to 450 °C, i.e., Zn2Al(OH)6·nH2O, ZnCuAl(OH)6·nH2O, Zn2Al0.75Fe0.25(OH)6·nH2O, and ZnCuAl0.5Fe0.5(OH)6·nH2O. After a contraction of the interlamellar distance, attributed to the loss of intracrystalline water molecules, this distance experiences an expansion (T > 175–225 °C) before the breakdown of the lamellar framework around 275–295 °C. Amorphous prenucleus clusters with crystallo-chemical local order of zinc-based oxide and zinc-based spinel phases, and if any of copper-based oxide, are formed at T > 175–225 °C well before the loss of stacking of LDH layers. This distance expansion has been ascribed to the migration of ZnII from octahedral layers to tetrahedral sites in the interlayer space, nucleating the nano-ZnO or nano-ZnM2O4 (M = Al or Fe) amorphous prenuclei. The transformation of these nano-ZnO clusters toward ZnO crystallites proceeds through an agglomeration process occurring before the complete loss of layer stacking for Zn2Al(OH)6·nH2O and Zn2Al0.75Fe0.25(OH)6·nH2O. For ZnCuAl(OH)6·nH2O and ZnCuAl0.5Fe0.5(OH)6·nH2O, a cooperative effect between the formation of nano-CuO and nano-ZnAl2O4 amorphous clusters facilitates the topochemical transformation of LDH to spinel due to the contribution of octahedral CuII vacancy to ZnII diffusion.
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