One of the major challenges in the circular economy relating to food packaging is the elimination of metallised film which is currently the industry standard approach to achieve the necessary gas barrier performance. Here, we report the synthesis of high aspect ratio 2D non-toxic layered double hydroxide (LDH) nanosheet dispersions using a non-toxic exfoliation method in aqueous amino acid solution. High O 2 and water vapour barrier coating films can be prepared using food safe liquid dispersions through a bar coating process. The oxygen transmission rate (OTR) of 12 μm PET coated film can be reduced from 133.5 cc·m −2 ·day −1 to below the instrument detection limit (<0.005 cc·m −2 ·day −1 ). The water vapour transmission rate (WVTR) of the PET film can be reduced from 8.99 g·m −2 ·day −1 to 0.04 g·m −2 ·day −1 after coating. Most importantly, these coated films are also transparent and mechanically robust, making them suitable for flexible food packing while also offering new recycling opportunities.

A series of silica@layered double hydroxides (SiO@MgAl-CO-AMO-LDHs) have been synthesised by in situ precipitation of MgAl-CO-LDH at room temperature in the presence of amorphous spherical silica particles (∼500 nm). We have systematically investigated a number of synthetic parameters in order to evaluate their effects on the composition, morphological and physical properties of the isolated materials. Syntheses carried out at moderate stirring speeds (e.g. 500 rpm) were found to promote the formation of vertically aligned LDH platelets with respect to the silica surface. Addition rates of the metal solutions slower than 0.43 mmol h were found to create a thicker LDH shell consisting of vertically aligned LDH platelets. When the metal solutions were added rapidly (0.86 mmol h), we observed that for both slow and fast stirring speeds the synthesised core-shell materials had thin LDH shells and the majority of the LDH precipitated independent of the silica, forming unbound "free" LDH.

Layered double hydroxides (LDH) or their derived mixed oxides present marked acid-base properties useful in catalysis, but they are generally agglomerated, inducing weak accessibility to the active sites. In the search for improving dispersion and accessibility of the active sites and for controlling the hydrophilic/hydrophobic balance in the catalysts, nanocomposite materials appear among the most attractive. In this study, a series of nanocomposites composed of LDH and reduced graphene oxide (rGO), were successfully obtained by direct coprecipitation and investigated as base catalysts for the Claisen–Schmidt condensation reaction between acetophenone and benzaldehyde. After activation, the LDH-rGO nanocomposites exhibited improved catalytic properties compared to bare LDH. Moreover, they reveal great versatility to tune the selectivity through their composition and the nature or the absence of solvent. This is due to the enhanced basicity of the nanocomposites as the LDH content increases which is assigned to the higher dispersion of the nanoplatelets in comparison to bulk LDH. Lewis-type basic sites of higher strength and accessibility are thus created. The nature of the solvent mainly acts through its acidity able to poison the basic sites of the nanocatalysts.

Nanohybrid materials based on l-leucine (l-Leu) and hydrotalcites (HT) were prepared by the ion-exchange and reconstruction method, under mild synthesis conditions. The location, amount and the form of the immobilized l-Leu are affected not only by the time of synthesis, but also by temperature and ultrasound treatment. The XRD results demonstrate that the immobilization occurs in either a vertical or oblique orientation with respect to the HT layers. The catalytic activity of these materials was tested in the aldol addition reaction of cyclohexanone with different aromatic aldehydes, affording mainly the syn-diastereomer. Furthermore, the present study demonstrates that both diastereo- and enantioselectivity can be easily modulated by the appropriate combination of nanohybrid catalyst, solvent and reaction time

A catalytic membrane reactor (CMR) was prepared using a commercial ceramic hollow fibre membrane of corundum and Pd‐loading was done using incipient wetness impregnation. This single Pd‐impregnated catalytic membrane reactor is able to impel different reactions by simply modifying the working parameters. Under very mild conditions, oxidation can be switched to hydrogenation reaction without losing the CMR activity. The catalytic tests were performed in semi‐batch mode at room temperature and 60ºC. The reactor was submerged into a vessel containing model solution of phenol or ibuprofen at concentrations in the range of 30–100 ppm. To one end of the membrane reactor hydrogen is supplied, whilst the other end was kept closed. Reactions were done suppling oxygen, air or no gas in the vessel. Depending on the availability of dissolved oxygen, the reactions followed different pathways leading to the hydrogenated or oxidized products. The oxidation pathway goes through the formation of H2O2 that further oxidize the organic matter, while when no oxygen is supply, the hydrogenation of the organic molecules takes place.

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Surface-initiated cationic polymerisation of ethylvinylether at single-crystals of the σ-alkane complex [Rh(Cy2PCH2CH2PCy2)(NBA)][BArF4] imparts air-tolerance to this highly reactive complex.

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