Search

Abstract A superior efficiency of MXene (Ti 3 C 2) nanosheet as a hybridization matrix over graphene is evidenced by comparative investigation on uniformly-stacked MnO 2 –Ti 3 C 2 and MnO 2 –reduced graphene oxide (rGO) nanohybrids. Density functional theory calculation and spectroscopic analyses demonstrate a stronger interfacial electronic coupling and greater charge transfer of polar MnO 2 with hydrophilic Ti 3 C 2 nanosheet than with hydrophobic rGO one, which maximizes the hybridization effect with the conductive nanosheet. Also, hybridization with Ti 3 C 2 nanosheet is more effective in enhancing the ion diffusivity and porosity of MnO 2 than that with strongly self-stacking rGO, which is attributable to weaker self-stacking tendency of Ti 3 C 2. Due to these hybridization effects, the MnO 2 –Ti 3 C 2 nanohybrid delivers larger specific capacitance with improved rate performance than does the MnO 2 –rGO nanohybrid, underscoring higher efficiency of MXene hybridization in improving electrode performance. This study clearly demonstrates that exfoliated MXene nanosheet can act as a superior hybridization matrix over rGO to explore strongly-coupled nanohybrids with improved energy-related functionality. Graphical abstract fx1 Highlights • MXene nanosheet shows superior efficiency as a hybridization matrix over graphene. • Efficient electrode materials are synthesized by hybridization with MXene nanosheet. • There is a stronger interfacial electronic coupling of MnO 2 with MXene than with rGO. • Hybridization with less self-stacking MXene nanosheet remarkably increases porosity. [ABSTRACT FROM AUTHOR]

Abstract: A most powerful antioxidant, glutathione (GSH), plays an important role in detoxification, immune response, and protection against reactive oxygen species. However, orally ingested GSH can be easily degradable to free amino acids by chemical and enzymatic hydrolysis, resulting in low bioavailability. The aim of this study was, therefore, to enhance GSH bioavailability by developing GSH–montmorillonite (MMT) hybrid system. It was also coated with polyvinylacetal diethylaminoacetate (AEA) for better stability. Both GSH–MMT and AEA–GSH–MMT hybrids were characterized by powder X-ray diffraction (PXRD), Fourier transformed infrared (FT-IR), and thermogravimetric analysis (TGA), indicating that GSH was successfully intercalated into the interlayer spaces of MMT. In vivo antioxidant activity assay revealed that AEA–GSH–MMT hybrid significantly increased antioxidant activity in the plasma after oral administration in mice. Pharmacokinetic study also indicated that AEA–GSH–MMT hybrid considerably increased the plasma concentration of GSH at 1h post-oral administration. Moreover, both the hybrid systems remarkably enhanced GSH delivery to the main target tissue, liver. All the results suggest that GSH–MMT hybrid systems have great potential to enhance bioavailability of oral GSH, providing new insight into their pharmaceutical application. [Copyright &y& Elsevier]

Abstract: Edible dyes such as Allura® Red AC (C18H14N2O8S2 2−), Sunset Yellow FCF (C16H10N2O7S2 2−), and Brilliant Blue FCF (C37H34N2O9S3 2−) were successfully intercalated into the gallery spaces of ZnAl layered double hydroxides (LDHs). Those organic–inorganic nanohybrids were synthesized by co-precipitating the aqueous solution of zinc nitrate and aluminum nitrate simultaneously in the presence of anionic dyes. From the X-ray diffraction and infrared spectroscopic analyses, we found that the dye molecules could be intercalated into hydroxide layers without any changes in their chemical and structural properties. The basal spacings were determined to be 24.0, 20.3, and 24.7Å for Allura® Red AC, Sunset Yellow FCF, and Brilliant Blue FCF intercalated LDHs, respectively. According to the solid UV–vis spectroscopic analyses, the absorbance intensity of dye-intercalated LDHs was clearly enhanced with the band narrowing compared to those of the corresponding dye salts due to the charge transfer between the host lattice and spatially confined dye molecules. [Copyright &y& Elsevier]

Folic acid derivatives such as folinic acid and methotrexate (MTX) have been successfully hybridized with layered double hydroxide (LDH) by ion-exchange reaction. The X-ray diffraction patterns and spectroscopic analyses indicate that these molecules intercalated into the hydroxide interlayer space are stabilized in the tilted longitudinal monolayer mode by electrostatic interaction. No significant changes in their structural and functional properties are found in the hybrids. The cellular uptake test of MTX–LDH hybrid is carried out in the fibroblast (human tendon) and SaOS-2 cell line (Osteosarcoma, human) by in vitro MTT (3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyl tetrazolium bromide) assay. The initial proliferation of SaOS-2 cell is more strongly suppressed by treatment with MTX–LDH hybrid than with MTX alone. This study clearly shows that LDH not only plays a role as a biocompatible-delivery matrix for drugs but also facilitates a significant increase in the delivery efficiency. [Copyright &y& Elsevier]

The anionic β-cyclodextrins, sulfopropylated-β-cyclodextrin and carboxyethylated-β-cyclodextrin, have been intercalated into a Zn/Al layered double hydroxide by an ion-exchanging reaction. X-ray diffraction patterns show single-phase hybrids with high crystallinity. Detailed orientations of intercalated anionic β-cyclodextrins are evaluated by considering the parameters such as the degree of charge compensation between host and guest, the area demand of β-cyclodextrin molecules, and the interlayer space of the intercalate. Based on the results, we elucidate a model for the arrangement of anionic β-cyclodextrin molecule in the layered double hydroxide. [Copyright &y& Elsevier]

We have successfully synthesized inorganic–inorganic, organic–inorganic and bio-inorganic nanohybrids by applying a chimie douce intercalation technique systematically to layered titanate, to Bi-based cuprate superconductors, Bi2Sr2Cam−1CumOy (m=1, 2, and 3; BSCCO), and to layered double hydroxides (LDHs), those which are of high importance in terms of basic understanding of intercalation reactions and also having practical application. The inorganic/inorganic hybrids were synthesized by exfoliation-restacking methods to obtain TiO2-pillared titanate. A novel pillaring procedure using an osmotic swelling had been developed to prepare TiO2-pillared layered titanate with a large surface area, high thermal stability, and enhanced photocatalytic activity. On the other hands, the organic/inorganic hybrids were achieved via intercalative complexation of iodine intercalated BSCOO with an organic salt of Py–CnH2n+1I (Py=pyridine). The high-Tc superconducting intercalate with its remarkable lattice expansion can be applied as a precursor for superconducting colloids when dispersed in an appropriate solvent. We were also able to demonstrate that the biomolecules stabilized in the interlayer space of layered double hydroxides (LDH), bio-inorganic hybrids, retain their chemical and biological integrity. If necessary, LDH, as a reservoir, can be intentionally removed by dissolving it in an acidic medium or interlayer biomolecules in LDH can be released via ion-exchange reaction in electrolyte. It can, therefore, be concluded that the inorganic LDH can play a role as a good host lattice for gene reservoir or carrier. These intercalative methods will provide remarkable synthetic routes to design new heterogeneous hybrid materials, which have the intrinsic properties starting materials and create synergetic effects by hybridization. [Copyright &y& Elsevier]