UTILIZATION OF GRAPHENE OXIDE IN BUILDING MATERIALS

Cement-based materials (CBM) is one of the most commonly used building materials. Due to their brittle nature (sudden failure, low tensile strength, low resistant to crack), CBMs were modified through the addition of various traditional fillers/ reinforcement such as fibres and supplementary cementutious materials. Advanced modifiers/fillers such as Graphene-based nanomaterials (GBM) were utilized due to their superior properties in upgrading properties of CBM. GBM have been firstly used to enhance various polymeric matrices for storage energy, sensors and bio-applications. Following that, GBM were utilized in CBM with remarkable improvements in properties. In the current paper, an overview on the synthesis and structure of one type of GBM; namely graphene oxide (GO) was presented. The impact of GO on properties of CBM was addressed. One of the most observations from the highlighted published work was that the enhancements in CBM properties were linked to the uniform dispersion of functionalized GO and template effect of GO in CBM. Although GO with its attractive properties in upgrading properties of CBM, the usage of GO in construction industry is still not at the same demand level as in other applications and further investigations are needed in this regard.

Template Effect of Multi-Phase Liquid Crystals

The template effects on stability of twist structure liquid crystals (LCs) were investigated. By refilling a cholesteric LC (CLC) of different pitch into a blue phase LC (BPLC) template or a sphere phase LC (SPLC) template, a multi-phase and multi-pitch twist structure LC, which includes the refilling CLC and intrinsic template BPLC or SPLC, can be fabricated. By refilling a CLC of different chiral pitch into a CLC template, a multi-pitch CLC that includes the refilling CLC and intrinsic CLC, can be fabricated. Twist structure LC devices with multi-phase and multi-pitch show great potential for applications in optical communication, displays, and LC lasing.

When the Metal Makes the Difference: Template Syntheses of Tridentate and Tetradentate Salen-Type Schiff Base Ligands and Related Complexes

The reaction of organic molecules mediated by a metal center (template synthesis) can result in a final connectivity that may differ from the one obtained in the absence of the metal. The condensation of carbonyl fragments with primary amines form C=N iminic bonds, the so-called Schiff bases, which can act as ligands for the templating metal center by means of the lone pair on the nitrogen atom. This review focuses on the template methods for the reaction between a carbonyl compound (mainly salicylaldehyde) and a primary aliphatic diamine able to prevent the double condensation on both amine groups and obtain tridentate N2O ligands. These adducts, still having one free amino group, can further react, yielding tetradentate salen-type Schiff base ligands. A screening over the transition metals able to show such a template effect will be presented, with particular attention to copper(II), together with their peculiar reactivity and the available crystal structure of the metal complexes and related coordination geometries.