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Nanofiller based on graphene and MgAl layered double hydroxides (G/LDHs) were synthesized successfully by co-precipitation method with varying graphene contents. The in situ polymerization of ethylene was conducted using 1-hexene as comonomer, zirconocene as a catalyst, MAO as co-catalyst, and G/LDHs as drop-in nanofiller. An increase in catalytic activity was recorded due to the addition of nanofiller. Furthermore, a maximum catalytic activity was observed for the nanofiller containing 100 mg of graphene. However, nanofiller containing higher amount graphene reduced the activity due to agglomeration of the graphene nanoparticles. Moreover, the degree of crystallinity decreased due to the addition of short chain branching in the copolymers. The thermal stability of the copolymers was analyzed using TGA. The effective activation energy (EA) was calculated using the Friedman method. The EA profiles thus obtained have revealed that the polymer nanocomposites having 100 mg of graphene have highest thermal stability than the neat copolymers. [ABSTRACT FROM AUTHOR]

Hybrids of graphene (G) and layered double hydroxides (LDHs) are promising nanomaterials due to their versatile properties and the large number of composition/preparation variables available for fine-tuning. Several techniques are available for the synthesis of these novel G/LDHs nanocomposites. This article reviews the recent developments in their synthesis and applications in the oxygen evolution reaction, supercapacitors, hybrid sensors, adsorption, catalysis, water purification, and flame retardant materials. [ABSTRACT FROM AUTHOR]

In this work, the potential of layered double hydroxide/graphene (LDH-G) hybrid as a sorbent for extraction and preconcentration of fifteen organochlorine pesticides (OCPs) in urine samples was evaluated. The LDH-G hybrid was synthesized by co-precipitation method and it was then characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The sorbent was then employed in membrane-protected stir-bar supported micro-solid-phase extraction (SB-μ-SPE) of OCPs in urine samples. This extraction approach is highly suitable for the samples representing matrix complexity such as urine because the sorbent is effectively protected inside the membrane. The extracted samples were analyzed by gas chromatography mass spectrometry. The factors that affect the performance of SB-μ-SPE were suitably optimized. This method demonstrated good linearity with coefficients of determination up to 0.9996. The limits of detection ranged between 0.22 and 1.38 ng mL −1 . The RSD values for intra and inter-day precision were also in a satisfactory range (2.7–9.5%). [ABSTRACT FROM AUTHOR]