ABSTRACT
Eucalyptus essential oil has remarkable industrial importance and biological properties due to its effectiveness against various diseases, reported throughout human history. Despite the extraordinary bioactivities of essential oil, its applications are limited due to volatility, insolubility in water, and less stability. Formulation of nanoemulsion is the best way to enhance the bio-efficacy of this essential oil and eliminate the factors responsible for limited application. This review article compiles the information regarding formulation of Eucalyptus essential oil-based nanoemulsion and their several biological activities and medicinal properties including antibacterial, antifungal, larvicidal, insecticidal, and cytotoxic activities etc. The bio-efficacy of essential oil-based nanoemulsion has also been found to be enhanced as compared utilization of essential oil alone. This review can be beneficial for researchers working on medicinal plant-based natural products, specifically containing Eucalyptus essential oil, to explore new research horizons in this emerging field.
ABSTRACT
Liquid Phase Exfoliation (LPE) is a very effective technique for the synthesis of few layered two dimensional (2D) nanosheets. There is a surge to find environment friendly solvents for efficient exfoliation of layered materials to produce 2D nanosheets. TiB2 is an important layered material with very little reported work on its 2D nanosheets. The present work is about successful LPE of TiB2 using deionized (DI) water as a clean, green and low cost dispersion medium to make TiB2 nanosheets. The impact of ultrasonication conditions i.e. input power and treatment duration for efficient synthesis of few layered 2D nanosheets in DI water is studied by Atomic Force Microscopy (AFM), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). It is found that by increasing input power, the layer thickness is reduced from bulk to 34 nm with lateral dimensions as huge as up to 5 µm. The increased treatment duration has further reduced the layer thickness to 21 nm associated with a decrease in lateral dimensions to about 1 µm. The mechanism of variation in the aspect ratio of the 2D nanosheets with ultrasonication power and treatment duration is explained. The optimum conditions for the fabrication of high aspect ratio 2D nanosheets of TiB2 owe to a greater acoustic cavitation intensity, an optimum treatment duration and a homogenous distribution of the cavitation events while using an appropriate size of the sonotrode in the sonicated volume during ultrasonication.
ABSTRACT
Various fillers such as zeolites, metal-organic framework, carbon, metal framework, graphene, and covalent organic framework have been incorporated into the polymers. However, these materials are facing issues such as incompatibility with the polymer matrix, which leads to the formation of non-selective voids and thus, reduces the gas separation properties. Recent studies show that hexagonal boron nitride (h-BN) possesses attractive characteristics such as high aspect ratio, good compatibility with polymer materials, enhanced gas barrier performance, and improved mechanical properties, which could make h-BN the potential candidate to replace conventional fillers. The synthesis of materials and membranes is the subject of this review, which focuses on recent developments and ongoing problems. Additionally, a summary of the mathematical models that were utilised to forecast how well polymer composites would perform in gas separation is provided. It was found in the previous studies that tortuosity is the governing factor for the determination of the effectiveness of a nanofiller as a gas barrier enhancer in polymer matrices. The shape of the nanofiller particles and sheets, disorientation and distribution of the nanofillers within the polymer matrix, state of aggregation and rate of reaggregation of the nanofiller particles, as well as the compatibility of the nanofiller with the polymer matrix all played a significant role in determining how well a particular nanofiller will perform in enhancing the gas barrier properties of the nanocomposites. For this purpose, this review has been focused not only on the experimentation work but also on the effect of tortuosity, exfoliation quality, compatibility, disorientation, and reaggregation of nanofillers.
