A review on antimicrobial mechanism and applications of graphene-based materials.

In recent years, graphene and its derivatives, owing to their phenomenal surface, and mechanical, electrical, and chemical properties, have emerged as advantageous materials, especially in terms of their potential for antimicrobial applications. Particularly important among graphene's derivatives is graphene oxide (GO) due to the ease with which its surface can be modified, as well as the oxidative and membrane stress that it exerts on microbes. This review encapsulates all aspects regarding the functionalization of graphene-based materials (GBMs) into composites that are highly potent against bacterial, viral, and fungal activities. Governing factors, such as lateral size (LS), number of graphene layers, solvent and GBMs' concentration, microbial shape and size, aggregation ability of GBMs, and especially the mechanisms of interaction between composites and microbes are discussed in detail. The current and potential applications of these antimicrobial materials, especially in dentistry, osseointegration, and food packaging, have been described. This knowledge can further drive research that aims to look for the most suitable components for antimicrobial composites. The need for antimicrobial materials has seldom been more felt than during the COVID-19 pandemic, which has also been highlighted here. Possible future research areas include the exploration of GBMs' ability against algae.

Mitigating exhaust emissions in CI engines using butanol-diesel-water microemulsions.

The current research work examines the usability of surfactant-free microemulsion fuels as a substitute in CI engines, with alcohol being used as an amphi-solvent. Studies were carried out on different compositions of microemulsions with 35% volume and 40% volume butanol, named ME35 and ME40, having 57.8-64.4% volume diesel and 0.6-2.2% volume water. Most of the microemulsions had properties such as viscosity, specific gravity, cloud point, and sulfur content comparable to those of diesel. The heating values and cetane indices of the microemulsions were 0.09-8.7% and 19.4-28.7% lower than diesel due to the addition of water and alcohol. The water and sediments percentages were found to be low, even after the addition of water, indicating the microemulsions were stable. ME40 showed an average of 0.6-3.5% improvement in BTE, but the BSFC was also increased by 5.3-8.9%. The emissions of HC, NOx, and PM showed an average decrease of 19.0-48.9%, 14.8-41.9%, and 10.06-50.24%, respectively, for all the microemulsions at all the loads. The CO emissions were lower at higher loads and vice versa, but the average CO emissions showed 5.16-31.9% decrease due to significant reductions at higher loads. It could, therefore, be concluded that microemulsions are a promising sustainable and cleaner substitute for diesel. Synopsis Microemulsion fuels successfully replaced up to 42% of diesel, with significant reduction in emissions of CO, HC, NOx, and PM.