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Bacterial contamination is a challenging issue that affect various sectors such as health and industries. Among various approaches, the use of nanomaterials as an antibacterial agent gains a lot of interest. The most widely studied antibacterial nanomaterials are metal or metal oxide based, which are not stable in water and prone to agglomeration, resulting in the reduction of their toxicity. To overcome this problem, the incorporation of graphene-based materials such as graphene oxide (GO) and reduced graphene oxide (rGO) together with metal or metal oxide nanoparticles forming nanocomposites has been proposed. GO and rGO are known to exhibit some toxicity towards microbes, however the formation of nanocomposites has the potential to significantly increase the overall antibacterial activity compared to the use of GO/rGO or metal/metal oxide nanomaterials alone. This article reviews the antibacterial action graphene-based materials and the impact of nanocomposites formation on the overall performance and toxicity mechanism of graphene-based nanocomposites. The antibacterial activity of GO and rGO is elaborated, with specific highlight on the difference between GO and rGO antibacterial properties. Next, the antibacterial action of graphene-based nanocomposites with special focus on silver nanocomposites and zinc oxide nanocomposites is discussed. The antibacterial performance of silver-GO nanocomposites and silver-rGO nanocomposites is compared through data collection of the literature. Similarly, comparison of zinc oxide-GO nanocomposites and zinc oxide-rGO nanocomposites performance is presented. [ABSTRACT FROM AUTHOR]

Synthesis of ZnO nanoparticles by the chemical coprecipitation route using inexpensive home laboratory apparatus was undertaken as undergraduate research during the emergency learning mode due to COVID-19 pandemic. A three-factor, two-level full factorial experiment was run to study the effects of zinc salt type (zinc nitrate and acetate), salt concentration (0.05, 0.10 M), and aging time (24, 48 hrs). Precipitation of the zinc nanoparticle precursor was undertaken by dropwise addition of NaOH solution to pH of 8.0. An improvized home appliance was used to provide air sparging during the aging process. XRD characterization of the nanoparticle product indicated the formation of ZnO with crystallite sizes in the 11.9–20.1 nm range. Whiteness index values measured by a mobile phone application were in the 72–81% range. Particle size distribution measured by DLS indicated median particle diameters in the 44–97 nm range and polydispersity index (PDI) in the 0.29 – 0.36 range, suggesting the presence of agglomerates. ANOVA statistical data treatment identified main and interaction effects influencing these physical properties. Overall, this experiment was able to provide a well-rounded research hands-on laboratory learning experience that included a proper statistical data treatment within the nationwide learning process restrictions necessitated by the pandemic. [ABSTRACT FROM AUTHOR]

Education is very important because its roles in enhancing the human resources and public welfare quality in Indonesia. One of the methods to upgrade education system is a development of Freedom Curricula with project-based learning concept. Freedom Curricula is a new flexible curricula policy option in the part of Freedom to Learn Program which is initiated by Indonesian Ministry of Education, Culture, Research, and Technology since 2021 to mitigate learning loss from COVID-19 pandemic. In Freedom Curricula, schools can develop their own curricula and course materials, depending on their own consideration. The Freedom Curricula can be implemented in several or all subjects in the school. This paper describes the conceptualization of a Freedom Curricula and its implementation plan in several industrial chemistry subjects (Industrial Chemical Processes, Chemical Engineering Operations, and Industrial Chemical Process Equipment) with project-based learning concept for vocational high school level. The designed Freedom Curricula consists of teaching syllabus, teaching module, laboratory practical module, and project-based learning module, and the implementation plan. The advantage of this Freedom Curricula implementation is the application of integrated learning, especially in practical learning activities. [ABSTRACT FROM AUTHOR]