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The efficacy of eggshells (ES) powders as an anticorrosive pigment with TiO2 nanoparticles in waterborne polyurethane coatings has been investigated. The experiment was conducted on mild steel in a corrosive solution of artificial seawater. Several characterizations to analyze the effects of ES addition were performed, including the classical weight loss method, water contact angle, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) and scanning electron microscopy with energy dispersive X-ray (SEM/EDX). The addition of ES powders was determined to increase the coating's protection efficiency until 20 wt% (P4). Furthermore, based on the morphological study, it was discovered that the best concentration managed to maintain the surface integrity of the coatings with no defects were detected even after 20 days of exposure.

The global increase in electrical device consumption has escalated the demand for excellent surge protectors. As a state-of-the-art technology, varistor has received considerable attention due to its outstanding versatility and wide range of applications. Hence, it is crucial to understand the development trend of varistor to expand the collaboration networks and propel its advancement. In this bibliometric article, several procedures were presented and analyzed to determine the global research trend of varistor based on the publication output each year, leading countries, most prolific authors, and co-occurrences of author keywords. After several stages of collecting and refining the textual information from the Scopus database, a total number of 2122 research articles and conference papers were retrieved between 1951 and 2021. Results show that since 1975, the annual number of publications has increased significantly, with 2020 recording the highest value of 1363 articles. China, the United States, South Korea, and Japan contributed around 60% of the total articles published. Moreover, three of the most prolific institutions associated with the research topic were ranked among the top 200 universities globally. The analysis of varistor research progress will provide a common overview of collaborative networks and potential collaborators for a better broadening of knowledge.

The conventional coatings are generally unsustainable in harsh environments and offer limited protection to the intended infrastructures. Recently, the emergence of plant-based components to enhance coatings has attracted significant attention due to their characteristics of anticorrosion, antifouling, antimicrobial, self-healing, and ultraviolet (UV) shielding. Almost all plant parts can be utilized as a potential material of interest, including leaves, flowers, oils, seeds, and fruits. The reason is that the extract from these parts possesses many phytochemicals that contribute to the properties stated above. In the coating industry, plant extract is introduced as a green additive and is said to share similar functions as synthetic additives, which is to enhance the protection ability of the coating. Moreover, they are non-toxic, safe to use, abundant, and environmentally- friendly.

The increasing awareness of people on green materials and chemistry has stimulated researchers around the globe to turn towards natural resources. As a growing topic with limitless potential, plants as corrosion inhibitors (PCI) have received substantial attention due to their eco-friendly, biodegradable, inexpensive, and abundantly available. Therefore, with the understanding of the importance of this topic, this study is conducted in the format of a descriptive systematic literature review (SLR) to assess the global research trends on PCI according to the number of published articles, co-authorships in correspond to countries/academic institutions and co-occurrences of author keywords. In the span of 25 years, from 1995 to 2020, 2237 articles from journal and conference proceedings were collected. Results have displayed that since 2003, the number of articles produced per year has increased significantly, wherein in 2020 alone, more than 250 articles have been published. The steady increment of publication has now resulted in a large accumulation of articles up until 2020. About 45% of the overall publications originate from India, Nigeria and China compared to other countries. In conclusion, the progress of PCI research presented in this study should provide a general overview of the correlation between researchers worldwide for better international collaboration and broadening knowledge.

With the trend for green technology, the study focused on utilizing a forgotten herb to produce an eco-friendly coating. Andrographis paniculata or the kalmegh leaves extract (KLE) has been investigated for its abilities in retarding the corrosion process due to its excellent anti-oxidative and antimicrobial properties. Here, KLE was employed as a novel additive in coatings and formulations were made by varying its wt%: 0, 3, 6, 9, and 12. These were applied to stainless steel 316L immersed in seawater for up to 50 days. The samples were characterized and analyzed to measure effectiveness of inhibition of corrosion and microbial growth. The best concentration was revealed to be 6 wt% KLE; it exhibited the highest performance in improving the ionic resistance of the coating and reducing the growth of bacteria.