Self-Healing Coatings for Steel-Reinforced Infrastructure

Infrastructure maintenance costs billions of dollars every year. The corrosion of steel reinforcement is one of the primary causes of the deterioration of concrete infrastructure. The standard protection for steel reinforcement is epoxy coating, but it becomes ineffective when damaged. An improvement to this system incorporates self-healing agents into the epoxy coating, automatically repairing damage and extending the life of the structure. This paper presents the results of experimentation conducted with the self-healing agent tung oil microencapsulated in a polymer shell and added to a two-part epoxy. Accelerated corrosion testing showed that the experimental coatings with microcapsules exhibited significantly longer lifespans than samples with unmodified epoxy coatings

Stock Market Simulation

With the resources available on the internet, a ten week stock market simulation was conducted to examine the effects of four different trading methods: swing trading, pair trading, trading the news, and growth investing. Results from the four trading methods were compared and analyzed. The experience obtained through this project may give investors the confidence to trade wisely in the future

Genome-Wide Analysis of <i>MBF1</i> Family Genes in Five Solanaceous Plants and Functional Analysis of <i>SlER24</i> in Salt Stress

Multiprotein bridging factor 1 (MBF1) is an ancient family of transcription coactivators that play a crucial role in the response of plants to abiotic stress. In this study, we analyzed the genomic data of five Solanaceae plants and identified a total of 21 MBF1 genes. The expansion of MBF1a and MBF1b subfamilies was attributed to whole-genome duplication (WGD), and the expansion of the MBF1c subfamily occurred through transposed duplication (TRD). Collinearity analysis within Solanaceae species revealed collinearity between members of the MBF1a and MBF1b subfamilies, whereas the MBF1c subfamily showed relative independence. The gene expression of SlER24 was induced by sodium chloride (NaCl), polyethylene glycol (PEG), ABA (abscisic acid), and ethrel treatments, with the highest expression observed under NaCl treatment. The overexpression of SlER24 significantly enhanced the salt tolerance of tomato, and the functional deficiency of SlER24 decreased the tolerance of tomato to salt stress. SlER24 enhanced antioxidant enzyme activity to reduce the accumulation of reactive oxygen species (ROS) and alleviated plasma membrane damage under salt stress. SlER24 upregulated the expression levels of salt stress-related genes to enhance salt tolerance in tomato. In conclusion, this study provides basic information for the study of the MBF1 family of Solanaceae under abiotic stress, as well as a reference for the study of other plants

Exogenous melatonin orchestrates multiple defense responses against Botrytis cinerea in tomato leaves

Infection of tomato leaves and fruits by necrotrophic fungal pathogen Botrytis cinerea causes considerable economic loss. Melatonin has multiple physiological functions and is considered a potential biocontrol agent for its positive effects on plant innate immunity. In tomato, melatonin reduces Botrytis-caused post-harvest fruit decay by activating jasmonic acid (JA) signaling. In this study, we analyzed the effects of melatonin on resistance to Botrytis and associated defense mechanisms in tomato leaves. Treatment of detached tomato leaves with melatonin at a concentration as low as 100 µM induced resistance to Botrytis based on reduced lesion size and fungal growth. Melatonin-induced resistance to gray mold was associated with activation of a complex set of defense mechanisms in tomato leaves. First, melatonin suppressed Botrytis-induced cell death and accumulation of reactive oxygen species (ROS), which was correlated with increased activities of ROS-scavenging enzymes and enhanced expression of their corresponding genes. Second, melatonin treatment induced callose synthase genes and promoted rapid and strong callose deposition in tomato leaves. Melatonin also induced other anti-microbial genes encoding chitinases, β-1,3-glucanases, phenylalanine ammonialyases and polyphenol oxidases. Third, melatonin increased Botrytis-induced expression of genes encoding SlWRKY33, SlMYC2 and SlERF transcription factors, which activate defense-related genes expression through JA and ethylene (ET) signaling pathways. By contrast, melatonin suppressed salicylic acid (SA) signaling based on reduced expression of the SlPR1 marker gene, which is known to antagonize defense against Botrytis. These results collectively indicate that exogenous melatonin orchestrates multiple signaling pathways to activate a complex set of defense mechanisms against Botrytis in tomato leaves

Self-Healing Coatings for Steel-Reinforced Concrete

Self-healing rebar coatings were prepared and investigated for steel-reinforced concrete, with the goal of creating coatings that can withstand construction site damage. Such damage to conventional coatings results in epoxy chipping or cracking and negates the coatings’ ability to resist corrosion. The coatings consisted of a conventional epoxy coating containing 10 wt % microencapsulated tung oil as the healing agent. Upon coating damage, the microcapsules ruptured, releasing tung oil that cured across the damaged area. In accelerated corrosion testing, the times to failure of steel-reinforced concrete with self-healing coatings were at least three times longer than steel-reinforced concrete with conventional coatings. After 150 days of accelerated corrosion testing, 83% of the samples with self-healing coatings exhibited no corrosion. No difference between undamaged and intentionally damaged specimens was observed, potentially because the damaged area was not large enough. These results suggest that natural product-based, self-healing coatings are able to passivate rebar surfaces in response to corrosion initiation, significantly increasing their corrosion protection ability. Pullout testing revealed that self-healing coatings exhibited comparable bond stresses compared to conventional coatings. In summary, this is a promising technology for extending service lives of steel-reinforced concrete structures with no reduction in interfacial bonding, which could have significant implications for infrastructure resilience and CO₂ emissions

Fluorine-free water-in-ionomer electrolytes for sustainable lithium-ion batteries.

The continuously increasing number and size of lithium-based batteries developed for large-scale applications raise serious environmental concerns. Herein, we address the issues related to electrolyte toxicity and safety by proposing a "water-in-ionomer" type of electrolyte which replaces organic solvents by water and expensive and toxic fluorinated lithium salts by a non-fluorinated, inexpensive and non-toxic superabsorbing ionomer, lithium polyacrylate. Interestingly, the electrochemical stability window of this electrolyte is extended greatly, even for high water contents. Particularly, the gel with 50 wt% ionomer exhibits an electrochemical stability window of 2.6 V vs. platinum and a conductivity of 6.5 mS cm-1 at 20 °C. Structural investigations suggest that the electrolytes locally self-organize and most likely switch local structures with the change of water content, leading to a 50% gel with good conductivity and elastic properties. A LiTi2(PO4)3/LiMn2O4 lithium-ion cell incorporating this electrolyte provided an average discharge voltage &gt; 1.5 V and a specific energy of 77 Wh kg-1, while for an alternative cell chemistry, i.e., TiO2/LiMn2O4, a further enhanced average output voltage of 2.1 V and an initial specific energy of 124.2 Wh kg-1 are achieved