Project description:An innovative and cost-effective method for enhancing CO2 capture by modifying the textural properties of derived activated biocarbons was explored. A molasses solution was prepared with a sucrose concentration of 1 mol/dm3. A two-step synthesis process was involved, which includes the hydrothermal synthesis of spherical carbonaceous materials from molasses followed by chemical activation. The carbonaceous material to activation agent ratio was studied from 1 to 4. The CO2 adsorption of all activated biocarbons was tested at 0, 10, and 20°C and a pressure of up to 1 bar. The results showed a significant correlation between CO2 adsorption and the textural properties of the activated biocarbons. The activated biocarbon with the highest CO2 adsorption of 7.1 mmol/g at 1 bar and 0°C was successfully produced by modifying with KOH. The selectivity of CO2 over N2 calculated on the basis of the Ideal Adsorbed Solution Theory was excellent (16.5). The Sips model was found to be the most suitable, and the isosteric heats of adsorption were also specified.
Project description:Extensive use of pesticides resulting in their accumulation in the environment presents a hazard for their non-target species, including humans. Hence, efficient remediation strategies are needed, and, in this sense, adsorption is seen as the most straightforward approach. We have studied activated carbon fibers (ACFs) derived from viscose fibers impregnated with diammonium hydrogen phosphate (DAHP). By changing the amount of DAHP in the impregnation step, the chemical composition and textural properties of ACFs are effectively tuned, affecting their performance for dimethoate removal from water. The prepared ACFs effectively reduced the toxicity of treated water samples, both deionized water solutions and spiked tap water samples, under batch conditions and in dynamic filtration experiments. Using the results of physicochemical characterization and dimethoate adsorption measurements, multiple linear regression models were made to reliably predict performance towards dimethoate removal from water. These models can be used to quickly screen among larger sets of possible adsorbents and guide the development of novel, highly efficient adsorbents for dimethoate removal from water.
Project description:Gastrointestinal cancers are characterized by a frequent incidence, a high number of associated deaths, and a tremendous burden on the medical system and patients worldwide. As conventional chemotherapeutic drugs face numerous limitations, researchers started to investigate better alternatives for extending drug efficacy and limiting adverse effects. A remarkably increasing interest has been addressed to chitosan and cyclodextrins, two highly versatile natural carbohydrate materials endowed with unique physicochemical properties. In this respect, numerous studies reported on fabricating various chitosan and cyclodextrin-based formulations that enabled prolonged circulation times, improved cellular internalization of carried drugs, preferential uptake by the targeted cells, reduced side effects, enhanced apoptosis rates, and increased tumor suppression rates. Therefore, this paper aims to briefly present the advantageous properties of these oligo- and polysaccharides for designing drug delivery systems, further focusing the discussion on nanocarrier systems based on chitosan/cyclodextrins for treating different gastrointestinal cancers. Specifically, there are reviewed studies describing promising solutions for colorectal, liver, gastric, pancreatic, and other types of cancers of the digestive system towards creating an updated framework of what concerns anticancer chitosan/cyclodextrin-based drug delivery systems.
Project description:Transcriptomes fiber and ovules were compared by applying serial analysis of gene expression (SAGE). Keywords: Tissue Comparison We constructed three SAGE libraries and sequenced 57321, 64188, and 69104 tags from fiber, Xu-142 ovule (ovule) and fl mutant ovules (fl) respectively of Upland Cotton, Gossypium hirsutum L. cv. Xu-142.
Project description:Rational design of materials for energy storage systems relies on our ability to probe these materials at various length scales. Solid-state NMR spectroscopy is a powerful approach for gaining chemical and structural insights at the atomic/molecular level, but its low detection sensitivity often limits applicability. This limitation can be overcome by transferring the high polarization of electron spins to the sample of interest in a process called dynamic nuclear polarization (DNP). Here, we employ for the first time metal ion-based DNP to probe pristine and cycled composite battery electrodes. A new and efficient DNP agent, Fe(III), is introduced, yielding lithium signal enhancement up to 180 when substituted in the anode material Li4Ti5O12. In addition for being DNP active, Fe(III) improves the anode performance. Reduction of Fe(III) to Fe(II) upon cycling can be monitored in the loss of DNP activity. We show that the dopant can be reactivated (return to Fe(III)) for DNP by increasing the cycling potential window. Furthermore, we demonstrate that the deleterious effect of carbon additives on the DNP process can be eliminated by using carbon free electrodes, doped with Fe(III) and Mn(II), which provide good electrochemical performance as well as sensitivity in DNP-NMR. We expect that the approach presented here will expand the applicability of DNP for studying materials for frontier challenges in materials chemistry associated with energy and sustainability.
Project description:Rotating ring disk electrodes (RRDEs) are a powerful and versatile tool for mechanistically investigating electrochemical reactions at electrode surfaces, particularly in the area of electroanalysis and catalysis. Despite their importance, only limited electrode materials (typically glassy carbon, platinum, and gold) and combinations thereof are available commercially. In this work, we present a method employing three-dimensional (3D) printing in conjunction with machined brass components to produce housing, which can accommodate any electrode material in, e.g., pressed powdered pellet, wafer, rod, foil, or vapor deposited onto a conductive substrate form. In this way, the range and usability of RRDEs is extended. This custom do-it-yourself (DIY) approach to fabricating RRDEs also enables RRDEs to be produced at a significant fraction of the cost of commercial RRDEs. To illustrate the versatility of our approach, coplanar boron-doped diamond (BDD) RRDEs are fabricated for the first time using the approach described. Experimental collection efficiencies for the redox couple FcTMA+/FcTMA2+ are found to be very close to those predicted theoretically. BDD electrodes serve as an ideal electrocatalyst support due to their low background currents, wide solvent potential window in aqueous solution, and chemical and electrochemical stability in acid and alkali solutions. The BDD RRDE configuration is employed to investigate the importance of surface-incorporated nondiamond carbon in BDD on hydrogen peroxide generation via the oxygen reduction reaction in acid solutions.
Project description:Activated carbons (ACs) for supercapacitors were synthesized from Eucommia ulmoides Oliver (EUO) wood by H3PO4 with systemic activation processes. The target structure of ACs could be prepared by adjusting the technological parameters. As the H3PO4 concentration was 25%, the mass ratio of feedstocks to activator was 1:4, the activation time was 6 h, and the activation temperature was 400 °C, the obtained AC revealed a high specific surface area (2033.87 m2·g-1) and well-developed mesoporous (the rate of mesoporous was 96.4%) with the best economic feasibility. Besides, it possessed excellent electrochemical performance: the maximum specific capacitance reached up to 252 F·g-1, the charging and discharging period was 3098.2 s at 0.2 A·g-1, and the retention rate of specific capacitance reached 92.3% after 10,000 cycles. This low temperature and convenience technology provide a valuable reference for synthesizing the EUO-based ACs, making high-value utilization on the EUO branches, and owning a broad application prospect in supercapacitors.
Project description:Understanding the strength development of alkali-activated materials (AAMs) with fly ash (FA) and granulated blast furnace slag (GBFS) is crucial for designing high-performance AAMs. This study investigates the strength development mechanism of AAMs using machine learning. A total of 616 uniaxial compressive strength (UCS) data points from FA-GBFS-based AAM mixtures were collected from published literature to train four tree-based machine learning models. Among these models, Gradient Boosting Regression (GBR) demonstrated the highest prediction accuracy, with a correlation coefficient (R-value) of 0.970 and a root mean square error (RMSE) of 4.110 MPa on the test dataset. The SHapley Additive exPlanations (SHAP) analysis revealed that water content is the most influential variable in strength development, followed by curing periods. The study recommends a calcium-to-silicon ratio of around 1.3, a sodium-to-aluminum ratio slightly below 1, and a silicon-to-aluminum ratio slightly above 3 for optimal AAM performance. The proposed design model was validated through laboratory experiments with FA-GBFS-based AAM mixtures, confirming the model's reliability. This research provides novel insights into the strength development mechanism of AAMs and offers a practical guide for elemental design, potentially leading to more sustainable construction materials.
Project description:Flexible energy storage devices are highly demanded for various applications. Carbon cloth (CC) woven by carbon fibers (CFs) is typically used as electrode or current collector for flexible devices. The low surface area of CC and the presence of big gaps (ca. micro-size) between individual CFs lead to poor performance. Herein, we interconnect individual CFs through the in-situ exfoliated graphene with high surface area by the electrochemical intercalation method. The interconnected CFs are used as both current collector and electrode materials for flexible supercapacitors, in which the in-situ exfoliated graphene act as active materials and conductive "binders". The in-situ electrochemical intercalation technique ensures the low contact resistance between electrode (graphene) and current collector (carbon cloth) with enhanced conductivity. The as-prepared electrode materials show significantly improved performance for flexible supercapacitors.