Luminescence Properties of CaF 2

Nanostructures of calcium fluoride (CaF2) doped with Eu, Tb, Dy, Cu, and Ag were synthesized by the coprecipitation method and studied for their thermoluminescence (TL) and photoluminescence (PL) properties. The PL emission spectrum of pure CaF2 nanostructure has a broad band in the 370–550 nm range. Similar spectra were observed in case of doped samples, beside extra bands related to these impurities. The maximum PL intensity was observed in Eu doped sample. The TL results of Eu, Cu, Ag, and Tb doped samples show weak glow peaks below 125°C, whereas Dy doped one is found to be highly sensitive with a prominent peak at 165°C. This sample was further exposed to a wide range of gamma rays exposures from 137Cs source. The response curve is linear in the 100 Gy-10 kGy range. It is also observed that the particle size of CaF2 nanostructure was significantly reduced by increasing Dy concentration. These results showed that Dy is a proper activator in the host of CaF2 nanostructure, providing a highly sensitive dosimeter in a wide range of exposures and also plays a role as a controlling agent for particle size growth

Disposable Patterned Electroceutical Dressing (PED-10) Is Safe for Treatment of Open Clinical Chronic Wounds

Objective: To evaluate if patterned electroceutical dressing (PED) is safe for human chronic wounds treatment as reported by wound care providers. Approach: This work reports a pilot feasibility study with the primary objective to determine physically observable effects of PED application on host tissue response from a safety evaluation point of view. For this pilot study, patients receiving a lower extremity amputation with at least one open wound on the part to be amputated were enrolled. Patients were identified through the Ohio State University Wexner Medical Center (OSUWMC) based on inclusion and exclusion criteria through prescreening through the Comprehensive Wound Center's (CWC) Limb Preservation Program and wound physicians and/or providers at OSUWMC. Wounds were treated with the PED before amputation surgery. Results: The intent of the study was to identify if PED was safe for clinical application based on visual observations of adverse or lack of adverse events on skin and wound tissue. The pilot testing performed on a small cohort (N = 8) of patients showed that with engineered voltage regulation of current flow to the open wound, the PED can be used with little to no visually observable adverse effects on chronic human skin wounds. Innovation: The PED was developed as a second-generation tunable electroceutical wound care dressing, which could potentially be used to treat wounds with deeper infections compared with current state of the art that treats wounds with treatment zone limited to the surface near topical application. Conclusion: Technology advances in design and fabrication of electroceutical dressings were leveraged to develop a tunable laboratory prototype that could be used as a disposable low-cost electroceutical wound care dressing on chronic wounds. Design revisions of PED-1 (1 kΩ ballast resistor) circumvented previously observed adverse effects on the skin in the vicinity of an open wound. PED-10 (including a 10 kΩ ballast resistor) was well tolerated in the small cohort of patients (N = 8) on whom it was tested, and the observations reported here warrant a larger study to determine the clinical impact on human wound healing and infection control

Thermoluminescence Characteristics of CaS: Ce Nanophosphors

The thermoluminescence characteristics of cerium doped calcium sulphide nanoparticles under UV radiations have been studied. The average grain size of the nanoparticles is found to be 53nm which is confirmed by TEM micrograph. The TL glow curve shows a single peak at 376K. TL intensity increases linearly unto 2hr UV exposure. Further increase in the dose results into a decrease of TL intensity. Variation in TL intensity as a function of cerium concentration is studied and 0.4mol% is found to be the optimum concentration for TL. The trap parameters namely, activation energy (E), order of kinetics (b) and frequency factor (s) of CaS: Ce (0.4 mole %) sample have been determined using Chen's method. The order of Kinetics is found to be 2 indicating retrapping of charge carriers in CaS: Ce nanoparticles. The effect of different heating rates has also been studied. The PL emission spectrum shows two peaks at 506nm and 565nm when excited at 450nm

Sustainable Sulfur-rich Copolymer/Graphene Composite as Lithium-Sulfur Battery Cathode with Excellent Electrochemical Performance

A sulfur-rich copolymer, poly(S-r-C-a) has been synthesized via a sustainable route, showing the utility of two major industrial wastes-elemental sulfur (petroleum waste) and cardanol (agro waste), to explore its potential as cathode material for Li-S batteries. The sulfur-rich copolymer exhibited a reduction in the active material dissolution into the electrolyte and a low self-discharge rate behavior during the rest time compared to an elemental sulfur cathode, indicating the chemical confinement of sulfur units. The presence of organosulfur moieties in copolymer suppress the irreversible deposition of end-discharge products on electrode surfaces and thus improve the electrochemical performances of Li-S batteries. This sulfur copolymer offered a reversible capacity of 892 mA h g(-1) at 2nd cycle and maintained the capacity of 528 mA h g(-1) after 50 cycles at 200 mA g(-1). Reduced graphene oxide (rGO) prepared via a sustainable route was used as a conductive filler to extract the better electrochemical performances from this sulfur copolymer. Such sustainable origin batteries prepared via economically viable showed an improved specific capacity of similar to 975 mA h g(-1) after 100 cycles at 200 mA g(-1) current rate with capacity fading of 0.15% per cycle and maintained a stable performance over 500 cycles at 2000 mA g(-1)

Cardanol benzoxazine-Sulfur Copolymers for Li-S batteries: Symbiosis of Sustainability and Performance

A sulfur-rich copolymer is synthesized via a sustainable, eco-friendly approach using two major wastes namely, elemental sulfur (industrial waste) and cardanol (agro waste) and its application as cathode active material in Li-S battery. The presence of chemically bound sulfur (90 wt%) utilising cardanol (10 wt%) derivative in the copolymer (S90) showed a reduction in the active material dissolution into the electrolyte. In addition, the organic sulfur units get dispersed into the insoluble/insulating Li-2 S-2/Li2S phase and thus found to suppress their irreversible dep-osition. Li-S battery based on S90/multi-walled carbon nano-tubes (MWCNT) (10 wt%) exhibited a reversible capacity of 1302 mAh g(-1) at 2nd cycle, maintaining a high reversible capacity of 928 mAh g(-1) after 70 cycles at a relatively constant coulombic efficiency over 99% at current rate of 200 mA g(-1). At 1000 mA g(-1) current rate, the composite cathode delivered a reversible capacity of 697 mAh g(-1) at 2nd cycle and retained 75% of its initial capacity even after 180 cycles

THERMOLUMINESCENCE CHARACTERISTICS OF CaS: Ce NANOPHOSPHORS

The thermoluminescence characteristics of cerium doped calcium sulphide nanoparticles under UV radiations have been studied. The average grain size of the nanoparticles is found to be 53nm which is confirmed by TEM micrograph. The TL glow curve shows a single peak at 376K. TL intensity increases linearly unto 2hr UV exposure. Further increase in the dose results into a decrease of TL intensity. Variation in TL intensity as a function of cerium concentration is studied and 0.4mol% is found to be the optimum concentration for TL. The trap parameters namely, activation energy (E), order of kinetics (b) and frequency factor (s) of CaS: Ce (0.4 mole %) sample have been determined using Chen's method. The order of Kinetics is found to be 2 indicating retrapping of charge carriers in CaS: Ce nanoparticles. The effect of different heating rates has also been studied. The PL emission spectrum shows two peaks at 506nm and 565nm when excited at 450nm

Multifunctional Multicomponent Highly Biocompatible pH-Responsive Iron-Oxide Embedded Nanodiamond Cargo for Artesunate to Inhibit Cancer Growth

The promise of artesunate’s (ART) role in anticancer properties steers a focus on drug repurposing. Potential nanocargo heterostructures, with each component having a specific role, are required for effective drug delivery. Here, we have developed a nanoformulation based on nanodiamonds studded with iron oxide that exhibits exceptional biocompatibility and effective cellular delivery of ART. The current drug delivery formulation has proven improved efficiency of the drug in generating higher reactive oxygen species (ROS), resulting in DNA damage and subsequent cellular apoptosis

Multifunctional Multicomponent Highly Biocompatible pH-Responsive Iron-Oxide Embedded Nanodiamond Cargo for Artesunate to Inhibit Cancer Growth

The promise of artesunate’s (ART) role in anticancer properties steers a focus on drug repurposing. Potential nanocargo heterostructures, with each component having a specific role, are required for effective drug delivery. Here, we have developed a nanoformulation based on nanodiamonds studded with iron oxide that exhibits exceptional biocompatibility and effective cellular delivery of ART. The current drug delivery formulation has proven improved efficiency of the drug in generating higher reactive oxygen species (ROS), resulting in DNA damage and subsequent cellular apoptosis