Supramolecular thermoplastics and thermoplastic elastomer materials with self-healing ability based on oligomeric charged triblock copolymers

Supramolecular polymeric materials constitute a unique class of materials held together by non-covalent interactions. These dynamic supramolecular interactions can provide unique properties such as a strong decrease in viscosity upon relatively mild heating, as well as self-healing ability. In this study we demonstrate the unique mechanical properties of phase-separated electrostatic supramolecular materials based on mixing of low molar mass, oligomeric, ABA-triblock copolyacrylates with oppositely charged outer blocks. In case of well-chosen mixtures and block lengths, the charged blocks are phase separated from the uncharged matrix in a hexagonally packed nanomorphology as observed by transmission electron microscopy. Thermal and mechanical analysis of the material shows that the charged sections have a T-g closely beyond room temperature, whereas the material shows an elastic response at temperatures far above this T-g ascribed to the electrostatic supramolecular interactions. A broad set of materials having systematic variations in triblock copolymer structures was used to provide insights in the mechanical properties and and self-healing ability in correlation with the nanomorphology of the materials

Cyclotron-based production of the theranostic radionuclide scandium-47 from titanium target

Production of scandium-47 as a therapeutic radionuclide and mighty in single-photon emission computed tomography (SPECT) technique has been investigated in this paper. The excitation function of 48,49,50,natTi(p,x) leading to the formation of 47Sc were computed using the TALYS-1.9 code to recommend the suitable energy range. Monte Carlo simulation code MCNPX was employed to estimate the integral yield based on the medium cyclotron. The target thickness was calculated using the SRIM code. A developed targetry system was designed and manufactured. An experimental yield for the formation of 47Sc was obtained on about 4.25 MBq/(μA h) by the proton interaction on natTi-foil at 5 μAh total current beam. The Liquid�Liquid Extraction (LLX) method was employed for the separation of radiochemical impurities. Quality control was performed by γ-ray spectrometry. A good agreement between experimental and simulated results can be certified for the procedure. © 2020 Elsevier B.V

High performing single-ion conducting block copolymer electrolytes based on poly(ethylene oxide) and specifically designed methacrylic sulfonamide

In the field of polymer electrolytes, new single-ion conductors have attracted increasing interest in recent years, mainly because of their intrinsic safety and peculiar chemical structure that can be tailored as desired to display unique properties, such as tLi+ ≈ 1. Nevertheless, their practical application is still limited by low ionic conductivity (σ, far below 10–5 S cm–1 at 25 °C). Herein, the preparation and characterization of new families of single-ion conducting copolymers based on the specifically designed lithium 1-[3-(methacryloyloxy)propylsulfonyl]-1-(trifluoromethylsulfonyl)imide (LiMTFSI) anionic monomer is described. RAFT polymerization was employed to prepare well-defined anionic di- and tri-block copolymers comprising poly(LiMTFSI) and poly(ethylene oxide) blocks. Block copolymers were semi crystalline with a single Tg. They showed very high σ (≈ 10–4 S cm–1 at 70 °C), impressive t+ ≈ 0.91 and wide 4.5 V electrochemical stability, combined with long lifetime up to 300 cycles and outstanding rate performance in LiFePO4/Li cells at different temperatures

Experimental study and simulation of 63Zn production via proton induce reaction

The 63Zn was produced by16.8 MeV proton irradiation of natural copper. Thick target yield for 63Zn in the energy range of 16.8 �12.2 MeV was 2.47 ± 0.12 GBq/μA.h. Reasonable agreement between achieved experimental data and theoretical value of thick target yield for 63Zn was observed. A simple separation procedure of 63Zn from copper target was developed using cation exchange chromatography. About 88 ± 5 of the loaded activity was recovered. The performance of FLUKA to reproduce experimental data of thick target yield of 63Zn is validated. The achieved results from this code were compared with the corresponding experimental data. This comparison demonstrated that FLUKA provides a suitable tool for the simulation of radionuclide production using proton irradiation. © 2018 Elsevier Lt

Single-ion block copolymer electrolytes based on poly(ethylene oxide) and methacrylic sulphonamide for lithium batteries

Polymer electrolytes are expected to replace flammable liquid electrolyte in next-generation lithium metal batteries. In addition to intrinsic enhanced safety, their chemical structure can be tailored in order to display unique properties such as lithium-ion transference number (t+) approaching unity, not otherwise achievable with conventional electrolytes. This new class of materials, namely Single-Ion Conductors, has attracted increasing interest in recent years. Nevertheless, practical applications of polymer electrolytes are still limited by low ionic conductivities (σ), typically far below 10-5 S cm-1 at 25 °C. In this work, new families of single-ion conducting copolymers based on the specifically designed lithium 1-[3-(methacryloyloxy)propylsulfonyl]-1-(trifluoromethylsulfonyl)imide (LiMTFSI) anionic monomer will be introduced. RAFT polymerization techniques were employed to prepare well-defined anionic di- and tri-block copolymers comprising poly(LiMTFSI) and poly(ethylene oxide) blocks. The effect of the macromolecular architecture and molecular weight on thermal and conduction properties will be discussed. Block copolymers were semicrystalline, showing a single glass transition temperature (Tg) due to the miscibility of the amorphous regions of both blocks. Both Tg and degree of crystallinity (Xc) were composition dependent and ranged from –55 to 7 ºC for Tg, and from 51 to 0% for Xc, respectively. Block copolymers showed very high σ as compared to previous examples (up to ≈ 10-4 S cm-1 at 70 ºC) combined with t+ ≈ 0.91. In addition to these promising features, solid polymer electrolytes were successfully tested in lithium metal cells at 70 ºC providing long lifetime up to 300 cycles, and outstanding rate performance up to C/2 (≈100 mAh g-1)

Single-Ion Conducting Polymer Electrolytes for Lithium Metal Polymer Batteries that Operate at Ambient Temperature

In the field of polymer electrolytes, new single-ion conductors have attracted increasing interest in recent years, mainly because of their intrinsic safety and peculiar chemical structure that can be tailored as desired to display unique properties, such as tLi+ ≈ 1. Nevertheless, their practical application is still limited by low ionic conductivity (σ, far below 10–5 S cm–1 at 25 °C). Herein, the preparation and characterization of new families of single-ion conducting copolymers based on the specifically designed lithium 1-[3-(methacryloyloxy)propylsulfonyl]-1-(trifluoromethyl sulfonyl)imide (LiMTFSI) anionic monomer is described. RAFT polymerization was employed to prepare well-defined anionic di- and tri-block copolymers comprising poly(LiMTFSI) and poly(ethylene oxide) blocks. Block copolymers were semi crystalline with a single Tg. They showed very high σ (≈ 10–4 S cm–1 at 70 °C), impressive t+ ≈ 0.91 and wide 4.5 V electrochemical stability, combined with long lifetime up to 300 cycles and outstanding rate performance in LiFePO4/Li cells at different temperatures

Experimental study and simulation of 63Zn production via proton induce reaction

The 63Zn was produced by16.8 MeV proton irradiation of natural copper. Thick target yield for 63Zn in the energy range of 16.8 �12.2 MeV was 2.47 ± 0.12 GBq/μA.h. Reasonable agreement between achieved experimental data and theoretical value of thick target yield for 63Zn was observed. A simple separation procedure of 63Zn from copper target was developed using cation exchange chromatography. About 88 ± 5 of the loaded activity was recovered. The performance of FLUKA to reproduce experimental data of thick target yield of 63Zn is validated. The achieved results from this code were compared with the corresponding experimental data. This comparison demonstrated that FLUKA provides a suitable tool for the simulation of radionuclide production using proton irradiation. © 2018 Elsevier Lt

Diosmin-Loaded Nanoemulsion-Based Gel Formulation: Development, Optimization, Wound Healing and Anti-Inflammatory Studies

The wound-healing process is complex and prone to interruption or failure, which can result in the development of chronic wounds that never heal. This can be overcome by seeking prompt medical attention, which will reduce the likelihood of complications and speed up the healing of the cutaneous wound. It has been established that functionalized engineered biomaterials are a possible strategy for starting skin wound care. The purpose of the current study is to develop a diosmin (DSM)-loaded nanoemulsion (NE)-based gel formulation and to investigate its wound healing and anti-inflammatory activity on rats. The DSM-loaded NEs (F1-F17) were developed and optimized with the help of Box–Behnken Design Expert. The DSM-Nes were developed using lauroglycol 90 (LG90®) as oil, Tween-80 as surfactant and transcutol-HP (THP) as co-surfactant. The optimized Nes showed globule size (41 ± 0.07 nm), polydispersity index (PDI) (0.073 ± 0.008) and percentage of entrapment efficiency (%EE) (87 ± 0.81%). This optimized DSM-loaded NEs (F1) was further evaluated and incorporated into 1% carbopol 940 gel. F1-loaded gel was then characterized for drug content, spreadability, in vitro release, wound healing, and anti-inflammatory studies. The developed gel of DSM was found to show significantly better (p < 0.05) wound-healing and anti-inflammatory activity

Single-Ion Conducting Block Copolymer Electrolytes For Solid State Lithium Batteries

Polymer electrolytes have been proposed as a replacement for conventional liquid electrolytes in lithium-ion batteries (LIBs) due to their intrinsic enhanced safety. Nevertheless, the power delivery of these materials is limited by the concentration gradient of the Li salt. Single-ion conducting polyelectrolytes represent the ideal solution since their nature prevents polarization phenomena. Herein, the preparation of a new family of single-ion conducting block copolymer polyelectrolytes via reversible addition-fragmentation chain transfer (RAFT) polymerization technique is reported. The new anionic monomer, namely lithium 1-[3-(methacryloyloxy)propylsulfonyl]-1-(trifluoromethyl-sulfonyl)imide (LiMTFSI) was designed, prepared and further used for the synthesis of well-defined anionic di- and tri-block copolymers via RAFT. Ionic block copolymers comprise poly(LiMTFSI) and poly(ethylene glycol) blocks. We introduce a novel approach for the creation of solid-state batteries by using the new family of single-ion conducting block copolymers as both the solid separator and the binder for electrode material. These single-ion conducting polymer electrolytes showed low Tg (−61 °C), high σ (~10-5 S cm-1 at 55 °C), lithium transference number ~1, and wide 4.5 V electrochemical stability. Owing to the combination of all mentioned properties, the resulting LiFePO4/Li cell prototypes deliver large capacities (> 130 mAh g−1), with impressive charge/discharge efficiency and capability to reversibly operate at high rates

Synthesis and Characterization of a Luminescent Cyclic Poly(ethylene oxide)-Polypyridyl Ruthenium Complex

We report the synthesis of a macrocyclic poly(ethylene oxide) (PEO) connected by one [Ru(bpy)3]2+ unit (where bpy = 2,2′-bipyridine), a photoactive metal complex that provides photosensitivity and potential biomedical applications to this polymer structure. The PEO chain provides biocompatibility, water solubility, and topological play. The macrocycles were successfully synthesized by copper-free click cycloaddition between a bifunctional dibenzocyclooctyne (DBCO)-PEO precursor and 4,4′-diazido-2,2′-bipyridine, followed by complexation with [Ru(bpy)2Cl2]. The cyclic product accumulated efficiently in MCF7 cancer cells and exhibited a longer fluorescence lifetime than its linear analogue, likely due to differences in the accessibility of the ligand-centered/intraligand states of Ru polypyridyls in both topologies