As a key component of lithium-ion batteries (LIBs), separator plays a crucial role in the performance and safety of LIBs. In this paper, a cellulose based porous membrane modified by nano CaCO3 is prepared conveniently by electrospinning. The membrane exhibits rich fibrous porous networks and uniform distribution of nanoparticles. Strengthed by CaCO3, the tensile strength of the cellulose porous membrane elevates from 4.7 ± 0.4 MPa to 7.7 ± 0.7 MPa. Besides, the modified membranes possess improved thermal stability and can maintain their original size after treatment at 150 °C and 180 °C. Also, the electrolyte uptake of cellulose/CaCO3 membrane is 73% higher than that of the pure cellulose membrane. Thus, the ionic conductivity of membrane achieves 1.08 mS cm-1 and the electrochemical window is about 4.8V, which meets the practical requirements of LIBs. Significantly, LiFePO4/Li battery this membrane can run for 230 cycles with a capacity retention of 97.4% and a discharge capacity of 149.0 mAh g-1, demonstrating the huge potential for high safety and next-generation LIBs.
Mid-infrared absorbers based on metamaterials are investigated intensively for gas detection applications, owing to its ability to achieve excellent light absorption by manipulating electromagnetic waves. Herein, we present a metamaterial absorber for the ultra-compact optical gas sensor. This absorber has 99.9% absorption at 6.2 μm. The full width at half-maximum of the peak was 720 nm. As a sensor, the absorber had an average linear spectral sensitivity of 876 nm/RIU and a detection limit of 1.141×10-5 RIU, when the RI of the gas medium varied between 1 and 1.05. The designed absorber would have great potential application in guiding the design of optical gas sensors.
Chiral Iridium complexes are very important for the preparation of circularly polarized light emitting diodes (CP-OLEDs). Three novel Iridium(III) complexes, Ir(dnfppy)2(Cl/pyrrole), Ir(dfppy)2(dpp) and Ir(tfmqz)2(sdpp) have been synthesized and characterized, respectively. These Iridium(III) complexes emitted deep-blue, blue and red photoluminescence with high quantum yields, for ((Ir(dnfppy)2(Cl/Pyrrole): λmax=447 nm, F=62.4%; Ir(dfppy)2(dpp): λmax=467 nm, F= 25%; Ir(tfmqz)2(sdpp): λmax=609 nm, F=73.7%). Compared with Ir(dnfppy)2(Cl/pyrrole), HOMO energy level of Ir(dfppy)2(dpp) and Ir(tfmqz)2(sdpp) was calculated to be −5.71/-5.73 eV, and LUMO energy level increased to be -2.75/-3.36 eV, respectively. CD spectra of two pairs of the enantiomers for Ir(dfppy)2(dpp) or Ir(tfmqz)2(sdpp) displayed symmetry with opposite polarization between 300 and 600 nm. The maximum external quantum efficiency (EQEmax) of OLEDs based on Ir(tfmpqz)2(sddp) was 13.8%, showing a relatively low efficiency roll-off with the EQE of 10.7% at 5000 cd/m2.
Microbial infections are considered as one of the most important concerns of the world community. Developing drug delivery systems based on formulation of nanoparticles with antimicrobial agents have shown beneficial effectiveness against microbial infections and related antimicrobial resistance. In this study we prepared and characterized a chitosan based hydrogel loaded with zinc oxide nanoparticles for controlling the release of vancomycin and also improving its antibacterial effect. Characterization studies demonstrated that the developed biopolymeric hydrogel was able to sustained and controlled the release of vancomycin in response to acidic media for 96 hours. Furthermore, antimicrobial studies showed siginificant and efficient antibacterial activity of prepared hydrogel against S. aureus and P. aeruginosa. Based on obtained results, it can be concluded that the prepared chitosan hydrogel containing ZnO nanoparticles has a desirable activity for controlling the release of vancomycin and improving its antibacterial properties.
In the present study, tin nanoparticles were green-synthesized using the aqueous extract of Foeniculum vulgare leaf aqueous extract. The synthesized SnNPs were characterized by analytical techniques including EDX, FE-SEM, XRD, UV-Vis., and FT-IR. The anti-human gastric cancer activity of SnNPs was evaluated using MTT assay. The nanoparticles were formed in a spherical shape in the range size of 26.45 to 38.53 nm. In the antioxidant test, the IC50 of F. vulgare, SnNPs@FV, and BHT against DPPH free radicals were 384, 119, and 71 µg/mL, respectively. In the cellular and molecular part of the recent study, the treated cells with SnNPs@FV were assessed by MTT assay for 48h about the cytotoxicity and anti-human lung cancer properties on normal (HUVEC) and lung cancer cell lines i.e., NCI-H2126, NCI-H1299, and NCI-H1437. The IC50 of SnNPs@FV were 108, 168, and 122 µg/mL against NCI-H2126, NCI-H1299, and NCI-H1437 cell lines, respectively. The viability of malignant lung cell line reduced dose-dependently in the presence of SnNPs@FV.
In this study, the Zn nanoparticles was synthesized using the peel extract of Citrus aurantium. The nanoparticles was characterized by different chemical technique including UV-Vis. and FT-IR spectroscopy, and SEM technique. The results revealed a spherical shape in the average size of 41.17 nm was identified for the green-synthesized nanoparticles. In the antioxidant test, the IC50 of nanoparticles and BHT against DPPH free radicals were 115 and 96 µg/mL, respectively. In the cellular and molecular part of the recent study, the treated cells with nanoparticles were assessed by MTT assay for 48h about the cytotoxicity and anti-human gastric cancer properties on normal (HUVEC) and gastric cancer cell lines i.e. NCI-N87 and MKN45. The IC50 of nanoparticles were 278 and 256 µg/mL against NCI-N87 and MKN45 cell lines, respectively. The viability of malignant gastric cell line reduced dose-dependently in the presence of Zn nanoparticles. It seems that the anti-human gastric cancer effect of recent nanoparticles is due to their antioxidant effects. After evaluating the effectiveness of this formulation in clinical trial researches, it can be a good alternative to chemotherapy drugs.
Chronic lesion has become a major biological burden for individual patients and health organizations. Using nanoparticles as drug delivery systems is remarkable nowadays. The unique properties of chitosan without any toxicity for living creations make it a suitable option for drug delivery. Epidermal growth factor (EGF) is one of the important agents for wound healing, cellular proliferation, extracellular matrix formation, and skin remodeling. A combination of these properties can accelerate the wound healing process. In this study, rh-EGF is embedded into the chitosan nanoparticles by the Ion-gelation method. Nanoparticles are characterized by TEM microscopy and the DLS method and conjugation efficacy is measured by FT-IR radiation. The antibacterial effect of manipulated nanoparticles was estimated by MIC/MBC methods. The cytotoxicity and proliferation were measured by MTT assay on the HFF-1 human fibroblast cell line. Migration assay was accomplished by in vitro scratch model and the gene expression analysis for TGF-β, VEGF, and PDGF were manipulated by the real time-PCR method. The obtained results were considered statistically signiﬁcant with P < 0.05. Obtained results illustrated no toxic effect on the HFF-1 cell line treated with Chitosan-EGF (CS-EGF). In cellular proliferation and migration assays, CS-EGF nanoparticles demonstrated a better effect than free rh-EGF. For the duration of 72h of the experiment, the whole scratch was covered by fibroblasts. The real time-PCR analysis also showed upregulation of all TGF-β, VEGF, and PDGF genes. As CS-EGF nanoparticles in the acceleration of the skin remodeling process showed promising results, subsequent studies might be useful.
Tetracalcium phosphate (TTCP) is one of the main powder components in self-setting calcium phosphate cements for hard tissue applications. In this study, two types of calcium phosphate/chondroitin sulfate bone cements in which TTCP powders in nanoscale-rod like (R-TTCP) and micro-conventional irregular shape (C-TTCP) were used. The first one was synthesized by reverse microemulsion chemical process and the second one, was prepared by thermal conventional method. The results showed that both cements formed hydroxyapatite as the result of cementation process. The R-TTCP cement revealed a slightly longer initial but no difference in final setting time, less compressive strength, higher porosity and better degradation behavior compared to C-TTCP one. The both cements presented similar tendency to the formation of a dense hydroxyapatite on their outer surfaces through immersion in simulated body fluid. Taking into consideration the initial porosity, the cement made from R-TTCP rod like nanopowder presented more aptness to participate in ion exchange in SBF resulting to fill the 15% more initial porosity via the precipitation of hydroxyapatite mineral. From the biological point of view, analysis of cytotoxicity and MG63 osteoblastic-cell behavior proved that the both cements had good viability and proper cell adhesion and activity.