Supercapacitor and high k properties of CNT-PbS reinforced quinoxaline amine based polybenzoxazine composites.

The new 2,3-diphenylquinoxalin-6-amine (dpqa) was designed and synthesized through an efficient and high yield condensation process. Data from FTIR and 1H-NMR spectroscopy have been adopted to ascertain the molecular structure of benzoxazine compounds. Furthermore, the quinoxaline amine based benzoxazine (BA-dpqa) was synthesized using bisphenol-A and paraformaldehyde followed by combining different weight percentages (1, 5 and 10 wt%) of (3-glycidyloxypropyl)trimethoxysilane functionalized CNT-PbS with benzoxazine to obtain nanocomposites. The thermal and morphological properties of the quinoxaline amine based neat polybenzoxazine matrix poly(BA-dpqa) and CNT-PbS/poly(BA-dpqa) composites were analysed by XRD, TGA and SEM analysis. The values of the degradation temperature (Td) obtained for neat poly(BA-dpqa) and 10 wt% CNT-PbS/poly(BA-dpqa) composites are 414 °C and 424 °C. Furthermore, the chair yield percentage was calculated as 33% and 35% respectively. The water contact angle of polybenzoxazine gradually increased from 89° to 127° proportional to the content of CNT-PbS. Among the composites, 10 wt% CNT-PbS reinforced poly(BA-dpqa) nanocomposites possess higher dielectric constant (k = 11.0) than other composites. The pseudocapacitor nature of the prepared electrodes is demonstrated by the good electrochemical performance according to the CV curve. Also, the prepared 10 wt% CNT-PbS/poly(BA-dpqa) (637 F g-1 at 5 A g-1 and 11.8 Ω) electrode shows better capacitance and lower charge transfer resistance values than 5 wt% CNT-PbS/poly(BA-dpqa) (613 F g-1 at 5 A g-1 and 13.2 Ω) and neat poly(BA-dpqa) (105 F g-1 at 5 A g-1 and 15.6 Ω) according to the charge/discharge curves and EIS spectra. 10 wt% CNT-PbS/poly(BA-dpqa) shows 99.2% cycling efficiency even at the 2000th cycle, which indicates the good electrochemical performance of the prepared electrode.

Optimisation of gelatin extraction from Unicorn leatherjacket (Aluterus monoceros) skin waste: response surface approach.

Physical properties of gelatin extracted from Unicorn leatherjacket (Aluterus monoceros) skin, which is generated as a waste from fish processing industries, were optimised using Response Surface Methodology (RSM). A Box-Behnken design was used to study the combined effects of three independent variables, namely phosphoric acid (H3PO4) concentration (0.15-0.25 M), extraction temperature (40-50 °C) and extraction time (4-12 h) on different responses like yield, gel strength and melting point of gelatin. The optimum conditions derived by RSM for the yield (10.58%) were 0.2 M H3PO4 for 9.01 h of extraction time and hot water extraction of 45.83 °C. The maximum achieved gel strength and melting point was 138.54 g and 22.61 °C respectively. Extraction time was found to be most influencing variable and had a positive coefficient on yield and negative coefficient on gel strength and melting point. The results indicated that Unicorn leatherjacket skins can be a source of gelatin having mild gel strength and melting point.

Multivariate polynomial fit: Decay heat removal system and pectin degrading Fe3 O4 -SiO2 nanobiocatalyst activity.

Herein, multivariate Lagrange's interpolation polynomial (MLIP) and multivariate least square (MLS) methods are used to derive linear and higher-order polynomials for two varied applications. (1) For an effective fabrication of Pectin degrading Fe3 O4 -SiO2 Nanobiocatalyst activity (IU/mg). Here, the three parameters namely: pH value, pectinase loading and temperature as independent variables are optimized for the maximal of anobiocatalyst activity as a dependent variable. (2) For a passive system reliability estimation of decay heat removal (DHR) of a nuclear power plant. The success criteria of the system depend on three types temperature that do not exceed their respective design safety limits and are considered as dependent variables and 14 significant parameters were used as independent variables. Statistically, the validation of these multivariate polynomials are done by testing of hypothesis. Comparative study of the proposed approach gives significance results in the first application have the optimum conditions for maximum activity using linear MLIP method is: 58.64 with pH = 4, pL = 250 and Temp = 4°C. The maximum activity using second order MLIP method is 59.825 and method of MLS is 59.8249 with the optimized values of an independent variables pH = 4, pL = 300 and Temp = 8°C depicted in Table 1. In DHR system, the significance results are obtained and depicted in Table 2.

Antibacterial Efficacy of Iron-Oxide Nanoparticles against Biofilms on Different Biomaterial Surfaces.

Biofilm growth on the implant surface is the number one cause of the failure of the implants. Biofilms on implant surfaces are hard to eliminate by antibiotics due to the protection offered by the exopolymeric substances that embed the organisms in a matrix, impenetrable for most antibiotics and immune cells. Application of metals in nanoscale is considered to resolve biofilm formation. Here we studied the effect of iron-oxide nanoparticles over biofilm formation on different biomaterial surfaces and pluronic coated surfaces. Bacterial adhesion for 30 min showed significant reduction in bacterial adhesion on pluronic coated surfaces compared to other surfaces. Subsequently, bacteria were allowed to grow for 24 h in the presence of different concentrations of iron-oxide nanoparticles. A significant reduction in biofilm growth was observed in the presence of the highest concentration of iron-oxide nanoparticles on pluronic coated surfaces compared to other surfaces. Therefore, combination of polymer brush coating and iron-oxide nanoparticles could show a significant reduction in biofilm formation.

The effect of gold and iron-oxide nanoparticles on biofilm-forming pathogens.

Microbial biofilms on biomaterial implants or devices are hard to eliminate by antibiotics due to their protection by exopolymeric substances that embed the organisms in a matrix, impenetrable for most antibiotics and immune-cells. Application of metals in their nanoparticulated form is currently considered to resolve bacterial infections. Gold and iron-oxide nanoparticles are widely used in different medical applications, but their utilisation to eradicate biofilms on biomaterials implants is novel. Here, we studied the effect of gold and iron oxide nanoparticles on Staphylococcus aureus and Pseudomonas aeruginosa biofilms. We report that biofilm growth was reduced at higher concentrations of gold and iron-oxide nanoparticles compared to absence of nanoparticles. Thus nanoparticles with appropriate concentration could show significant reduction in biofilm formation.