Kavita A. Deshmukh

Alteration of the electronic structure and the optical properties of graphitic carbon nitride by metal ion doping

The photoluminescence quenching of graphitic carbon nitride (GCN) was systematically investigated with the doping of transition metal ions. The photoluminescence spectra of metal doped and pristine GCN were monitored and the trend of quenching efficiency was found to be Cu2+ > Co2+ > Mn2+. Interestingly, with the increasing doping concentration of different metal ions simultaneous red shift and luminescence quenching was determined in the photoluminescence spectra as well as increased absorption tail in longer wavelength hence enhancement in the bandgap. The change in the optical properties could be mainly due to structural reconstruction and doping induced electronic redistribution is discussed.

Effect of Cryo-Ageing at Liquid Nitrogen Temperature and Subsequent Thermal-Annealing on the Interface of Talc Filled Polypropylene with Different Particle Size

Polypropylene (PP) based materials are widely used because of their low cost, good processability and good balance of properties but its low stiffness and strength greatly hinders its even wider utilization. In order to overcome this, PP is reinforced with different fillers. In composites; the issue of interface between the filler and matrix is of importance. Thus in the present paper, the effect of cryo-ageing and subsequent thermal-annealing on the PP-talc filled composites have been studied to monitor its effect on the interface. The composites with talc of different particle sizes are examined for mechanical and structural properties after treatment. The mechanical properties are evaluated by testing its tensile strength and wear performance, whereas, the study of structural properties by FTIR and SEM reveals some structural changes. These results have further been discussed and evaluated to find out the effect of these treatments on interface of various selected talc filled PP composite.

Inflorescence type morphology and mirror–mist–hackle pattern in tensile fractograph of MWCNT/PBT nano-composites

Abstract Polybutylene terephthalate (PBT) is extensively used for automobile and aircraft components, which are prone to continuous damage and, thus, are expected to have superior mechanical properties. With the aim of achieving this, carbon nanotube (CNT) reinforced polymer composites are steadily gaining importance. To address this area, the present study deals with the fabrication and characterization of PBT reinforced with multi-walled CNTs (0.1 to 0.5 wt.%) and its effect on tensile strength. The strength of the composite increased at first and later reduced marginally with increasing filler content. A study of fractured surfaces of the composites showed formation of CNT–polymer inflorescence type morphology which indicated that the nanotubes within the polymer matrix act as an anchor for carrying and distributing the load during fracture. This demonstrates appreciable interfacial bonding between polymer matrix and the CNTs.

Two-Dimensional Double Hydroxide Nanoarchitecture with High Areal and Volumetric Capacitance

The development of high volumetric or areal capacitance energy storage devices is critical for the future electronic devices. Hence, the hunting for next-generation electrode materials and their design is of current interest. The recent work in the two-dimensional metal hydroxide nanomaterials demonstrates its ability as a promising candidate for supercapacitor due to its unique structure and additional redox sites. This study reports a design of freestanding high-mass-loaded copper-cobalt hydroxide interconnected nanosheets for high-volumetric/areal-performance electrode. The unique combination of hydroxide electrode with high mass loading (26 mg/cm2) exhibits high areal and volumetric capacitance of 20.86 F/cm2 (1032 F/cm3) at a current density of 10 mA/cm2. This attributes to the direct growth of hydroxides on porous foam and conductivity of copper, which benefits the electron transport. The asymmetric supercapacitor device exhibits a high energy density of 21.9 mWh/cm3, with superior capacitance retention of 96.55% over 3500 cycles.