Improved Dielectric Properties of Epoxy Nano Composites

Epoxy-based nanodielectrics with 2, 5 and 7 wt.% of organically modified montmorillonite clay (oMMT) were prepared using high shear melt mixing technique. The interface of oMMT and epoxy of the nanodielectrics play a very important role in improving electrical, mechanical, thermal and wear properties. Therefore detailed study on the interfacial effects of filler-matrix has been investigated for understanding the chemical bonding using Fourier transform infrared spectroscopy (FTIR) and the cross linking between polymer and filler was studied using glass transition temperature (Tg) through differential scanning calorimetry (DSC). Further, positron annihilation lifetime spectroscopy (PALS) was used to determine precise and accurate value of free volume of the nanodielectrics. The interaction between the nanoparticles and polymer chains has a direct bearing on dielectric strength characteristics of the epoxy-oMMT nanocomposite system and accordingly, the ac dielectric strength of the nanodielectrics increases with the addition of oMMT into epoxy up to 5 wt.% and further increase in filler loading (7 wt.%) causes decrease in ac dielectric strength

Mechanical and Tribological Properties of Epoxy Nano Composites for High Voltage Applications

The tribological and mechanical properties of organomodified montmorillonite (oMMT)-incorporated Epoxy (Epoxy-oMMT), vinyl ester (vinyl ester-oMMT) and titanium dioxide (TiO2)-filled Epoxy (Epoxy-TiO2) nanocomposites are discussed below. Implications of introducing oMMT and TiO2 nanoparticles on mechanical and dry sliding wear properties are presented using micrographs of cast samples and through observations of wear affected surface of nanocomposites. Distribution of nanoparticles and their influence on properties are being emphasized for understanding the wear properties. The data on mechanical and tribological properties determined experimentally are compared with published literature. The main focus is to highlight the importance of nanofillers in the design of wear-resistant thermoset polymer composites. A detailed study of strength and moduli of Epoxy-oMMT, Epoxy-TiO2 and vinyl ester-oMMT nanocomposites was taken up as a part of the investigation. A discussion on density, hardness, tensile, flexural test data, and friction and wear of nanocomposites and analysis of results by comparison with prevalent theoretical models and published results of experiments are presented

Development and Characterization of Poly Ethylene-Co-Vinyl Acetate (PEVA) Hybrid Nanocomposite Encapsulates for Solar PV

In the solar photo voltaic (PV) module, encapsulant material provides the environmental protection, insulation, optical absorption, besides serving as a good adhesive between solar cell and components of PV module for improving the efficiency. It is desired to develop an improved encapsulating material by incorporating the light absorbing inorganic nanofillers in thermoplastic polymers. One such matrix material is poly ethylene-co-vinyl acetate (PEVA), finding its importance in solar materials, such as PV modules and agricultural greenhouse polymer sheets. Inorganic nanofillers have the potential to transmit necessary radiance in the UV spectra, which can improve the PV panel efficiency. In this study, the optimum effect of inorganic fillers such as organically modified montmorillonite clay (OMMT) and titanium dioxide (TiO2) anatase in PEVA matrix is observed. The fabricated nanocomposite films were etched from the glass mold. The morphology and miscibility of fabricated nanocomposite films were analyzed and investigated by scanning electron microscopy (SEM), X-ray diffraction technique (XRD), UV-Vis absorption (UV-Vis), and Fourier-Transform Infrared Spectroscopy (FTIR). The dielectric properties of the fabricated hybrid nanocomposite films were analyzed for its insulation behavior. The thermal behavior was studied using Thermo-gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The hybrid nanocomposite with 5.0 weight percentage (wt.%) OMMT and 5.0 weight percentage (wt.%) of TiO2 indicates lowest dielectric constant of 2.4 and marginal increase in dissipation factor with respect to frequency. Increased thermal stability, glass transition temperature, high transmittance and optimum UV-shielding efficiency were found with the same wt.% in the proposed work

Digitally strengthened, midwife-led intervention to reach the unreached mothers across ten conflict-prone provinces of Afghanistan during humanitarian crisis

Background: Coronavirus disease 2019 (COVID-19) pandemic had significant negative impact on sexual and reproductive health (SRH) with devastating impact on pregnant women in resource constrain humanitarian settings. This paper provides detailed account of a community midwife-led intervention in ten humanitarian settings of Afghanistan using world health organization (WHO) emergency disaster risk management (EDRM) framework.Objectives: The project is aimed at increasing access to Integrated Package of Essential SRH Services and Minimal Initial Service Package (MISP) with a specific focus on prevention of Postpartum Haemorrhage (PPH) and screening and management of preeclampsia and eclampsia.Methods: The project was implemented through 150 Community outreach midwives (COMs). Each midwife served 300 households; mentored by gynaecologists and supervisors. Midwives were trained through a digitally enabled, simulation based training and equipped with a set of off-the shelf devices and kits.Results: During COVID-19 pandemic and in absence of health care services during crisis, this intervention has played as a lifesaving intervention for the community in Afghanistan. Variable digital literacy, sociocultural barriers, reluctance in adapting to digital platforms, security and uncertainties were some of the challenges faced. Adaptation of outreach methods integrated high impactful digital technologies has been the most appropriate strategy "to reach the unreached".Conclusion: Through this model, national and global stakeholders were engaged even during the crisis in Afghanistan. It also provided vital inputs for the donors, governments, civil society organizations and other stakeholders for sustaining and advancing the delivery of quality SRH services in humanitarian settings