Volume 11, Issue 11, November 2020

Water and Sanitation Management: During and after COVID-19 Pandemic

Soumya Kar; Rajiv Gupta

Advanced Materials Letters, 2020, Volume 11, Issue 11, Pages 1-6
DOI: 10.5185/amlett.2020.111570

Pandemics have threatened human civilization time and again. Currently, the whole world is dealing with COVID-19, a never seen situation in a hundred years, after the deadly Spanish Flu during 1918-1920. With no specific medicines or vaccines, the best way to keep infections under control is by maintaining personal hygiene and social distancing, as per WHO guidelines. Hygiene and sanitization are ensured with clean water, a highly stressed resource in today's times. In this perspective, we try to cover the immediate management of water resources and sanitation facilities in stalling the spread of the pandemic. Further, suggestions regarding robust water and sanitation infrastructure and management practices have been discussed that can be adopted by the administration and modified as per local requirements. This pandemic is no less than a disaster, though not natural, but ecological. Past epidemics are pointing towards an increase in the occurrence of a public health crisis of current magnitude and more. This calls for a paradigm shift towards development and preparedness.

Polymeric Energy Materials: Development and Challenges

Sugam Shivhare; Praveen Kumar Loharkar; Supriya Vyas; Malvika Sharma; Vivekanand S. Bagal

Advanced Materials Letters, 2020, Volume 11, Issue 11, Pages 1-6
DOI: 10.5185/amlett.2020.111571

The discovery of conjugated, conducting polymers (CPs) polyacetylene (PA) in 1977 opened up a new frontier in the field of polymer science for both academia and industries. CPs possess characteristics such as excellent tunability, ease of synthesis, eco-friendliness, processability etc. These features have enabled the exploration of its applicability in energy and electronics devices. It has also paved way for extensive research world over to develop novel methods for synthesizing CPs with required properties. An important area in the field of synthesis of CPs is to produce conducting nanocomposites with the combination of conducting polymers and inorganic materials in order to achieve high magnitude of electrical conductivity. Several polymeric materials such as, as poly(3,4ethylenedioxythiophene) (PEDOT), polypyrrole (PPy), and polyaniline (PANI) have exhibited potential in various applications such as, “energy harvesting”, “energy storage”, “light emitting”, and “sensing”. The objective of this review is to develop better understanding on conducting polymers used for energy and electronics application. The review presents the state of research in the development of CPs with a focus on general synthesis method, morphology and dependent properties along with the discussion on challenges with possible solutions.

Influence of Different Copolymer Based Compatibilizers on Performance of Pristine and Recycled PP/PE blends

C. Rosales; A. Costantino; G. Palazzo; C. Bernal; R. Defacio Dutra; V. Pettarin

Advanced Materials Letters, 2020, Volume 11, Issue 11, Pages 1-8
DOI: 10.5185/amlett.2020.111572

One of the big engineering challenges in recycling thermoplastics is to manufacture competitive products in terms of mechanical properties such as toughness or strength. This process by which recycled waste is transformed into materials with improved performance, adding value and widening their application field, is known as upcycling. One of the strategies to improve PE/PP blends performance is to add a special compatibilizer, and this is the aim of the present work. To achieve this objective, four different commercial masterbatch compatibilizers based on copolymers were added to pristine blends. The compatibilizer that induced the best performance in virgin blends was selected to be applied in post-consumer recycled (PCR) blends, after minimizing its dosage to diminish costs. All blends were prepared simulating industrial processing conditions. Microstructure and morphology of blends were analyzed by DSC and SEM. Tensile and fracture studies were carried out at quasi-static loading conditions. Fracture surfaces were studied by SEM. It was observed that results found for pristine blends were consistent with those of recycled blends, and the addition of compatibilizing masterbatches improved the performance of both pristine and recycled PP/PE blends, in spite of the unpredictable composition and the presence of impurities of PCR blends.

Bio Ceramics: New Material from Mangrove Bark

Pratishtha Powar; Dattatray Gaikwad

Advanced Materials Letters, 2020, Volume 11, Issue 11, Pages 1-4
DOI: 10.5185/amlett.2020.111573

Mangroves are salt-tolerant plants of tropical and subtropical intertidal regions of the world. The specific regions where these plants occur are termed as 'mangrove ecosystem'. They are having an ecological role as primary producers.  In future there is a need to find out natural compounds to come over against chemical compounds. As these compounds reported to have carcinogenic effects. An attempt was made to find out largest sources of plants, the mangroves. They are facing various types of stresses; they are rich in several secondary metabolites. So, some mangrove barks are tested as a new source as a bio ceramic material by using bone marrow mesenchymal stem cells (BMMSCs). From the study it is revealed that among all tested barks, prop root bark of Rhizophora mucronata shows higher biocompatibility for cell adhesion. Thus, this study will enlighten the use of natural products to replaces chemical health hazards for ceramic material as ecofriendly materials. 

Hybrid Physical Chemical Vapour Deposition (HPCVD) of Superconducting MgB2 Thin Films on three Dimensional Copper Substrates

Nilanjal Misra; Reza Valizadeh; Virendra Kumar

Advanced Materials Letters, 2020, Volume 11, Issue 11, Pages 1-6
DOI: 10.5185/amlett.2020.111574

The present work reports the design, development and application of a novel Hybrid Physical Chemical Vapour Deposition (HPCVD) technique for depositing MgB2 thin films, with potential superconductivity, directly on three dimensional (3D) surfaces. A novel solenoid magnetron based set up was used for depositing MgB2 thin films on 3D surfaces of Cu tube. Mg rod was used as the sputter target and source of Mg while high purity BBr3 was used as a novel boron precursor, which was injected into the system using Argon as carrier gas. The plasma mediated decomposition of BBr3 in presence of H2 gas was followed by chemical reaction between Mg and B atoms to deposit MgB2 film on the substrate. Samples were characterized by SEM, EDX, XRD and SQUID techniques. SEM-EDX confirmed deposition of a homogeneous, pore free and dense MgB2 film, while XRD analysis revealed the film to be polycrystalline and multiphasic rather than being purely c-axis oriented. Superconductivity analysis carried out using SQUID measurements indicated a sharp transition with Tc value of 39 K. From the M-H hysteresis loop, the lower critical field Hc1 and critical current density Jc at 4.2 K were calculated to be 700 Oe and 3.5 x 10 7 A/cm 2 , respectively.

Photoinduced Electron Transfer Reactions of tris(4,4’-dimethoxy-2,2’-bipyridyl)ruthenium(II)cation with Quinones in Aqueous Medium

T. Sumitha Celin; G. Allen Gnana Raj

Advanced Materials Letters, 2020, Volume 11, Issue 11, Pages 1-6
DOI: 10.5185/amlett.2020.111575

Photoinduced electron transfer reactions of [Ru(dMeObpy)3] 2+ complex with quinones have been studied in  aqueous medium by luminescent quenching technique. The complex shows an absorption and emission maximum of 448 nm and 608 nm respectively in aqueous medium. It has an excited state lifetime of 232 ns. The quenching rate constant kq is sensitive to the nature of the quencher and the electron transfer distance between the luminophore and the quencher, the reduction potential of the quinones. The nature of quenching is confirmed from ground state absorption studies. The oxidative nature of quenching is confirmed from the formation of Ru 3+ ion and quinone anion radical. Structural effects also influence the rate of electron transfer reaction.

A Comparative Study of Green Synthesized AgNPs using Carissa Carandas and Nerium indicum Leaves and its Activities against Selected Human Pathogens and MCF 7 Cell

Prabhakara Rao Dasari; Sofia Pilli; Ravi Jon

Advanced Materials Letters, 2020, Volume 11, Issue 11, Pages 1-6
DOI: 10.5185/amlett.2020.111576

The present work reports an ecofriendly method for biosynthesis of AgNPs using an aqueous leaves extracts of Carissa carandas and Nerium indicum plants. These extracts play a significant role for the formation of AgNPs. The obtained AgNPs were characterized by Ultraviolet–Visible Spectrophotometry. The UV-spectrum showed that the absorbance peak at 440 nm. TEM analysis shown morphology and crystalline of nanoparticles as 20 and 40 nm sizes and spherical shape. The SEM and EDXA analysis was shown identify elemental composition and confirm the NPs of desired elements. The FTIR analysis showed functional group elements as amide, hydroxyl and amino groups in NPs. These results were confirming the AgNPs have been best activity against human pathogens. The AgNPs showed high potential antibacterial activity toward the selected pathogenic bacteria. Therefore, Carissa carandas and Nerium indicum leaves aqueous extract AgNPs can provide application in future development as nano-medicine, nanotechnology as antifungal activity on Aspergillus niger and candida albicans and then anticancer activity on MCF-7 cell line. Finally, the Nerium indicum leaves aqueous extract AgNPs were more effective in antibacterial, antifungal and anticancer activity than Carissa carandas AgNPs.

Design and Modelling of Carbon Fiber Grid Structure based Carbon/Epoxy Composites for Enhanced Microwave Absorbing Properties

Aayushi Arya; I. Srikanth

Advanced Materials Letters, 2020, Volume 11, Issue 11, Pages 1-6
DOI: 10.5185/amlett.2020.111577

Frequency Tunable Microwave absorbers in desired low thickness is a critical requirement in electronics, radar and military applications where Electro Magnetic Interference has become a major concern. Composite are obvious choice of absorbers in above applications. The aim of this paper is to investigate the use of carbon fiber grid layers as Frequency Selective Surface (FSS) on Carbon Filler based Glass-Epoxy composites. In this work, three key points are highlighted, first is design, modeling of FSS grid, using equivalent circuit model and Transmission Line Theory, second is the use of fillers including Milled Carbon Fibers and Carbon Nano Tubes (CNTs) for microwave absorption, third is to have the desired reflection loss at specified thickness of around 6-7 mm which is low as compared to recent trends. It is found that the factors like the number of grid layers , their unit cell dimensions,  type of filler, and the top surface layer, affects the resonance frequency and hence the microwave absorption characteristics of the composite laminates. The results are satisfactory showing minimum of -9.8 Db of Reflection Loss at 6-7 mm thickness laminates, for varied range of frequency.

Elaboration and Characterization of Macroporous Bioceramics using Polymeric Sponge Replication Method

Kamel Chaari; Jamel Bouaziz; Khaled Bouzouita

Advanced Materials Letters, 2020, Volume 11, Issue 11, Pages 1-6
DOI: 10.5185/amlett.2020.111578

Biomedical porous fluorapatite scaffolds were fabricated using an improved polymeric sponge replication method. The specific formulations and distinct processing techniques such as the mixture of water and dispersant (Sodium TriPolyPhosphate) as solvent, the multiple coatings with the desired viscosity of the Fap slurries were duplicated from Chaari et al. [11]. The heat treatment was conducted in two stages: a delicate stage of polymeric structure degradation at 290 0 C and then at 600 0 C followed by a sintering stage at 1000 0 C for three hours. The obtained porous Fap scaffolds had uniform porous structures with completely interconnected macropores of 850 μm. In addition, micropores of 4 μm were formed in the skeleton of the scaffold. Finally, the porous Fap scaffold with a porosity of 65 vol.% and a surface of 400 mm 2 had a compressive strength of 7 MPa.