Volume 10, Issue 3, March 2019


Intelligent healthcare for future medicine

Ashutosh Tiwari

Advanced Materials Letters, 2019, Volume 10, Issue 3, Pages 151-151
DOI: 10.5185/amlett.2019.1003

Healthcare technology continues to grow, in almost all usefully processes, involved from patient care to database management and from lab research to innovation in devices. Technological elevate in healthcare devices confer user-friendly services, while Artificial Intelligence (AI) in machines and computational discipline acclaim overall sense of healthcare perspective. Today, there are many technological advancements and models that help in Drug discovery connections, minimizing errors in Health system, Maternal mortality, Drug-interaction risks and relationships among genes, environment, diseases and other entities. Researchers can produce new theories to utilize the subsequent unique representations and proof supported forecasts. Fuelled by intellectual stage, Watson for Drug Discovery conveys a psychological stage for the characteristic dialect to prepare in the existing area of Science This AI-based methodology gives Watson, for Drug Discovery, a chance to filter and break down the huge learning base more completely and quicker than straightforward enquiry instruments or unaided research groups. 

Review of nanoscale layered transition metal chalcogenide superconductors

Yuan He; Dong Yan; Lei Shi; Shu Wang; Zhiang Xie; Huixia Luo

Advanced Materials Letters, 2019, Volume 10, Issue 3, Pages 152-163
DOI: 10.5185/amlett.2019.2175

Here we summarized the nanoscale layered transition metal chalcogenide superconductors, mainly based on the experimental results. In transition-metal chalcogenides the interplay between strong electron-electron and electron-phonon interactions produces a wide variety of instability ranging from charge density wave to superconducting state. The majority of bulk transition-metal dichalcogenides Tcs are normally between 2 and 4 K. At present, superconducting transition-metal chalcogenides generally show low transition temperature (Tc < 10 K). Fe based transition-metal chalcogenides have certain higher Tc (in the range of 10 ~ 50 K). As have been reported, nano-transition-metal chalcogenides may be one of the routes to improve the superconducting transition temperature. In this review, we would like to give a brief introduction of superconductor development and crystal structure of transition-metal chalcogenides. Furthermore, we will describe major synthesis and physical properties of nano-transition-metal chalcogenides. Finally, recent status and outlook of superconductor based on nano-transition-metal chalcogenides are discussed. 

Evaluation of NSAIDs antioxidant activity on lipid peroxidation in splenocyte membranes

Helena Ferreira; Joana Tavares; Anabela Cordeiro-da-Silva; José L. F. C. Lima; Salette Reis

Advanced Materials Letters, 2019, Volume 10, Issue 3, Pages 164-169
DOI: 10.5185/amlett.2019.2096

Here we summarized the nanoscale layered transition metal chalcogenide superconductors, mainly based on the experimental results. In transition-metal chalcogenides the interplay between strong electron-electron and electron-phonon interactions produces a wide variety of instability ranging from charge density wave to superconducting state. The majority of bulk transition-metal dichalcogenides’ Tcs are normally between 2 and 4 K. At present, superconducting transition-metal chalcogenides generally show low transition temperature (Tc < 10 K). Fe based transition-metal chalcogenides have certain higher Tc (in the range of 10 ~ 50 K). As have been reported, nano-transition-metal chalcogenides may be one of the routes to improve the superconducting transition temperature. In this review, we would like to give a brief introduction of superconductor development and crystal structure of transition-metal chalcogenides. Furthermore, we will describe major synthesis and physical properties of nano-transition-metal chalcogenides. Finally, recent status and outlook of superconductor based on nano-transition-metal chalcogenides are discussed. 

Morphological, structural, thermal and degradation properties of polylactic acid-waxy maize starch nanocrystals based nanocomposites prepared by melt processing

Pooja Takkalkar; Mahalaxmi Ganapathi; Maha Al-Ali; Nhol Kao; Gregory Griffin

Advanced Materials Letters, 2019, Volume 10, Issue 3, Pages 170-177
DOI: 10.5185/amlett.2019.2185

Currently used petroleum-based polymers have adversely affected the environment in various ways, mainly due to their non-biodegradability. This undesirable aspect of commercial polymers led to increased interest in the research area of biodegradable polymer nanocomposites. Polylactic acid (PLA) based nanocomposites, with three different loadings of waxy maize starch nanocrystals (WSNC) as nanofiller (1, 3 and 5 wt%), were melt-blended in a Haake Rheomix. The morphological, structural, thermal and abiotic degradation characteristics of the prepared PLA-WSNC nanocomposites were studied to determine the effects of adding WSNC at different loadings in PLA. The results indicated that WSNC were dispersed uniformly at lower loadings (0-3 wt%) and agglomerated at higher loadings (5 wt%) within the PLA matrix. All PLA-WSNC nanocomposites were found to be stable over the processing temperature range of 25-220 ºC. In addition, there was no considerable change in the glass transition temperature and the melting point of the nanocomposites. Though, the cold crystallization temperature was reduced with the increase of WSNC loadings. The abiotic degradation studies, used as an initial screening tool, indicated that WSNC can accelerate the degradation process of PLA.  As a result, the degradation rate was improved for all the PLA-WSNC nanocomposites. The PLA-WSNC-3 wt% was found to be the optimum concentration to enhance the crystallinity and morphological property of PLA, and beyond that the properties were affected by agglomeration. 

Influence of surfactant on the patterning behavior of nanosilver within polyacrylamide nanogels

Sadiya Anjum; Shamayita Patra; Bhuvanesh Gupta

Advanced Materials Letters, 2019, Volume 10, Issue 3, Pages 178-179
DOI: 10.5185/amlett.2019.2120

Functional patterning and alignment of metallic nanoparticles are gaining enormous interest in electronics, photonics and sensing areas. In the present work, we have investigated the water-in-oil emulsion polymerization for the growth of functional silver nanoparticles within polyacrylamide chains. These functional nanoparticles undergo different alignment and patterning with the variation of surfactant concentration. As the surfactant in the emulsion increases, the resultant nanoparticles are linearly aligned into nanofiber with some branching. However, at 10% concentration of surfactant, these fibers are fused and quasi-circular pattern was observed. The average size of the nanoparticles was observed to be in the range of 5 to 25 nm. Whereas, the size of line pattern was observed in some microns with branching or interconnectivity of nanometer range.

Cell study of the biomimetic modifications on a CoCrMo alloy for biomedical applications

Virginia Paredes; Emiliano Salvagni; José María Manero

Advanced Materials Letters, 2019, Volume 10, Issue 3, Pages 180-184
DOI: 10.5185/amlett.2019.2196

The number of cells adhered and their morphology on implants are indicative of its adaptation. Accordingly, the field of cellular behavior and biomimetic modifications in inorganic materials for biomedical applications show a notable increase in scientific studies. Whence, in this study, the immobilization of peptide sequences and the biological behavior on CoCrMo alloy will be evaluated. To validate the biomimetic modifications carried out on the surfaces we were proposing as hypothesis that a higher density of biomolecules bring about better cellular response. The methodology employed included 2 stages: I) Surfaces biomimetic modification: samples were initially bio activated with nitric acid, followed samples were biofunctionalizated with APTES+Maleimide and finally peptide sequences were immobilized of surface (RGD, FHRRIKA, PHSRN RGD/FHRRIKA or RGD/PHSRN). II) To evaluate the biomimetic modification, were performed studies of cell adhesion. The techniques used for characterization were X-ray photoelectron spectroscopy (XPS), contact angle (CA), immunofluorescence, scanning electron microscope (SEM). The results indicated that samples with RGD and RGD/FHRRIKA exhibited higher number of cells adhered and also cells more spread on the surface, which suggests that they were adapted to the surface, it is demonstrated that the biomimetic modifications carried out are able to successfully induce the bone tissue repair process. 

SPIONs and curcumin co-encapsulated mixed micelles based nanoformulation for biomedical applications

Ganeshlenin Kandasamy; Atul Sudame; Dipak Maity

Advanced Materials Letters, 2019, Volume 10, Issue 3, Pages 185-188
DOI: 10.5185/amlett.2019.2169

In this work, we have synthesized oleylamine (OM)-coated hydrophobic monodispersed SPIONs with an average particle size of ~9 nm via thermal decomposition method. The as-prepared hydrophobic SPIONs are co-encapsulated along with a drug (curcumin, Cur) within the mixed micelles based nanoformulations which is made of d-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS) and Pluronic F127 while keeping the TPGS:F127 ratios at 100:0, 75:25, 50:50, 25:75 and 0:100. Then, the nanoformulations are characterized for hydrodynamic size via dynamic light scattering (DLS) technique, and drug/SPIONs encapsulation efficiencies are determined via UV-vis spectroscopy. Among all the nanoformulation, the mixed micelle with 50:50 TPGS:F127 has exhibited relatively lower hydrodynamic diameter (Dh) (~ 84 nm), better encapsulation efficiencies of Cur and SPIONs (~95% / 56%), and high yield (above 90%). Moreover, morphology and encapsulation of SPIONs/Cur inside the optimized 50:50 TPGS:F127 nanoformulation is confirmed by TEM. In addition, only 10% of Cur is released during 12h time period from optimized nanoformulation indicating the sustained-release property, whereas ~68% of Cur is quickly released in free Cur experiments for the same time period. Hence, the SPIONs/Cur are efficiently co-encapsulated inside the TPGS:F127 mixed micelle based nanoformulation which could be used for further biomedical applications.

Fabrication of Y2O3 coatings by cold-spray

Lingyan Kong; Rifei Han; Yang Yang; Jiayi LI; Tianying Xiong; Tiefan Li

Advanced Materials Letters, 2019, Volume 10, Issue 3, Pages 189-192
DOI: 10.5185/amlett.2019.2188

As a candidate material against plasma etching, yttrium oxide has been coated onto etching chamber by plasma spray technique. However, the plasma spray technique introduces undesirable coating properties such as porous structure and deleterious thermal effects. To reduce the disadvantage of thermal impact, cold spray was used as an alternative technology to deposit thick and dense yttrium oxide coatings.  Many studies have shown that the powders suitable for cold spray process should be with a size around 20μm. However, the Y2O3 are ceramics, it is difficult to form coatings by cold spray due to the lack of ductility when using the powders with a size about 20 μm. It is also difficult for nano-particles to get through the bow shock of cold spray process, which may cause deceleration or even deflection of lighter particles away from the surface, and therefore fail to be cold sprayed.  In this paper, we use Y2O3 with an original average size of 30 nm to form agglomerated Y2O3 particles by hydrothermal treatment. After the hydrothermal treatment, the nano-size Y2O3 agglomerated together to a size around 20 μm and then deposited by cold spray. Y2O3 coatings were forming in this way. In this research, Y2O3 nanoscale powder was tailored into a loose agglomerated structure by hydrothermal treatment, and it was found that the addition of inorganic salt promote the agglomeration process. Cold spray experiments verified the cold spray suitability of the as-modified particle. Gas temperature greatly affects the coating thickness and microstructure, and optimal spraying parameter was fixed at 600 °C. An excellent yttria coating was successfully fabricated on aluminum alloy 6061 with a maximum thickness of 200 µm and a low porosity less than 1% using compressed air as propellant gas. The loose aggregated feedstock fractured during impact instead of deformation. It is demonstrated that particle structure is key factor for ceramic deposition by cold spray technique. 

Triclinic LiVPO4F/C cathode for aqueous rechargeable lithium-ion batteries

Rangaswamy Puttaswamy; Suresh Gurukar Shivappa; Mahadevan Kittappa Malavalli; Yanjerappa Arthoba Nayaka

Advanced Materials Letters, 2019, Volume 10, Issue 3, Pages 193-200
DOI: 10.5185/amlett.2019.2141

Triclinic LiVPO4F/C composite material is synthesized by Reaction under autogenic pressure at elevated temperature (RAPET) method and for the first time, we have evaluated the electrochemical properties and performance in aqueous electrolyte. Structural and morphological features of the material has been characterized using X-ray diffraction and scanning electron microscopy techniques. The electrochemical properties and performance of the material has been evaluated by using cyclic voltammetry, galvanostatic charge/discharge studies, electrochemical impedance spectroscopic technique and potentiostatic intermittent titration technique. The complete electrochemical studies of LiVPO4F/C composite material has been performed in 0.1M Li2NO3 with 0.05 mL glycerine as an additive in 10 mL of H2O as an aqueous electrolyte and its working mechanism was described using standard three-electrodes as well as two electrode configurations. 

PRAP-CVD: Up-scalable process for the deposition of PEDOT thin films

Bianca Rita Pistillo; Kevin Menguelti; Didier Arl; Renauld Leturcq; Damien Lenoble

Advanced Materials Letters, 2019, Volume 10, Issue 3, Pages 201-205
DOI: 10.5185/amlett.2019.2186

Plasma radicals assisted polymerization via CVD (PRAP-CVD) is emerging as an efficient alternative to conventional vapour based techniques to synthesise and deposit conjugated polymers. PRAP-CVD process is based on the concomitant but physically separated injection of low-energy oxidative radical initiators and vaporized monomer species into a reactor where temperature and pressure are finely controlled. Gas phase oxidative radicals are generated by a remote plasma chamber from a pure or diluted initiator. The low deposition temperature, below 100 °C, allows polymers to be directly synthesised on a wide range of substrates, including fabric, paper and plastic, without any thermal degradation and keeping a high degree of surface conformality. Additionally, the PRAP-CVD does not require post-deposition rinsing procedure which allows a wider range of application. PRAP-CVD PEDOT depositions have been carried out on different substrates with a transparency higher than 80% in the visible range. 

Effect of storage time, plasticizer formulation and extrusion parameters on the performance of thermoplastic starch films

M. Paula Guarás; Vera A. Alvarez; Leandro N. Ludueña

Advanced Materials Letters, 2019, Volume 10, Issue 3, Pages 206-214
DOI: 10.5185/amlett.2019.2205

A twin screw extrusion processing method was developed for the preparation of thermoplastic starch (TPS) for packaging applications. Different plasticizer combinations were used looking for the minimal temperature profile in the extruder in order to prevent the thermal degradation of TPS. The effect of storage time at 25 °C and 50% of relative humidity on the properties of TPS was studied. Plasticized TPS samples observed by scanning electron microscopy showed homogeneous fracture surfaces without unstructured starch granules. X-ray diffractometry tests showed retro gradation of all TPS formulations with progressive Vh-type crystal structure formation. Temperature for maximum thermal degradation rate of raw materials was shifted to higher values after preparing the TPS, suggesting not only physical but also chemical interactions between plasticizers and starch molecules. Mechanical properties were significantly improved replacing 10 wt. % of glycerol by water as plasticizer, which was attributed to the increased gelatinization degree and the reduction of thermal degradation. 

Effect of silver nanoparticles on the ammonia gas sensing behavior in diphenylamine based conjugated polymer

Pallavi S.G; Vishnumurthy K.A.; K. Natarajan

Advanced Materials Letters, 2019, Volume 10, Issue 3, Pages 215-221
DOI: 10.5185/amlett.2019.2122

In this paper, ammonia sensor operating at room temperature based on diphenylamine conjugated polymer has been designed and developed. The structure of the polymer was established by UV-Visible, FT-IR and NMR characterization techniques. The polymer was doped with silver nanoparticles by ex-situ method in 0.6 wt%, 1.2wt% and 1.8wt% to form silver nano-composites. The thin films of the polymer and its composites were cast by spin coating on the glass plate. The response of the polymer and its composite with silver nanoparticles has been studied for gas sensor applications. The polymer showed selectivity towards ammonia gas, whereas the polymer composite with silver nanoparticles exhibited selectivity towards ammonia gas and also to ethanol vapors. The response towards ammonia gas was found to increase with the increase in loading of silver nanoparticles. Reproducibility of the polymer and its composite is studied and is found to improve with the loading of silver nanoparticles. 

Study the possibility of using sisal fibres in building applications

R. Alajmi; B.F. Yousif; F.M. Alajmi; A. Shalwan

Advanced Materials Letters, 2019, Volume 10, Issue 3, Pages 222-229
DOI: 10.5185/amlett.2019.2178

In this study, the potential of utilizing natural fibres in construction substances is studied such as the compression strength and heat conductivity. Gypsum walls are reinforcement using sisal fibres for the industrial and construction applications. The sisal fibre has been washed by fresh water and treated with concentration of NaOH (6%), to achieve a real interfacial adhesion between the gypsum and sisal fibres. To survey the impact of different volume fractions of glass and sisal fibres on the conductivity of gypsum, a newly designed heat conductivity test setup was developed. Also, compressive test was carried out for the selected materials. The scanning electron microscopy (SEM) is using to figure out the failure mechanisms by examining the samples after compressive test. The test outcomes detected that the addition of fibres to the gypsum matrix enhances the compressive strength and led to minify brittleness. The optimum fibre content for sisal fibre-gypsum composite and glass fibre-gypsum composite are at 25 vol. and 30 vol. %, respectively. The pure gypsum samples have achieved the highest value of thermal conductivity among other composite samples in thermal conductivity test. The thermal conductivity of the composites reduce with the increase of fibre volume fraction for both glass and sisal addition of the fibres. Due to porous nature of sisal fibre-gypsum composites, as the presence of air voids work as traps and impeded the heat transfer, sisal fibre-gypsum composites performs better than glass fibre-gypsum composites as an insulation material.