Volume 8, Issue 11, November 2017

Healthcare materials & medical technology conference

Ashutosh Tiwari

Advanced Materials Letters, 2017, Volume 8, Issue 11, Pages 1004-1004
DOI: 10.5185/amlett.2017/11001

International Association of Advanced Materials (IAAM) pleased to announce Healthcare Materials & Medical Technology Conference 2018, Singapore with collaboration of VBRI Press AB, Sweden. The conference aims to provide a forum to promote scientific exchanges in the field of healthcare materials & medical technology including fundamental understandings, synthesis, characterisations and technological developments, discuss the most recent innovations and to foster global networks and collaborative ties between leading international researchers across various disciplines from medical, clinical, digital health, drug delivery, nanomedicine and clinical devices.

Advancement in the sulfone-based dendrimers: From synthesis to application

Shaziya Khanam; Sunil K. Rai; Ashish K. Tewari

Advanced Materials Letters, 2017, Volume 8, Issue 11, Pages 1005-1019
DOI: 10.5185/amlett.2017.1609

The development of sulfone-based macromolecules (polymer to dendrimers) has been inspired and prompted by much interesting importance of sulfone chemistry. Literature reveals that dendrimers are more demanding than the polymer in many aspects, because of its unique structural properties. Inspite of increasing importance and applications of dendrimers, it has a lot of hindrance regarding the tedious way of synthesis, which requires large excess of reagent and several problems in isolation. Therefore, time to time several tactics of synthesis has been developed. It was also well known that sulfonylation reaction is not only fast and easy to handle but also aryl sulfonylchloride derivatives are inexpensively available. Nowadays, sulfone-based dendrimers are exponentially expanding its application in disciplines of science which lie in organic synthesis, material sciences, combinatorial chemistry,  medicinal chemistry and chemical biology. In this review, we have compiled the types of dendrimer and chiefly focused on the synthesis of sulfone-based dendrimers and their applications, in short. Further, future prospect of sulfone-based dendrimers in various branches of science has been outlined.

Impedimetric analysis of interaction between DNA and phytochemical constituents’ of Calotropis procera for pre-clinical evaluation

Seetharamaiah Nalini; Seetharamaiah Nandini; Shivayogeeswar E. Neelagund; Jose Savio Melo; Gurukar Shivappa Suresh

Advanced Materials Letters, 2017, Volume 8, Issue 11, Pages 1020-1028
DOI: 10.5185/amlett.2017.1554

In this report, extractions of the Calotropis procera polyphenols have been carried out in conventional soxhlet assisted extraction (SAE) and it is compared with microwave assisted extraction (MAE). As an extension of our previous work reported, we attempted to study the electrochemical interaction of the aqueous plant extract with DNA modified electrode Gr/PAH/NT-G/PPy/DNA. The binding constant Kf determined using UV-Vis spectroscopy was found to be 4.91×10 -1 and 4.55×10 -1 µmol dm -3 for soxhlet assisted plant extract (SAPE) and microwave assisted plant extract (MAPE) respectively. This was consistent with the electrochemical determination of Kf 4.31×10 -6 and 4.71×10 -4 µmol dm -3 for SAPE and MAPE respectively. Further the surface coverage area (Γs) of the electrode fabricated using DNA was calculated using Chronocoulometry for the plant extracts. The linear range of the aqueous extract on the Gr/PAH/NT-G/PPy/DNA modified electrode was found to be from 1-250 µmol dm -3 , with a limit of detection of 0.22 and 0.29 µmol dm -3 mL -1 for SAPE and MAPE respectively. The limit of quantification was found to be 0.68 and 0.88 µmol dm -3 mL -1 for SAPE and MAPE respectively. As a result Calotropis procera can be studied further to applied for anticancer activity. Moreover, electrochemical methods can be a promising technique in drug analysis.

Morphological and electrical characterization of Cu-doped PbS thin films with AFM

Illia Dobryden; Baligh Touati; Abdelaziz Gassoumi; Alberto Vomiero; Najoua Kamoun; Nils Almqvist

Advanced Materials Letters, 2017, Volume 8, Issue 11, Pages 1029-1037
DOI: 10.5185/amlett.2017.1545

Lead sulphide (PbS) is a direct band gap IV–VI intrinsic p-type semiconductor with good potential for application in solar cells, sensors, etc. Doping the films with Cu 2+ ions may improve the electrical properties. Here, Cu-doped PbS films were deposited on conducting glass substrates. The morphology, topography and thickness of the doped PbS films were examined using atomic force microscopy (AFM) and high-resolution SEM. AFM analysis showed decreasing surface roughness and grain size with the increase of Cu 2+ concentration from 0.5 to 2.0 at%. Local surface electrical measurements using conducting AFM and Kelvin probe force microscopy showed the possibility to probe semi-quantitatively the changes in surface potential, work function, and Fermi level upon doping of the films. The estimated apparent work function for the un-doped PbS grains in the film was slightly above 4.5 eV, while it decreased to a minimum value of 4.43-4.45 eV at 1–1.5 at% Cu-doping. Conducting AFM measurements showed that local resistance of the doped samples is lower than on pure PbS films. These results indicate Cu doping as an effective strategy to tune the electrical properties of PbS thin films toward the development of suitable optically active materials for application in photovoltaics. 

New insight into minimal architecture based carbon nanotubes anode with improved mechanical properties for Li-ion battery

Satish Teotia; B.P. Singh; Anisha Chaudhary; Indu Elizabeth; Anchal Srivastava; Saroj Kumari; S. R. Dhakate; S. Gopukumar; R. B. Mathur

Advanced Materials Letters, 2017, Volume 8, Issue 11, Pages 1038-1045
DOI: 10.5185/amlett.2017.1692

The quick advancement of flexible energy storage gadgets has persuaded individuals to look for reliable electrodes with high mechanical flexibility and remarkable electrochemical performance. In the present study, we demonstrate a simple and scalable process to fabricate a flexible, light-weight, free-standing polyvinylidene fluoride-multiwalled carbon nanotubes (PVDF-MWCNT) composite paper, which can be specifically utilized as a flexible anode for lithium ion batteries (LIBs). The excellent binding of MWCNT with PVDF matrix, developed by a straightforward vacuum filtration process, provides sufficient structural integrity to the composite paper. The breaking strength of the PVDF-MWCNT composite paper so formed is found to be 3.5 MPa with strain to failure of 11.25%. The composite paper so developed shows a good cycle reversible charge capacity when used as anode in a standard Li-ion battery. The PVDF-MWCNT composite paper provides a novel pathway to large scale fabrication of flexible electrodes which can be used without conducting support of copper sheet. 

Variation of crystallinity of Cu and Cu2O nanowires arrays grown in various pores of porous alumina membrane

Yu-Min Shen; Dipti. R. Sahu;Jow-Lay Huang; Wen-Fang Chiu; Sheng-Chang Wang; Pramoda K. Nayak

Advanced Materials Letters, 2017, Volume 8, Issue 11, Pages 1046-1051
DOI: 10.5185/amlett.2017.1493

Various pore sizes of a porous alumina membrane were fabricated using H2SO4 and H2C2O4 electrolyte under different ionization voltages. Cu nanowire arrays with high aspect ratios, uniform pore size, and ordered pore arrangement were synthesized using the above porous alumina membrane (PAM). Moreover, Cu2O nanowire arrays were prepared through the oxidization of Cu metal nanowire arrays. From the microstructure and compositional analysis, it was observed that pores of different sizes, i.e. 20~30, 70~90 and 90~100 nm could be obtained by controlling various electrolytes and anodization voltage. The Cu nanowire synthesized with various pore sizes were found to be single crystal (20~90 nm) and polycrystalline (90~100nm) respectively. The single crystal Cu with (111) direction was occurred due to homogeneous current density distribution and relationship between current density (J) and nucleus radius (ro). After oxidation of Cu, the Cu2O nanowires with the pore sizes of 20~100 nm was found to be single crystal. The rearranged of Cu and O2 lattice sites promotes the enhancement of crystalline property. 

Hydrothermal synthesis and electrochemical properties of MnFe2O4 nanoplates

Hanfeng Liang; Xun Xu; Jinqing Hong; Zhoucheng Wang

Advanced Materials Letters, 2017, Volume 8, Issue 11, Pages 1052-1056
DOI: 10.5185/amlett.2017.1543

MnFe2O4 nanoplates have been synthesized by a simple hydrothermal method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) have been employed to characterize the structure and morphology of the as-prepared sample. The results show that the products are plate-like morphology with 100-500 nm in length and 100-200 nm in thickness. Contrast experiments indicate that the formation of the plate-like nanostructure could be ascribed to the effect of citrate complexation. Magnetic measurements at 300 K gave the saturation magnetization and the coercive field of nanoplates 39.2 emu g -1 and 91.5 Oe, respectively. The electrochemical performance as anode material for lithium-ion batteries was further evaluated by cyclic voltammetry (CV), electrochemical impedance and charge-discharge measurements. It was demonstrated that the material could provide an initial reversible capacity of 1067 mAh g -1 at a current density of 0.1 mA cm -2 over the voltage range from 0.5 to 3.0 V. 

Composite BME-AuNPs: Chemopreventive effect on skin carcinoma and inhibition on leukemia blood cancer cells

Ramesh Gunti; Gangappa Dharmapuri; Sumanjoshi Doddapaneni; Chander Amgoth

Advanced Materials Letters, 2017, Volume 8, Issue 11, Pages 1057-1064
DOI: 10.5185/amlett.2017.1733

Herein, the chemopreventive effect of oral and topical administration of composite of alcoholic plant extracts of Butea monosperma (Lam.) Taub. (BME) leaves and gold nanoparticles (Au NPs) have been investigated. The tumor growth has been initiated by the 7, 12-dimethyl benz (a) anthracene (DMBA) and skin tumorigenesis in male Swiss albino mice were promoted by the 12-O-tetradecanoylphorbol-13-acetate (TPA). However, malignant feature of the skin tumors were treated with composite of (BME-Au NPs) to reduce the tumor incidence, tumor burden, tumor yield, cumulative number of tumors, tumor size, mass, and volume, respectively. Furthermore, studies were extended to treat CML (chronic myeloid leukemia) K562 (blood cancer) cells with the combination of DMBA/TPA-(BME-Au NPs) and it show greater (~80%) cellular inhibition on cancer cells. Compare to BME alone the composite of (BME-Au NPs) shows significant effect on skin carcinoma and as well on cancer cells. 

Effect of the incorporation of a microencapsulated healing agent in an epoxy-amine fiber reinforced composite material

Julieta Guti

Advanced Materials Letters, 2017, Volume 8, Issue 11, Pages 1065-1071
DOI: 10.5185/amlett.2017.1550

The objective of this work was to study the effect of incorporating a microencapsulated healing agent in an epoxy matrix and E-glass fiber reinforced composite. Microcapsules were prepared via oil-in-water emulsion polymerization method with dicyclopentadiene as core material and poly(urea-formaldehyde) (PUF) as shell material. The suitable formulation for the epoxy matrix was selected based on the study of the rheological and mechanical properties of various chemical systems. Different amounts of microcapsules were incorporated and the most appropriate processing method (mixing, curing and post-curing cycle) was evaluated. Furthermore, flexural and fracture tests were carried out and the distribution of the capsules as well as the interfacial adhesion with the epoxy matrix were studied. Finally, the processing of fiber reinforced composites, with and without microcapsules, was carried out by compression molding and the mechanical properties of the composites were studied (modulus and maximum flexural strain) from testing three-point bending. The resulting samples with 32 wt. % of fibers and matrices with no microcapsules were compared. Compression molding technique did not affect the integrity of the microcapsules inside the composites. 

Investigations of nanostructured three-phase-foams and their application in foam concretes – A summary

Christina Kr

Advanced Materials Letters, 2017, Volume 8, Issue 11, Pages 1072-1079
DOI: 10.5185/amlett.2017.1593

Recently, a new approach was developed and published which focuses on the preparation of inorganic foams and their application in foam concrete production. Through the incorporation of nanostructured pozzolans in the foam structure, so-called three-phase-foams show a higher stability than foams only based on surfactants. Due to pozzolanic hardening, shrinkage cracks were healed and reaction products can be observed. By implementation of nanotubes in the foam structure as nanoreinforcement, a further stabilization was reached. After incorporation of wet three-phase-foams in cement paste, foam concretes with improved mechanical properties were achieved. It was also shown that the pore size distribution was similar to the introduced three-phase-foams and also smaller pore sizes can be observed compared to foam concretes based on surfactant foams. Additionally, a specific shell-like pore structure was obtained and a theoretical model developed. This could be confirmed by investigations of the influence of the surfactant used on the formation and carbonation of calcium hydroxide. To further enhance the mechanical properties of foam concretes based on three-phase-foams, an UHPC (Ultra-high Performance Concrete) formulation has been applied. Resultant UHPC foam concretes showed dense packed borders, improved homogeneity related to the pore size distribution and enhanced mechanical properties. Furthermore, the UHPC approach was combined with nanoreinforcement. 

Concentration-dependent electrochemical synthesis of quantum dot and nanoparticles of copper and shape-dependent degradation of methyl orange

Kalawati Saini; Rajaya Shree Pandey

Advanced Materials Letters, 2017, Volume 8, Issue 11, Pages 1080-1088
DOI: 10.5185/amlett.2017.1663

Quantum dot of copper (Cu) and nanoparticles of copper and copper oxide (Cu2O, 6CuOCu2O, Cu3O4) were synthesized by electrochemical route using the tri-sodium citrate (TSC) and ascorbic acid as a capping and reducing agent. The synthesis was done at 3.2 V, 311 K and 15 V, 373 K using copper rod as a working electrode and platinum wire as a reference electrode. The electrochemical set up was kept under inert nitrogen-purged conditions. Cu nanoparticles were synthesized in large-scale for the first time by direct dissolution of Cu 2+  into the solution of capping agent from copper electrode in the electrochemical cell. Nanoparticles were characterized by using UV–visible absorption spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) techniques. High resolution TEM pictures showed the formation of different shapes of nanostructures such as spherical, dendrites and leaf-shape respectively. The copper nanoparticles in presence of 200 mM of ascorbic acid were obtained with sizes of 2.10 - 4.81 nm in spherical shape and 24.5 - 49.4 nm with 2.88 mM of ascorbic acid. At lower concentration, the particles were also obtained in leaf-shape with ascorbic acid. The leaf shape was also obtained with 250 mM of TSC. This new kind of synthesis method shows the excellent stability compared with that of another chemical method of copper nanoparticles. These particles were used for degradation of methyl orange. The kinetic study of methyl orange with leaf shape particle capping via TSC shows complete degradation of methyl orange in 120 min.