Advances in Natural Sciences: Nanoscience and Nanotechnology

Type 2 diabetes mellitus is a common metabolism disorder characterized by high glucose in the bloodstream, especially in the case of insulin resistance and relative insulin deficiency. Nowadays, it is very common in middle-aged people and involves such dangerous symptoms as increasing risk of stroke, obesity and heart failure. In Vietnam, besides the common treatment of insulin injection, some herbal medication is used but no unified optimum remedy for the disease yet exists and there is no production of antidiabetic drugs in the domestic market yet. In the development of nanomedicine at the present time, drug design is considered as an innovative tool for researchers to study the mechanisms of diseases at the molecular level. The aim of this article is to review some common protein targets involved in type 2 diabetes, offering a new idea for designing new drug candidates to produce antidiabetic drugs against type 2 diabetes for Vietnamese people

The efficiency of the application of surface enhanced Raman spectroscopy (SERS) technique to each specified purpose significantly depends on the choice of the SERS substrate with an appropriate structure as well as on its performance. Until the present time a rich variety of SERS substrates was fabricated. They can be classified according to their structures. The present work is a review of main types of SERS substrates for using in the trace analysis application. They can be classified into 4 groups: (1) Substrates using gold nanoparticles (AuNPs) with spherical shape such as colloidal AuNPs, AuNPs fabricated by pulsed laser deposition, by sputtering or by capillary force assembly (CFA), substrates fabricated by electrospinning technique, substrates using metallic nanoparticle arrays fabricated by electron beam lithography combined with CFA method, substrates using silver nanoparticle (AgNP) arrays grain by chemical seeded method, substrates with tunable surface plasmon resonance, substrates based on precies subnanometer plasmonic junctions within AuNP assemblies, substrates fabricated by simultaneously immobilizing both AuNPs and AgNPs on the same glass sides etc. (2) Substrates using nanostructures with non-spherical shapes such as gold nanowire (NW), or highly anisotropic nickel NW together with large area, free-standing carpets, substrates with obviously angular, quasi-vertically aligned cuboid-shaped TiO2 NW arrays decorated with AgNPs, substrates using gold nanoprism monolayer films, substrates using silver nanocube dimmers or monodisperse close-packed gold nanotriangle monolayers. (3) Substrates using multiparticle complex nanostructure such as nanoparticle cluster arrays, gold nanoflowers and nanodendrites. (4) Flexible substrate such as paper-based swab with gold nanorods, adhesive polymer tapes fabricated by inkjet printing method and flexible and adhesive SERS tapes fabricated by decorating AuNPs via the conventional drop-dry method

In the present study, Penicillium species extract isolated from Calophyllum apetalum was used for the synthesis of silver nanoparticles and it was confirmed by changing the color of the silver nitrate UV–Vis spectrum. The synthesized nanoparticles have been characterized by biophysical techniques such as scanning electron microscopy and x-ray diffraction

Composites based on polyaniline (PANi) and rice husk (RH) were prepared by two methods: the first one was chemical method by combining RH contained in acid medium and aniline using ammonium persulfate as an oxidation agent and the second one was that of soaking RH into PANi solution. The presence of PANi combined with RH to form nanocomposite was clearly demonstrated by infrared (IR) spectra as well as by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images. Lead(II) and cadmium(II) ion concentrations in solution before and after adsorption process on those composites were analysed by atomic adsorption spectroscopy. Of the above preparation methods, the soaking one provided a composite onto which the maximum adsorption capacity was higher for lead(II) ion (200 mg g−1), but lower for cadmium(II) ion (106.383 mg g−1) in comparison with the chemical one. However, their adsorption process occurring on both composites also fitted well into the Langmuir isotherm model

Thin layers of pure TiO2 and TiO2 doped by different amounts of Fe2O3 have been prepared by the sol–gel method with tetraisopropyl orthotitanate and Fe(NO3)3. Physico-chemical properties of catalysts were characterized by BET Adsorption, x-ray Diffraction (XRD), FE-SEM, as well as Raman and UV-Vis spectroscopy. The photocatalytic activity of the obtained materials was investigated in the reaction of complete oxidation of p-xylene in gas phase under the radiation of UV (λ=365 nm) and LED (λ=470 nm) lamps. It has been found that the particle size of all samples was distributed in the range 20–30 nm. The content of the rutile phase in Fe-doped TiO2 samples varied in the range 6.8 to 41.8% depending on the Fe content. Iron oxide doped into TiO2 enables the photon absorbing zone of TiO2 to extend from UV towards visible waves as well as to reduce its band gap energy from 3.2 to 2.67 eV. Photocatalytic activities of the TiO2 samples modified by Fe3+ have been found to be higher than those of pure TiO2 by about 2.5 times.

SiO2 nanoparticles (NPs) were synthesized by the sol–gel method in an ultrasound reactor and monodispersed NPs with an average particle size of 10–12 nm were obtained. The synergy occurring in blending NPs and anionic surfactant solutions was identified by ultra-low interfacial tension (IFT) reduction measured by a spinning drop tensiometer (Temco500). The oil displacement efficiency of the synergistic blends and surfactant solutions at Dragon South-East (DSE) reservoir temperature was evaluated using contact angle measurement (Dataphysics OCA 20). It was found that SiO2/surfactant synergistic blends displace oil as well as their original surfactant solutions at the same 1000 ppm total concentration. Abundant slag appearing in the SiO2/surfactant medium during oil displacement could be attributed to an adsorption of surfactants onto the NPs. The results indicate that at a concentration of 1000 ppm in total, the original surfactant SS16-47A and its blend with SiO2NPs in the ratio of 8:2 exhibited an IFT reduction as high as fourfold of the IFT recorded for the DSE oil–brine interface and very high speed of oil displacement. Therefore, it could potentially be applicable to enhanced oil recovery (EOR) in high-temperature reservoirs with high hardness-injection-brine, like the one at DSE. This opens up a new direction for developing effective EOR compositions, which require less surfactant and are environmentally safer

Composite of nickel-doped Li4Ti5O12 and carbon (designated as Ni–Li4Ti5O12/C) is synthesized by solid-state reaction with sucrose added as the conductive carbon source. For comparison, nickel-doped Li4Ti5O12 (designated as Ni–Li4Ti5O12) is obtained under similar conditions. Both materials are characterized by x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray spectroscopy, charge–discharge cycling and cyclic voltammetry. Analysis of SEM images shows that Ni–Li4Ti5O12/C consists of smaller particles than Ni–Li4Ti5O12. Charge/discharge cycling as well as cyclic voltammetry studies prove that Ni–Li4Ti5O12/C electrodes perform much better than those made from Ni–Li4Ti5O12. The specific capacities of the Ni–Li4Ti5O12/C composite are close to the theoretical capacity of Li4Ti5O12 even at high current rates—the discharge capacity of Ni–Li4Ti5O12/C at 2C is equal to 164 mA h g−1

In this paper we present silver nanoparticles ink synthesis targeting conductive patterns for micro fabricated devices by inkjet printing technology. The well dispersed nanoparticles ink was composed of silver colloid with an average particle diameter less than 10 nm. These nanoparticles were protected by a capping layer of poly(N-vinylpyrrolidone) (PVP) even at silver concentration of 20 wt%. Stable aqueous inks were formulated by using a combination of solvent and co-solvents and under vigorous stirring. Various factors affecting the adhesion between the ink and the substrate were investigated, such as solvent and co-solvent content. The ink containing 20 wt% silver has a viscosity of about 9.5 cP and a surface tension of 32 to 36 mN m−1 at room temperature, meeting inkjet printer requirements. The ink stored under ambient conditions was stable against aggregation for more than one month. Silver nanoparticles patterns have been successfully printed on various substrates

An overview of the studies of structural characteristics of nanomaterials and nanosystems, performed by neutron scattering methods, is presented. The considered examples include optically active oxide materials, biological systems and solutions for track membrane etching. It is shown that features of structural organization at the nanoscale, including cluster formation, aggregation and packing modification, play an important role in the formation of the physical properties of materials

The nanomaterials based on metal oxides or semiconductor nanoparticles and nanowires appear to demonstrate the unique physical and also functional properties. Those properties, in general, allow constructing a large number of individual nanodevices for promising applications in nanoelectronics, photonics and biomedical technology. Such individual nanodevices represent interesting building blocks for new type of hierarchical mechanical nano-assembling. Mechanical hierarchical nano-assembly of functional nanoscale/meso-macroscale devices into macroscopic devices opens up the new perspectives for the creating of micro-meso and macro-devices and their arrays for many applications. The report describes the physical principle and design of the shape memory based nanogrippers as well as the preliminary results of the manipulation of CNTs, InP, ZnO nanowires and nanoparticles as building blocks for biomedical sensors