Nanoscience & Nanotechnology-Asia - Volume 4, Issue 1, 2014

We are very proud to bring you the first issue of Nanoscience and Nanotechnology-Asia for the year 2014 by Bentham Science Publishers. The journal aim is to provide a unique forum for scientific publications of high quality research on all the most recent advances in Nanoscience and nanotechnology with an emphasis on research in Asia and Japan. With time, no doubt we are publishing different interesting manuscripts in our esteemed journal Nanoscience and Nanotechnology-Asia and hope for the best. Nanoscience and Nanotechnology has become increasingly important new area of research in recent years. Nanoscience is understood more broadly as the science behind the ability to employ nanotechnology. The challenges faced by nanoscience and nanotechnology cannot be solved by techniques or methods used by single science or by using only one technology. It requires an interdisciplinary science or multiple technology. Our journal thus could serve as a gateway for publications of nanoscience and nanotechnology researches from different disciplines that could have a direct impact on the human being.

Aligned carbon nanotube (A-CNT) has been extensively studied due to their high potential in many applications. Despite the fact that catalyst preparation is the key role to grow A-CNTs, the parameter of catalytic chemical vapor deposition (C-CVD) also influences A-CNT growth and its morphologies. This review focused to critically synthesize the published data in scientific report on A-CNT for better understanding the C-CVD parameter governing vertically A-CNT growth. The review will mainly discuss the influence of C-CVD processing temperature, C-CVD processing time, and carbon feedstock in A-CNT growth and its effects on A-CNT morphologies. Challenges and future perspectives in the synthesis of aligned carbon nanotubes have also been discussed.

The thixotropic and injectable properties of physical aqueous gels derived from N,N'-dibenzoyl-L-cystine (1, DBC) and its dimethyl ester (2) at room temperature (RT) are described. The characterization of the materials was carried out by oscillatory rheological measurements, including thixotropy-loop tests, and field emission scanning electron microscopy (FE-SEM). Moreover, the effects of gelator concentration and added DMSO on the gel stability are also discussed. Interestingly, comparative studies revealed, among other effects, that esterification of DBC has a positive effect on both the critical gelation concentration (CGC(1) = 4.5 mM; CGC(2) = 2.0 mM) and the gel-to-sol transition temperature of the gels (Tgel(1) = 65 °C; Tgel(2) = 78 °C), whereas the thixotropic-response was significantly hampered.

Nanotechnology is an emergent field with numerous applications in drug delivery, clinical medicine, nutriceuticals as well as in other fields also. In this techno, Solid lipid nanoparticles (SLN) is a part which consist solid colloidal particles ranging in size from 1 to 1000 nm and act as “magic bullet” when coupled with ligands/targeting ligands. SLN consisting of a solid-lipid promising advance delivery of lipophilic drugs and also used as an alternate for conventional carriers such as micro-emulsions, liposomes and nanoparticles based on natural/synthetic polymers. They are formulated from synthetic/natural lipids and optimize the drug delivery to provide a protection to sensitive drugs and obtain better/improve bioavailability with less toxicity (as compared to polymeric NPs) due to its biodegradable/bioacceptable nature. Moreover, Surface Modified SLNs is a new promising approach for protein loading and antigen delivery system.

The room-temperature fluorescence spectroscopy of zinc telluride quantum dots is investigated. ZnTe quantum dots are synthesized by a chemical route in ethylene glycol with different reactant concentrations and reaction temperatures. Prepared samples are characterized by X-ray diffractometry (XRD) and high resolution transmission electron microscopy. XRD investigation shows the cubic structured ZnTe nanoparticles. The size measurement shows an approximate size of 4-12 nm quantum dots. UV-Vis absorption spectroscopy shows the size-quantization effect and the band gap energy increases by an amount 2.16 eV of the quantum dots. Furthermore as the chemical parameters change, the size of quantum dot changes systemically and the fluorescence peak is observed in 554 nm – 585 nm.

Zinc oxide nanoparticles (ZnO NPs) have been synthesized through microwave irradiation by using different surfactants (Polyvinyl pyrrolidone (PVP), Polyethylene glycol (PEG) and Sodium dodecyl benzene sulphonate SDBS)) and co-reagents (NH3 and NaOH). The synthesized samples were analyzed by thermogravimetric and differential thermal analysis (TG-DTA), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning and transmission electron microscopy (SEM and TEM). Depending on the surfactants and reagents used, various ZnO nanostructures having spherical, rectangle, star-like, needle and rod-like structures with different crystallite size have been obtained. The optical and photoluminescence properties of the samples were investigated and discussed in terms of the different surfactant and reagents used for the synthesis.

In this investigation, a cost effective approach has been developed to fabricate photoelectrochemical (PEC) solar cell on cheap steel substrate sensitized with natural dye and performance has been compared with CdS quantum dots (QDs) sensitized PEC cell. The performance of natural dye sensitized PEC cells has been found to be better than QDs senstitized cell and comparable to conventional high cost ITO-FTO based solar cell which makes use of costly synthetic dyes. For the purpose, microwave synthesis of TiO2 and electrophoretic deposition(EPD) of porous, high quality TiO2 thin films on steel substrate using microwave synthesized nanocrystaline TiO2 has been carried out. The prepared TiO2 thin films were sensitized using natural dyes and QDs of CdS for PEC cell application. Effect of different sensitizers on TiO2 photoanodes was studied using 1M KOH electrolyte in a PEC cell using electrochemical impedance spectroscopy (EIS). Conversion of visible light into electricity has been accomplished using these cells with natural sensitizer providing short circuit current density (Jsc) and open circuit voltage (Voc) values comparable to conventional high cost traditional dyes. The maximum Jsc and Voc are found to be 450.40μAcm^136;’2 and 242.43 mV, respectively, under 10mWcm^136;’2 of illumination for natural dye.

Titanium oxide is known as a photocatalytic material that promotes the generation of hydrogen and oxygen from water by sunlight irradiation. In the present study, titanium oxide particles were treated by water jet cavitation generated using an ejector nozzle. Sub-stream suction occurs in small-sized high-pressure ejector nozzles because of the dynamic high pressure. The water containing titanium oxide powder or a mixed powder of titanium oxide and platinum enters the high-pressure water flow as a sub-stream. In the ejector nozzle, generation, growth, and collapse of cavitation are repeated with the particles of titanium oxide and platinum. Because the cavitation has an extremely high collapse pressure, the surface of the titanium oxide particles is processed by the microjets of cavitation in a so-called reactor comprising the ejector nozzle. The titanium oxide particles subjected to ejector cavitation (EC) processing were investigated for improvements to their photocatalytic properties under ultraviolet irradiation. It was found that noted that nano-level roughness is formed by EC processing. The TiO2 particles or TiO2 particles supported by Pt particles as a cocatalyst containing water were introduced into a vacuum chamber and the gases such as hydrogen and oxygen from the particle surfaces were measured by quadrupole mass spectrometry under ultraviolet irradiation. The EC processing was found to increase the amount of gases generated, including hydrogen and oxygen. Moreover, the amount of hydrogen in particular increases remarkably when both EC processing and support of platinum as a co-catalyst are used. It was also found that the titanium TiO2 particles were supporting minute platinum particles that detached from the original Pt particles during EC processing.