Soft Nanoscience Letters
ISSN / EISSN : 21600600 / 21600740
Current Publisher: Scientific Research Publishing, Inc. (10.4236)
Total articles ≅ 99
Latest articles in this journal
Soft Nanoscience Letters, Volume 9, pp 35-44; doi:10.4236/snl.2019.93003
Abstract:This paper reports the feasibility of synthesis and characterization of nano-porous silicon (NPS) powder and (Nickel/nano-porous silicon, Ni/NPS) nano-composite prepared using dual techniques (alkaline chemical etching process and ultra-sonication technique). The structural and the optical properties of the fabricated structures are inspected using X-ray Diffraction, Fourier Transform Infrared Spectrophotometer, Raman Spec-troscopy, and Fluorescence Spectrophotometer Photoluminescence. All the results have agreed that NPS is one of the most suitable materials used as active material in the LED fabrication; by changing the main factors in the preparation process, so the different physical and chemical properties are obtained. NPS produces two emission regions that correspond to orange-red and dark red; on the other hand, (Ni/NPS) produce the yellow emission. So, the photoluminescence emission is controllable by adjusting the preparation conditions. The optical data recorded here are useful for the production of the nanoscale optical devices.
Soft Nanoscience Letters, Volume 9, pp 45-57; doi:10.4236/snl.2019.94004
Abstract:Cellulose nanofiber (CNF) is a fibrous and nano-sized substance produced by decomposition of bulk-type cellulose which is a main component of plants. It has high strength comparable to steel, and it shows low environmental load during a cycle of production and disposal. Besides it has many excellent properties and functions such as high rigidity, light-weight, flexibility and shape memory effect, so it is expected as a next-generation new material. Usually it is composed of many cellulose micro fibrils (CMFs) in which molecular chains of cellulose are aggregated in a crystal structure, the knowledge of mechanical properties for each CMF unit is important. Since actual fibrils are complicatedly intertwined, it is also crucial to elucidate the transmission mechanism of force and deformation not only in one fibril but also in between fibrils. How the dynamic and hierarchical structure composed of CMFs responds to bending or torsion is an interesting issue. However, little is known on torsional characteristics (shear modulus, torsional rigidity, etc.) concerning CMF. In general, in a wire-like structure, it is difficult to enhance torsional rigidity and strength, compared with tensile ones. Therefore, in this study, we try to build a hierarchical model of CNF by multiplying CMF fibers and to conduct molecular dynamics simulation for torsional deformation, by using hybrid model between all-atom and united-atoms model. First, shear modulus was estimated for one CMF fibril and it showed a value close to the experimental values. Also, we assume a state in which two CMFs are ideally arranged in parallel, and create a hierarchical structure. We evaluate the dependence on the temperature for the bond strength and toughness in the hierarchical structures. Furthermore, we mentioned the transmission mechanism between components of a hierarchical structure.
Soft Nanoscience Letters, Volume 9, pp 1-16; doi:10.4236/snl.2019.91001
Abstract:Pure and Cadmium (Cd) doped Cerium oxide nanoparticles (CeNPs) have been synthesised by the simple chemical co-precipitation technique. Cadmium ions of concentrations 1, 3 and 5 mol% were doped to investigate their influence on the structural and optical properties of CeO2. The synthesised samples have been subjected to X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis and high-resolution transmission electron microscopy (HRTEM). The XRD and Raman patterns have witnessed the cubic structure of the cerium oxide nanoparticles. The average particle size of CeO2 was found to be around 10 nm. SEM image has also ascertained that the grain size of pure CeO2 appeared is bigger than that of the Cd-doped, which intern indicates the grain growth upon doping. Besides, the antibacterial activity of the cadmium doped cerium oxide nanoparticles against some human pathogens revealed that they have exhibited the maximum zone of inhibition against gram-positive bacteria than the gram-negative species. Further, the cytotoxic effect of Cd-doped CeO2 sample is examined in cultured (MCF-7, A549 and Hep-2) cell.
Soft Nanoscience Letters, Volume 9, pp 17-33; doi:10.4236/snl.2019.92002
Abstract:We consider a hybrid heterostructure containing an inorganic quantum well in close proximity with organic material as overlayer. The resonant optical pumping of Frenkel exciton can lead to an efficient indirect pumping of Wannier excitons. As organic material in such a hybrid structure, we consider crystalline tetracene. In tetracene, the singlet exciton energy is close to twice the one of triplet exciton state and singlet exciton fission into two triplets can be efficient. This process in tetracene is thermally activated and we investigate here how the temperature-dependent exciton energy transfer affects the functional properties of hybrid organic-inorganic nanostructures. We have obtained the exact analytical solution of diffusion equation for organics at different temperatures defining different diffusion lengths of excitons. The effectiveness of energy transfer in hybrid with tetracene was calculated by definite method for two selected temperatures that open possibility to operate in full region of temperatures. Temperature dependence of energy transfer opens a new possibility to turn on and off the indirect pumping due to energy transfer from the organic subsystem to the inorganic subsystem.
Soft Nanoscience Letters, Volume 8, pp 9-19; doi:10.4236/snl.2018.82002
Soft Nanoscience Letters, Volume 8, pp 1-7; doi:10.4236/snl.2018.81001
Abstract:Silver nanoparticles were synthesized using eco-friendly method with extract of Carica papaya as reducing and stabilizing agent. The silver precursor used was silver nitrate solution. A visible colour change from colourless to reddish brown confirmed the formation of the nanoparticles and the UV-Vis spectroscopy showed surface plasmon resonance of 435 nm for the silver nanoparticle. The mean particle size was 250 nm while the polydispersity index was 0.22. The antimicrobial activity of the synthesized nanoparticles was studied against Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Staphylococcus aureus. The silver nanoparticles biosynthesized showed satisfactory antimicrobial activity against the test isolates. Antimicrobial property of the nanoparticles was similar (P > 0.05). Generally, MIC values of the samples against the microorganisms tested ranged from 25 - 100 mg/ml. Pseudomonas aeruginosa was most sensitive while Staphylococcus aureus and Bacillus subtilis were least sensitive to the silver nanoparticles.
Soft Nanoscience Letters, Volume 7, pp 1-15; doi:10.4236/snl.2017.71001
Abstract:With aim to increase set of modern commercial optoelectronic devices we investigate the optical properties of new triple semiconductor-organics-semiconductor nanostructure having two semiconductor layers with organic layer between. This will be development to majority of modern publications with investigations of only double hybrid nanostructures with one contacting semiconductor layer and one organic layer. It is supposed that the energy of exciton in the first layer is larger than the energy of exciton in organic layer and that the energy of exciton in organic layer is larger in comparison with energy of exciton in second semiconductor layer. It was shown that installation of organics leads to some frequencies at different parameters or to reflection increasing and transmission decrease or to reverted dependence. New recurrent method of inverted calculation for fields is proposed and using this method the frequency dependences of optical characteristics have been calculated. The role of second semiconductor layer in considered triple structure has been estimated.
Soft Nanoscience Letters, Volume 7, pp 17-26; doi:10.4236/snl.2017.72002
Abstract:A series of Ni1-xCuxFe2O4 (0.0 ≤ x ≤ 1.0) nanofibers have been synthesized employing electrospinning method at 650°C. The effect of Cu substitution on structural, morphology and magnetic properties of NiFe2O4 nanofibers is reported. The XRD analysis showed the formation of single-phase cubic spinel Ni-Cu ferrite and an increasing behavior of lattice constant. The surface morphology is characterized by SEM, it is investigated that nanofibers have uniform and continuous morphology. The VSM results showed Cu substitution played an important role in magnetic properties of Ni1-xCuxFe2O4. The saturation magnetization (Ms) decreases linearly with increasing Cu2+ content, while coercivity (Hc) has slowly decreased before x ≤ 0.5, and then sharply increased to 723.9 Oe for x = 1.0. The magnetic properties of Ni1-xCuxFe2O4 can be explained in Neel’s model, cation distribution and shape anisotropy.
Soft Nanoscience Letters, Volume 6, pp 1-10; doi:10.4236/snl.2016.61001
Abstract:The aim of present study was to use QbD approaches to evaluate the effect of independent product variables and their interaction on particle size of sodium fluoride and then obtain the optimized experimental condition for predefined particle size of sodium fluoride. The sodium fluoride is mainly used in dental preparation for delivering the fluoride ion to the tooth enamel for that nano-particle size is required. Nowadays the milling process is used to reduce the particle size. But that process has some limitations due to crystalline nature of sodium fluoride; for overcoming those limitations, lyophilization method is used. A 43 level full factorial design was used to study the significant influence of process and product variables i.e. 1) Concentration of sodium fluoride, 2) Concentration of PVP, 3) Sample volume, 4) Drying surface, on particle size of sodium fluoride. The experimental design result shows that independent product variables significantly modify the structure and improve particle size reduction of sodium fluoride.
Soft Nanoscience Letters, Volume 6, pp 31-36; doi:10.4236/snl.2016.62003
Abstract:The silicon oxide nano-powders (SiOx-NPs) were obtained in an atmospheric microwave plasma torch using a gas-phase silicon tetrachloride (SiCl4) with N2 and H2. The gas-phase SiCl4 was injected with H2 gas into the microwave plasma torch generated by N2 and air swirl gas, and then the dark brown powders were deposited on the inner wall of a quartz tube. The sample was analyzed by an X-ray photoelectron spectroscopy (XPS), a scanning electron microscope (SEM), an energy dispersive spectrometer (EDS), and an X-ray diffraction (XRD). The average size and oxidation x values of synthesized SiOx-NPs were approximately 230 nm and 0.91, respectively. Furthermore, the volumetric charge capacity is 1127 mAh/g and has 89.2% retention after 100 cycles.