Soft Nanoscience Letters
ISSN / EISSN : 2160-0600 / 2160-0740
Current Publisher: Scientific Research Publishing, Inc. (10.4236)
Total articles ≅ 101
Latest articles in this journal
Soft Nanoscience Letters, Volume 10, pp 1-15; doi:10.4236/snl.2020.101001
The polymer nanocomposites have been the exponentially growing field of research for developing the materials in last few decades. The remarkable improvement in the polymer nanocomposite is found when a small amount of nanosized particles are added to a polymer matrix. The addition of inorganic solid nanoparticles (typically in the form of fibres, flakes, spheres or fine particles) into polymer matrix increases their physical, structural and mechanical properties. Since the polymer-nano composites have been the staple of modern polymer industry, their durability under various environmental conditions and degradability after their service life are also essential fields of research. This leads to focus on preparation & characterization of polymer nanocomposite. This article is intended to review the status of worldwide research in this aspect. The successful application of nano particles depends upon both the correct preparation techniques followed by testing through characterization. Surface modification can improve the inherent characteristics of the nano particles and serve to prepare nano composites inexistent in nature. Therefore, some tools as their various properties like electrical, optical and morphological can be used to optimize the preparation of polymer nano composites. This chapter will make an overview about different routes to prepare polymer-based nano composites by extrusion, synthesis of nano particles by sol-gel reactions, sputtering and mainly by physical evaporation deposition method.
Soft Nanoscience Letters, Volume 10, pp 17-26; doi:10.4236/snl.2020.102002
Nanotechnologies, nanoparticles and nanomaterials, which are part of everyday life today, are the subject of intense research activities and a certain amount of media coverage. In this article, the concepts of nanotechnologies, nanoparticles and nanosciences are defined and the interest in this scale of the matter is explained by specifying in particular the particular properties of nanoobjects. Large-scale applications of nanoparticles, particularly in the field of chemicals, everyday life and catalysis are presented.
Soft Nanoscience Letters, Volume 9, pp 45-57; doi:10.4236/snl.2019.94004
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 17-33; doi:10.4236/snl.2019.92002
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 9, pp 35-44; doi:10.4236/snl.2019.93003
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 1-16; doi:10.4236/snl.2019.91001
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 8, pp 1-7; doi:10.4236/snl.2018.81001
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 8, pp 9-19; doi:10.4236/snl.2018.82002
Transition metal chalcogenide nanocomposite thin films deposited by chemical routes are currently attracting wide attention being inexpensive, simple and have utility for large area applications. The role of substrate becomes very important in film deposition as well as in controlling their properties due to strain induced properties modification and lattice mismatch. CuS/PVA nanocomposite thin films were successfully deposited on glass and silicon substrates using sol-gel technique. Thin films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), UV-visible (UV-VIS) and Raman spectroscopy. Structural data confirm the amorphous nature of as grown films which transform into crystalline films after annealing at 200°C. The degree of crystallinity seems to be better in film deposited on silicon substrate in comparison to those grown over glass substrate with average crystallite sizes ≅ 4.00 nm and 7.00 nm for films deposited on glass and silicon substrate respectively. Atomic force microscopy (AFM) images in dynamic as well as contact modes display nanoparticles embedded in polymer network. The films surface roughness parameters quantitatively estimated from AFM micrographs are compared. Raman spectra show a sharp peak at ≅474 cm¯1 assigned to S-S stretching mode of S2 ions in films grown on both substrates and associated as due to presence of hexagonal (covellite) crystal structure. Optical band gaps of thin film on glass and silicon substrate are 2.10 eV and 2.02 eV respectively. The effect of substrate on the measured properties is discussed.
Soft Nanoscience Letters, Volume 7, pp 17-26; doi:10.4236/snl.2017.72002
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 7, pp 1-15; doi:10.4236/snl.2017.71001
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.