This project is focusing on the shape of silver nanoparticles and the aspect ratio of silver nanowires for the control of their absorption spectrum in the visible light to infrared ranges. Synthesis of metal nanoparticles has become increasingly important in science and engineering. Being able to control the processes is vital to success in applications and uncovering the mechanisms of nanoparticle production. Nanowires are one of the varieties of nanoparticles that will be utilized for this project. There are many different metals that can be used to synthesize nanowires, I am focusing on silver. Silver exhibits the highest thermal conductivity out of all metals (Sun, 2001). Silver nanowires with a large aspect ratio also show an absorbance of higher wavelengths then other nanoparticles, like spherical silver nanoparticles (Sun, 2001). Other silver particles that exhibit similar characteristics and show a higher wavelength absorbance will be considered as well. Controlling reaction conditions allow plasmonic, oscillatory quantum motion, colloids to obtain architecturally predictable nanostructures and can be used to understand their optical properties (Motl, 2013). There are many shapes that nanoparticles can take up. Each shape, on the nanoscale shows different properties that can be utilized, such as conductivity, anisotropy, and, what I am interested in, absorbance of light.
I have used the work that Jana et al. conducted regarding a batch process synthesis of silver nanowires as a basis for generation of our silver nanowires. I will use a solution based process that is cost effective, quick, and easy to control for the uniform synthesis of silver nanowires and other silver nanoparticles. Microreactor-assisted nanomaterial de...
... middle of paper ...
...in any of my future endeavors.
References
Choi, C. H. (2013). Synthesis of colloidal metal oxide nanocrystals and nanostructured surfaces using a continuous flow microreactor system and their applications in two-phase boiling heat transfer.
Jana, N. R., Gearheart, L., & Murphy, C. J. (2001). Wet chemical synthesis of silver nanorods and nanowires of controllable aspect ratio Electronic supplementary information (ESI) available: UV–VIS spectra of silver nanorods. See http://www. rsc.org/suppdata/cc/b1/b100521i. Chemical Communications, (7), 617-618.
Motl, N. E., Smith, A. F., DeSantis, C. J., & Skrabalak, S. E. (2014). Engineering plasmonic metal colloids through composition and structural design. Chemical Society Reviews.
Sun, Y., Gates, B., Mayers, B., & Xia, Y. (2002). Crystalline silver nanowires by soft solution processing. Nano Letters, 2(2), 165-168.
Colloidal silver is particles of silver broken down or mixed into liquid. In the early 20th, ,century colloidal silver or as it is more popularly known “silver water” was marketed as a cure for tumors; now in alternative medicine it is referenced as a cure all with healing properties.
Nano-thermal analysis methods are also known as micro-thermal procedures and they use the principle of characterizing highly localized materials on a micrometer. The characterization is then changed from a micrometer scale to a sub-micrometer scale with the temperature being regulated to the specified units. The application of nano-thermal analysis methods started towards the end of the 20th century. Although it has been applied in several other fields including microelectronics, its application in pharmaceuticals has not been that popular.
The small size ranging from 0.1 to 10 micrometres of nanobots make it difficult to be constructed. The process of working atom by atom and molecule by molecule is monotonous work and the miniaturization of synthetic mechanisms to a nanoscale will only be achievable with the advancement of research in metallurgy.
This experiment determined the validity of existing pool boiling curve models for spheres in nitrogen. We quenched copper, stainless steel and brass spheres of two different diameters in a pool of nitrogen. We created boiling curves comparing the temperature difference between the sphere surface and saturated nitrogen to the heat flux from the sphere. The curves were then compared to Rohsenow’s material dependent equation for nucleate boiling and other models to predict the minimum and maximum heat fluxes, independent of surface material. The relationship between heat flux and temperature change is different than the relationship found by Rohsenow, and is size and material dependent. We also found that maximum and minimum heat flux depends on material and radius. There is no correlation between thermal conductivity and heat transfer coefficient based on our findings; however, spheres with a larger diameter have larger maximum convection heat transfer coefficient.
Native Silver, or more commonly know as just “silver,” is a mineral that is created from the element silver (also called Argentum; abbreviated on the periodic table as Ag). It is seldom found as a native element mineral. Instead, it has tendencies to mix together with other minerals such as quartz, gold, and copper.1 11 Silver is actually not really reactive. It is even considered one of the “noblest” of the transition metals, noblest meaning “least chemically reactive.”5 In fact, it is used in many dishes as a fancy garnish that is able (and sometimes meant) to be eaten. Native silver also has one of the highest conductivity rates, both electrical and thermal, of metals. Because of this property, it is used in many electronic circuits as a thin coating.5 Due to its shiny, lustrous quality, native silver is also used for jewelry, decorations, and ornaments.
If soap and water don't work, and you are feeling a bit brave, you can make homemade cleaners that work well on silver. These cleaners include making combinations out of baking soda and water, as well as ones made of olive oil and lemon juice. This not only can clean your silver, but leave it smelling lemony fresh!
Alford, Terry L., L. C. Feldman, and James W. Mayer. Fundamentals of Nanoscale Film Analysis. New York: Springer, 2007. Print.
Grundmann, Marius. Physics of Semiconductors: An Introduction Including Devices and Nanophysics. New York: Springer, 2006. Print.
Nanoparticles are defined as particulate materials with at least one dimension of less than 100 nanometers (nm), even the particles could be zero dimension in the case of quantum dots (Bar et al., 2009). Metal nanoparticles have been of great interest due to their distinctive features such as catalytic, optical, magnetic and electrical properties (Rassaei et al., 2008).
The sol–gel method allows the synthesis of TiO2 nanoparticles with different morphologies like sheets, tubes, particles, wires, rods, mesoporous and aerogels. The sol–gel method is also used due to the easy technique, low price, the purity of oxides obtained and the lower synthesis temperatures.
In the 1970s, scientists discovered the SERS phenomenon, in which pyridine molecules were absorbed onto a roughened silver surface, resulting in a significant enhancement of the Raman signals [2]. It was found that SERS can enhance the scattering effect markedly, even up to 1014 times the common Raman signal [3], which overcame the low sensitivity of the common Raman technique. The enhancement is mainly owing to the amplification of the light resulting from the excitation of localized surface plasmon resonances
Silver nanoparticles has been shown huge variations in its property from the macro scale, it’s one of the most studied nanoparticles. The silver nanoparticles has been
Nanoparticles have got considerable attention globally in recent years due to their wide range of applications in many fields like pharmaceutical applications environmental pollution control, catalysis, biological tagging, drug delivery systems, photonics, optoelectronics and material chemistry (Ghosh et al., 2012). Nanoparticles are considered to be the building blocks of next generation of electronics, optoelectronics, and various chemical biochemical sensors, in therapeutics and diagnostics (Pavani et al., 2013).
The reduction of silver ions was observed using spectroscopic analysis by measuring the spectral wave length change and observed a peak at 430nm. The spectrum produced due to the bioreduction of silver ions and its Surface Plasmon Resonance (SPR) at room temperature was observed using Thermo UV10 Spectrophotometer at a band width of 1nm.
Nanomaterials describe (in principle) ingredients the single units of which (in at least one dimension) between 1 and 1000 nanometers (10−9 meter) but is usually 1—100 nm (the usual definition of nanoscale[1]).