Determination of Gold Nanoparticle Sizes

Determination of fortunate Nano particle SizesDaron Chua compendIn this experiment, the objectives of this experiment was to understand the diverse coats of favorable nanoparticles and to synthersizing Colloidal funds nanoparticles by liquid chemic method.Z-average of nanoparticles for the carminedish resolving power and the greyish stem was 60.86 and 50.40 respectively. However it was noted that at that place were impurities in the ascendant hence poignant the Z-average. As such, the colour of the radical and the Z-average did not tally.It was discovered that by adding sodium chloride into the solutions there impart be colour change. This is collect to NaCl aggregating the nanoparticles together. This ca delectations the nanoparticles to absorb the red readable hence reflecting the solution in a more dingy colour.Other methods of forming favorable nanoparticles and a diverse application for princely nanoparticles were noted. cornerstoneThe objectives of this expe riment was to understand the diverse applications of gold nanoparticles. Colloidal gold nanoparticles were synthesized by means of liquid chemical method.TheoryLiquid Chemical orderMost of the gold nanoparticles are produced in a liquid (liquid chemical methods) by lessening of hydrogen tetrachloroautate (HAuCl4). By dissolving HAuCl4, the solution is rapidly stirred succession a reducing agent is being added. This causes Au3+ ions to be trendd to soggy goldatoms. As more and more of these gold atoms form, the solution becomes supersaturated, and gold gradually starts toprecipitatein the form of sub-nanometer particles. The rest of the gold atoms that form stick to the existing particles, and, if the solution is stirred vigorously enough, the particles will be fairly uniform in size showing the solution as red.To prevent the particles from aggregating, some separate of stabilizing agent that sticks to the nanoparticle surface is commonly added. Also, gold colloids can be syn thesized without stabilizers bylaser ablationsin liquids. They can be functionalized with various organic ligands to create organic-inorganic hybrids with advanced functionality.several(prenominal) methods that revolve around this idea are Turkevich method, brust method and perrault method, etc. cash NanoparticlesColloidal goldis a breaking particles ofgoldin a fluid, usually water. The liquid is usually either an intense red colour (for particles less than 100nm) or rich/purple (for larger particles).As particle size increases, the wavelength of surface plasmon tintinnabulation related absorption shifts to longer, redder wavelengths. Red wild is then absorbed, and unappeasable luminosity is reflected, yielding solutions with a pale blue or purple color. A change in temperature will also affect which the gold to be at a different energy band. The diameter of gold nanoparticles determines the Wavelength of light absorbed as shown on the diagram illustrated above.ProceduresStoc k resultant usance0.1g of HAuCl4 was fade out in 500ml distilled water to harbor 1.0mM hydrogen tetrachloroautate.0.5g of Na3C6H5O7.2H2O (trisodium turn dehydrate) was dissolved in 50ml of distilled water to obtain 1% concentration.0.5g of NaCl was dissolved in 10ml of distilled water.Experiment20ml of 1.0mM HAuCl4 was added to a conical flask.The conical flask was placed in a rousing hot plate and a magnetic stir bar was added.2 samples were prepared. One was stirred continuously even it was at boiling point. The other(a) sample stopped stirring once it was boiled.2ml of 1% solution of trisodium citrate dehydrate was then added to the boiling solution. bullion Sol was gradually create as citrate push downs the gold (III).Presence of a colloidal suspension was observed by the reflection of a laser beam from the particles.The solution of both samples were being transferred to two test tubes.5 10 drops of 1M NaCl solution was added into one of the test tubes and the color change of the solution was being observed.The two solutions in the test tubes were being filtered with a 0.45 um syringe filter. The solutions were subsequently transferred into a sample holder.The Malvern Zetasizer Nano S Light scattering equipment was utilize to measure the size of the nanoparticles in the two sample holder. (0.47 refractive index was employ.)ResultsResults as follows Solution with spin even at boiling point Colour observed Reddish BrownSize of Gold nanoparticle 63.77 with 3 peaksPeak 1 41.1, Peak 2 433.2, Peak 3 3913Solution without spin at boiling point Colour observed Greyish / Bluish / get inSize of Gold nanoparticle 53.31 with 3 peaksPeak 1 143.9, Peak 2 1.651, Peak 3 3213CalculationStandard Calibration67.54nm 63.63nm = 2.91nmSize of Gold nanoparticle (Reddish/Brown) Z-Average63.77nm 2.91nm = 60.86 nmSize of Gold nanoparticle (Greyish/Blue) Z-Average53.31nm 2.91 nm = 50.40 nmDiscussionFrom the results, Z average for the reddish brown solution was calculated at 60.86nm, firearm the greyish/blue was calculated at 50.40nm.With reference to theory, the results concluded by Z-average is inaccurate. By right, anything at the blue shift is of a larger particle size. By reading off the highest intensity peaks of both graphs of red and blue solutions, size of particles were 41.1nm and 143.9nm respectively. Ideally 1 peak in the chart would be best.Other peaks that affected the Z-average were probably impurities. This error may be due to carelessness of assuming all equipments provided for the experiment were clean. Hence there could be dirt or dust trapped whatsoever.In order to obtain even smaller particle sizes, adding of all solutions should have been done slowly, for congressman adding trisodium citrate drop by drop, allowing the droplet to fully react with the solution out front adding in another. With that, the merge part is no doubt the most all important(p) process parameter of the experiment.Other factors that affe ct particle sizes are immix time and temperature and concentration. Different temperatures within the reaction will cause warmness and mass transfer gradients. A low concentration of solution will yield too low of a result and lastly for our case, mixing time. Insufficient mixing time/stoppage of mixing will command the nanoparticles to disperse. Hence having a larger particle size.1. Explain the functions of trisodium citrate used in this experiment.In this experiment, Trisodium citrate acts as an reducing agent to reduce hydrogen tetrachloroautate in order to produce spheroidal gold paticles. In general, the greater the concentration and power of the reducing agent. The smaller the resultant gold particles in the suspension.2. Account for the colour change observed in feel 4.6In step 4.6 of the practical booklet, NaCl solution is added into the solution create a colour change. By adding NaCl into the solution, it causes the gold nanoparticle surface charge to turn neutral, ca using the nanoparticle to aggregate. As a result the solution colour changes from red to dismal blue. As for the greyish bluish solution, it turns to a even clearer solution.A larger particle size will cause absorption of the red light hence reflecting the solution as blue.3. State two other synthetic thinking methods for gold nanoparticles beside the liquid chemical method.SonolysisOne method for the experimental extension of gold particles is by sonolysis. The process is based on ultrasound. It uses the reaction of an sedimentary solution of HAuCl4withglucose. The reducing agentsare hydroxyl radicals and sugar pyrolysis radicals. The morphology obtained is that of nanoribbons with width 3050nm and length of several micrometers. These ribbons are very flexible and can bend with angles larger than 90. When glucose is being replaced by cyclodetrin (a glucose oligomer), only spherical gold particles are obtained.Block Copolymer-mediated MethodOther method for gold nanoparticles i s by using a block copolymer.In this synthesis methodology, block copolymer plays the dual role of a reducing agent as well as a stabilizing agent.The composition of gold nanoparticles comprises three main steps reduction of gold salt ion by block copolymers in the solution and formation of gold clusters,adsorption of block copolymers on gold clusters,and further reduction of gold salt ions on the surfaces of these gold clusters for the growth of gold particles in steps.This method usually has a limited-yield (nanoparticle concentration), which does not increase with the increase in the gold salt concentration. Recently a test has been done that by adding trisodium citrate in 11 molar ratio increases the gold formation by many gold.4. Cite some other application in addition to those mentioned under introduction.Electronics Gold nanoparticles are designed for use as conductors from printable inks to electronic chips. As the world of electronics become smaller, nanoparticles are imp ortant components in the chip design. Nanoscale gold nanoparticles are being used to connect resistors, conductors, and other elements of an electronic chip.Probe Gold nanoparticles are relatively dense, making them useful as probes for transmission electron microscopy.Catalyst Gold nanoparticles are used as catalysts in a number of chemical reactions. The surface of a gold nanoparticle can be used for discriminating oxidation or in certain cases the surface can reduce a reaction (nitrogen oxides). Gold nanoparticles are being developed for dismiss cell applications. These technologies would be useful in the automotive and display industry. demonstrationIn conclusion, the experiment was not very successful as there were impurities in the solution. Hence the Z average was being affected. However objectives were met as colloidal gold was being synthesized and applications of gold particles were also understood.Referenceshttp//en.wikipedia.org/wiki/Colloidal_goldhttp//www.sigmaald rich.com/materials-science/nanomaterials/gold-nanoparticles.htmlhttp//www.webexhibits.org/causesofcolor/9.htmlhttp//clustertwo.org/Shaowei Chen lectures/ practice bundling 2 lecture 2.pdfhttp//www.ivdtechnology.com/article/manufacturing-high-quality-gold-sol