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The Effect of Temperature on the Aggregation of Colloidal Gold

Shannon Cattie. The Effect of Temperature on the Aggregation of Colloidal Gold. Problem. How does temperature affect the rate of aggregation of colloidal gold?. Background Information. What is Colloidal Gold? Binary liquid mixture, containing gold nanoparticles

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The Effect of Temperature on the Aggregation of Colloidal Gold

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  1. Shannon Cattie The Effect of Temperature on the Aggregation of Colloidal Gold

  2. Problem • How does temperature affect the rate of aggregation of colloidal gold?

  3. Background Information • What is Colloidal Gold? • Binary liquid mixture, containing gold nanoparticles • Can be ingested orally to treat arthritis, hypertension, skin conditions, heart rhythm, depression, inflammation, circulation, pain and stress relief, nerve complaints, and act as an IQ booster • History of Colloidal Gold • Appearance in the Old Testament of the Bible (Exodus 32) • Alexandria, Egypt • Ancient Rome • Used for photography in 1842 in the process of crysotype

  4. Background Information • Nanotechnology • Deals with processes that take place on the nanometer scale, which is one billionth of a meter. • Properties of metals are different on the Nano scale than in bulk. • Aggregation • The formation of aggregates causing a change in color • For the most part, irreversible • An aggregate is a group of particles which are held together; they can be held together in any way

  5. Background Information • Why add Salt to Aggregate Colloidal Gold? • Gold particles in colloidal solutions are negatively charged, so they repel each other. They cannot clump together. • Salt shields negative charges, causing clumping • Why does Colloidal Gold turn Blue after Aggregation? • Because of the change in the light spectra • Salt (NaCl) • Suppose to lower the temperature in which aggregation occurs • Enhances aggregation

  6. Hypothesis • If the temperature of colloidal gold is raised, then the particles of the colloidal gold will aggregate more readily than those at lower temperatures.

  7. Materials To make the colloidal gold For each trial Cuvetteand cap 1000 μLof 1 M sodium chloride solution 3mL of colloidal gold 100μL of the solution VernierSpectro-vis Vernier Logger Pro Software 10 mL Graduated Cylinder Micropipette Thermometer • 20 mL of 1mM hydrogen tetrachloroaurate solution • Distilled water • 2mL of 1% trisodium citrate solution • Hot plate • Erlenmeyer flask • Graduated cylinder • Crucible tongs • Aluminum Foil • Refrigerator

  8. Procedure – Making the Colloidal Gold • Measure 20 mL of 1mM hydrogen tetrachloroaurate solution in a graduated cylinder • Pour the 20 mL of 1mM hydrogen tetrachloroaurate solution into a 250 mL Erlenmeyer Flask • Add distilled water to the 200 mL mark on the Erlenmeyer flask • Place the Erlenmeyer flask onto a hot plate and turn the hot plate on a medium-high setting • Bring to a gentle boiling • Measure 2mL of 1% trisodium citrate solution using a 10 mL graduated cylinder • Add the 2mL of 1% trisodium citrate solution to the boiling solution in the Erlenmeyer flask • Continue heating the solution at a gentle boil for about 10 minutes until the solution is stable at a ruby or wine-red color and no longer changes color • After the color stabilizes, remove the Erlenmeyer flask from the hot plate and allow to cool • Add distilled water until the solution reaches 200 mL again

  9. Procedure – Testing the Aggregation • Begin by hooking up the spectrometer to the computer and opening Logger Pro • Measure 3 mL of Colloidal gold into a 10 mL graduated cylinder • Pour it into a cuvette • Cap the cuvette, wipe the sides of excess liquid, and place into the spectrometer • Locate the peak of absorption on the graph and record • Heat colloidal gold to 30°C by using a hot plate, let sit for the day and accumulate to room temperature (10°C), or place in refrigerator and cool to 10°C

  10. Procedure – Testing the Aggregation 7. Recordthe peak absorption on each graph after following this procedure: • Add colloidal gold to the cuvette • Place into Spectro-vis • Record peak absorption • Measure 100 microliters of sodium chloride solution using a micropipette • Add the 100 microliters of sodium chloride solution into the cuvette • Shake the cuvette once, and let sit for approximately 20 seconds • Return toSpectro -Vis and record peak absorbtion • Repeat steps d-g nine times

  11. Variables • Independent variable: Sodium chloride solution • Dependent variable: Aggregation rate • Control: Room temperature • Constants: Colloidal gold and amount of sodium chloride solution added

  12. Data – Colloidal Gold at 10°C

  13. Data – Colloidal Gold at 20°C

  14. Data – Colloidal Gold at 30°C

  15. Data – Comparison of all Three

  16. Possible Errors and Improvements Possible Errors: • The testing took place on different days • Slight temperature, humidity, and weather change • Change in temperature as the trials were in progress • Temperature of sodium chloride solution Improvements to this experiment: • Make the sodium chloride solution the same temperature as the colloidal gold, removing any difference in temperature between what was recorded • Monitor the solution temperature during procedure

  17. Conclusion • The data received showed all three temperatures aggregated similarly. • The hypothesis was rejected at the temperatures tested. • Further testing would be needed to conclude whether higher temperatures of colloidal gold increase the rate of aggregation.

  18. Importance of this experiment • Pertains much to recent scientific discoveries about nanotechnology • Nanotechnologists are testing the ability of colloidal gold to target cancer tumors.

  19. Works Cited • Aslan, K., Lakowicz, J. R., & Geddes, C. D. (2004, Winter/Spring). • Nanogold-plasmon-resonance-based glucose sensing. Retrieved from • http://www.theinstituteoffluorescence.com/Publications%20PDF/23.pdf • Colloidal Gold [Medical treatments using colloidal gold]. (1971). Retrieved from • http://www.alchemistsworkshop.com/ • CytImmune Sciences. (2011). What is Colloidal Gold? Retrieved from http://www.cytimmune.com/ • go.cfm?do=Page.View&pid=15 • Goldman, M. V. (n.d.). Absorption Spectra. In Absorption Spectra. Retrieved from Colorado Commission • on Higher Education and the National Science Foundation website: http://www.colorado.edu/ • physics/2000/quantumzone/fraunhofer.html • IUPAC. (2002, September 5). STABILITY OF COLLOIDAL SYSTEMS, AGGREGATION, COAGULATION, FLOCCULATION. • Retrieved from http://old.iupac.org/reports/2001/colloid_2001/manual_of_s_and_t/node35.html • Malvern Instruments Ltd. (2011). Colloidal Aggregation. Retrieved from • http://www.malverninstruments.fr/LabEng/industry/nanotechnology/colloids_aggregation.htm • NANOYOU. (2011, July/August). Experiment with colorimetric gold nanosensors - Teacher guide (age • 11-13) [A Teacher's guide for experiments with colloidal gold]. Retrieved from • http://www.slideshare.net/NANOYOUproject/ • experiment-with-colorimetric-gold-nanosensors-teacher-guide-age-1113 • Otwinowski, J. (2007, August 26). Temperature Induced Aggregation of Colloids [Journal testing the • effects of temperature on aggregation of colloids]. Retrieved from http://staff.science.uva.nl/ • ~pschall/People/Alumni/Thesis_JakubOtwinowski.pdf • Science In Motion. (2010). #24 Study of Colloidal Gold Solution. Retrieved from • http://www.philasim.org/newmanual/exp24.pdf • Solomatin, S. V., Bronich, T. K., Eisenberg, A., Kabanov, V. A., & Kabanov, A. (2004, February 17). • Colloidal Stability of Aqueous Dispersions of Block Ionomer Complexes:  Effects of • Temperature and Salt [The effects temperature has on colloidal gold]. Retrieved from • http://pubs.acs.org database. • Space Today Online. (2003). Understanding Space Technology Spectrometers . Retrieved from • http://www.spacetoday.org/SolSys/Spectrometers/Spectrometers.html • The Physics Classroom. (1996-2012). Color and Vision. Retrieved from comPADRE website: • http://www.physicsclassroom.com/class/light/u12l2a.cfm • Utopia Silver Supplements. (2005). The First Spiritual Recipe by The Great Physician [The history of • Colloidal Gold]. Retrieved from http://www.colloidalgold.com/history.htm

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