Printing Silver Nanogrids on Glass: A Hands-on Investigation of Transparent Conductive Electrodes
Silver Nanogrid/Nanowire Importance The next generation of optoelectronic devices requires transparent conductive electrodes to be lightweight, flexible, cheap, and compatible with large scale manufacturing methods. https://www.youtube.com/watch?v=uvzdbaxo2z8 Kumar, A,. Zhou, C.; The Race to Replace Tin-Doped Indium Oxide: Which Material Will Win? ACS Nano, 4, 11-14.
Silver Nanowire Synthesis Polyol Method: Silver nitrate is reduced by ethylene glycol in the presence of poly(vinylpyrrolidone) (PVP) and copper(ii) chloride. PVP acts as a stabilizing agent, while the copper chloride likely controls the rate of silver reduction and initial seed formation. Korte, K. Rapid Synthesis of Silver Nanowires. 2007 NNIN REU Program, Seattle, WA, 2007; 28-29.
Silver Nanowire Synthesis Template-Assisted Nanowire Synthesis Bentley, A. K.; Farhoud, A. B.; Ellis, A. B.; Lisensky, G. C.; Crone, W. C. J. Template Synthesis and Magnetic Manipulation of Nickel Nanowires. J. Chem. Educ. 2005, 82, 765-767.
Objectives 1. To provide a simple and low-cost experiment that allows introductory nanotechnology students to become familiar with micro- and nanofabrication (direct-printing methods) with real-world relevance. 2. To provide students with opportunities to use various characterization techniques. 3. To introduce students to template modification.
Associated Labs Microcontact-Printing of PVP Grid ENGR 1050: Introduction to Nanotechnology Conductive AFM MSE 2320: Introduction to Scanning Probe Microscopy Bright-Field Microscopy MSE 1820: Fundamentals of Microscopy
Publication Sanders. W. C.; Fabrication of Polyvinylpyrrolidone Micro-/Nanostructures Utilizing Microcontact Printing. J. Chem. Ed. 2015, 92, 1908-1912.
Publication Sanders. W. C., Valcarce, R., Iles, P., Smith, J. S.; Glass, G., Gomez, J., Johnson, G., Johnston, D., Morham, M., Beefus, E., Oz, A., Tomaraei, M.; Printing Silver Nanogrids on Glass. J. Chem. Ed. 2017, 94, 758-763.
Soft Lithography Soft organic materials are used to transfer patterns to substrates. Conformal contact: Stamp is elastic enough to conform to the substrate.
Preparing PDMS Stamps 10 g of silicone elastomer 0.9 g of curing agent Mix for one minute
Microcontact Printing Master AFM image of compact disk.
Preparing PDMS Stamps 1. Cut a CD square 5. Remove stamp from dish 3. Place CD in a shallow dish 2. Remove labels *PDMS is cured on a hot plate for 15-20 minutes 4. Pour PDMS over CD*
Polyvinylpyrrolidone Binder in many pharmaceutical tablets. Adhesive in glue and hot-melt sticks. Used to increase the solubility of drugs in liquid and semi-liquid forms. Found in personal care products (shampoos, toothpastes) and paints.
PVP/Silver Ion Interactions M + M + M + PVP has a strong tendency for complex formation with small molecules and readily interacts with metal cations in solution. Khan, M. S.; Gul, K.; Rehman, N. U. Interaction of Polyvinylpyrrolidone with Metal Chloride Aqueous Solutions. Chin. J. Polym. Sci. 2004, 22, 581-584.
Challenge 1: PDMS/Solution Interaction Water on PDMS Alcohol on PDMS PVP is soluble in water and various alcohols.
Challenge 2: Humidity Small amounts of water can result in the formation of beaded PVP structures. Yuya, N.; Kai, W.; Kim, B. S.; Kim, I. S. Morphology Controlled Electrospun Poly(vinylpyrrolidone) Fibers: Effects of Organic Solid and Relative Humidity. J. Mat. Sci. Eng. with Adv. Tech., 2010, 2, 97-112.
Challenge 2: Humidity The presence of water can also result in the formation of PVP films. Yuya, N.; Kai, W.; Kim, B. S.; Kim, I. S. Morphology Controlled Electrospun Poly(vinylpyrrolidone) Fibers: Effects of Organic Solid and Relative Humidity. J. Mat. Sci. Eng. with Adv. Tech., 2010, 2, 97-112.
Challenge 2: Humidity Small traces of water on the surface of stamps and substrates is removed by heating with a hot plate for approximately 10 minutes prior to the experiment.
Procedure: Spin Coat PVP
Procedure: Microcontact-Printing
Procedure: Microcontact-Printing
Procedure: Microcontact-Printing
Procedure: Sputter Coating with Copper Comparison of cross-sectional data for a PVP grid with no copper layer, and for the same PVP grid after addition of the copper layer suggests the thickness of the copper layer is approximately 5 nanometers thick. Sanders. W. C., Valcarce, R., Iles, P., Smith, J. S.; Glass, G., Gomez, J., Johnson, G., Johnston, D., Morham, M., Beefus, E., Oz, A., Tomaraei, M.; Printing Silver Nanogrids on Glass. J. Chem. Ed. 2017, 94, 758-763.
Procedures: Metallization 4 Ag + (aq)+ C 6 H 5 O 7 Na 3(aq) + 2 H 2 O (l) 4 Ag 0 (s) + C 6 H 5 O 7 H 3(aq) + 3 Na + (aq) + H + (aq) + O 2(g) Ratyakshi; Chauhan, R. P. Colloidal Synthesis of Silver Nano Particles. Asian J. Chem. 2009, 21, S113-116.
Silver Grid on Glass
Optical Images Optical microscope image of PVP grid (40x objective)
Optical Images Optical microscope image of silver grid (40x objective)
AFM Data: Physical Dimensions Atomic force microscope images of copper-coated PVP grid before the reaction with silver nitrate/sodium citrate solution (a) and after the reaction (b). A cross-sectional profile of both AFM scans (c). Sanders. W. C., Valcarce, R., Iles, P., Smith, J. S.; Glass, G., Gomez, J., Johnson, G., Johnston, D., Morham, M., Beefus, E., Oz, A., Tomaraei, M.; Printing Silver Nanogrids on Glass. J. Chem. Ed. 2017, 94, 758-763.
SEM Data EDS scan on and off the silver nanogrid pattern (a). EDS spectra of both scans (b). Sanders. W. C., Valcarce, R., Iles, P., Smith, J. S.; Glass, G., Gomez, J., Johnson, G., Johnston, D., Morham, M., Beefus, E., Oz, A., Tomaraei, M.; Printing Silver Nanogrids on Glass. J. Chem. Ed. 2017, 94, 758-763.
SEM Data Sanders. W. C., Valcarce, R., Iles, P., Smith, J. S.; Glass, G., Gomez, J., Johnson, G., Johnston, D., Morham, M., Beefus, E., Oz, A., Tomaraei, M.; Printing Silver Nanogrids on Glass. J. Chem. Ed. 2017, 94, 758-763.
Conductivity Sanders. W. C., Valcarce, R., Iles, P., Smith, J. S.; Glass, G., Gomez, J., Johnson, G., Johnston, D., Morham, M., Beefus, E., Oz, A., Tomaraei, M.; Printing Silver Nanogrids on Glass. J. Chem. Ed. 2017, 94, 758-763.
Acknowledgements SLCC Chemistry Department SLCC Engineering Department Dr. Peter Iles Ron Valcarce Dr. James Smith Joven Calara Gabe Glass Jesus Gomez Glen Johnson Aimee Oz Maclaine Morham Mohammad Tomarei Aubrey Lines Myles Van Weerd John Meyers Davies Young Cristofer Page Kyle Salisbury Dan Johnston Elliot Befus