Green synthesis of micron-sized silver flakes and their application in conductive ink


A facile, green method for fabrication of conductive ink composed of Ag flakes was developed for use in flexible printed electronics. The Ag flakes were prepared using AgNO3, nontoxic l-ascorbic acid (Vc) and polyvinylpyrrolidone (PVP) serving as a metal salt, reducing agent and capping agent, respectively. The prepared Ag flakes were characterized by XRD, SEM, and TGA. The combination of PVP and FeCl3 was found to be critical for the formation of the Ag flakes, and reaction activity was affected by temperature. Samples obtained at 140 °C were composed of Ag flakes with an average size of 0.94 ± 0.3 μm. A new fabrication method for producing conductive patterns was designed using a syringe with varying dispersion areas, allowing the ink (Ag flakes and organic solvent) to be applied directly onto a flexible photo paper. The conductivity and flexibility of the pattern were experimentally tested under varying reaction temperatures and bending cycles. Increasing contact area and packing density between Ag flakes resulted in an improved conductivity of the bending pattern. After more than 5000 bending cycles, the patterns were sintered at 160 °C and the resistivity increased from 4.6 ± 0.6 to 22.4 ± 0.8 μΩ cm, acceptable values for practical applications. Sample conductive lines drawn by the Ag flake ink exhibited excellent conductive performance and mechanical integrity, demonstrating a promising method for the formation of flexible microelectrodes or electronic devices.

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  1. 1

    Cao Q, Kim HS, Pimparkar N, Kulkarni JP, Wang C, Shim M, Rogers JA (2008) Medium-scale carbon nanotube thin-film integrated circuits on flexible plastic substrates. Nature 454:495–500

    CAS  Article  Google Scholar 

  2. 2

    Hu A, Guo JY, Alarifi H, Patane G, Zhou Y, Compagnini G, Xu CX (2010) Low temperature sintering of Ag nanoparticles for flexible electronics packaging. Appl Phys Lett 97:153117

    Article  Google Scholar 

  3. 3

    Liao YC, Kao ZK (2012) Direct writing patterns for electroless plated copper thin film on plastic substrates. ACS Appl Mater Interfaces 4:5109–5113

    CAS  Article  Google Scholar 

  4. 4

    Mayer C, Palkovits R, Bauer G, Schalkhammer T (2001) Surface enhanced resonance of metal nano clusters: a novel tool for Proteomics. J Nanopart Res 3:359–369

    Article  Google Scholar 

  5. 5

    Siegel AC, Phillips ST, Dickey MD, Lu N, Suo Z, Whitesides GM (2010) Foldable printed circuit boards on paper substrates. Adv Funct Mater 20:28–35

    CAS  Article  Google Scholar 

  6. 6

    Kamyshny A, Steinke J, Magdassi S (2011) Metal-based inkjet inks for printed electronics. Open Appl Phys J 4:19–36

    CAS  Article  Google Scholar 

  7. 7

    Li W, Chen M, Wei J, Li W, You C (2013) Synthesis and characterization of air-stable Cu nanoparticles for conductive pattern drawing directly on paper substrates. J Nanopart Res 15:1949

    Article  Google Scholar 

  8. 8

    Li W, Li W, Wang M, Liu G, Chen M (2016) Direct writing of stable Cu–Ag-based conductive patterns for flexible electronics. RSC Adv 6:10670–10676

    CAS  Article  Google Scholar 

  9. 9

    Kosmala A, Wright R, Zhang Q, Kirby P (2011) Synthesis of silver nano particles and fabrication of aqueous Ag inks for inkjet printing. Mater Chem Phys 129:1075–1080

    CAS  Article  Google Scholar 

  10. 10

    Grouchko M, Kamyshny A, Magdassi S (2009) Formation of air-stable copper–silver core–shell nanoparticles for inkjet printing. J Mater Chem 19:3057–3062

    CAS  Article  Google Scholar 

  11. 11

    Jang S, Seo Y, Choi J, Kim T, Cho J, Kim S, Kim D (2010) Sintering of inkjet printed copper nanoparticles for flexible electronics. Scr Mater 62:258–261

    CAS  Article  Google Scholar 

  12. 12

    Russo A, Ahn BY, Adams JJ, Duoss EB, Bernhard JT, Lewis JA (2011) Pen-on-paper flexible electronics. Adv Mater 23:3426–3430

    CAS  Article  Google Scholar 

  13. 13

    Tai YL, Yang ZG (2011) Fabrication of paper-based conductive patterns for flexible electronics by direct-writing. J Mater Chem 21:5938–5943

    CAS  Article  Google Scholar 

  14. 14

    Li W, Wang Y, Wang M, Li W, Tan J, You C, Chen M (2016) Synthesis of stable Cu core Ag shell and Ag particles for direct writing flexible paper-based electronics. RSC Adv 6:62236–62243

    CAS  Article  Google Scholar 

  15. 15

    Chen D, Qiao X, Qiu X, Chen J, Jiang R (2011) Large-scale synthesis of silver nanowires via a solvothermal method. J Mater Sci Mater Electron 22:6–13

    Article  Google Scholar 

  16. 16

    Wiley B, Sun Y, Mayers B, Xia Y (2005) Shape-controlled synthesis of metal nanostructures: the case of silver. Chem Eur J 11:454–463

    CAS  Article  Google Scholar 

  17. 17

    Chen J, Lu G, Zhu L, Flagan RC (2007) A simple and versatile mini-arc plasma source for nanocrystal synthesis. J Nanopart Res 9:203–213

    Article  Google Scholar 

  18. 18

    Hong HK, Park CK, Gong MS (2010) Preparation of Ag/PVP nanocomposites as a solid precursor for silver nanocolloids solution. Bull Korean Chem Soc 31:1252–1256

    CAS  Article  Google Scholar 

  19. 19

    Wang H, Qiao X, Chen J, Wang X, Ding S (2005) Mechanisms of PVP in the preparation of silver nanoparticles. Mater Chem Phys 94:449–453

    CAS  Article  Google Scholar 

  20. 20

    Xu LY, Yang GY, Jing HY, Wei J, Han YD (2013) Pressure-assisted low-temperature sintering for paper-based writing electronics. Nanotechnology 24(35):355204

    CAS  Article  Google Scholar 

  21. 21

    Li W, Li W, Wei J, Tan J, Chen M (2014) Preparation of conductive Cu patterns by directly writing using nano-Cu ink. Mater Chem Phys 146:82–87

    Article  Google Scholar 

  22. 22

    Li W, Chen M, Li W, You C, Wei J, Zhi L (2014) Synthesis of air stable silver nanoparticles and their application as conductive ink on paper based flexible electronics. Mater Res Innov 18(sup4):S4–723

    Google Scholar 

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The authors acknowledge the financial support for this work from the National Nature Science Foundation of China (No. 51501129), Tianjin “131” Innovative Talents (the third level in 2015).

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Correspondence to Yun Zhao or Minfang Chen.

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Li, W., Xu, X., Li, W. et al. Green synthesis of micron-sized silver flakes and their application in conductive ink. J Mater Sci 53, 6424–6432 (2018).

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