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Xiong, Ziye (2017) AG-CU BIMETALLIC NANOPARTICLE SYNTHESIS AND PROPERTIES. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

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Ziye Xiong, PhD University of Pittsburgh, 2017

Silver(Ag)-Copper(Cu) bimetallic nanoparticles (NPs) were synthesized by chemical reduction with the assistance of a microwave reactor. Considering the difference in redox potential of Ag(I) and Cu(II), the effect of heating method was compared using ‘one-pot’ and ‘two-pot’ synthesis of Ag-Cu shell-core and Ag-Cu core-shell nanoparticles. One-pot synthesis naturally results in Ag-Cu core-shell nanoparticles since silver has the higher redox potential than copper. In the two-pot synthesis of Ag-Cu core-shell nanoparticles, the effect of the heating conditions was compared. At the highest reaction temperature (175◦C), the galvanic reaction by which silver reduction occurred through the oxidation copper metal, was suppressed and higher Cu/Ag phase ratios could be achieved.
Nanoparticles properties were examined in the following areas: (i) nanoparticle solubil- ity and antibacterial effects, (ii) sintering behavior and electrical conductivity of nanoparticle films. Enhanced antibacterial effects were observed for mixtures of Ag and Cu nanoparticles against planktonic M.smegmatis silver resistant mutants as well as the wild type when compared to the antibacterial effects of pure Ag or Cu NPs alone. However, solubility tests in deionized water, showed that very low Ag ion concentrations resulted when copper was present either in bimetallic nanoparticles or in mixtures of Ag and Cu NPs. This was attributed to a galvanic effect that suppressed the oxidation of silver.
The deposition of nanoparticles on surfaces was studied in terms of the ability of the deposited nanoparticles to inhibit the growth the biofilm. Printed silver nanoparticle dots deposited on microfilters exhibited significant antibacterial effect in inhibiting the growth of biofilm over the whole micro filter surface. Increasing the areal coverage of the dots or their size decreased the number and the size of bacterial colonies.
Finally, the sintering behavior of Ag–Cu shell core nanoparticles proved superior to that of Cu nanoparticles and to mixture of silver and copper nanoparticles. This resulted in higher electrical conductivity in the nanoparticle films sintered at lower temperature. This is thought to be due to the higher fraction of Ag-Ag particle contacts.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Xiong, Ziyeziyexiong2010@gmail.comzix2
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairNettleship,
Committee MemberLee,
Committee MemberWang,
Committee MemberLeu,
Date: 27 September 2017
Date Type: Publication
Defense Date: 16 May 2017
Approval Date: 27 September 2017
Submission Date: 8 May 2017
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Number of Pages: 171
Institution: University of Pittsburgh
Schools and Programs: Swanson School of Engineering > Materials Science and Engineering
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: Ag-Cu bimetallic nanoparticles,two-pot synthesis, core shell structure,solubility, sintering,
Date Deposited: 27 Sep 2017 19:19
Last Modified: 27 Sep 2017 19:19

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  • AG-CU BIMETALLIC NANOPARTICLE SYNTHESIS AND PROPERTIES. (deposited 27 Sep 2017 19:19) [Currently Displayed]


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