Directed assembly of nanoparticles into continuous microstructures by standing surface acoustic waves

Directed-assembly by standing surface acoustic waves (SSAWs) only requires an acoustic contrast between particles and their surrounding medium. It is therefore highly attractive as this requirement is fulfilled by almost all dispersed systems. Previous studies utilizing SSAWs demonstrated mainly rev...

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Main Authors: Sazan, Haim, Piperno, Silvia, Layani, Michael, Magdassi, Shlomo, Shpaisman, Hagay
Other Authors: School of Materials Science and Engineering
Format: Article
Language:English
Published: 2020
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Online Access:https://hdl.handle.net/10356/142549
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1425492020-06-24T04:22:30Z Directed assembly of nanoparticles into continuous microstructures by standing surface acoustic waves Sazan, Haim Piperno, Silvia Layani, Michael Magdassi, Shlomo Shpaisman, Hagay School of Materials Science and Engineering Engineering::Materials Nanoparticle Sintering Directed Assembly Directed-assembly by standing surface acoustic waves (SSAWs) only requires an acoustic contrast between particles and their surrounding medium. It is therefore highly attractive as this requirement is fulfilled by almost all dispersed systems. Previous studies utilizing SSAWs demonstrated mainly reversible microstructure arrangements from nanoparticles. The surface chemistry of colloids dramatically influences their tendency to aggregate and sinter; therefore, it should be possible to form permanent microstructures with intimate contact between nanoparticles by controlling this property. Dispersed silver nanoparticles in a microfluidic channel were exposed to SSAWs and reversibly accumulated at the pressure nodes. We show that addition of chloride ions that remove the polyacrylic capping of the nanoparticles trigger their sintering and the formation of stable conducting silver microstructures. Moreover, if the destabilizing ions are added prior to nanoparticle assembly while continuously streaming the dispersion through the acoustic aperture, the induced aggregation leads to formation of significantly thinner microstructures, which are (for the first time) unlimited in length by the acoustic apparatus. This new approach overcomes the discrepancy between the need for organic dispersants to prevent unwanted aggregation in the dispersion, and the end product's requirement for intimate contact between the colloidal particles. 2020-06-24T04:22:30Z 2020-06-24T04:22:30Z 2019 Journal Article Sazan, H., Piperno, S., Layani, M., Magdassi, S., & Shpaisman, H. (2019). Directed assembly of nanoparticles into continuous microstructures by standing surface acoustic waves. Journal of colloid and interface science, 536, 701-709. doi:10.1016/j.jcis.2018.10.100 0021-9797 https://hdl.handle.net/10356/142549 10.1016/j.jcis.2018.10.100 30408690 2-s2.0-85055965761 536 701 709 en Journal of colloid and interface science © 2018 Elsevier Inc. All rights reserved.
institution Nanyang Technological University
building NTU Library
country Singapore
collection DR-NTU
language English
topic Engineering::Materials
Nanoparticle Sintering
Directed Assembly
spellingShingle Engineering::Materials
Nanoparticle Sintering
Directed Assembly
Sazan, Haim
Piperno, Silvia
Layani, Michael
Magdassi, Shlomo
Shpaisman, Hagay
Directed assembly of nanoparticles into continuous microstructures by standing surface acoustic waves
description Directed-assembly by standing surface acoustic waves (SSAWs) only requires an acoustic contrast between particles and their surrounding medium. It is therefore highly attractive as this requirement is fulfilled by almost all dispersed systems. Previous studies utilizing SSAWs demonstrated mainly reversible microstructure arrangements from nanoparticles. The surface chemistry of colloids dramatically influences their tendency to aggregate and sinter; therefore, it should be possible to form permanent microstructures with intimate contact between nanoparticles by controlling this property. Dispersed silver nanoparticles in a microfluidic channel were exposed to SSAWs and reversibly accumulated at the pressure nodes. We show that addition of chloride ions that remove the polyacrylic capping of the nanoparticles trigger their sintering and the formation of stable conducting silver microstructures. Moreover, if the destabilizing ions are added prior to nanoparticle assembly while continuously streaming the dispersion through the acoustic aperture, the induced aggregation leads to formation of significantly thinner microstructures, which are (for the first time) unlimited in length by the acoustic apparatus. This new approach overcomes the discrepancy between the need for organic dispersants to prevent unwanted aggregation in the dispersion, and the end product's requirement for intimate contact between the colloidal particles.
author2 School of Materials Science and Engineering
author_facet School of Materials Science and Engineering
Sazan, Haim
Piperno, Silvia
Layani, Michael
Magdassi, Shlomo
Shpaisman, Hagay
format Article
author Sazan, Haim
Piperno, Silvia
Layani, Michael
Magdassi, Shlomo
Shpaisman, Hagay
author_sort Sazan, Haim
title Directed assembly of nanoparticles into continuous microstructures by standing surface acoustic waves
title_short Directed assembly of nanoparticles into continuous microstructures by standing surface acoustic waves
title_full Directed assembly of nanoparticles into continuous microstructures by standing surface acoustic waves
title_fullStr Directed assembly of nanoparticles into continuous microstructures by standing surface acoustic waves
title_full_unstemmed Directed assembly of nanoparticles into continuous microstructures by standing surface acoustic waves
title_sort directed assembly of nanoparticles into continuous microstructures by standing surface acoustic waves
publishDate 2020
url https://hdl.handle.net/10356/142549
_version_ 1681056771180855296