Physics of Fluids - Publications

Pick up move and release of nanoparticles utilizing co-non-solvency of PNIPAM brushes ,

Open Access
Nanoscale 9, 1670–1675 (2017)

Authors

	Yunlong Yu
	Ricardo Arturo López de la Cruz
	B.D. Kieviet
	Hubert Gojzewski
	Adeline Pons
	G. Julius Vancso
	Sissi de Beer

BibTeΧ

@Article{C6NR09245D,
author ="Yu, Yunlong and Lopez de la Cruz, Ricardo A. and Kieviet, Bernard D. and Gojzewski, Hubert and Pons, Adeline and Julius Vancso, G. and de Beer, Sissi",
title  ="Pick up{,} move and release of nanoparticles utilizing co-non-solvency of PNIPAM brushes",
journal  ="Nanoscale",
year  ="2017",
volume  ="9",
issue  ="4",
pages  ="1670-1675",
publisher  ="The Royal Society of Chemistry",
doi  ="10.1039/C6NR09245D",
url  ="http://dx.doi.org/10.1039/C6NR09245D",
abstract  ="A critical complication in handling nanoparticles is the formation of large aggregates when particles are dried e.g. when they need to be transferred from one liquid to another. The particles in these aggregates need to disperse into the destined liquid medium{,} which has been proven difficult due to the relatively large interfacial interaction forces between nanoparticles. We present a simple method to capture{,} move and release nanoparticles without the formation of large aggregates. To do so{,} we employ the co-non-solvency effect of poly(N-isopropylacrylamide) (PNIPAM) brushes in water-ethanol mixtures. In pure water or ethanol{,} the densely end-anchored macromolecules in the PNIPAM brush stretch and absorb the solvent. We show that under these conditions{,} the adherence between the PNIPAM brush and a silicon oxide{,} gold{,} polystyrene or poly(methyl methacrylate) colloid attached to an atomic force microscopy cantilever is low. In contrast{,} when the PNIPAM brushes are in a collapsed state in a 30-70 vol% ethanol-water mixture{,} the adhesion between the brush and the different counter surfaces is high. For potential application{,} we demonstrate that this difference in adhesion can be utilized to pick up{,} move and release 900 silicon oxide nanoparticles of diameter 80 nm using only 10 [times] 10 [small mu ]m2 PNIPAM brush."}