References: 1. A. Pal, P. Khajornrungruang, and S. V. Babu RSC Adv. 5 (2015) 71830 ; 2. A. Pal, P. Khajornrungruang, C. Netzband, S. Alety, S. V. Babu Nanotechnology 27 (2016) 075708

Key findingso In situ real time imaging of nano/micro structures

o Visualized in situ the growth of Ag ribbons

o No tedious sample preparation like TEM and SEM is needed

Instrument setup

o Evanescent wave (EW) scattering imaging method using a total internal

reflection technique to image and characterize the growth of silver ribbons

in situ in solution is described.

o Visualized in real time of the products of galvanic displacement between

Cu/Ag+ and Ag/Au3+ systems.

o This technique can also be used to characterize/analyze other nano/micro

structures in real time.

Abstract

REAL TIME IMAGING BY EVANESCENT WAVE SCATTERINGAngshuman Pal,1 Ramtej Popuri,1 Panart Khajornrungruang,2 and S.V. Babu1

1. Center for Advanced Materials Processing, Clarkson University, Potsdam USA; 2. Kyushu Institute of Technology, Japan

Ag nanowires with Au3+ ions

Ag ribbons with Au3+ ions

Cu nanowires with Ag+ ions

Galvanic displacement reactions

Cu nanoparticles with Ag+ ions

Time-sequenced EW images of Ag ribbons with Au3+ ions SEM images

0 20 40 60 80 100 1200

20

40

60

80

100

120

140

160

Particle size (nm)

Gre

y V

alue

30 nm

60 nm

110 nm

Scattering intensity vs particle size

Growth of Ag ribbons with Ag+ concentration

Ag+

(M)Induction time (s)

Growth rate (μm/s)

0.2 7±2 ~2.80.1 12±2 ~1.20.05 17±3 ~0.8

(a) -(d) sequential images (40 s intervals); Ag (0.01M)

EW images Ag ribbon formation SEM images

1 μm

EW and SEM images of the formation of different microstructures

(a-d : 0.2M; e-g : 0.1M; i-l : 0.05M)

HAuCl 4

Cu nanowires

Ag ribbons

Ag ribbons

Au or Au-Agnaoparticles

(See references)

1

2

3

4

o

o

0 50 100 150 2000

0.2

0.4

0.6

0.8

1

Penetration depth (nm)

Inte

nsity

(I/I₀

)

Penetration depth of EW

Pene

tratio

n de

pth

of E

W