quantum dots Continuous flow purification of …Supporting Information Continuous flow purification...

Supporting Information

Continuous flow purification of nanocrystal

quantum dots

Duckjong Kim,* †, §, Hye Kyung Park†, Hyekyoung Choi†,§, Jaehong Noh†, Kyungnam Kim†,

and Sohee Jeong,* †,§

†Department of Nano Mechanics, Korea Institute of Machinery and Materials (KIMM),

Daejeon 305-343, South Korea.

§Korea University of Science and Technology (UST), 206 Gajeong-ro, Daejeon 305-350,

South Korea.

* To whom correspondence should be addressed, dkim@kimm.re.kr, sjeong@kimm.re.kr

Electronic Supplementary Material (ESI) for Nanoscale.This journal is © The Royal Society of Chemistry 2014

Microfluidic Chip Fabrication

Si wafer dry etching

Si-Si direct bonding

/ Thermal bonding

Electrode patterning

on glass wafer

Glass wafer sand

blasting

Si-glass anodic

bonding

A A’

A A’

glass

glass

Si

Si

electrode (Cr/Au)

electrode (Cr/Au)

cross-sectional view

Figure S1: Fabrication process and fabricated microfluidic chip.

QD size analysis

Before electrophoretic purification After electrophoretic purification

A B

Figure S2. TEM micrographs of the CdSe QDs before (A) and after (B) electrophoretic purification at 50 V. CdSe QDs before and after our process are 5.10±0.64 nm and

5.10±0.61 nm in diameter respectively.

The effect of the solution environment (dilution) on removal of ligands

Figure S3. ATR-FTIR spectra of CdSe QDs capped with oleate before (blue line) and after

(red line) 100 fold dilution by hexane.