Supporting information
Supplementary materials I:
UV-vis absorption and PL spectra of a series of prepared aqueous CdTe QDs
Fig. S1 shows the typical UV-vis absorption and PL spectra of a series of prepared
CdTe QDs with different sizes in Milli-Q water. The UV-vis absorption spectrum
shows the characteristic electron-hole pair (excitonic) peak representative of the band
gap energy. The positions of excitonic peak shift to longer wavelengths as the QDs
ensemble grows to larger diameters. During the growth of the particles, smaller
particles will dissolve and become the constituents of larger particles, a process
known as Ostwald ripening[1].
1.4
1.0
GQD YQD
1.2
RQD
0.8
UV-vis Absorbance
0.6
0.8
0.6
0.4
0.4
0.2
0.2
0.0
400
PL intensity (Normalized)
1.0
0.0
500
600
700
Wavelength(nm)
Fig. S1 UV-vis absorption (dash) and PL spectra (solid, λex =400nm ) of thioglycolic acid-capped
CdTe QDs (GQD-green, YQD-yellow, RQD-red) in aqueous solution with three different sizes.
Average particle size calculation
All samples demonstrate a well-resolved absorption maximum of the 1s-1s
1
electronic transition, indicating a sufficiently narrow size distribution of the CdTe
QDs prepared[2]. The average particle size is estimated according to literature[3]:
D  (9.8127  107 )3  (1.7147  103 )2  (1.0064)  (194.84)
eq1
where D is the diameter of the particles and λ is the wavelength of the first electronic
transition.
The average particle sizes were 2.0(GQD), 2.8(YQD), 3.5 (RQD) nm and
the shifts of excitonic peak in absorption curves were 490, 522 to 581 nm. Meanwhile,
the PL emission peak shifts of QDs were 534 (green emission), 551 (yellow emission),
619 nm (red emission) with an increase of the size of QDs, which indicates that the
whole spectra between these two wavelengths is covered by the CdTe QDs with
intermediate size.
Supplementary materials II:
Theoretical Mn calculations of IPUs by feeding ratios of three components
N OH 2 N ionicdiol  2 N PEG  2 N TDI

 N ionicdiol  N PEG  N TDI
2
2
m
N
M
 N PEGM PEG  N TDI M PEG
MnPUs  PUs  ionicdiol ionicdiol
N PUs
N ionicdiol  N PEG  N TDI
N PUs 
eq2
eq3
N: molar number
M: molecular weight
Mn: number-average molecular weight
m: mass
Supplementary materials III:
Hard and charge content calculations in IPUs
The hard segment content equals to the weight percentage of charged ionic diol and
TDI (eq4) and the charge content equals to the weight percentage of charged ionic
diol (eq5). The hard and charge contents can be calculated using eq6 and eq7 which
2
are derived from eq4 and eq5. The relative molar contents (in eq6 and eq7) of the
three components in the ionic IPUs can be calculated by the integral of signals
(assigned in Fig.1a in the main text) in 1H NMR spectra according to the formula
shown in eq8-10:
hard segment % 
charge % 
mTDI
mTDI  mionicdiol
 100%
mTDI  mionicdiol  m PEG
mionicdiol
 100%
 mionicdiol  m PEG
hard segment % (NMR) 
charge % (NMR) 
[PEG] 
eq5
[TDI]  M TDI  [ionic diol]  M ionicdiol
100%
[TDI]  M TDI  [ionic diol]  M ionicdiol  [PEG]  M PEG
eq6
[ionic diol]  M ionicdiol
100%
[TDI]  M TDI  [ionic diol]  M ionicdiol  [PEG]  M PEG
eq7
Ic
2
eq8
I a  I d  2I c
3
eq9
[ionic diol] 
[TDI] 
eq4
[I e  2I c  I f  2I c  I j ] I e  I f  I j  4I c I e  I f  I j  I b  7I c


4
4n
4n
n
eq10
[ionic diol]: the relative molar content of ionic diol
Ij : the integral of signal j shown in the 1H NMR spectra in Fig. 1a of the main text
n: polymerization degree of of PEG
M: molecular weight
m: mass
References:
1.
Peng, X. G.; Wickham, J.; Alivisatos, A. P. J Am Chem Soc 1998, 120, 5343-5344.
2.
Murray, C. B.; Norris, D. J.; Bawendi, M. G. J Am Chem Soc 1993, 115, 8706-8715.
3.
Yu, W. W.; Qu, L. H.; Guo, W. Z.; Peng, X. G. Chem Mater 2003, 15, 2854-2860.
3