Shunsuke Sakamoto 1,2 , Yusuke Sanada 1,2 , Mizuha Sakashita 1,2 , Koichi Nishina 1 , Keita Nakai 3 ,
Shin-ichi Yusa 3 and Kazuo Sakurai* 1,2
1 Department of Chemistry and Biochemistry, The University of Kitakyushu,
1-1 Hibikino, Kitakyushu, Fukuoka 808-0135, Japan.
2 Structural Materials Science Laboratory SPring-8 Center, RIKEN Harima Institute Research,
1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5148, Japan.
3 Department of Materials Science and Chemistry, Graduate School of Engineering, University of Hyogo,
2167 Shosha, Himeji, Hyogo 671-2280, Japan.
* Corresponding author: Kazuo Sakurai
E-mail address: sakurai@kitakyu-u.ac.jp (KS)
Contents
I. Fitting Models of SAXS
II. Hydrodynamic radius and TEM image of PICs
According to Pedersen et al 1,2 , the form factor form micelles consisting of spherical core and Gaussian corona chains can be expressed by use of four terms: the self-correlation of the core: , the self-correlation of the corona chains: , the cross term between the core and the corona chains: , and the cross term between different corona chains: S .
F q N agg
2 2
C
F q N agg
2 F q N agg
C
S q N agg
( N agg
1)
2 S q
(s1)
Here q is the magnitude of the scattering vector, N agg
is the aggregation number,
C and
Ch
are the excess scattering lengths of core and corona blocks, respectively. For polymeric micelles, the first term in eq s1 may be regarded as that of homogeneous sphere with radius R
C
:
F q R
C
( ,
C
A q R s C
)] 2
3 sin qR qR cos qR
C C C
( qR
C
) 3
2
(s2)
Here, represents the scattering amplitude of a solid sphere with the radius of R and we assumed that the thickness of the interface between the core and corona region is negligibly small. The second term in eq s1 is the self-correlation of the corona chains, which can be expressed by a Debye function with a radius of gyration ( R g, pMPC
) for the individual corona chain; in the present case the pMPC chain.
F
Ch g, pMPC
)
2
[exp( q 2 R 2
( q R g, pMPC
) 4 q 2 R 2 ]
(s3)
To eliminate complication and decrease the number of adjustable parameters, we assume that the corona chain density is a constant regardless of the distance from the interface. On this assumption, eq s1 can be rewritten with the corona size of :
N agg
2
C
A q R
C
)
Ch
A q R
Ch
)
2 N
2 agg Ch Ch
, R g
)
N
2 agg Ch s
( ,
Ch
)
(s4)
The first term in eq s4 coincides with the scattering intensity from a double layered sphere with and .
In the present case, the first term contributed dominantly at the low q (ca., 0.3 < q ), while the second one became more substantial in the high q in the case of q > 1.0, because the first one decays as while the second one decays as at highq .
3
In the similar manner, the scattering form factor for a mono-layered vesicle consisting of a solid plate and
Gaussian corona chains attached to the plate surface can be expressed by the equation of four-layered spheres with the innermost layer being the same electron density with the solvent:
)
i
4
1
i i 1
V A s
( q , R i
)
2
N agg
2 F ( q ) (s5)
Where R
2
R
1
R
4
R
3
, which is the thickness of the inner and outer layer of pMPC, ρ i
is the electron density of the i th layer, ρ solv
is the electron density of the solvent and
1
5 solv
,
1 2
4
5 due to the same chemical component of pMPC, and N agg
β 2 Ch was given from the total number of the electron of the shell
chains and the aggregation number N agg
β 2 Ch
= ( N agg
β
Ch
) 2 / N agg
= [( ρ
3
– ρ
2
)( V
2
– V
1
) + ( ρ
5
– ρ
4
)( V
4
– V
3
)] 2 / N agg
.
When N agg
> 30, the third term in eq s4 became negligibly small; therefore, we omitted this term in eq s5.
For the case of cylinders with a finite length of L , we used the following equation similar with eq s5, assuming Gaussian chains attaching on the cylinder surface with the radius of R g , pMPC
.
/2
0
N agg
2
1 2
cy
( ,
1
2 solv
cy
( ,
2
2
N agg
2 F q
(s6)
j qL
(
qR sin
Here, ρ
1
and ρ
2
is the electron densities of the core and shell regions, V
1
and V
2
is the volume of the core and shell cylinders given by V i
= π R i
2 L , N agg
β 2 Ch
was calculated from the same manner of vesicle N agg
β 2 Ch
=
( N agg
β
Ch
) 2 / N agg
= [( ρ
2
– ρ sol
)( V
2
– V
1
)] 2 / N agg
, j and
0
J are the zero-th order of the spherical Bessel function
1 and the 1 st order of the Bessel function, respectively.
Figure S1. (a) Hydrodynamic radius ( R h
) and (b) scattering intensity for the PIC micelles with f + = 0.5 at C p
= 1.0 g/L in 0.1 M NaCl aqueous solutions at 25 °C as a function of sodium chloride concentration ([NaCl]):
P
100
M
96
/P
100
A
99
(C10, ○), P
100
M
48
/P
100
A
45
(C05, ▲), and P
100
M
27
/P
100
A
27
(C03, ◊).
3
Figure S2. Transmission Electron Microscopy (TEM) for C50 and observed short worm-like cylinders
Reference
1 Choi, S.-H., Bates, F. S. & Lodge, T. P. Structure of Poly(styrene-b-ethylene-alt-propylene) Diblock
Copolymer Micelles in Squalane†. The Journal of Physical Chemistry B 113, 13840-13848, doi:10.1021/jp8111149 (2009).
2 Pedersen, J. S., Svaneborg, C., Almdal, K., Hamley, I. W. & Young, R. N. A Small-Angle Neutron and X-ray
Contrast Variation Scattering Study of the Structure of Block Copolymer Micelles: Corona Shape and
Excluded Volume Interactions. Macromolecules 36, 416-433, doi:10.1021/ma0204913 (2003).
Roe, R. J. Methods of X-ray and Neutron Scattering in Polymer Science . (2000).