Supporting Information
Efficient Synthesis of Monodisperse, Highly Crosslinked, and “Living”
Functional
Polymer
Microspheres
by
the
Ambient
Temperature
Iniferter-Induced “Living” Radical Precipitation Polymerization
MAN ZHAO, HONGTAO ZHANG, FENGNING MA, YING ZHANG, XIANZHI GUO,
HUIQI ZHANG*
Key Laboratory of Functional Polymer Materials (Nankai University), Ministry of Education,
Department of Chemistry, Nankai University, Tianjin 300071, P. R. China
Tel/Fax: +86-2223507193; E-mail: zhanghuiqi@nankai.edu.cn
FIGURE S1 SEM images of poly(4-VP-co-EGDMA) microspheres prepared via the ambient
temperature ILRPP with different monomer loadings (the samples a, b, c, d, e, f, and g
correspond to entries 1, 3, 5, 7, 9, 11, and 13 in Table 1, respectively). The scale bar
corresponds to 1 μm in parts a-g.
1
Determination of the Molecular Weights of the Free PHEMA and PNIPAAm (Generated
During the Surface-Initiated ILRP in the Presence of Sacrificial Iniferter) by 1H NMR
Technique
1
H NMR spectra of BDC and the free PHEMA and PNIPAAm generated during the
surface-initiated ILRP in the presence of sacrificial iniferter were measured by using Varian
Unity plus-400 spectrometer (400 MHz).
Fig. S2a presents the 1H NMR spectrum of BDC, which agrees well with its chemical
structure.
Fig. S2b shows the 1H NMR spectrum of the free PHEMA, from which its number-average
molecular weight (Mn,NMR,PHEMA) could be derived by using the following equation:
Mn,NMR,PHEMA = 2.5 × (Sd ⁄ Sf) × MHEMA + MBDC
where Sd and Sf refer to the integral of the peak d around 3.59 ppm and that of the peaks f
around 7.15 ppm, respectively, MHEMA is the molar mass of HEMA, and MBDC is the molar
mass of BDC.
The 1H NMR spectrum of the free PNIPAAm is shown in Fig. S2c, from which its
number-average molecular weight Mn,NMR,PNIPAAm can be derived by using the following
equation:
Mn,NMR,PNIPAAm = 5 × (Sc ⁄ Sf) × MNIPAAm + MBDC
where Sc and Sf refer to the integral of the peak c around 3.79 ppm and that of the peaks f
around 7.20 ppm, MNIPAAm is the molar mass of NIPAAm, and MBDC is the molar mass of
BDC.
2
FIGURE S2 1H NMR spectra of BDC in CDCl3 (a), PHEMA in DMSO-d6 (b), and
PNIPAAm in D2O (c).
Characterization
of
the
Ungrafted
Poly(4-VP-co-EGDMA)
Microspheres
and
Poly(4-VP-co-EGDMA) Microspheres with Surface-Grafted PHEMA or PNIPAAm
Brushes by Using Atomic Force Microscopy (AFM)
AFM measurements were performed with an NTEGRA Prima AFM (NT-MDT, Moscow,
Russia). All the topography images were realized in intermittent contact model using the same
NSG10-A tip (NT-MDT, Moscow, Russia) under ambient conditions (21 °C and 22 % relative
humidity). Image processing and RMS (Root Mean Square) analysis were performed with the
Nova software.
3
Fig. S3 presents the AFM images of the ungrafted poly(4-VP-co-EGDMA) microspheres
and the grafted polymer microspheres with PHEMA or PNIPAAm brushes. It can be seen
clearly that all these polymer microspheres have quite smooth surfaces, as revealed both by
their three-dimensional AFM images of the top areas (400 × 400 nm2) and by their rather
small flattened surface RMS values (RMS = 1.961, 1.067, and 2.097 nm for the ungrafted
polymer microspheres, PHEMA brushes-grafted polymer microspheres, and PNIPAAm
brushes-grafted polymer microspheres, respectively).
FIGURE S3 AFM images of the ungrafted poly(4-VP-co-EGDMA) microspheres (a1-a3),
PHEMA brushes-grafted poly(4-VP-co-EGDMA) microspheres (b1-b3), and PNIPAAm
brushes-grafted poly(4-VP-co-EGDMA) microspheres (c1-c3), including the AFM images of
certain number of polymer microspheres (a1,b1,c1), the three-dimensional AFM images of the
top areas (400 × 400 nm2) of the selected polymer microspheres (a2,b2,c2), and the
corresponding 3rd order flattened AFM height images of the selected top areas of the polymer
microspheres (a3,b3,c3).
4