1. 1.20 1.19 1.17
1.19
1.18
40
50
60
70
80
90
100
0
50
100
150
200
250
300
350
400
450
500
0 20 40 60
MicellarIntensitydiameter,Iav(nm)
DaughterpolymerMn(kg/mol)
DP of template copolymer (PVBT)
15 17 19 21 23 25 27
Retention Time (mins)
6 13 22 34 41 48
30
40
50
60
70
80
90
100
110
5 15 25 35 45
Meanintensitydiameter,Iav(nm)
Mn of template polymer (kg/mol)
Core Size Exp.
Overall Size Exp.
13 16 19 22 25 28 31
Retention Time (mins)
61-11 129-22 281-44
TP
Mn
(g/mol)
Daughter Polymer (PVBA)
Mn (g/mol) Mw (g/mol) Đ
PSt129-b-PVBT6 15200 - - -
PSt129-b-PVBT13 16900 348850 418334 1.20
PSt129-b-PVBT22 19100 318650 439291 1.19
PSt129-b-PVBT34 22000 323100 377674 1.17
PSt129-b-PVBT41 23700 333714 397563 1.19
PSt129-b-PVBT48 25400 342249 402106 1.18
Lim Dong Quan
Supervisor: Prof. Per B Zetterlund
Template Radical Polymerisation with VBA
Micelle Core Size effect
• Figures below shows Size Exclusion Chromatography (SEC) trace of
polymer mixture (PSt-b-PVBT and PVBA)
• GPC using DMAc as eluent
• Higher MW polymer will have a shorter retention time
[1] Ronan McHale, J.P.P., Per. B. Zetterlund, Rachel K.O'Reilly, Biomimetic
Radical Polymerization via Cooperative Assembly of Segregating Templates.
Nature Chemistry, 2012: p. 491-497.
[2] Tan, Y.Y., The Synthesis of Polymers by Template Polymerization. Progress
in Polymer Science, 1994. 19: p. 561-588.
[3] Masel, R.I., Principles of Adsorption and Reaction on Solid Surfaces. 1996,
Urbana: John Wiley & Sons, Inc.
Fine tuning template radical polymerisation in micellar
nanoreactors
Templating Effect
• Radical polymerisation of monomer lined-up against a template polymer (TP)
• Interactions between polymer units and monomer e.g. hydrogen bonding
• Assumes Langmuir adsorption model[2][3]
• Termination rate constant, kT decreases
• Overall rate of polymerisation, Rp increases
Tp°C
Initiator
Aims and Objective
 To form different lengths of template diblock copolymers (PSt-b-
PVBT) as micelle building blocks (unimers) by: (1) manipulating the
PVBT block DP whilst keeping PSt block constant (2) increasing the
overall size of template polymer
 Characterise the micelle size formed by dissolving TP in CHCL3
 Perform template radical polymerisation of VBA monomers in CHCl3
in the presence of template polymers with AIBN as initiator
Segregated Micelles
• Micelle act as nanoreactors
• Approximately one radical per micelle
• Termination rate constant, kT decreases
• One daughter chain per micelle
Overall Micelle Size effect
Introduction
Micellisation
10 mg of diblock
copolymer
Dissolved in 1
ml of CHCl3
Template Polymer Synthesis
129
6
13
22
34
41
48
Micelle Core Size Overall Micelle Size
61 11
22
44
129
281
Degree of
polymerisation,
DP
[PSt]
(mol/L)
[VBT]
(mol/L)
Hours
X
(%)
Ð
Mn
(g/mol)
Mw
(g/mol)
CoreSize
PSt129-b-PVBT6
0.012 0.657 20 15 1.25 15209 18999
PSt129-b-PVBT13
0.012 0.688 64 27 1.30 16905 22020
PSt129-b-PVBT22
0.012 0.688 121 45 1.30 19085 24872
PSt129-b-PVBT34
0.005 0.602 20 33 1.26 21993 27627
PSt129-b-PVBT41
0.005 0.590 20 39 1.27 23688 30099
PSt129-b-PVBT48
0.012 1.376 20 29 1.32 25384 33627
Overall
Size
PSt61-b-PVBT11
0.002 0.643 14 15 1.29 8997 11568
PSt129-b-PVBT22
0.012 0.688 121 45 1.30 19085 24872
PSt281-b-PVBT44
0.005 0.787 - 38 1.38 40622 55957
• VBT added to PSt in
DMF @125°C to
synthesize template
polymer (TP)
• NMP (TEMPO-group)
polymerisation since
inactive at 60°C during
TRP with VBA
• Mass ratio of PVBT to
PSt in overall micelle
size exp. kept constnat
at 30%
• Medium dispersity for
all at ~1.3
• Size of micelles characterized using DLS technique
• PSt129-b-PVBT6 (Iav) data point omitted from plot as it
registered an Iav ~ 282nm with PDI of 1.0 (likely be due
to dust or particulate) since scattering intensity ∝ MW2
• All other micelles have a 0.02 < PDI < 0.40
• Aggregation number of micelle may be a primary factor
for the relatively same Iav~ 45 nm between TP(6),TP(13)
and TP(22) for core size exp.
• Further analysis recommended:
• Static light scattering to obtain micellar MW
• TEM imaging for direct visual observation
• An overall increase in micelle Iav as DP increases
CHCl3 @ 60°C
DMAc
+
Template Radical Polymerisation with VBA in CHCl3
Template Polymer Mn (g/mol)
Daughter Polymer (PVBA)
Mn (g/mol) Mw (g/mol) Đ
PSt61-b-PVBT11 9000 - - -
PSt129-b-PVBT22 19100 318650 439291 1.19
PSt281-b-PVBT44 40600 - - -
Inspired by DNA’s replication process, McHale et al. employed a biomimetic approach to yield extremely high
daughter polymer molecular weigh (MW) that is very well defined (Ð < 1.2) via free radical polymerisation[1]. The
concept involves a templating effect that occurs in segregated micelles (nanoreactors). In this study, we seek to
investigate the effect of micellar core size and its overall size on the final daughter polymer MW by template
polymerising vinylbenzyl adenine (VBA) with poly(styrene(St)-b-vinylbenzyl thymine(VBT))
References Conclusion
• Micelle core size has no apparent effect on daughter polymer MW within the range explored
• Micelle core size seems to have an impact on reaction conversion
• Higher micelle core size seems to increase reaction conversion
• More investigation is required for micelle overall size effects due to absence of daughter polymer peaks (may be
due to insufficient initiator)
• More characterisation analysis is encouraged as supplementing data e.g. SLS and Cryo-TEM
PSt-b-PVBT
PVBA
• Ultrahigh daughter polymer
MW (>300 kg/mol) at ~17m
• Minimal deviation (4%)
between the daughter
polymer MW
• Peak intensity of daughter
polymer increases with
larger micellar cores/
heavier MW of TP
• Narrow dispersity for all
daughter polymers (Ð <
1.2)
• No daughter polymer for
TP(6)