Angewandte Chemie International Edition
10.1002/anie.202010429
COMMUNICATION
and 1H-NMR spectroscopy. Our technology allows access to
larger scale, controlled and safe production of SCNPs using
different chemistries. In addition, through adequate evaporation
and solvent recovery, this process can be made environmentally
benign. The exploration of continuous solvent recovery in
combination with flow is currently under investigation and will be
reported in due time.
Acknowledgements
The authors are grateful for support from the Israel Science
Foundation (grant No 354/19). O.G. is grateful to funding from the
Irwin and Joan Jacobs fellowship. H.B.D. is grateful to funding
from by a Lady Davis fellowship. C.B.-K. acknowledges funding
from the Australian Research Council (ARC) in the context of a
Laureate Fellowship underpinning his photochemical research
program as well as continued support by the Queensland
University of Technology (QUT).
Keywords: Polymer nanoparticles • Cross-linking •
Intramolecular collapse • Flow chemistry • Photochemistry
Figure 3. Intramolecular CL degree as a function of SCNP productivity (in grams
per hour) (top) and UV irradiation time (bottom) in flow (blue, ♦) and batch (green,
●
) systems using a polymer containing 9.4% AnM.
[
[
1]
2]
T. Aida, E. W. Meijer, S. I. Stupp, Science 2012, 335, 813–817.
T. P. Moneypenny, H. Liu, A. Yang, I. D. Robertson, J. S. Moore, J.
Polym. Sci. Part A Polym. Chem. 2017, 55, 2935–2948.
Given the positive results observed with the original
[
[
3]
4]
T. Yamamoto, Y. Tezuka, Polym. Chem. 2011, 2, 1930–1941.
A. M. Hanlon, C. K. Lyon, E. B. Berda, Macromolecules 2016, 49,
polymers, we explore a second set of polymers, where the
number of AnM moieties in the backbone is doubled to 20 mol%.
Berda and co-workers demonstrated that higher ratios of AnM in
the linear precursor lead to a relatively higher degree of
intramolecular CL as a function of irradiation time.[42] This effect
can be benefited from in flow-chemistry, as the photon density is
2
–14.
[
5]
E. Blasco, B. T. Tuten, H. Frisch, A. Lederer, C. Barner-Kowollik,
Polym. Chem. 2017, 8, 5845–5851.
[6]
[7]
J. A. Pomposo, I. Perez-Baena, F. Lo Verso, A. J. Moreno, A. Arbe,
J. Colmenero, ACS Macro Lett. 2014, 3, 767–772.
-
on average - higher throughout the solution as compared to
batch systems,[43] generating
a
larger fraction of excited
A. Latorre-Sánchez, J. A. Pomposo, Polym. Int. 2016, 65, 855–860.
J. Chen, E. S. Garcia, S. C. Zimmerman, Acc. Chem. Res. 2020,
anthracenes. When comparing the dimerization conversion,
between the two flow experiments, it can be seen that when 20
mol% AnM is used (refer to the SI, Table S1), the CL ratios
increase, relative to the polymer with 9.4 mol% AnM by a factor of
[
[
[
[
[
8]
5
3, 1244–1256.
9]
M. A. J. Gillissen, I. K. Voets, E. W. Meijer, A. R. A. Palmans,
Polym. Chem. 2012, 3, 3166–3174.
-1
3
,
.4 for the fastest flow rate (300 µL s ) although this effect is less
10]
11]
12]
E. Huerta, P. J. M. Stals, E. W. Meijer, A. R. A. Palmans, Angew.
Chem. Int. Ed. 2013, 52, 2906–2910.
pronounced at slower flow rates (longer reaction times), given
these results are closer to full conversion. In contrast, the majority
of the batch results present ca. 2.7 times higher CL ratio
compared to the polymer containing 9.4 mol% AnM after the same
irradiation time, and, more importantly, it seems that equilibrium
is reached at lower relative conversions (refer to the SI, Figure
S18).
H. Rothfuss, N. D. Knöfel, P. W. Roesky, C. Barner-Kowollik, J. Am.
Chem. Soc. 2018, 140, 5875–5881.
I. Perez-Baena, F. Barroso-Bujans, U. Gasser, A. Arbe, A. J.
Moreno, J. Colmenero, J. A. Pomposo, ACS Macro Lett. 2013, 2,
7
75–779.
In summary, we pioneer the continuous production of
SCNPs in photoflow. We demonstrate that flow systems for SCNP
synthesis present critical advantages over batch mode, including
faster reaction kinetics, improved chemical yield at shorter and
longer times, a safer production line, better control over the folding
chemistry, in addition to faster and continuous production,
allowing access to larger quantities of SCNPs. The UV irradiation
time was significantly reduced using flow chemistry: the fastest
[13]
[14]
M. E. Mackay, T. T. Dao, A. Tuteja, D. L. Ho, B. Van Horn, H. C.
Kim, C. J. Hawker, Nat. Mater. 2003, 2, 762.
S. Aharonovich, C. E. Diesendruck, React. Funct. Polym. 2018, 131,
237–242.
[
[
[
[
15]
16]
17]
18]
A. Levy, F. Wang, A. Lang, O. Galant, C. E. Diesendruck, Angew.
Chem. Int. Ed. 2017, 56, 6431–6434.
A. Levy, R. Feinstein, C. E. Diesendruck, J. Am. Chem. Soc. 2019,
1
41, 7256–7260.
-1
flow rate tested (18 mL min , 5.5 min exposure time) produced
SCNPs with intramolecular CL rates that required 33 (9.4 AnM %)
or 44 min (20 AnM%) UV exposure when carried out in batch. The
intramolecular collapse was readily followed using SEC, UV-vis
O. Galant, S. Bae, F. Wang, A. Levy, M. N. Silberstein, C. E.
Diesendruck, Macromolecules 2017, 50, 6415–6420.
O. Galant, S. Bae, M. N. Silberstein, C. E. Diesendruck, Adv. Funct.
Mater. 2019, 1901806.
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