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Controlled Synthesis and Fluorescence Tracking of Highly Uniform PolyN-isopropylacrylamide Microgels
Published on: September 8, 2016
Microgels with controlled network topologies by photocrosslinking-assisted continuous precipitation polymerization
Jacek J Walkowiak1, Inga Litzen2, Joanna Michalska-Walkowiak3
1Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany; DWI - Leibniz-Institute for Interactive Materials e.V, Forckenbeckstraße 50, 52074 Aachen, Germany; Sustainable Polymer Synthesis Group, Aachen-Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Urmonderbaan 22, 6167 RD Geleen, the Netherlands.
Researchers developed a novel photo-crosslinking method for continuous microgel synthesis, enabling precise control over crosslink distribution. This advancement allows tuning microgel properties by adjusting retention time in flow reactors.
Area of Science:
- Polymer Chemistry
- Materials Science
- Nanotechnology
Background:
- Microgels are versatile polymeric nanoparticles with applications in drug delivery, sensing, and catalysis.
- Controlling the crosslink density and distribution within microgels is crucial for tailoring their properties.
- Conventional synthesis methods often lack precise control over network architecture.
Purpose of the Study:
- To introduce a new synthesis methodology for microgels using photo-crosslinking-assisted continuous precipitation polymerization.
- To investigate the influence of retention time on microgel characteristics, including size, morphology, and crosslink distribution.
- To demonstrate precise control over the spatial arrangement of crosslinks within the microgel network.
Main Methods:
- Utilized a comonomer with a photo-crosslinkable 4-oxocyclopent-2-en-1-yl group as a substitute for conventional crosslinking agents.
- Employed a flow reactor system to control the retention time (Rt) during continuous precipitation polymerization.
- Applied dynamic and static light scattering (DLS/SLS) and small-angle X-ray scattering (SAXS) to analyze microgel structure and crosslink distribution.
- Characterized microgel morphology and network properties using atomic force microscopy (AFM).
Main Results:
- The photo-crosslinking approach enabled precise control over the distribution of crosslinks in microgels.
- Microgel size, morphology, and polymer chain packing density were successfully modulated by varying the retention time (Rt).
- SAXS and DLS/SLS confirmed excellent control over crosslink distribution during polymerization.
- AFM revealed differences in microgel stiffness and polymer network arrangement correlated with increased Rt.
Conclusions:
- Photo-crosslinking-assisted continuous precipitation polymerization offers a robust method for synthesizing microgels with tailored crosslink architectures.
- Retention time in the flow reactor is a key parameter for controlling microgel properties.
- This methodology provides a pathway to design advanced microgel materials with specific mechanical and structural characteristics.
