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Synthesis of Monodisperse Cylindrical Nanoparticles via Crystallization-driven Self-assembly of Biodegradable Block Copolymers
Published on: June 20, 2019
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Molecular Engineering of Nanostructures in Disordered Block Polymers.
Nicholas Hampu1, Marc A Hillmyer2
1Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States.
ACS Macro Letters
|June 1, 2022
Summary
Researchers synthesized block copolymers to study composition fluctuations. Tuning styrene content revealed transitions from mean-field to fluctuating disordered states, offering control over nanostructures.
Area of Science:
- Polymer Science
- Materials Science
- Soft Matter Physics
Background:
- Block copolymers exhibit microphase separation into ordered nanostructures.
- Understanding the disordered state is crucial for controlling nanostructure formation.
- Composition fluctuations play a significant role in the disordered state of block copolymers.
Purpose of the Study:
- To synthesize poly(methyl methacrylate-stat-styrene)-block-polylactide (P(MMA-stat-S)-block-PLA) diblock terpolymers.
- To investigate the impact of varying block interaction parameters on composition fluctuations in the disordered state.
- To explore the transition from mean-field disordered to fluctuating disordered states.
Main Methods:
- Synthesis of symmetric P(MMA-stat-S)-block-PLA diblock terpolymers.
- Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and small-angle X-ray scattering (SAXS).
- Annealing above order-disorder transition temperatures (TODT) followed by rapid quenching and vitrification.
- Scanning electron microscopy (SEM) and N2 sorption analysis after PLA removal.
Main Results:
- A broad range of segregation strengths was achieved by tuning styrene content.
- Transitions from mean-field disordered to fluctuating disordered states were observed with increasing segregation strength.
- Evidence of a bicontinuous fluctuating disordered state was found using SAXS and N2 sorption analysis.
Conclusions:
- The extent of microphase segregation and domain continuity in disordered block copolymers can be tuned.
- Synthetic design and thermal stimuli are effective methods for controlling nanostructures.
- This work provides guidance for designing disordered block polymers with targeted nanostructures for technological applications.
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